Search

Age-related macular degeneration (AMD) is the most prevalent ocular disease in the elderly, resulting in blindness. Oxidative stress plays a role in retinal pigment epithelium (RPE) pathology observed in AMD. Tocopherols are potent antioxidants that prevent cellular oxidative damage and have been shown to upregulate the expression of cellular antioxidant proteins. Here, we determined whether oxidative stress and tocopherols, using either normal cellular conditions or conditions of sublethal cellular oxidative stress, alter the expression of proteins mediating sterol uptake, transport, and metabolism. Human telomerase transcriptase-overexpressing RPE cells (hTERT-RPE) were used to identify differential expression of proteins resulting from treatments. We utilized a proteomics strategy to identify protein expression changes in treated cells. After the identification and organization of data, we divided the identified proteins into groups related to biological function: cellular sterol uptake, sterol transport and sterol metabolism. Exposure of cells to conditions of oxidative stress and exposure to tocopherols led to similar protein expression changes within these three groups, suggesting that α-tocopherol (αT) and γ-tocopherol (γT) can regulate the expression of sterol uptake, transport and metabolic proteins in RPE cells. These data suggest that proteins involved in sterol transport and metabolism may be important for RPE adaptation to oxidative stress, and these proteins represent potential therapeutic targets.

Eight furostanol glycosides including five undescribed compounds, named tribufurostanosides A-E (1-5), and three known ones (6-8) were isolated from the fruits of Tribulus terrestris L. Their chemical structures were determined by the IR, HR-ESI-MS, 1D-, and 2D-NMR spectra. Furostanols 1-8 significantly inhibited nitric oxide production in LPS activated RAW 264.7 cells with IC 50 values ranging from 14.2 to 64.7 μM, compared to that of the positive control compound, dexamethazone (IC 50 13.6 μM)., (© 2024 Wiley-VHCA AG, Zurich, Switzerland.)

There is an urgent need to provide immediate and effective options for the treatment of prostate cancer (PCa) to prevent progression to lethal castration-resistant PCa (CRPC). The mevalonate (MVA) pathway is dysregulated in PCa, and statin drugs commonly prescribed for hypercholesterolemia, effectively target this pathway. Statins exhibit anti-PCa activity, however the resulting intracellular depletion of cholesterol triggers a feedback loop that restores MVA pathway activity, thus diminishing statin efficacy and contributing to resistance. To identify drugs that block this feedback response and enhance the pro-apoptotic activity of statins, we performed a high-content image-based screen of a 1508 drug library, enriched for FDA-approved compounds. Two of the validated hits, Galeterone (GAL) and Quinestrol, share the cholesterol-related tetracyclic structure, which is also evident in the FDA-approved CRPC drug Abiraterone (ABI). Molecular modeling revealed that GAL, Quinestrol and ABI not only share structural similarity with 25-hydroxy-cholesterol (25HC) but were also predicted to bind similarly to a known protein-binding site of 25HC. This suggested GAL, Quinestrol and ABI are sterol-mimetics and thereby inhibit the statin-induced feedback response. Cell-based assays demonstrated that these agents inhibit nuclear translocation of sterol-regulatory element binding protein 2 (SREBP2) and the transcription of MVA genes. Sensitivity was independent of androgen status and the Fluva-GAL combination significantly impeded CRPC tumor xenograft growth. By identifying cholesterol-mimetic drugs that inhibit SREBP2 activation upon statin treatment, we provide a potent "one-two punch" against CRPC progression and pave the way for innovative therapeutic strategies to combat additional diseases whose etiology is associated with SREBP2 dysregulation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Djulis ( Chenopodium formosanum Koidz ), is rich in nutrients and contains various bioactive components such as polyphenols and alkaloids. The new compound has a broad application prospect, including food additives, health products, drugs, etc. The purpose of this study was to find out new compounds from Djulis. It was found that 24 compounds including 7 phenols, 11 flavonoids, 4 plant alkaloids, 2 sterols. Among those, TCI-CF-22-S (Methyl 3,6-dihydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-23-S (Methyl 6-hydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-24-S (Kaempferol-3-O-b-D-apifuranosyl-(1→2)-a-L-arabinopyranoside) were isolated from djulis sources for the first time, and the structures of compounds were assigned by 1D, 2D NMR spectroscopy. TCI-CF-01(Caffeic acid), TCI-CF-02 (20-Hydroxyecdysone), TCI-CF-03 (Japonicone), TCI-CF-04 (3,4-Dihydroxyphenylacetiate), TCI-CF-05 (Quercetin-3-O-rutinoside-7-O-rhamnopyranoside), TCI-CF-06 (Guanosine), TCI-CF-07(Adenine), TCI-CF-08 (Coumaric acid) increased collagen production, and TCI-CF-03 (Japonicone), TCI-CF-04 (3,4-Dihydroxyphenylacetiate), TCI-CF-06 (Guanosine), TCI-CF-17 (Rutin), TCI-CF-20 (Protocatechuic acid) decreased advanced glycation end products (AGEs). In addition, TCI-CF-22-S (Methyl 6-hydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate), TCI-CF-23-S (Methyl 3,6-dihydroxy-2-oxo-1,2,3,4-tetrahydroquinoline-3-carboxylate) inhibited the formation of fatty oil droplets. Djulis has 24 compounds that may have various applications, including increasing collagen production and reducing advanced glycation end products and fatty oil droplets.

The hedgehog (Hh) signaling pathway has long been a hotspot for anti-cancer drug development due to its important role in cell proliferation and tumorigenesis. However, most clinically available Hh pathway inhibitors target the seven-transmembrane region (7TM) of smoothened (SMO), and the acquired drug resistance is an urgent problem in SMO inhibitory therapy. Here, we identify a sterol analog Q29 and show that it can inhibit the Hh pathway through binding to the cysteine-rich domain (CRD) of SMO and blocking its cholesterylation. Q29 suppresses Hh signaling-dependent cell proliferation and arrests Hh-dependent medulloblastoma growth. Q29 exhibits an additive inhibitory effect on medulloblastoma with vismodegib, a clinically used SMO-7TM inhibitor for treating basal cell carcinoma (BCC). Importantly, Q29 overcomes resistance caused by SMO mutants against SMO-7TM inhibitors and inhibits the activity of SMO oncogenic variants. Our work demonstrates that the SMO-CRD inhibitor can be a new way to treat Hh pathway-driven cancers., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aflatoxins B1 (AFB1) a dangerous type of aflatoxin, poses a serious threat to human health. Meanwhile, Taraxasterol, a bioactive compound in dandelion, exhibits strong anti-inflammatory and antioxidant activity. Therefore, the aim of this study was to investigate the impact of AFB1 on the intrinsic and extrinsic pathways of apoptosis, as well as evaluate the protective role of taraxasterol in the TM3 Leydig cell line. Cell viability was evaluated using an MTT assay, measuring the effects of 3.6 µM AFB1 and varying concentrations of taraxasterol. Expression levels of Caspase 3,8, and 9 were analyzed with RT-qPCR, and flow cytometry was used to assess cell cycle progression and apoptotic alterations. The findings of this study demonstrated that exposure to 3.6 µM of AFB1 resulted in an upregulation of Caspase 3 and Caspase 9 expression, indicating an activation of apoptotic pathways in TM3 cells. Additionally, the analysis of apoptosis revealed a significant increase in cellular apoptosis at this AFB1 concentration. However, when TM3 cells were exposed to 5 µM of taraxasterol, a downregulation of Caspase 3 and Caspase 9 expression was observed, suggesting a protective effect against apoptosis. Moreover, the apoptotic rate in TM3 cells was reduced in the presence of 5 µM of taraxasterol. Consequently, this study highlights the potential of taraxasterol as a protective agent against AFB1-induced apoptosis and suggest its potential application in regulating cell survival and apoptosis-related processes. Further investigations are necessary to elucidate the underlying mechanisms and evaluate the clinical implications of taraxasterol in the context of fertility disorders and other conditions associated with AFB1 exposure., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Touraj Zamirnasta reports financial support was provided by Kermanshah University of Medical Sciences. Touraj Zamirnasta reports a relationship with Kermanshah University of Medical Sciences that includes: non-financial support. Touraj Zamirnasta has patent non pending to non. Touraj Zamirnasta., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

PD-1/PD-L1 monoclonal antibodies exhibit promising therapeutic effectiveness in multiple cancers. However, developing a simple and efficient non-antibody treatment strategy using the PD-1/PD-L1 signaling pathway still remains challenging. In this study, we developed a flow cytometry assay to screen bioactive compounds with PD-L1 inhibitory activity. A total of 409 marine natural products were screened, and sokotrasterol sulfate (SKS) was found to efficiently suppress the IFN-γ-induced PD-L1 expression. SKS sensitizes the tumor cells to antigen-specific T-cell killing in the T cell-tumor cell coculture system. Mechanistically, SKS directly targeted Janus kinase (JAK) to inhibit the downstream activation of signal transducer and activator of transcription (STAT) and the subsequent transcription of PDL1 . Our findings highlight the immunological role of SKS that may act as a basis for a potential immunotherapeutic agent.

The understanding of the role of LXR in the regulation of macrophages during inflammation is emerging. Here, we show that LXR agonist T09 specifically increases 15-LOX abundance in primary human M2 macrophages. In time- and dose-dependent incubations with T09, an increase of 3-fold for ALOX15 and up to 15-fold for 15-LOX-derived oxylipins was observed. In addition, LXR activation has no or moderate effects on the abundance of macrophage marker proteins such as TLR2, TLR4, PPARγ, and IL-1RII, as well as surface markers (CD14, CD86, and CD163). Stimulation of M2-like macrophages with FXR and RXR agonists leads to moderate ALOX15 induction, probably due to side activity on LXR. Finally, desmosterol, 24( S ),25-Ep cholesterol and 22( R )-OH cholesterol were identified as potent endogenous LXR ligands leading to an ALOX15 induction. LXR-mediated ALOX15 regulation is a new link between the two lipid mediator classes sterols, and oxylipins, possibly being an important tool in inflammatory regulation through anti-inflammatory oxylipins.

Background: Artificially fermented dark loose tea is a type of novel dark tea prepared via fermentation by Eurotium cristatum. The effects of artificially fermented dark loose tea on lipid metabolism are still unclear., Objectives: This study aimed to explore if artificially fermented dark loose tea has the same effects as naturally fermented dark loose tea in regulating hepatic lipid metabolism., Methods: Thirty-six 8-wk-old male C57BL/6 mice were randomly divided into 6 treatment groups, including normal control (NC), high-fat diet (HFD), positive control (PC), Wuniuzao dark raw tea (WDT), Wuniuzao naturally fermented dark loose tea (NFLT), and Wuniuzao artificially fermented dark loose tea (AFLT) groups. The HFD, PC, WDT, NFLT, and AFLT groups were fed a HFD. The PC group was supplemented with atorvastatin (10 mg/kg). The WDT group was supplemented with WDT (300 mg/kg), the NFLT group with NFLT (300 mg/kg), and the AFLT group with AFLT (300 mg/kg)., Results: The study compared the effect of WDT, NFLT, and AFLT on liver steatosis and gut microbiota disorder in obese mice. All 3 tea extracts reduced body weight, glucose tolerance, and serum lipid concentrations. Via sterol-regulatory element binding protein (SREBP)-mediated lipid metabolism, all 3 tea extracts alleviated hepatic steatosis in mice with obesity. Furthermore, NFLT and AFLT intervened in the abundance of Firmicutes, Bacteroidetes, Clostridia, Muribaculaceae, and Lachnospiraceae., Conclusion: In mice with obesity induced by a HFD, WDT, NFLT, and AFLT may improve hepatic steatosis through an SREBP-mediated lipid metabolism. Moreover, NFLT and AFLT improved the composition of gut microbiota., (Copyright © 2023 American Society for Nutrition. Published by Elsevier Inc. All rights reserved.)

Here we examined the membrane binding and pore formation of amphidinol 3 (AM3) and its truncated synthetic derivatives. Importantly, both of the membrane affinity and pore formation activity were well correlated with the reported antifungal activity. Our data clearly demonstrated that the C1-C30 moiety of AM3 plays essential roles both in sterol recognition and stable pore formation. Based on the current findings, we updated the interacting model between AM3 and sterol, in which the moiety encompassing from C21 to C67 accommodates a sterol molecule with forming hydrogen bonds with the sterol hydroxy group and van der Waals contact between AM3 polyol and sterol skeleton. Although the conformation of the C1-C20 moiety of AM3 is hard to specify due to its flexibility, the region likely contributes to stabilization of pore structure., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: Radiotherapy with bladder preservation is highly acceptable among patients bearing bladder cancer (BCa), but the occurrence of secondary tolerance (ARR) during treatment is one of the important reasons for the failure of clinical radiotherapy. COX-2 has been frequently reported to be highly expressed and associated with radio-resistance in various cancers. In this study, the feasibility of Taraxasterol (Tara) as a radiosensitizer was investigated, and the target effect of Tara on COX-2 and its underlying mechanism were explored., Methods and Materials: The toxicity of Tara toward BCa cells was detected with the MTT method and cells in response to IR or Tara + IR were compared by clone formation assay. Next, a small RNA interference system (siRNA) was employed to decrease endogenous COX-2 expression in BCa cells, and the stem cell-like features and motion abilities of BCa cells under different treatments were investigated using microsphere formation and transwell chamber assay, respectively. Meanwhile, the expression of a series of inflammation-related molecules and stem cell characteristic molecules was determined by qRT-PCR, western blot and ELISA method. In vivo studies, BCa cells were subcutaneously injected into the right flank of each male mouse. Those mice were then grouped and exposed to different treatment: Tara, IR, IR + Tara and untreated control. The volumes of each tumor were measured every two days and target proteins were detected with immunohistochemical (IHC) staining., Results: The results show that COX-2 decline, due to COX-2 knocking-down or Tara treatment, could greatly enhance BCa cells' radiosensitivity and significantly decrease their migration, invasion and microsphere formation abilities, companied with the reduce of JAK2, phos-STAT3, MMP2 and MMP9 expression. However, Tara could not further reduce the expression of an above molecule of cells in COX-2-deficient BCa cells. Correspondingly, Tara treatment could not further enhance those siCOX-2 BCa cells response to IR., Conclusions: Our data support that Tara can improve the radiosensitivity of BCa cells by targeting COX-2/PGE 2 . The mechanism may involve regulating STAT3 phosphorylation, DNA damage response protein activation, and expression of MMP2/MMP9.

Primarily sourced from Asteraceae family herbs such as the Dandelion, Taraxasterol is a pentacyclic triterpenoid lauded for its extensive biological functionalities. Its therapeutic potency is demonstrated in various disease models, encompassing enteritis, arthritis, acute hepatic injury, and pneumonia. Scientific literature underscores its anti-inflammatory, antioxidant, and antineoplastic attributes. The primary aim of this study is to thoroughly explore the diseasemodulating mechanisms and effects of taraxasterol. We endeavor to provide an exhaustive review of the experimental subjects, intervention components, distinct action modalities, contributing factors, and protein pathway expressions associated with taraxasterol, systematically represented via diagrams and tables. Such a schematic representation encourages a continued academic dialogue concerning taraxasterol's pharmacological characteristics. This review is envisioned as a practical guide for the selection of experimental subjects and methodologies in prospective research. It is intended to further illuminate taraxasterol's pharmacodynamics, thereby offering theoretical and empirical justification for its clinical application., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Infections caused by Candida spp. pose a continuing challenge for modern medicine, due to widespread resistance to commonly used antifungal agents (e.g., azoles). Thus, there is considerable interest in discovering new, natural compounds that can be used in combination therapy with conventional antibiotics. Here, we investigate whether the natural compounds surfactin and capric acid, in combination with posaconazole, enhance the growth inhibition of C. albicans strains with alterations in sterols and the sphingolipids biosynthesis pathway. We demonstrate that combinations of posaconazole with surfactin or capric acid correspond with the decreased growth of C. albicans strains. Moreover, surfactin and capric acid can independently contribute to the reduced adhesion of C. albicans strains with altered ergosterol biosynthesis to abiotic surfaces (up to 90% reduction in adhesion). A microscopic study of the C. albicans plasma membrane revealed that combinations of those compounds do not correspond with the increased permeabilization of the plasma membrane when compared to cells treated with posaconazole alone. This suggests that the fungistatic effect of posaconazole in combination with surfactin or capric acid is related to the reduction in adhesion of C. albicans .

Introduction: Farnesol, derived from farnesyl pyrophosphate in the sterols biosynthetic pathway, is a molecule with three unsaturations and four possible isomers. Candida albicans predominantly secretes the trans , trans -farnesol ( t , t -FOH) isomer, known for its role in regulating the virulence of various fungi species and modulating morphological transition processes. Notably, the evolutionary divergence in sterol biosynthesis between fungi, including Candida albicans , and trypanosomatids resulted in the synthesis of sterols with the ergostane skeleton, distinct from cholesterol. This study aims to assess the impact of exogenously added trans , trans -farnesol on the proliferative ability of Leishmania amazonensis and to identify its presence in the lipid secretome of the parasite., Methods: The study involved the addition of exogenous trans , trans -farnesol to evaluate its interference with the proliferation of L. amazonensis promastigotes. Proliferation, cell cycle, DNA fragmentation, and mitochondrial functionality were assessed as indicators of the effects of trans , trans -farnesol. Additionally, lipid secretome analysis was conducted, focusing on the detection of trans , trans -farnesol and related products derived from the precursor, farnesyl pyrophosphate. In silico analysis was employed to identify the sequence for the farnesene synthase gene responsible for producing these isoprenoids in the Leishmania genome., Results: Exogenously added trans , trans -farnesol was found to interfere with the proliferation of L. amazonensis promastigotes, inhibiting the cell cycle without causing DNA fragmentation or loss of mitochondrial functionality. Despite the absence of trans , trans -farnesol in the culture supernatant, other products derived from farnesyl pyrophosphate, specifically α-farnesene and β-farnesene, were detected starting on the fourth day of culture, continuing to increase until the tenth day. Furthermore, the identification of the farnesene synthase gene in the Leishmania genome through in silico analysis provided insights into the enzymatic basis of isoprenoid production., Discussion: The findings collectively offer the first insights into the mechanism of action of farnesol on L. amazonensis . While trans , trans -farnesol was not detected in the lipid secretome, the presence of α-farnesene and β-farnesene suggests alternative pathways or modifications in the isoprenoid metabolism of the parasite. The inhibitory effects on proliferation and cell cycle without inducing DNA fragmentation or mitochondrial dysfunction raise questions about the specific targets and pathways affected by exogenous trans , trans -farnesol. The identification of the farnesene synthase gene provides a molecular basis for understanding the synthesis of related isoprenoids in Leishmania . Further exploration of these mechanisms may contribute to the development of novel therapeutic strategies against Leishmania infections., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Pinheiro, Andrade-Neto, Mantuano-Barradas, Pereira, Barbosa, de Oliveira, Menna-Barreto, Cunha-Júnior and Torres-Santos.)

Four new 26-carboxylated ergostane-type sterols (Sarcodonol A-D) were isolated from 70% ethanol extracts of dried fruiting bodies of Sarcodon imbricatus. Their chemical structures were elucidated using 1D- and 2D-nuclear magnetic resonance and high-resolution electrospray ionization mass spectrometry, and confirmed by comparison with previously reported data. As far as we know, this is the first instance of isolating a 26-carboxylated ergostane-type sterol from nature. The determined antiviral efficacy of sarcodonol A-D (1-4) against HCoV-OC43 in MRC-5 cells confirmed that sarcodonol D (4) had significant antiviral activity. Notably, sarcodonol D (4) potently blocked virus infection at low-micromolar concentration and showed high SI (IC 50  = 2.26 μM; CC 50  > 100 μM; SI > 44.2). In addition, this research shows that the antiviral effect of sarcodonol D (4) via reduced apoptosis increased by viral infection is through mitochondrial stress regulation. This suggests that sarcodonol D (4) is a potential candidate for use as an antiviral treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Anxiolytic effect of ethanol, hexane extracts and pure compounds β- sito sterol glucoside and bergenin isolated from Adenanthera pavonina AP (Fabaceae) and Peltophorum pterocarpum PP (Fabaceae) leaves were monitored in this study. Mice were treated with dose of 125mg/kg body weight of ethanol and hexane leaves extracts of both tested plants while, 5mg/kg body weight of β-sito sterol glucoside and 25mg/kg body weight of bergenin. The effect was monitored by hole board test, forced swimming test, open field apparatus and stationary rod test. Results from neuropharmacological effects revealed that ethanol extract of AP leaves and hexane extract of PP leaves had significant anxiolytic (forced swimming test) exploratory (head dip and open field test) and neuro activator activity (stationary rod test) at tested dose. The greatest anti-depressant and anxiolytic effect was found in ethanol extract of AP leaves when compared to all treated drugs. A part from memory enhancing effects, diazepam treated mice also exhibited anxiolytic and antidepressant effects and found comparable with ethanol extract of AP. These findings may clarify the impact of ethanol, hexane extracts and pure substances β-sitosterol glucoside and bergenin at tested concentrations, as well as their potential to treat the Parkinson's and related disorders as an alternative therapy.

Six steroid conjugates of bile acids and sterol derivatives have been synthesized using the click chemistry method. The azide-alkyne Huisgen cycloaddition of the propionyl ester of lithocholic, deoxycholic and cholic acid with azide derivatives of cholesterol and cholestanol gave new bile acid-sterol conjugates linked with a 1,2,3-triazole ring. Previously, sterols were converted to bromoacetate substituted derivatives by reaction with bromoacetic acid bromide in anhydrous dichloromethane. These compounds were then converted to azide derivatives using sodium azide. The propiolic esters of lithocholic, deoxycholic and cholic acids were obtained by reaction with propiolic acid in the presence of p-toluenesulfonic acid. Additionally, two of these steroids: methyl 3α-propynoyloxy-12α-acetoxy-5β-cholane-24-oate and methyl 3α-propynoyloxy-7 α,12α-diacetoxy-5β-cholane-24-oate were also obtained and characterized for the first time. All conjugates were obtained in good yields using an efficient synthesis method. The structures of all conjugates and the four substrates were confirmed by spectral ( 1 H- and 13 C NMR, FT-IR) analysis, mass spectrometry (ESI-MS), and PM5 semiempirical methods. The pharmacotherapeutic potential of the synthesized compounds was estimated based on the in silico Prediction of Activity Spectra for Substances (PASS) method. The cytotoxicity of the compounds was in vitro evaluated in a hemolytic assay using human erythrocytes as a cell model. The in silico and in vitro study results indicate that the selected compound possesses an interesting biological activity and can be considered as potential drug design agent. Additionally, molecular docking was performed for the selected conjugate., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Escin is a mixture of over 30 glycosylated triterpenoid (saponin) structures, extracted from the dried fruit of horse chestnuts. Escin is currently used as an anti-inflammatory, and has potential applications in the treatment of arthritis and cancer. Engineered yeast would enable production of specific bioactive components of escin at industrial scale, however many saponins have been shown to be toxic to yeast. Here we report that a Saccharomyces cerevisiae strain specifically lacking the sterol C-5 desaturase gene ERG3, exhibits striking enhanced tolerance to escin treatment. Transcriptome analyses, as well as pre-mixing of escin with sterols, support the hypothesis that escin interacts directly with ergosterol, but not as strongly with the altered sterols present in erg3Δ. A diverse range of saponins are of commercial interest, and this research highlights the value of screening lipidome mutants to identify appropriate hosts for engineering the industrial production of saponins., (© 2023. Springer Nature Limited.)

Edible insects are increasingly gaining popularity as research reveals multiple benefits. However, the rediscovery of natural products from insects as medicinal agents has received limited attention. This study aimed at evaluating the diversity of sterols in extracts of nine edible insects and potential antibacterial activities. Dichloromethane extracts of these insects were analyzed using gas chromatography-mass spectrometry to identify important sterols, followed by evaluation of their anti-bacterial activities. Nineteen sterols were identified with the highest recorded in African fruit beetle [Pachnoda sinuata (47.37%)], crickets [Gryllus bimaculatus (36.84%) and Scapsipedus icipe (31.58%)]. Cholesterol was the most prevalent, except in black soldier fly (Hermetia illucens). Bioactivity revealed S. icipe as the most potent extract against Escherichia coli and Bacillus subtilis whereas G. bimaculatus was highest against Methicillin-susceptible Staphylococcus aureus 25923. These findings unravels the diversity of sterols in edible insects and their possible application in food, pharmaceutical and cosmetic industries., (© 2023. The Author(s).)

Certain members of the order Mucorales can cause a life-threatening, often-fatal systemic infection called mucormycosis. Mucormycosis has a high mortality rate, which can reach 96 to 100% depending on the underlying condition of the patient. Mucorales species are intrinsically resistant to most antifungal agents, such as most of the azoles, which makes mucormycosis treatment challenging. The main target of azoles is the lanosterol 14α-demethylase (Erg11), which is responsible for an essential step in the biosynthesis of ergosterol, the main sterol component of the fungal membrane. Mutations in the erg11 gene can be associated with azole resistance; however, resistance can also be mediated by loss of function or mutation of other ergosterol biosynthetic enzymes, such as the sterol 24-C-methyltransferase (Erg6). The genome of Mucor lusitanicus encodes three putative erg6 genes (i.e., erg6a , erg6b , and erg6c ). In this study, the role of erg6 genes in azole resistance of Mucor was analyzed by generating and analyzing knockout mutants constructed using the CRISPR-Cas9 technique. Susceptibility testing of the mutants suggested that one of the three genes, erg6b , plays a crucial role in the azole resistance of Mucor . The sterol composition of erg6b knockout mutants was significantly altered compared to that of the original strain, and it revealed the presence of at least four alternative sterol biosynthesis pathways leading to formation of ergosterol and other alternative, nontoxic sterol products. Dynamic operation of these pathways and the switching of biosynthesis from one to the other in response to azole treatment could significantly contribute to avoiding the effects of azoles by these fungi. IMPORTANCE The fungal membrane contains ergosterol instead of cholesterol, which offers a specific point of attack for the defense against pathogenic fungi. Indeed, most antifungal agents target ergosterol or its biosynthesis. Mucormycoses-causing fungi are resistant to most antifungal agents, including most of the azoles. For this reason, the drugs of choice to treat such infections are limited. The exploration of ergosterol biosynthesis is therefore of fundamental importance to understand the azole resistance of mucormycosis-causing fungi and to develop possible new control strategies. Characterization of sterol 24-C-methyltransferase demonstrated its role in the azole resistance and virulence of M. lusitanicus. Moreover, our experiments suggest that there are at least four alternative pathways for the biosynthesis of sterols in Mucor . Switching between pathways may contribute to the maintenance of azole resistance., Competing Interests: The authors declare no conflict of interest.

A series of thirty 1,2,3-triazolylsterols, inspired by azasterols with proven antiparasitic activity, were prepared by a stereocontrolled synthesis. Ten of these compounds constitute chimeras/hybrids of 22,26-azasterol (AZA) and 1,2,3-triazolyl azasterols. The entire library was assayed against the kinetoplastid parasites Leishmania donovani, Trypanosoma cruzi, and Trypanosoma brucei, the causatives agents for visceral leishmaniasis, Chagas disease, and sleeping sickness, respectively. Most of the compounds were active at submicromolar/nanomolar concentrations with high selectivity index, when compared to their cytotoxicity against mammalian cells. Analysis of in silico physicochemical properties were conducted to rationalize the activities against the neglected tropical disease pathogens. The analogs with selective activity against L. donovani (E4, IC 50 0.78 μM), T brucei (E1, IC 50 0.12 μM) and T. cruzi (B1- IC 50 0.33 μM), and the analogs with broad-spectrum antiparasitic activities against the three kinetoplastid parasites (B1 and B3), may be promising leads for further development as selective or broad-spectrum antiparasitic drugs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

Background: Ozone (O3) exposure causes respiratory effects including lung function decrements, increased lung permeability, and airway inflammation. Additionally, baseline metabolic state can predispose individuals to adverse health effects from O3. For this reason, we conducted an exploratory study to examine the effect of O3 exposure on derivatives of cholesterol biosynthesis: sterols, oxysterols, and secosteroid (25-hydroxyvitamin D) not only in the lung, but also in circulation., Methods: We obtained plasma and induced sputum samples from non-asthmatic (n = 12) and asthmatic (n = 12) adult volunteers 6 hours following exposure to 0.4ppm O3 for 2 hours. We quantified the concentrations of 24 cholesterol precursors and derivatives by UPLC-MS and 30 cytokines by ELISA. We use computational analyses including machine learning to determine whether baseline plasma sterols are predictive of O3 responsiveness., Results: We observed an overall decrease in the concentration of cholesterol precursors and derivatives (e.g. 27-hydroxycholesterol) and an increase in concentration of autooxidation products (e.g. secosterol-B) in sputum samples. In plasma, we saw a significant increase in the concentration of secosterol-B after O3 exposure. Machine learning algorithms showed that plasma cholesterol was a top predictor of O3 responder status based on decrease in FEV1 (>5%). Further, 25-hydroxyvitamin D was positively associated with lung function in non-asthmatic subjects and with sputum uteroglobin, whereas it was inversely associated with sputum myeloperoxidase and neutrophil counts., Conclusion: This study highlights alterations in sterol metabolites in the airway and circulation as potential contributors to systemic health outcomes and predictors of pulmonary and inflammatory responsiveness following O3 exposure., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Perryman et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The marine environment is considered a vast source in the discovery of structurally unique bioactive secondary metabolites. Among marine invertebrates, the sponge Theonella spp. represents an arsenal of novel compounds ranging from peptides, alkaloids, terpenes, macrolides, and sterols. In this review, we summarize the recent reports on sterols isolated from this amazing sponge, describing their structural features and peculiar biological activities. We also discuss the total syntheses of solomonsterols A and B and the medicinal chemistry modifications on theonellasterol and conicasterol, focusing on the effect of chemical transformations on the biological activity of this class of metabolites. The promising compounds identified from Theonella spp. possess pronounced biological activity on nuclear receptors or cytotoxicity and result in promising candidates for extended preclinical evaluations. The identification of naturally occurring and semisynthetic marine bioactive sterols reaffirms the utility of examining natural product libraries for the discovery of new therapeutical approach to human diseases.

Leishmaniasis is a neglected tropical disease that still infects thousands of people per year throughout the world. The occurrence of resistance against major treatments for this disease causes a healthcare burden in low-income countries. Eugenol is a phenylpropanoid that has shown in vitro antileishmanial activity against Leishmania mexicana mexicana ( Lmm ) promastigotes with an IC 50 of 2.72 µg/mL and a high selectivity index. Its specific mechanism of action has yet to be studied. We prepared large unilamellar vesicles (LUVs), mimicking Lmm membranes, and observed that eugenol induced an increase in membrane permeability and a decrease in membrane fluidity at concentrations much higher than IC 50 . The effect of eugenol was similar to the current therapeutic antibiotic, amphotericin B, although the latter was effective at lower concentrations than eugenol. However, unlike amphotericin B, eugenol also affected the permeability of LUVs without sterol. Its effect on the membrane fluidity of Lmm showed that at high concentrations (≥22.5× IC 50 ), eugenol increased membrane fluidity by 20-30%, while no effect was observed at lower concentrations. Furthermore, at concentrations below 10× IC 50 , a decrease in metabolic activity associated with the maintenance of membrane integrity revealed a leishmaniostatic effect after 24 h of incubation with Lmm promastigotes. While acidocalcisomes distribution and abundance revealed by Trypanosoma brucei vacuolar H + pyrophosphatase (TbVP1) immunolabeling was not modified by eugenol, a dose-dependent decrease of lipid droplets assessed by the Nile Red assay was observed. We hereby demonstrate that the antileishmanial activity of eugenol might not directly involve plasma membrane sterols such as ergosterol, but rather target the lipid storage of Lmm .

Alcoholic fatty liver disease (AFLD) is an early stage of alcohol-related liver disease characterized by abnormal lipid metabolism in hepatocytes. To date, to our knowledge, there have been no effective strategies for preventing or treating alcohol-related liver disease besides alcohol abstinence. Berberine (BBR) is the main bioactive ingredient extracted from traditional Chinese medicines, such as Coptis and Scutellaria, which protect liver function and relieve liver steatosis. However, the potential role of BBR in AFLD remains unclear. Therefore, this study investigated the protective effects of BBR against Gao-binge model-induced AFLD in 6- to 8-week-old C57BL/6J male mice in vivo and ethyl alcohol (EtOH)-induced alpha mouse liver 12 (AML-12) cells in vitro. The results showed that BBR (200 mg/kg) attenuated alcoholic liver injury and suppressed lipid accumulation and metabolism disorders in vivo. Consistently, BBR effectively inhibited the expression of sterol regulatory element-binding transcription factor 1C, sterol regulatory element-binding transcription factor 2, fatty acid synthase, and 3-hydroxy-3-methylglutaryl-CoenzymeA reductase in EtOH-stimulated AML-12 cells in vitro and promoted the expression of sirtuin 1 (SIRT1) in EtOH-fed mice and EtOH-treated AML-12 cells. Furthermore, SIRT1 silencing attenuated the hepatic steatosis alleviation potential of BBR treatment. Mechanistically, molecular docking revealed the binding effect of BBR and adenosine monophosphate-activated protein kinase (AMPK). The results of further studies showed that a decrease in AMPK activity was accompanied by a significant inhibition of SIRT1 expression. SIRT1 silencing attenuated the protective effect of BBR, whereas the inhibition of its expression had no apparent effect on AMPK phosphorylation, suggesting that SIRT1 acts downstream of AMPK in AFLD. Collectively, BBR ameliorated abnormal lipid metabolism and alleviated EtOH-induced liver injury via the AMPK/SIRT1 pathway in AFLD mice., (Copyright © 2022 United States & Canadian Academy of Pathology. Published by Elsevier Inc. All rights reserved.)

Alcoholic liver disease is one of the leading causes of liver-related morbidity and mortality worldwide, but effective treatments are still lacking. Honokiol, a lignin-type natural compound isolated from the leaves and bark of Magnolia plants, has been widely studied for its beneficial effects on several chronic diseases. Accumulating studies have revealed that honokiol displays a potential therapeutic effect on alcoholic liver disease. In this study, the protective activity of honokiol on alcoholic liver disease was confirmed due to its significant inhibitory activity on the expression levels of inflammatory cytokines (such as tumor necrosis factor-alpha, interleukin-6, and interleukin-1 β ) in EtOH-fed mice and in EtOH-induced AML-12 cells. Meanwhile, the expression of the lipid metabolic parameter sterol regulatory element-binding protein-1c was also reduced. However, peroxisome proliferator-activated receptor α was increased in animal and cell experiments, which indicates that the activity of honokiol was related to its regulated activity on lipid metabolism. The result showed that honokiol significantly inhibited the expression level of p38 α in vivo and in vitro . Blocking p38 α inhibited the expression levels of tumor necrosis factor-alpha, interleukin-6, interleukin-1 β , and sterol regulatory element-binding protein-1c but promoted the expression level of peroxisome proliferator-activated receptor α compared with the honokiol-treated group. Moreover, the forced expression level of p38 α further produced the opposite effect on inflammatory cytokines and lipid metabolism indicators. Furthermore, p38 α has been related to the activation of the nuclear factor kappa B signaling pathway. In our study, honokiol significantly inhibited the activation of the nuclear factor kappa B signaling pathway mediated by p38 α . In conclusion, the results suggest that honokiol might be an effective regulator of p38 α by downregulating the nuclear factor kappa B signaling pathway, thereby reducing the inflammatory response and lipid metabolism disorder in alcoholic liver disease., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Introduction: Antifungal therapy for aspergillosis is becoming problematic because of the toxicity of currently available drugs, biofilm formation on host surface, and increasing prevalence of azole resistance in Aspergillus fumigatus . Plants are rich source of bioactive molecules and antimicrobial activity of aromatic bioactive compounds draws attention because of its promising biological properties. The present study elucidated the antibiofilm activity of 4-allyl-2-methoxyphenol (eugenol) against azole-resistant environmental A. fumigatus isolates., Methods: Soil samples were collected from agricultural fields across India; azole-resistant A. fumigatus (ARAF) were isolated followed by their molecular identification. Antibiofilm activity of eugenol was calculated via tetrazolium based-MTT assay. The expression of the multidrug efflux pumps genes MDR1, MDR4 , transporters of the MFS gene, erg11A gene encoding 14α demethylase, and transcription regulatory genes, MedA , SomA and SrbA , involved in biofilm formation of A. fumigatus were calculated by quantitative real time PCR., Results: Out of 89 A. fumigatus isolates, 10 were identified as azole resistant. Eugenol exhibited antibiofilm activity against ARAF isolates, ranging from 312 to 500 µg/mL. Confocal laser scanning microscopy analysis revealed absence of extracellular matrix of ARAF biofilm after eugenol treatment. The gene expression indicated significantly low expression of efflux pumps genes MDR1 , MDR4 , erg11A and MedA in eugenol treated ARAF isolates when compared with untreated isolates., Conclusions: Our results demonstrate that eugenol effects the expression of efflux pump and biofilm associated genes as well as inhibits biofilm formation in azole resistant isolates of A. fumigatus ., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Sen, Gupta, Vijay, Vermani Sarin, Shankar, Hameed and Vijayaraghavan.)

The nuclear receptors-liver X receptors (LXR α and β) are potential therapeutic targets in cardiovascular and neurodegenerative diseases because of their key role in the regulation of lipid homeostasis and inflammatory processes. Specific oxy(phyto)sterols differentially modulate the transcriptional activity of LXRs providing opportunities to develop compounds with improved therapeutic characteristics. We isolated oxyphytosterols from Sargassum fusiforme and synthesized sidechain oxidized sterol derivatives. Five 24-oxidized sterols demonstrated a high potency for LXRα/β activation in luciferase reporter assays and induction of LXR-target genes APOE , ABCA1 and ABCG1 involved in cellular cholesterol turnover in cultured cells: methyl 3β-hydroxychol-5-en-24-oate ( S1 ), methyl (3β)-3-aldehydeoxychol-5-en-24-oate ( S2 ), 24-ketocholesterol ( S6 ), (3β,22E)-3-hydroxycholesta-5,22-dien-24-one ( N10 ) and fucosterol-24,28 epoxide ( N12 ). These compounds induced SREBF1 but not SREBP1c-mediated lipogenic genes such as SCD1 , ACACA and FASN in HepG2 cells or astrocytoma cells. Moreover, S2 and S6 enhanced cholesterol efflux from HepG2 cells. All five oxysterols induced production of the endogenous LXR agonists 24(S)-hydroxycholesterol by upregulating the CYP46A1 , encoding the enzyme converting cholesterol into 24(S)-hydroxycholesterol; S1 and S6 may also act via the upregulation of desmosterol production. Thus, we identified five novel LXR-activating 24-oxidized sterols with a potential for therapeutic applications in neurodegenerative and cardiovascular diseases.

Genome-scale metabolic modeling (GEM) is one of the key approaches to unpack cancer metabolism and for discovery of new drug targets. In this study, we report the Transcriptional Regulated Flux Balance Analysis-CORE (TRFBA-), an algorithm for GEM using key growth-correlated reactions using hepatocellular carcinoma (HCC), an important global health burden, as a case study. We generated a HepG2 cell-specific GEM by integrating this cell line transcriptomic data with a generic human metabolic model to forecast potential drug targets for HCC. A total of 108 essential genes for growth were predicted by the TRFBA-CORE. These genes were enriched for metabolic pathways involved in cholesterol, sterol, and steroid biosynthesis. Furthermore, we silenced a predicted essential gene, 11-beta dehydrogenase hydroxysteroid type 2 ( HSD11B2 ), in HepG2 cells resulting in a reduction in cell viability. To further identify novel potential drug targets in HCC, we examined the effect of nine drugs targeting the essential genes, and observed that most drugs inhibited the growth of HepG2 cells. Some of these drugs in this model performed better than Sorafenib, the first-line therapeutic against HCC. A HepG2 cell-specific GEM highlights sterol metabolism to be essential for cell growth. HSD11B2 downregulation results in lower cell growth. Most of the compounds, selected by drug repurposing approach, show a significant inhibitory effect on cell growth in a wide range of concentrations. These findings offer new molecular leads for drug discovery for hepatic cancer while also illustrating the importance of GEM and drug repurposing in cancer therapeutics innovation.

Difenoconazole sensitivity was assessed in three populations of the apple scab agent Venturia inaequalis of the Krasnodar region. One of the populations was fungicide naïve population; its sample was collected in natural habitats of the eastern crabapple Malus orientalis in foothills of the Severskii raion. The two other populations were from commercial orchards of the apple variety Reinette Simirenko (the Krasnoarmeiskii and Dinskoi raions), where fungicide treatments with various agents, including those with difenoconazole as an active ingredient, were performed on a regular basis. Single-spore V. inaequalis isolates were isolated from fresh leaves with signs of the disease or fallen leaves with fungal fruiting bodies. The median effective concentration (EC 50 ) was defined as the concentration that halves the colony growth and was estimated in a series of in vitro experiments with 120 isolates. Difenoconazole (Score EC, 250 mg/L, Syngenta) was used at six concentrations: 0.005, 0.01, 0.025, 0.05, 0.5, and 1 mg a.i./L. Mean EC 50 values were 0.0078 mg a.i./L in the natural population and 0.12 and 0.25 mg a.i./L in the orchard populations. Fungicide sensitivity was lower in both of the orchard populations; their resistance factors were estimated at 16 and 32. The proportion of sensitive and low-sensitive isolates differed between the two orchard populations. A discriminatory dose, or single-assessment concentration (SAC), of 0.01 mg a.i./L was proposed to simplify the laboratory monitoring of the difenoconazole sensitivity in V. inaequalis by using a test for relative growth (RG) of the mycelium. Comparable results were obtained with EC 50 and RG at the discriminatory dose. The portion of isolates with RGs exceeding the threshold (RG > 70%) was 97% in one of the orchard populations. The results indicate that difenoconazole resistance develops in V. inaequalis populations from commercial orchards of the Krasnodar region., (© 2022. Pleiades Publishing, Ltd.)

Human leishmaniasis is an infectious disease caused by Leishmania protozoan parasites. Current chemotherapeutic options against the deadly disease have significant limitations. The ergosterol biosynthetic pathway has been identified as a drug target in Leishmania. However, remarkable differences in the efficacy of antifungal azoles that inhibit ergosterol biosynthesis have been reported for the treatment of leishmaniasis. To better understand the sterol biosynthetic pathway in Leishmania and elucidate the mechanism underlying the differential efficacy of antifungal azoles, we developed a new LC-MS/MS method to study sterol profiles in promastigotes of three Leishmania species, including two L. donovani, one L. major and one L. tarentolae strains. A combination of distinct precursor ion masses and LC retention times allowed for specific detection of sixteen intermediate sterols between lanosterol and ergosterol using the newly developed LC-MS/MS method. Although both posaconazole and fluconazole are known inhibitors of fungal lanosterol 14α-demethylase (CYP51), only posaconazole led to a substantial accumulation of lanosterol in azole-treated L. donovani promastigotes. Furthermore, a key intermediate sterol accumulated by 40- and 7-fold when these parasites were treated with posaconazole and fluconazole, respectively, which was determined as 4α,14α-dimethylzymosterol by high resolution mass spectrometry and NMR spectroscopy. The identification of 4α,14α-dimethylzymosterol supports a branched ergosterol biosynthetic pathway in Leishmania, where lanosterol C4- and C14-demethylation reactions occur in parallel rather than sequentially. Our results suggest that selective inhibition of leishmanial CYP51 is insufficient to effectively prevent parasite growth and dual inhibitors of both CYP51 and the unknown sterol C4-demethylase may be required for optimal antiparasitic effect., Competing Interests: Declaration of competing interest Authors declare no competing interests or conflict of interest., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is an endoplasmic reticulum (ER)-localized integral membrane protein that catalyzes the rate-limiting step in the synthesis of cholesterol and many nonsterol isoprenoids including geranylgeranyl pyrophosphate (GGpp). HMGCR is subjected to strict feedback control through multiple mechanisms to ensure cells constantly produce essential nonsterol isoprenoids, but do not overaccumulate cholesterol. Here, we focus on the mechanism of feedback control of HMGCR that involves its sterol-induced ubiquitination and ER-associated degradation (ERAD) that is augmented by GGpp. We will also discuss the how GGpp-regulated intracellular trafficking of the vitamin K2 synthetic enzyme UbiA prenyltransferase domain-containing protein-1 (UBIAD1) inhibits HMGCR ERAD to balance the synthesis of sterol and nonsterol isoprenoids. Finally, we will summarize various mouse models, the characterization of which establish that sterol-accelerated, UBIAD1-modulated ERAD plays a major role in regulation of HMGCR and cholesterol metabolism in vivo., (Copyright © 2022 Cold Spring Harbor Laboratory Press; all rights reserved.)

To explore the effect and mechanism of taraxasterol on sepsis-induced acute respiratory distress syndrome (ARDS). Twenty-four male SD rats were randomly divided into four groups: the control group, model (lipopolysaccharide, LPS) group, lipopolysaccharide+taraxasterol (LPS + TXL) group, and lipopolysaccharide+ulinastatin (LPS + UTI) group. The model of sepsis-induced ARDS was established by intraperitoneal injection of LPS. The lung water content of the rats in each group was determined by the dry/wet ratio. Pathology of rat lung tissue was observed through H&E staining. Wright staining was applied to count the number of neutrophils, macrophages, and total cells. ELISA was utilized to measure the levels of the inflammatory factors TNF-α, IL-1β, and IL-6 in bronchoalveolar lavage fluid (BALF). Biochemical detection was adopted to check the levels of myeloperoxidase (MPO), superoxide dismutase (SOD) and catalase (CAT) in lung tissue. Western blotting was performed to check the protein expression of IL-12, iNOS, Arg-1, and Mrc1 in lung tissue. Compared with the LPS group, both taraxasterol and ulinastatin significantly decreased lung tissue water content, improved lung tissue injury, reduced the number of neutrophils, macrophages and total cells, and decreased the level of inflammatory factors. In addition, taraxasterol and ulinastatin also reduced the content of MPO and the expression of IL-12 and iNOS and increased the activity of SOD and CAT as well as the protein expression of Arg-1 and Mrc1. Taraxasterol can suppress macrophage M1 polarization to alleviate the inflammatory response and oxidative stress, thereby treating sepsis-induced ARDS., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Dengue virus (DENV) is considered one of the most important pathogens in the world causing 390 million infections each year. Currently, the development of vaccines against DENV presents some shortcomings and there is no antiviral therapy available for its infection. An important challenge is that both treatments and vaccines must be effective against all four DENV serotypes. Nordihydroguaiaretic acid (NDGA), isolated from Larrea divaricata Cav. (Zygophyllaceae) has shown a significant inhibitory effect on a broad spectrum of viruses, including DENV serotypes 2 and 4., Purpose: We evaluated the in vitro virucidal and antiviral activity of NDGA on DENV serotype 1 (DENV1), including the study of its mechanism of action, to provide more evidence on its antiviral activity., Methods: The viability of viral particles was quantified by the plaque-forming unit reduction method. NDGA effects on DENV1 genome and viral proteins were evaluated by qPCR and immunofluorescence, respectively. Lysosomotropic activity was assayed using acridine orange and neutral red dyes., Results: NDGA showed in vitro virucidal and antiviral activity against DENV1. The antiviral effect would be effective within the first 2 h after viral internalization, when the uncoating process takes place. In addition, we determined by qPCR that NDGA decreases the amount of intracellular RNA of DENV1 and, by immunofluorescence, the number of cells infected. These results indicate that the antiviral effect of NDGA would have an intracellular mechanism of action, which is consistent with its ability to be incorporated into host cells. Considering the inhibitory activity of NDGA on the cellular lipid metabolism, we compared the antiviral effect of two inhibitors acting on two different pathways of this type of metabolism: 1) resveratrol that inhibits the sterol regulatory element of binding proteins, and 2) caffeic acid that inhibits the 5-lipoxygenase (5-LOX) enzyme. Only caffeic acid produced an inhibitory effect on DENV1 infection. We studied the lysosomotropic activity of NDGA on host cells and found, for the first time, that this compound inhibited the acidification of cell vesicles which would prevent DENV1 uncoating process., Conclusion: The present work contributes to the knowledge of NDGA activity on DENV. We describe its activity on DENV1, a serotype different to those that have been already reported. Moreover, we provide evidence on which stage/s of the viral replication cycle NDGA exerts its effects. We suggest that the mechanism of action of NDGA on DENV1 is related to its lysosomotropic effect, which inhibits the viral uncoating process., Competing Interests: Declaration of Competing Interest All data were generated in-house, and no paper mill was used. All authors agree to be accountable for all aspects of work ensuring integrity and accuracy.”, (Copyright © 2022. Published by Elsevier GmbH.)

Scope : Atherosclerosis (AS) is the leading cause of ischemic disease. However, the anti-AS effects of astaxanthin and its potential mechanisms remain unclear. This study is aimed to investigate the function of astaxanthin-rich extract (ASTE) on AS and gut microbiota as well as the difference from atorvastatin (ATO) in apolipoprotein E-deficient (ApoE -/- ) mice. Methods and results : Wild type (WT) and ApoE -/- mice were divided into seven groups: the low-fat diet (LFD) and high-fat diet (HFD) groups (in both types) as well as three ApoE -/- groups based on HFD added with two doses of ASTE and one dose of ATO, respectively. After 30 weeks of intervention, results showed that ASTE significantly inhibited body weight increase, lipids accumulation in serum/liver, and AS-lesions in the aorta. Furthermore, fundus fluorescein angiography and retinal CD31 immunohistochemical staining showed that ASTE could alleviate the occurrence of AS-retinopathy. H&E staining showed that ASTE could protect the colon's mucosal epithelium from damage. The gas chromatographic and gene expression analyses showed that ASTE promoted the excretion of fecal acidic and neutral sterols from cholesterol by increasing LXRα, CYP7A1, and ABCG5/8 and decreasing FXR, NPC1L1, ACAT2, and MTTP expressions. Remarkably, the ASTE administration maintained the gut barrier by enhancing gene expression of JAM-A, Occludin, and mucin2 in the colon and reshaped gut microbiota with the feature of blooming Akkermansia . Conclusion : Our results suggested that ASTE could prevent AS in both macrovascular and/or microvascular as well as used as novel prebiotics by supporting the bile acid excretion and growth of Akkerman sia.

Antibiotic residue has become an emerging environmental contaminant, while the toxicological effects and underlying mechanisms caused by the co-exposure to multiple veterinary antibiotics were rarely studied. In this study, male Sprague Dawley rats were exposed to monensin (M) (1, 2, 10 mg/(kg·body weight (BW)) combined with sulfamethazine (S) (60, 120, 600 mg/(kg·BW)) or single drugs for 28 consecutive days. The body weight, hematological and blood biochemical parameters, organ coefficients, and histopathology were analyzed to discover their combined toxicity effect. Transcriptomic analysis was used to reveal the possible mechanisms of their joint toxicity. Compared with the control group, the weight gain rate was significantly reduced in the H-M+S and H-S, and alkaline phosphatase in H-M+S was significantly increased. Furthermore, relative liver and kidneys weight was significantly increased, and the liver of H-M+S showed more severe lesions in histopathological analysis. For H-M+S, H-M and H-S, transcriptomic results showed that 344, 246, and 99 genes were differentially expressed, respectively. The Gene Ontology terms mainly differ in sterol biosynthetic process and steroid hydroxylase activity. The Kyoto Encyclopedia of Genes and Genome pathways showed abnormal retinol metabolism, metabolism of xenobiotics by cytochrome P450, and drug metabolism-cytochrome 450; the common 30 genes were screened from the network of protein-protein interaction. The results showed that mixed contamination of M and S produces hepatotoxicity by interfering with linoleic acid metabolism, retinol metabolism and CYP450 enzyme-dominated drug metabolism. Further analysis showed that Cyp1a2, Cyp2c61, Ugt1a3, and Ugt1a5 might be the key genes. These findings could provide more evidence for investigating the toxic effects and metabolism of mixed antibiotics contamination in mammals., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

We examined the effects of the extracts from two traditional Chinese medicine plants, Cuscuta chinensis and Eucommia ulmoides, on the healthspan of the model organism Caenorhabditis elegans . C. chinensis increased the short-term memory and the mechanosensory response of aged C. elegans. Furthermore, both extracts improved the resistance towards oxidative stress, and decreased the intracellular level of reactive oxygen species. Chemical analyses of the extracts revealed the presence of several bioactive compounds such as chlorogenic acid, cinnamic acid, and quercetin. A fraction from the C. chinensis extract enriched in zingibroside R1 improved the lifespan, the survival after heat stress, and the locomotion in a manner similar to the full C. chinensis extract. Thus, zingibroside R1 could be (partly) responsible for the observed health benefits of C. chinensis . Furthermore, a hydroxygallic acid derivative and the sterol lipid 4-alpha-formyl-stigmasta-7,24(241)-dien-3-beta-ol are abundantly present in the C. chinensis extract and its most bioactive fraction, but hardly in E. ulmoides , making them good candidates to explain the overall healthspan benefits of C. chinensis compared to the specific positive effects on stress resistance by E. ulmoides . Our findings highlight the overall anti-aging effects of C. chinensis in C. elegans and provide first hints about the components responsible for these effects.

Hepatic lipid synthesis through SREBP has recently been found to be regulated not only through the canonical pathway involving SCAP in response to sterol deficiency, but also through the PIDDosome and CASP2. In this issue, Kim et al. identify a novel interaction between these two pathways in diet-induced non-alcoholic steatohepatitis., Competing Interests: Declaration of interests The author declares no competing interests., (Copyright © 2022. Published by Elsevier Inc.)

Objective: Non-alcoholic steatohepatitis (NASH) has become a global medical problem. Currently, there is no approved pharmacologic treatment for this condition. Previous studies have suggested that in the pathogenesis of this disease, regulatory pathways associated with de novo lipogenesis and β-oxidation pathways genes are misregulated. Capparis spinosa (CS) belongs to the family of Capparidaceae and is a traditional plant used to treat various diseases, particularly dyslipidemia. The compounds and extracts of this plant in In vivo and in vitro studies resulted in a reduction in lipid profiles and glucose. However, the mechanism of these effects remains unknown. This study aimed to evaluate the effects of (CS) fruit extract on NASH compared to fenofibrate and explored the related molecular mechanism., Results: In the rats (n = 40) model of NASH, biochemical and histopathological examinations showed that liver steatosis, inflammation, and hepatic fibrosis were markedly attenuated in response to CS and fenofibrate interventions. At the molecular level, CS treatment down-regulated sterol regulatory element-binding protein-1c (SREBP-1c) (p < 0.001), acetyl-CoA carboxylase (ACC) (p < 0.001), and up-regulated Carnitine palmitoyltransferase I (CPT1) expression (p < 0.001). In conclusion, CS has favorable therapeutic effects for NASH, which was associated with ameliorating steatosis and fibrosis via regulation of the DNL and β-oxidation pathway genes., (© 2022. The Author(s).)

Cyclic lipopeptides (CLiPs) are secondary metabolites produced by a variety of bacteria. These compounds show a broad range of antimicrobial activities; therefore, they are studied for their potential applications in agriculture and medicine. It is generally assumed that the primary target of the CLiPs is the cellular membrane, where they can permeabilize the lipid bilayer. Model membrane systems are commonly used to investigate the effect of lipid composition on the permeabilizing activity of CLiPs, but these systems do not represent the full complexity of true biological membranes. Here, we introduce a novel method that uses sterol-auxotrophic oomycetes to investigate how the activity of membrane-active compounds is influenced by alterations in membrane sterol composition. More specifically, we investigated how ergosterol, cholesterol, beta-sitosterol and stigmasterol affect the activity of the structurally related Pseudomonas-derived CLiPs tolaasin and sessilin against the oomycete Pythium myriotylum. Both compounds were effective against oomycetes, although tolaasin was considerably more active. Interestingly, tolaasin and sessilin effects were similarly reduced by the presence of sterols, with cholesterol showing the highest reduction of activity., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The endolysosomal system not only is an integral part of the cellular catabolic machinery that processes and recycles nutrients for synthesis of biomaterials, but also acts as signaling hub to sense and coordinate the energy state of cells with growth and differentiation. Lysosomal dysfunction adversely influences vesicular transport-dependent macromolecular degradation and thus causes serious problems for human health. In mammalian cells, loss of the lysosome associated membrane proteins LAMP1 and LAMP2 strongly affects autophagy and cholesterol trafficking. Here we show that the previously uncharacterized Drosophila Lamp1 is a bona fide ortholog of vertebrate LAMP1 and LAMP2. Surprisingly and in contrast to lamp1 lamp2 double-mutant mice, Drosophila Lamp1 is not required for viability or autophagy, suggesting that fly and vertebrate LAMP proteins acquired distinct functions, or that autophagy defects in lamp1 lamp2 mutants may have indirect causes. However, Lamp1 deficiency results in an increase in the number of acidic organelles in flies. Furthermore, we find that Lamp1 mutant larvae have defects in lipid metabolism as they show elevated levels of sterols and diacylglycerols (DAGs). Because DAGs are the main lipid species used for transport through the hemolymph (blood) in insects, our results indicate broader functions of Lamp1 in lipid transport. Our findings make Drosophila an ideal model to study the role of LAMP proteins in lipid assimilation without the confounding effects of their storage and without interfering with autophagic processes. Abbreviations : aa: amino acid; AL: autolysosome; AP: autophagosome; APGL: autophagolysosome; AV: autophagic vacuole (i.e. AP and APGL/AL); AVi: early/initial autophagic vacuoles; AVd: late/degradative autophagic vacuoles; Atg : autophagy-related; CMA: chaperone-mediated autophagy; Cnx99A: Calnexin 99A; DAG: diacylglycerol; eMI: endosomal microautophagy; ESCRT: endosomal sorting complexes required for transport; FB: fat body; HDL: high-density lipoprotein; Hrs: Hepatocyte growth factor regulated tyrosine kinase substrate; LAMP: lysosomal associated membrane protein; LD: lipid droplet; LDL: low-density lipoprotein; Lpp: lipophorin; LTP: Lipid transfer particle; LTR: LysoTracker Red; MA: macroautophagy; MCC: Manders colocalization coefficient; MEF: mouse embryonic fibroblast MTORC: mechanistic target of rapamycin kinase complex; PV: parasitophorous vacuole; SNARE: soluble N-ethylmaleimide sensitive factor attachment protein receptor; Snap: Synaptosomal-associated protein; st: starved; TAG: triacylglycerol; TEM: transmission electron microscopy; TFEB/Mitf: transcription factor EB; TM: transmembrane domain; tub: tubulin; UTR: untranslated region.

Four previously undescribed ergostane-type sterols, aspersterols A-D ( 1 - 4 ), were isolated from a deep-sea-derived fungus, Aspergillus unguis IV17-109. The structures of the new compounds were determined by extensive analyses of their spectroscopic data, pyridine-induced deshielding effect, Mosher's method, and electronic circular dichroism calculations. The key feature of these sterols is the presence of a rare unsaturated side chain with conjugated double bonds at Δ 17 and Δ 22 . The absolute configuration of C-24 in the side chain was determined by hydrogenation and comparing 13 C NMR chemical shifts of the hydrogenated products with literature values. In addition, aspersterol A ( 1 ) is the second representative of anthrasteroids with a hydroxy group at the C-2 position. Compound 1 showed cytotoxicity against six cancer cell lines, with GI 50 values of 3.4 ± 0.3 to 4.5 ± 0.7 μM, while 2 - 4 showed anti-inflammatory activity, with IC 50 values ranging from 11.6 ± 1.6 to 19.5 ± 1.2 μM.

Marine microalgae are receiving great interest as sustainable sources of bioactive metabolites for health, nutrition and personal care. In the present study, a bioassay-guided screening allowed identifying an enriched fraction from SPE separation of the methanolic extract of the marine diatom Thalassiosira rotula with a chemically heterogeneous composition of cytotoxic molecules, including PUFAs, the terpene phytol, the carotenoid fucoxanthin and the phytosterol 24-methylene cholesterol (24-MChol). In particular, this latter was the object of deep investigation aimed to gain insight into the mechanisms of action activated in two tumour cell models recognised as resistant to chemical treatments, the breast MCF7 and the lung A549 cell lines. The results of our studies revealed that 24-MChol, in line with the most studied β-sitosterol (β-SIT), showed cytotoxic activity in a 3-30 µM range of concentration involving the induction of apoptosis and cell cycle arrest, although differences emerged between the two sterols and the two cancer systems when specific targets were investigated (caspase-3, caspase-9, FAS and TRAIL).

Alternaria alternata botybirnavirus 1 (AaBRV1) was isolated from a strain of Alternaria alternata , causing watermelon leaf blight in our previous research. The effect of AaBRV1 on the phenotype of its host fungus, however, was not determined. In the present study, a novel strain of AaBRV1 was identified in A. tenuissima strain TJ-NH-51S-4, the causal agent of cotton Alternaria leaf spot, and designated as AaBRV1-AT1. A mycovirus AaBRV1-AT1-free strain TJ-NH-51S-4-VF was obtained by protoplast regeneration, which eliminated AaBRV1-AT1 from the mycovirus AaBRV1-AT1-infected strain TJ-NH-51S-4. Colony growth rate, spore production, and virulence of strain TJ-NH-51S-4 were greater than they were in TJ-NH-51S-4-VF, while the sensitivity of strain TJ-NH-51S-4 to difenoconazole, as measured by the EC 50 , was lower. AaBRV1-AT1 was capable of vertical transmission via asexual spores and horizontal transmission from strain TJ-NH-51S-4 to strain XJ-BZ-5-1 hyg (another strain of A. tenuissima ) through hyphal contact in pairing cultures. A total of 613 differentially expressed genes (DEGs) were identified in a comparative transcriptome analysis between TJ-NH-51S-4 and TJ-NH-51S-4-VF. Relative to strain TJ-NH-51S-4-VF, the number of up-regulated and down-regulated DEGs in strain TJ-NH-51S-4 was 286 and 327, respectively. Notably, the expression level of one DEG-encoding cytochrome P450 sterol 14α-demethylase and four DEGs encoding siderophore iron transporters were significantly up-regulated. To our knowledge, this is the first documentation of hypervirulence and reduced sensitivity to difenoconazole induced by AaBRV1-AT1 infection in A. tenuissima .

Previous investigations of the Leishmania infantum eIF4A-like protein (LieIF4A) as a potential drug target delivered cholestanol derivatives inhibitors. Here, we investigated the mode of action of cholesterol derivatives as a novel scaffold structure of LieIF4A inhibitors on the RNA-dependent ATPase activity of LieIF4A and its mammalian ortholog (eIF4AI). We compared their biochemical effects on RNA-dependent ATPase activities of both proteins and investigated if rocaglamide, a known inhibitor of eIF4A, could affect LieIF4A as well. Kinetic measurements were conducted at different concentrations of ATP, of the compound and in the presence of saturating whole yeast RNA concentrations. Kinetic analyses showed different ATP binding affinities for the two enzymes as well as different sensitivities to 7-α-aminocholesterol and rocaglamide. The 7-α-aminocholesterol inhibited LieIF4A with a higher binding affinity relative to cholestanol analogs. Cholesterol, another tested sterol, had no effect on the ATPase activity of LieIF4A or eIF4AI. The 7-α-aminocholesterol demonstrated an anti- Leishmania activity on L. infantum promastigotes. Additionally, docking simulations explained the importance of the double bond between C5 and C6 in 7- α -aminocholesterol and the amino group in the C7 position. In conclusion, Leishmania and mammalian eIF4A proteins appeared to interact differently with effectors, thus making LieIF4A a potential drug against leishmaniases.

Recently, some preclinical and clinical studies have demonstrated the ability of brown seaweeds in reducing the risk factors for metabolic syndrome. Here, we analyzed the beneficial effect of a nutraceutical formulation containing a phytocomplex extracted from seaweeds and chromium picolinate in animal models of liver steatosis of differing severities (rats with non-alcoholic fatty liver disease (NAFLD) and its complication, non-alcoholic steatohepatitis (NASH)). This treatment led to a significant drop in hepatic fat deposition in both models (p < 0.01 vs. untreated animals), accompanied by a reduction in plasma inflammatory cytokines, such as interleukin 6, tumor necrosis factor α, and C reactive protein, and myeloperoxidase expression in liver tissue. Furthermore, a modulation of the molecular pathways involved in lipid metabolism and storage was demonstrated, since we observed the significant reduction of the mRNA levels of fatty acid synthase, diacylglycerol acyltransferases, the sterol-binding protein SREBP-1, and the lipid transporter perilipin-2, in both treated NAFLD and NASH rats in comparison to untreated ones. In conclusion, this nutraceutical product was effective in reducing liver steatosis and showed further beneficial effects on hepatic inflammation and glycemic control, which were particularly evident in rats characterized by a more severe condition, thus representing a therapeutic option for the treatment of NAFLD and NASH patients.

Intracellular sterol transport proteins (STPs) are crucial for maintaining cellular lipid homeostasis by regulating local sterol pools. Despite structural similarities in their sterol binding domains, STPs have different substrate specificities, intracellular localisation and biological functions. In this review, we highlight recent advances in the determination of STP structures and how this regulates their lipid specificities. Furthermore, we cover the important discoveries relating to the intracellular localisation of STPs, and the organelles between which lipid transport is carried out, giving rise to specific functions in health and disease. Finally, serendipitous and targeted efforts to identify small molecule modulators of STPs, as well as their ability to act as tool compounds and potential therapeutics, will be discussed., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The ethyl acetate and dichloromethane-soluble fractions, from a soft coral Sarcophyton trocheliophorum total methanolic extract, exhibited significant anti-leishmanial and cytotoxic activities. These active fractions yielded a new cembranoid diterpene ( 1 ), two known analogues [sarcotrocheliol ( 2 ) and sarcophine ( 3 )], and two sterols [(24 S )-24-methylcholesterol ( 4 ) and gorgosterol ( 5 )]. The structure of the new diterpene ( 1 ) was determined via a detailed analysis of its spectroscopic data. Compounds 3 and 5 demonstrated noticeable cytotoxicity on A549 (IC 50 17.4 ± 1.9 µg/ml) and HepG2 (IC 50 17.7 ± 1.5 µg/ml) cell lines, respectively. None of the isolates 1‒5 showed detectable anti-leishmanial activity (IC 50 >100 µg/ml).

β-Amyloid toxicity (Aβ) is an important pathological factor of Alzheimer's disease (AD). Studies have shown that genistein can reduce the toxicity of Aβ to a certain extent; however, the specific mechanism is still uncertain. In the study, we applied Caenorhabditis elegans strains expressing Aβ peptides to evaluate the role of genistein inhibiting Aβ toxicity and the undying mechanism. Genistein influencing the sterol metabolism pathway, the HSP-16.2 pathway, and lipofuscin in different strains of C. elegans were studied using reverse transcription-polymerase chain reaction, fluorescence labeling, RNA interference (RNAi), and so forth. Our results showed that genistein alleviated the paralysis of transgenic C. elegans strains. Furthermore, in AD C. elegans, genistein reduced the fluorescence of lipofuscin, downregulated the messenger RNA (mRNA) level of vit-3 and vit-6 which were related to the sterol metabolism pathway, significantly increased the mRNA level and protein level of HSP-16.2, increased the nuclear translocation of the DAF-16 transcription factor and increased the survival rate after heat stress, which was closely associated with HSP-16.2 levels. However, the paralysis-alleviating effect of genistein was greatly reduced because of RNAi-mediated inhibition of hsp-16.2, indicating that the anti-Aβ toxicity effect of genistein was greatly dependent on HSP-16.2. The above results suggest that genistein inhibiting the toxicity of Aβ in C. elegans, is involved in the modulation of the sterol metabolism pathway by promoting transcription factor DAF-16 translocation into the nucleus, increasing the expression level of HSP-16.2, and reducing the levels of lipofuscin through its antioxidant activity., (© 2022 Wiley Periodicals LLC.)