Search

Prion diseases, known as a group of fatal neurodegenerative disorders caused by prions, remain incurable despite extensive research efforts. In a recent study, crude extract from Curcuma phaeocaulis Valeton (Cp) showed promising anti-prion efficacy in in vitro and in vivo models, prompting further investigation into their active compounds. We endeavored to identify the chemical constituents of the Cp extract and discover potential anti-prion agents. With the use of centrifugal partition chromatography (CPC), major constituents were isolated from the n-hexane (HX) fraction of the extract in a single step. Spectroscopic analysis confirmed the presence of curcumenone, curcumenol, and furanodienone. Subsequent efficacy testing in a cell culture model of prion disease identified curcumenol and furanodienone as active compounds. This study underscores the potential of natural products in the search for effective treatments against prion diseases.

Lycii Radicis Cortex (LRC) is a traditional medicine in East Asia with various beneficial effects, including antioxidant, anti-inflammatory, anti-tumor, anti-diabetic, and anti-depressant properties. However, its potential effects on skeletal muscle atrophy have not been studied. In this study, the protective effects of LRC extract (LRCE) on dexamethasone (DEX)-induced muscle atrophy were investigated in C2C12 myotubes and mice. We evaluated the effect of LRCE on improving muscle atrophy using a variety of methods, including immunofluorescence staining, quantitative polymerase chain reaction (qPCR), Western blot, measurements of oxidative stress, apoptosis, ATP levels, and muscle tissue analysis. The results showed that LRCE improved myotube diameter, fusion index, superoxide dismutase (SOD) activity, mitochondrial content, ATP levels, expression of myogenin and myosin heavy chain (MHC), and reduced reactive oxygen species (ROS) production in dexamethasone-induced C2C12 myotubes. LRCE also enhanced protein synthesis and reduced protein degradation in the myotubes. In mice treated with DEX, LRCE restored calf thickness, decreased mRNA levels of muscle-specific RING finger protein 1 (MuRF1) and atrogin-1, and increased insulin-like growth factor 1 (IGF-1) mRNA level. Moreover, LRCE also repaired gastrocnemius muscle atrophy caused by DEX. Although human studies are not available, various preclinical studies have identified potential protective effects of LRCE against muscle atrophy, suggesting that it could be utilized in the prevention and treatment of muscle atrophy.

Bioactivity-guided isolation was conducted using centrifugal partition chromatography (CPC) from an extract of Sinomenium acutum rhizome, which has shown promising preventive effects in a dexamethasone-induced C2C12 myotube atrophy model. CPC was operated with a solvent system of n-butanol–acetonitrile–water (10:2:8, v/v/v, containing 0.5% triethylamine) in dual mode (ascending to descending), which provided a high recovery rate (>99%) with a high resolution. Then, the preventive effects of the obtained CPC fractions were examined against dexamethasone-induced atrophy in C2C12 myotubes according to the weight ratios of the obtained fractions. The active fractions were further purified by semi-preparative HPLC that led to obtaining five alkaloids, one lignan glycoside, and one phenylpropanoid glycoside. Among these, at a concentration of 1 nM, sinomenine, magnoflorine, and acutumine could ameliorate dexamethasone-induced myotube atrophy in C2C12 myotubes by 9.3%, 13.8%, and 11.3%, respectively.

The unsaturated aldehyde trans-2-nonenal is known to be generated by lipid peroxidation at the surface of the skin in an aging-related manner and has harmful effects on keratinocytes in the skin. In this study, the protective effect of a Lycii Radicis Cortex (LRC) extract against trans-2-nonenal-induced cell damage on human keratinocyte cell lines (HaCaT) was investigated. Notably, treatment with the LRC extract resulted in an increase in cell survival, while trans-2-nonenal decreased the viability of HaCaT cells. For identification of interaction between the LRC extract and trans-2-nonenal, this mixture was incubated in simulated physiological conditions, showing a strong decrease in the amount of trans-2-nonenal by the LRC extract. Subsequent LC-ESI-MS analysis revealed that kukoamine B (KB) formed Schiff base-derived pyridinium adducts with trans-2-nonenal. Thus, these results suggest that KB could be a potential agent that may protect HaCaT cells by forming new products with trans-2-nonenal.

Pueraria lobata (Willd.) Ohwi. is a widely used medicinal plant in Korea, China, and Japan. The flower of P. lobata (Puerariae Flos) contains various bioactive substances such as triterpenoidal saponins and isoflavonoids. In this study, we developed a quantitative analysis of the isoflavones of Puerariae Flos by quantitative proton nuclear magnetic resonance (qHNMR) spectroscopy using the internal calibrant (IC). From the qHNMR results, the isoflavone content was found to be 7.99% and 10.57% for the MeOH sonication extract (PLs) and the MeOH reflux extract (PLr) of Puerariae Flos, respectively. The quantified isoflavone content was validated using the conventional analytical method, high-performance liquid chromatography with ultraviolet detection (HPLC-UV). The present study shows that validated qHNMR spectroscopy is a reliable method for quantifying and standardizing the isoflavone content in Puerariae Flos.

Patulin, a mycotoxin, is known to have cytotoxic effects, but few studies have focused on the involvement of the endoplasmic reticulum (ER) stress response in patulin toxicity and the natural compounds that attenuate it in HepG2 cells. This study tested the ability of patulin to induce ER stress, and that of four thiols and three thioethers to attenuate patulin-induced ER stress in HepG2 cells. Patulin dose-dependently inhibited cell proliferation (IC50, 8.43 μM). Additionally, patulin was found to increase the expression levels of ER stress-related genes and/or protein markers, including BiP, CHOP, and spliced XBP1, in HepG2 cells compared to the vehicle control, indicating its potential in ER stress induction. Patulin-induced cytotoxicity in HepG2 cells was reduced by naturally occurring thiol compounds (glutathione, L-acetyl-L-cysteine, cysteine, and captopril), but not by thioether compounds (sulforaphane, sulforaphene, and S-allyl-L-cysteine). Patulin-thiol co-treatment decreased CHOP expression and BiP and CHOP levels in HepG2 cells but did not alter BiP expression. Spliced XBP1 expression was decreased by patulin-thiol co-treatment. Thus, patulin induced ER stress in HepG2 cells and thiols, but not in thioethers, attenuated patulin-induced ER stress.

A new steroidal saponin, 26-O-β-d-glucopyranosyl-(25R)-furost-5-ene-3β,22α,26-triol 3-O-(1−4)-β-d-glucopyranosyl-α-l-rhamnopyranosyl-(1−2)-[α-l-rhamnopyranosyl-(1−4)]-β-d-glucopyranoside [asparacochioside A (1)] was isolated from a hot water extract of the roots of Asparagus cochinchinensis, together with the known steroidal saponins protodioscin (2), methyl protodioscin (3), aspacochioside A (4), aspacochioside C (5), 15−hydroxypseudoprotodioscin (6), and chamaedroside E (7). The structure of the new compound 1 was determined by interpretation of its spectroscopic data (1D- and 2D-NMR and HR−Q−TOF−MS) and sugar analysis. The isolated compounds 1−7 were tested for their in vitro cytotoxicity against human ovarian cancer cell lines (A2780 and SKOV3). Asparacochioside A (1) exhibited a significant cytotoxicity against both A2780 and SKOV3 cells with IC50 values of 5.25 ± 2.2 and 46.82 ± 9.43 μM, respectively. Furthermore, asparacochioside A (1) significantly increased the percentage of Annexin V-positive cells (apoptotic cells), suggesting that asparacochioside A induces ovarian cancer cell death via apoptosis.

Gastrodia elata is widely used in traditional medicine and contains various types of metabolites with pharmacological activity. In the course of searching for neuroprotective molecules associated with the potential of G. elata in the treatment of neurodegenerative disorders, two new phenolic compounds (1 and 2) and a new tripeptide (3), together with 16 known compounds (4–19), were isolated from the rhizomes of G. elata. The structures of the compounds were determined by the interpretation of spectroscopic data, including nuclear magnetic resonance and mass spectrometry data. All obtained compounds were assessed for their ability to protect neuronal cells against neurotoxicity and neuroinflammation. Of these, 4 and 5 were found to possess moderate activities in HT22 hippocampal neuronal cells, whereas 2, 6, and 7 showed weak activities in R28 retinal cells. Additionally, compound 9 showed moderate inhibitory activity on lipopolysaccharide-induced nitric oxide production in BV2 microglial cells.

Two tetrahydrofurofurano lignans (1 and 2), four phenylpropanoids (3–6), and two alkamides (7 and 8) were isolated from the EtOAc-soluble fraction of the roots of Asarum sieboldii. The chemical structures of the isolates were identified by analysis of spectroscopic data measurements, and by a comparison of their data with published values. The isolates (1, 2, 4–8) were evaluated for their cytotoxicity against human ovarian cancer cells (A2780 and SKOV3) and immortalized ovarian surface epithelial cells (IOSE80PC) using a MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay. Of the isolates, (−)-asarinin (1) exhibited the most potent cytotoxicity to both A2780 and SKOV3 cells. A propidium iodide/annexin V-fluorescein isothiocyanate (V-FITC) double staining assay showed that (−)-asarinin (1) induces apoptotic cell death in ovarian cancer cells. In addition, (−)-asarinin (1) increased the activation of caspase-3, caspase-8, and caspase-9 in ovarian cancer cells. Pretreatment with caspase inhibitors attenuated the cell death induced by (−)-asarinin (1). In conclusion, our findings show that (−)-asarinin (1) from the roots of A. sieboldii may induce caspase-dependent apoptotic cell death in human cancer cells.

The present investigation of the chemical constituents of the stem barks of Ailanthus altissima has resulted in the isolation of six canthinone-type alkaloids, including a new compound, (R)-5-(1-hydroxyethyl)-canthine-6-one (1), and five known compounds (2–6). Moreover, four phenyl propanoids (7–10), two lignans (11 and 12), two triterpenoids (13 and 14) and a fatty acid (15) having previously known chemical structures were isolated during the same course of this study. The structure of the new compound was elucidated by physical (m.p., [α]D) and spectroscopic data (1H-NMR, 13C-NMR, 2D NMR, and HR-DART-MS) interpretation and its absolute configuration was determined by electronic circular dichroism (ECD) data and quantum chemical calculations. The inflammatory activities of the isolates were screened on lipopolysaccharide (LPS)-induced nitric oxide (NO), a proinflammatory mediator, in RAW 264.7 cells. Among these isolated compounds, six compounds exhibited significant inhibition of NO production, with IC50 values in the range of 5.92 ± 0.9 to 15.09 ± 1.8 μM.