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Purple grape juice produces a significant amount of grape pomace (GP) as a by-product, which can be reused as a raw material in producing craft beers with bioactive properties. The objective of this study was to produce craft beers with the addition of GP during the fermentation process to evaluate the incorporation of bioactive compounds, aiming at using a by-product generated in the production of grape juice. Craft beer was produced, incorporating GP at concentrations of 1%, 5%, and 10% (w/w), and the physicochemical, technological, bioactive, and sensory properties were evaluated. The beers with the highest concentrations of GP (10% w/w) exhibited higher bioactive concentrations, including phenolic compounds (308 mg GAE/L), flavonoids (0.05 g of quercetin/L), anthocyanins (754.6 mg cyanidin-3-glucoside/L), and antioxidant capacities, as measured by DPPH (1878.2 µM Trolox/L), ABTS (4294.5 µM Trolox/L), and FRAP (844.7 mg ascorbic acid/L) methods. Adding GP promoted lower brightness (62.2) and intensified the a*, b*, and chroma parameters (18.0, 10.1, and 20.6, respectively), with the pigments of GP contributing to changes in the color parameters. However, increased sedimentation was observed under both conditions analyzed (4 °C and 25 °C), due to the higher presence of particulate matter from GP (3.4% and 3.7%, respectively). In general, for sensory analysis, while the knowledge of beneficial effects did not significantly change emotional responses, there were distinct emotional profiles associated with different beer samples. Utilizing GP for the bioactivation of beer is a positive approach to enhance its overall properties and an effective way to address issues related to the disposal of this by-product. [ABSTRACT FROM AUTHOR]

The emergence of drug‐resistant strains of Mycobacterium tuberculosis (M.tb), the causative agent of tuberculosis, is on the rise and increasing antimicrobial resistance is a global threat. This phenomenon necessitates new drug design methods such as a prodrug strategy to develop novel antitubercular agents. The prodrug strategy is a viable and useful means to improve the absorption, distribution, metabolism, excretion and toxicity (ADMET) profiles of pharmacologically active agents. Granulomas are a pathological hallmark of M.tb infection and bear a remarkable resemblance to the tumour microenvironment, including regions of hypoxia. The hypoxic environment observed in the two structures offer an exceptional opportunity to deliver antitubercular agents selectively in a similar manner to hypoxia activated prodrugs in cancer therapy. Nitroimidazoles have been studied extensively as bioactivated prodrugs of cancer, and their suitability as substrates for mammalian reductases highlight their huge potential. This review will discuss the mechanism of action and resistance mechanisms of the current prodrugs used for the treatment of tuberculosis. It will also highlight the potential advantages and challenges of using hypoxia activated prodrugs as a viable strategy to target latent M.tb in hypoxic regions of granulomas. [ABSTRACT FROM AUTHOR]

A new procedure for the bioactivation of alumina-based porous ceramic constructs was introduced. The constructs were built with the aim of mimicking the structural and mechanical properties of the human cortical bone. Bioactivation was achieved by adding wollastonite and acidic surface treatment (piranha solution). Structural studies (SEM, CAT) confirmed that adequate pore size and interconnectivity were obtained. Uniaxial compression tests showed that the values of Young's moduli and compressive strength were reduced, from 5 to 1 GPa, and from 45 to 15 MPa, respectively, as the wollastonite content increased from 0 to 40 wt.%. Proliferative, histological and fluorescence results confirmed that cell proliferation rate of bone-marrow-derived mesenchymal stem cells were significantly enhanced by increasing wollastonite content. No cytotoxic effect was observed. In summary, the fabricated bioceramics exhibited suggestive structural and mechanical properties and they could be useful for the practical bone tissue engineering applications without any adverse biological effects. [Display omitted] • New porous alumina bioactivated with CaSiO 3 and piranha solution were obtained by SPS. • Constructs have adequate porous size (>100 μ m) and high interconnectivity (>90%). • Mechanical properties of the porous samples mimic those of the human cortical bone. • CaSiO 3 content increased the bioactivity of porous alumina by apatite calcium phosphate precipitation. • CaSiO 3 content upregulated stem cell's proliferation in alumina constructs. [ABSTRACT FROM AUTHOR]

Cytochrome P450 (CYP)3A4 induction by drugs and pesticides plays a critical role in the enhancement of pyrrolizidine alkaloid (PA) toxicity as it leads to increased formation of hepatotoxic dehydro-PA metabolites. Addressing the need for a quantitative analysis of this interaction, we developed a physiologically-based toxicokinetic (PBTK) model. Specifically, the model describes the impact of the well-characterized CYP3A4 inducer rifampicin on the kinetics of retrorsine, which is a prototypic PA and contaminant in herbal teas. Based on consumption data, the kinetics after daily intake of retrorsine were simulated with concomitant rifampicin treatment. Strongest impact on retrorsine kinetics (plasma AUC 24 and C max reduced to 67% and 74% compared to the rifampicin-free reference) was predicted directly after withdrawal of rifampicin. At this time point, the competitive inhibitory effect of rifampicin stopped, while CYP3A4 induction was still near its maximum. Due to the impacted metabolism kinetics, the cumulative formation of intestinal retrorsine CYP3A4 metabolites increased to 254% (from 10 to 25 nmol), while the cumulative formation of hepatic CYP3A4 metabolites was not affected (57 nmol). Return to baseline PA toxicokinetics was predicted 14 days after stop of a 14-day rifampicin treatment. In conclusion, the PBTK model showed to be a promising tool to assess the dynamic interplay of enzyme induction and toxification pathways. [ABSTRACT FROM AUTHOR]

Abstract Background The fish embryo acute toxicity (FET) test with the zebrafish (Danio rerio) was developed to assess the acute fish toxicity of chemicals or environmental samples as a replacement for the Acute Fish Test (AFT) with juvenile fish. However, the FET is not yet established in the regulatory context. One reason is the (postulated) difference between the biotransformation capacities of embryos and juvenile fish. The present study was designed to develop a procedure for external metabolization of test substances prior to testing in the FET. The workflow allows simultaneous exposure of the embryos to the maternal substances and their potential metabolites throughout the entire exposure period. After a 2 h incubation of the samples at 37 °C with non-toxic concentrations of a rat liver S9 homogenate or an animal-free (ewoS9R) metabolization system, freshly fertilized zebrafish embryos are added and incubated up to 120 h post-fertilization at 26 °C. Five biotransformable model substances (allyl alcohol, benzo[a]pyrene (B[a]P), chlorpyrifos (CP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and bisphenol A (BPA)) were evaluated for embryotoxicity with and without external metabolization. Results Only for allyl alcohol, external metabolization with both rat S9 and ewoS9R resulted in significantly higher embryotoxicity than under non-premetabolized conditions and, thus, in a better correlation of FET and AFT data. For B[a]P, CP, TDCPP and BPA, there was no relevant difference between data derived from the FET (with and without pre-metabolization) and literature AFT data; even though the FET results with and without pre-metabolization differed significantly for BPA (with rat S9 and ewoS9R) and TDCPP (rat S9 only). Conclusions External pre-metabolization appears a promising add-on to the FET protocol to improve the correlation with AFT data of certain biotransformable substances and might help to strengthen the FET as an alternative to the AFT and finally to reduce or replace sentient animals used for acute fish toxicity data in the regulatory context. Graphical Abstract

Cytochrome P450 (P450)-mediated bioactivation, which can lead to the hepatotoxicity through the formation of reactive metabolites (RMs), has been regarded as the major problem of drug failures. Herein, we purposed to establish machine learning models to predict the bioactivation of P450. On the basis of the literature-derived bioactivation dataset, models for Benzene ring, Nitrogen heterocycle and Sulfur heterocycle were developed with machine learning methods, i.e., Random Forest, Random Subspace, SVM and Naïve Bayes. The models were assessed by metrics like "Precision", "Recall", "F-Measure", "AUC" (Area Under the Curve), etc. Random Forest algorithms illustrated the best predictability, with nice AUC values of 0.949, 0.973 and 0.958 for the test sets of Benzene ring, Nitrogen heterocycle and Sulfur heterocycle models, respectively. 2D descriptors like topological indices, 2D autocorrelations and Burden eigenvalues, etc. contributed most to the models. Furthermore, the models were applied to predict the occurrence of bioactivation of an external verification set. Drugs like selpercatinib, glafenine, encorafenib, etc. were predicted to undergo bioactivation into toxic RMs. In vitro, IC50 shift experiment was performed to assess the potential of bioactivation to validate the prediction. Encorafenib and tirbanibulin were observed of bioactivation potential with shifts of 3–6 folds or so. Overall, this study provided a reliable and robust strategy to predict the P450-mediated bioactivation, which will be helpful to the assessment of adverse drug reactions (ADRs) in clinic and the design of new candidates with lower toxicities. [ABSTRACT FROM AUTHOR]

Background: The fish embryo acute toxicity (FET) test with the zebrafish (Danio rerio) was developed to assess the acute fish toxicity of chemicals or environmental samples as a replacement for the Acute Fish Test (AFT) with juvenile fish. However, the FET is not yet established in the regulatory context. One reason is the (postulated) difference between the biotransformation capacities of embryos and juvenile fish. The present study was designed to develop a procedure for external metabolization of test substances prior to testing in the FET. The workflow allows simultaneous exposure of the embryos to the maternal substances and their potential metabolites throughout the entire exposure period. After a 2 h incubation of the samples at 37 °C with non-toxic concentrations of a rat liver S9 homogenate or an animal-free (ewoS9R) metabolization system, freshly fertilized zebrafish embryos are added and incubated up to 120 h post-fertilization at 26 °C. Five biotransformable model substances (allyl alcohol, benzo[a]pyrene (B[a]P), chlorpyrifos (CP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and bisphenol A (BPA)) were evaluated for embryotoxicity with and without external metabolization. Results: Only for allyl alcohol, external metabolization with both rat S9 and ewoS9R resulted in significantly higher embryotoxicity than under non-premetabolized conditions and, thus, in a better correlation of FET and AFT data. For B[a]P, CP, TDCPP and BPA, there was no relevant difference between data derived from the FET (with and without pre-metabolization) and literature AFT data; even though the FET results with and without pre-metabolization differed significantly for BPA (with rat S9 and ewoS9R) and TDCPP (rat S9 only). Conclusions: External pre-metabolization appears a promising add-on to the FET protocol to improve the correlation with AFT data of certain biotransformable substances and might help to strengthen the FET as an alternative to the AFT and finally to reduce or replace sentient animals used for acute fish toxicity data in the regulatory context. [ABSTRACT FROM AUTHOR]

This study was conducted to compare the effects of an innovative plasma surface treatment device that does not need a gas supply for titanium disks with two different surface topographies: the prototypical machined surface (MAC) and one of the most diffused roughened ones (SL) obtained through grit blasting and acid etching. A total of 200-MAC and 200-SL titanium disks were used. Each group of disks was divided into four sub-groups of 40 samples each that were subjected to five different tests. Among these, 150-MAC and 150-SL were considered the test group, and they were treated with plasma for 15, 30, and 60 s after being removed from the sterile packaging. On the other hand, 50-MAC and 50-SL were considered the control group, and they were only removed from sterile plastic vials. The samples were analyzed to evaluate the capability of the plasma treatment in influencing protein adsorption, cell adhesion, proliferation, and microbial growth on the test group disks when compared to the untreated disks. Protein adsorption was significantly enhanced after 20 min of plasma treatment for 15 and 30 s on the MAC and SL disks. Plasma treatment for 15 and 30 s significantly increased the level of adhesion in both treated samples after 30 min. Furthermore, the MAC samples showed a significant increase in cell adhesion 4 h after plasma treatment for 15 s. The SEM analysis highlighted that, on the treated samples (especially on the MAC disks), the cells with a polygonal and flat shape prevailed, while the fusiform- and globular-shaped cells were rare. The encouraging results obtained further confirm the effectiveness of plasma treatments on cell adhesion and fibroblast activity. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive overview of techniques and graft materials used for repairing peripheral nerve defects. It discusses current approaches to peripheral nerve injury, including autografts, allografts, and nerve conduits, and examines the advantages and disadvantages of each method. The authors emphasize the importance of considering both the material and topography of nerve conduits in promoting nerve regeneration. Different designs, such as conduits with porous walls, grooved walls, multichannels, and fillers, are explored. The article suggests that a combination of synthetic and natural polymers may be the ideal choice for nerve conduit fabrication. The text also highlights the significance of providing topographic cues in the design of conduits for repairing peripheral nerve defects, and offers strategies such as porous and grooved walls, multi-channel conduits, and the use of fillers like fibers or hydrogels to enhance the structure and bioactivation of conduits. The article includes author contributions, funding sources, conflict of interest, and a disclaimer that the claims expressed in the article are solely those of the authors. It also provides several references for further reading on the topic of nerve conduit design and peripheral nerve regeneration. [Extracted from the article]

Purple grape juice produces a significant amount of grape pomace (GP) as a by-product, which can be reused as a raw material in producing craft beers with bioactive properties. The objective of this study was to produce craft beers with the addition of GP during the fermentation process to evaluate the incorporation of bioactive compounds, aiming at using a by-product generated in the production of grape juice. Craft beer was produced, incorporating GP at concentrations of 1%, 5%, and 10% (w/w), and the physicochemical, technological, bioactive, and sensory properties were evaluated. The beers with the highest concentrations of GP (10% w/w) exhibited higher bioactive concentrations, including phenolic compounds (308 mg GAE/L), flavonoids (0.05 g of quercetin/L), anthocyanins (754.6 mg cyanidin-3-glucoside/L), and antioxidant capacities, as measured by DPPH (1878.2 µM Trolox/L), ABTS (4294.5 µM Trolox/L), and FRAP (844.7 mg ascorbic acid/L) methods. Adding GP promoted lower brightness (62.2) and intensified the a*, b*, and chroma parameters (18.0, 10.1, and 20.6, respectively), with the pigments of GP contributing to changes in the color parameters. However, increased sedimentation was observed under both conditions analyzed (4 °C and 25 °C), due to the higher presence of particulate matter from GP (3.4% and 3.7%, respectively). In general, for sensory analysis, while the knowledge of beneficial effects did not significantly change emotional responses, there were distinct emotional profiles associated with different beer samples. Utilizing GP for the bioactivation of beer is a positive approach to enhance its overall properties and an effective way to address issues related to the disposal of this by-product.

SCO‐267 is a potent G‐protein‐coupled receptor 40 agonist that is undergoing clinical development for the treatment of type 2 diabetes mellitus. The current work was undertaken to investigate the bioactivation potential of SCO‐267 in vitro and in vivo. Three SCO‐267‐derived glutathione (GSH) conjugates (M1–M3) were found both in rat and human liver microsomal incubations supplemented with GSH and nicotinamide adenine dinucleotide phosphate. Two GSH conjugates (M1–M2) together with two N‐acetyl‐cysteine conjugates (M4–M5) were detected in the bile of rats receiving SCO‐267 at 10 mg/kg. The identified conjugates suggested the generation of quinone‐imine and ortho‐quinone intermediates. CYP3A4 was demonstrated to primarily catalyze the bioactivation of SCO‐267. In addition, SCO‐267 concentration‐, time‐, and NADPH‐dependently inactivated CYP3A in human liver microsomes using testosterone as a probe substrate, along with KI and kinact values of 4.91 μM and 0.036 min−1, respectively. Ketoconazole (a competitive inhibitor of CYP3A) displayed no significant protective effect on SCO‐267‐induced CYP3A inactivation. However, inclusion of GSH showed significant protection. These findings revealed that SCO‐267 undergoes a facile CYP3A4‐catalyzed bioactivation with the generation of quinone‐imine and ortho‐quinone intermediates, which were assumed to be involved in SCO‐267 induced CYP3A inactivation. These findings provide further insight into the bioactivation pathways involved in the generation of reactive, potentially toxic metabolites of SCO‐267. Further studies are needed to evaluate the influence of SCO‐267 metabolism on the safety of this drug in vivo. [ABSTRACT FROM AUTHOR]

Biocompatible and biodegradable foams prepared using the high-pressure foaming technique have been widely investigated in recent decades as porous scaffolds for in vitro and in vivo tissue growth. In fact, the foaming process can operate at low temperatures to load bioactive molecules and cells within the pores of the scaffold, while the density and pore architecture, and, hence, properties of the scaffold, can be finely modulated by the proper selection of materials and processing conditions. Most importantly, the high-pressure foaming of polymers is an ideal choice to limit and/or avoid the use of cytotoxic and tissue-toxic compounds during scaffold preparation. The aim of this review is to provide the reader with the state of the art and current trend in the high-pressure foaming of biomedical polymers and composites towards the design and fabrication of multifunctional scaffolds for tissue engineering. This manuscript describes the application of the gas foaming process for bio-scaffold design and fabrication and highlights some of the most interesting results on: (1) the engineering of porous scaffolds featuring biomimetic porosity to guide cell behavior and to mimic the hierarchical architecture of complex tissues, such as bone; (2) the bioactivation of the scaffolds through the incorporation of inorganic fillers and drugs. [ABSTRACT FROM AUTHOR]

A fundamental knowledge of applied organic chemistry is an important weapon in the arsenal of drug metabolism scientists, particularly ones engaged in the design and/or the conduct of biotransformation studies or as drug hunters. Application of basic organic chemistry concepts (e.g., nucleophilicity/electrophilicity, bond polarity, electron flow, etc.) are important in elucidating structures of complex metabolites, arising from the metabolism of xenobiotics, and rationalizing the biotransformation mechanisms leading to their formation. An appreciation for the art of using mechanistic chemistry insights to study metabolic processes is usually gained during graduate training (MS and/or PhD) in academic laboratories specialized in the fields of chemical toxicology, medicinal chemistry, and/or enzymology. Select examples of academic research efforts, wherein mechanistic organic chemistry concepts were successfully applied to rationalize and establish structure-metabolism toxicology relationship trends for the oxidative metabolism of alicyclic amines are highlighted in this manuscript. The co-authors of this manuscript participated in some of this research work during their academic training, and went on toward a career in the pharmaceutical industry, where they applied their academic training toward studies on the metabolism of new drug substances, which also included efforts exploring the chemical basis for a toxicological consequence(s) in the preclinical discovery setting. The latter attribute is highlighted with a case study exploring metabolic activation pathways with a small molecule 5-HT2C agonist, which was genotoxic in the in vitro Ames assay. [ABSTRACT FROM AUTHOR]

This study was conducted to compare the effects of an innovative plasma surface treatment device that does not need a gas supply for titanium disks with two different surface topographies: the prototypical machined surface (MAC) and one of the most diffused roughened ones (SL) obtained through grit blasting and acid etching. A total of 200-MAC and 200-SL titanium disks were used. Each group of disks was divided into four sub-groups of 40 samples each that were subjected to five different tests. Among these, 150-MAC and 150-SL were considered the test group, and they were treated with plasma for 15, 30, and 60 s after being removed from the sterile packaging. On the other hand, 50-MAC and 50-SL were considered the control group, and they were only removed from sterile plastic vials. The samples were analyzed to evaluate the capability of the plasma treatment in influencing protein adsorption, cell adhesion, proliferation, and microbial growth on the test group disks when compared to the untreated disks. Protein adsorption was significantly enhanced after 20 min of plasma treatment for 15 and 30 s on the MAC and SL disks. Plasma treatment for 15 and 30 s significantly increased the level of adhesion in both treated samples after 30 min. Furthermore, the MAC samples showed a significant increase in cell adhesion 4 h after plasma treatment for 15 s. The SEM analysis highlighted that, on the treated samples (especially on the MAC disks), the cells with a polygonal and flat shape prevailed, while the fusiform- and globular-shaped cells were rare. The encouraging results obtained further confirm the effectiveness of plasma treatments on cell adhesion and fibroblast activity.

In severe peripheral nerve injuries, nerve conduits (NCs) are good alternatives to autografts/allografts; however, the results the available devices guarantee for are still not fully satisfactory. Herein, differently bioactivated NCs based on the new polymer oxidized polyvinyl alcohol (OxPVA) are compared in a rat model of sciatic nerve neurotmesis (gap: 5 mm; end point: 6 weeks). Thirty Sprague Dawley rats are randomized to 6 groups: Reverse Autograft (RA); Reaxon®; OxPVA; OxPVA + EAK (self-assembling peptide, mechanical incorporation); OxPVA + EAK-YIGSR (mechanical incorporation); OxPVA + Nerve Growth Factor (NGF) (adsorption). Preliminarily, all OxPVA-based devices are comparable with Reaxon® in Sciatic Functional Index score and gait analysis; moreover, all conduits sustain nerve regeneration (S100, β-tubulin) without showing substantial inflammation (CD3, F4/80) evidences. Following morphometric analyses, OxPVA confirms its potential in PNI repair (comparable with Reaxon®) whereas OxPVA + EAK-YIGSR stands out for its myelinated axons total number and density, revealing promising in injury recovery and for future application in clinical practice.

The role of acyl glucuronide (AG) metabolites as mediators of drug-induced toxicities remains controversial, in part due to difficulties in studying this group of reactive drug conjugates. Confounding factors include the bioactivation of carboxylic acid drugs by alternative pathways, AG-mediated inhibition of key enzymes and transporters, and unanticipated interactions with several biological systems. These issues, together with the inherent instability of AGs under physiological conditions, have led to significant challenges in assessing the human safety of AGs according to current regulatory guidances. Despite important advances in the analytical methodology used to detect, identify and quantify AGs in biological fluids and tissues, there is a lack of information on the molecular mechanisms that underlie the toxicity of carboxylic acid-containing drugs and their AG metabolites. This review summarizes the current status of the field, and the de-risking strategies that have been adopted to minimize the likelihood of AG-mediated toxicity in drug discovery and lead optimization programs. [ABSTRACT FROM AUTHOR]

Due to their unique properties, titanium (Ti) and Ti-alloys are particularly suitable for biomedical devices. Ti has a high specific strength and low Young's modulus (reducing stress shielding), high corrosion resistance, and superior biocompatibility. However, Ti's moderately low Young's modulus (100-110GPa) is still considerably higher than to bones (5-30GPa). The)8-Ti phase, whose elastic modulus is closer to the bone, can be kept by increasing the contents of non-toxic ß stabilizing elements. Besides stress shielding and corrosion resistance, adjusted bioactivity (bone-bonding ability) is another primary prerequisite for implants that can be improved by ultrafine-grained (UFG) microstructures and surface modification (anodization and acid+alkaline treatment). UFG by HPT also enhances wear resistance and mechanical properties. Representative alloys (Ti-6Al-7Nb (TAN), Ti-13-Nb-13Zr (TNZ), and Ti-35Nb-7Zr-5Ta (TNZT)) and cp-Ti, were presented in this overview. Samples started with different phases and morphologies. Deformation by HPT induced phase transformation in the alloys, which depended on the amounts of a or ß stabilizers, the strain rate, applied loads, and starting phases and a morphologies. Grain sizes were reduced to about 120 nm. Mechanical properties depended mainly on the number of grain boundaries and their nature and different phases, sizes, and strengths. Young's modulus diminished when the ß was increased. Polished surfaces and cp-Ti presented similar corrosion resistance, improved by surface treatments, which reached maximum protection in anodized samples processed by HPT. After bioactivity tests, different growth rates for various processing conditions and alloys were observed, the highest for the TNZ alloy, and improved after HPT processing. [ABSTRACT FROM AUTHOR]

Alice T Epitropoulos,1,2 Sheraz M Daya,3 Cynthia Matossian,4 Alan G Kabat,5,6 Gretchen Blemker,5 Kristen Striffler,5 Laura Hendrix,5 Marian Macsai,5 Andrea Gibson5 1Ophthalmic Surgeons & Consultants of Ohio, the Eye Center of Columbus, Columbus, OH, USA; 2Department of Ophthalmology, the Ohio State University Wexner Medical Center, Columbus, OH, USA; 3Centre for Sight, London, UK; 4Matossian Eye Associates, Pennington, NJ, USA; 5Oyster Point Pharma, Inc, Princeton, NJ, USA; 6Salus University, Elkins Park, PA, USACorrespondence: Andrea Gibson, Oyster Point Pharma, Inc, 202 Carnegie Center, Suite 109, Princeton, NJ, 08540, USA, Tel +1-860-227-1034, Fax +1-856-433-8439, Email agibson@oysterpointrx.comPurpose: To evaluate OC-01 [varenicline solution nasal spray (VNS)] tear production and symptom outcomes in patients with dry eye disease by age, gender, race, ethnicity, and artificial tear use status.Patients and Methods: Adults ≥ 22 years of age diagnosed with dry eye disease, with Ocular Surface Disease Index score ≥ 23, corneal fluorescein staining score ≥ 2 in ≥ 1 region or ≥ 4 for all regions, and baseline Schirmer Test Score (STS) ≤ 10 mm, with no restrictions on eye dryness score (EDS). Efficacy was assessed using integrated data from ONSET-1 and ONSET-2 [vehicle control (VC), n=294; OC-01 VNS 0.03 mg, n=308]. Subgroups included age (≤ 55, 56− 65, > 65 years), gender (male, female), race (White, Black or African American), ethnicity (Hispanic or Latino, Not Hispanic or Latino), and artificial tear use (yes, no). Analysis of covariance models, with the covariates treatment, study site, and baseline severity measures, were used to calculate treatment−VC differences. Consistency of effect among subgroups was evaluated by conducting interaction tests.Results: Consistency of treatment effect across subgroups was observed for all endpoints, with P value for all treatment−subgroup interaction terms > 0.05. For % of patients with ≥ 10mm improvement in STS and least squares (LS) mean change from baseline in STS and EDS, there was improvement in tear production across demographic group categories. Artificial tear use did not change STS or EDS outcomes with OC-01 VNS.Conclusion: OC-01 VNS improved tear production and patient-reported symptom outcomes across a broad range of patients by age, gender, race, and ethnicity, and regardless of artificial tear use status at baseline. OC-01 VNS demonstrated a consistent benefit across an extensive range of patients with dry eye disease.Keywords: bioactivation, dry eye disease, nicotinic acetylcholine receptor, tear production, varenicline nasal spray

Oxidative stress is a contributing factor to Parkinson's disease (PD). Considering the prevalence of sporadic PD, environmental exposures are postulated to increase reactive oxygen species and either incite or exacerbate neurodegeneration. We previously determined that exposure to the common soil bacterium, Streptomyces venezuelae (S. ven), enhanced oxidative stress and mitochondrial dysfunction in Caenorhabditis elegans, leading to dopaminergic (DA) neurodegeneration. Here, S. ven metabolite exposure in C. elegans was followed by RNA-Seq analysis. Half of the differentially identified genes (DEGs) were associated with the transcription factor DAF-16 (FOXO), which is a key node in regulating stress response. Our DEGs were enriched for Phase I (CYP) and Phase II (UGT) detoxification genes and non-CYP Phase I enzymes associated with oxidative metabolism, including the downregulated xanthine dehydrogenase gene, xdh-1. The XDH-1 enzyme exhibits reversible interconversion to xanthine oxidase (XO) in response to calcium. S. ven metabolite exposure enhanced XO activity in C. elegans. The chelation of calcium diminishes the conversion of XDH-1 to XO and results in neuroprotection from S. ven exposure, whereas CaCl2 supplementation enhanced neurodegeneration. These results suggest a defense mechanism that delimits the pool of XDH-1 available for interconversion to XO, and associated ROS production, in response to metabolite exposure. [ABSTRACT FROM AUTHOR]

In vitro metabolism of bicyclol was studied using liver microsomes, hepatocytes and human recombinant cytochrome P450 enzymes. Liquid chromatography-benchtop orbitrap mass spectrometry technique was utilised to identify the metabolites. A total of 19 metabolites, including 5 new metabolites (M2, M3, M4, M5 and M16) were tentatively identified. Among these metabolites, M6&M8 (demethylenation), M9&M10 (demethylation) and M19 (glucuronidation) were the major metabolites. In glutathione (GSH)-supplemented liver microsomes, 5 new GSH conjugates were found and tentatively identified. The formation was assumed to be through demethylenation of methylenedioxyphenyl to form catechol derivatives, which further underwent oxidation to form ortho-quinone intermediates, reacting with GSH to form stable adducts. CYP3A4 and 2C19 were demonstrated to be the major enzymes responsible for the bioactivation of bicyclol. This study provided valuable information on the metabolic fate of bicyclol in liver microsomes and hepatocytes, and the bioactivation pathways were reported for the first time, which would be helpful for us to understand the potential drug-drug interactions and the possible side effect of this drug. [ABSTRACT FROM AUTHOR]

Metabolic activation is the primary cause of chemical toxicity including hepatotoxicity. Cytochrome P450 2E (CYP2E) is involved in this process for many hepatotoxicants, including acetaminophen (APAP), one of the most common analgesics and antipyretics. Although the zebrafish is now used as a model for toxicology and toxicity tests, the CYP2E homologue in zebrafish has not been identified yet. In this study, we prepared transgenic zebrafish embryos/larvae expressing rat CYP2E1 and enhanced green fluorescent protein (EGFP) using a β-actin promoter. Rat CYP2E1 activity was confirmed by the fluorescence of 7-hydroxycoumarin (7-HC), a metabolite of 7-methoxycoumarin that was specific for CYP2 in transgenic larvae with EGFP fluorescence (EGFP [+]) but not in transgenic larvae without EGFP fluorescence (EGFP [−]). APAP (2.5 mM) caused reduction in the size of the retina in EGFP [+] larvae but not in EGFP [−] larvae, while APAP similarly reduced pigmentation in both larvae. APAP at even 1 mM reduced the liver size in EGFP [+] larvae but not in EGFP [−] larvae. APAP-induced reduction of liver size was inhibited by N-acetylcysteine. These results suggest that rat CYP2E1 is involved in some APAP-induced toxicological endpoints in the retina and liver but not in melanogenesis of the developing zebrafish. [ABSTRACT FROM AUTHOR]

Endogenous estradiol (E2) exerts diverse physiological and pharmacological activities, commonly used for hormone replacement therapy. However, prolonged and excessive exposure to E2 potentially increases estrogenic cancer risk. Reportedly, CYP1 enzyme-mediated biotransformation of E2 is largely concerned with its balance between detoxification and carcinogenic pathways. Among the three key CYP1 enzymes (CYP1A1, CYP1A2, and CYP1B1), CYP1A1 and CYP1A2 mainly catalyze the formation of nontoxic 2-hydroxyestradiol (2-OH-E2), while CYP1B1 specifically catalyzes the formation of genotoxic 4-hydroxyestradiol (4-OH-E2). 4-OH-E2 can be further metabolized to electrophilic quinone intermediates accompanied by the generation of reactive oxygen species (ROS), triggering DNA damage. Since abnormal alterations in CYP1 activities can greatly affect the bioactivation process of E2, regulatory effects of xenobiotics on CYP1s are essential for E2-associated cancer development. To date, thousands of natural and synthetic compounds have been found to show potential inhibition and/or induction actions on the three CYP1 members. Generally, these chemicals share similar planar polycyclic skeletons, the structural motifs and substituent groups of which are important for their inhibitory/inductive efficiency and selectivity toward CYP1 enzymes. This review comprehensively summarizes these known inhibitors and/or inductors of E2-metabolizing CYP1s based on chemical categories and discusses their structure-activity relationships, which would contribute to better understanding of the correlation between xenobiotic-regulated CYP1 activities and estrogenic cancer susceptibility. [ABSTRACT FROM AUTHOR]

The mammalian cytochrome P450 monooxygenase CYP4B1 can bioactivate a wide range of xenobiotics, such as its defining/hallmark substrate 4-ipomeanol leading to tissue-specific toxicities. Similar to other members of the CYP4 family, CYP4B1 has the ability to hydroxylate fatty acids and fatty alcohols. Structural insights into the enigmatic role of CYP4B1 with functions in both, xenobiotic and endobiotic metabolism, as well as its unusual heme-binding characteristics are now possible by the recently solved crystal structures of native rabbit CYP4B1 and the p.E310A variant. Importantly, CYP4B1 does not play a major role in hepatic P450-catalyzed phase I drug metabolism due to its predominant extra-hepatic expression, mainly in the lung. In addition, no catalytic activity of human CYP4B1 has been observed owing to a unique substitution of an evolutionary strongly conserved proline 427 to serine. Nevertheless, association of CYP4B1 expression patterns with various cancers and potential roles in cancer development have been reported for the human enzyme. This review will summarize the current status of CYP4B1 research with a spotlight on its roles in the metabolism of endogenous and exogenous compounds, structural properties, and cancer association, as well as its potential application in suicide gene approaches for targeted cancer therapy. [ABSTRACT FROM AUTHOR]

We conducted multi-parametric studies on thermotolerant phosphate solubilizing bacteria useful in bioactivation of rock phosphate. Selected two different thermotolerant phosphate solubilizing cultures. Statistical optimization found pH, ammonium sulfate and EDTA concentration to be the significant variables for high phosphate solubilization by Bacillus sp. BISR-HY63. Alkaline phosphatase production by Brevibacillus sp. BISR-HY07 was increased from 1400 unitsL−1 to 3000 unitsL−1. Partial purification of alkaline phosphatase performed by size exclusion and anion-exchange chromatography and the enzyme purified by 76 folds. Organic compost prepared and inoculated with alkaline phosphatase producing bacterium BISR-HY07 for increasing it's efficacy. Soluble P decreased from 9.5 mgKg−1 to 4.1 mgKg−1 and available P increased from 200 mgKg−1 to 1000 mgKg−1 after incubation of 50 days. When cultures used as bioinoculants, total P content absorbed by the plants inoculated by Brevibacillus sp. BISR-HY07 along with rock phosphate was highest and significantly higher at 9.3 gkg−1. Shoot length of plants treated by rock phosphate and Brevibacillus sp. BISR-HY07 found to be highest and significantly higher at 31.5 cm. Root length, shoot biomass and root biomass of plants treated by rock phosphate and Bacillus sp. BISR-HY63 was highest but not significantly high at 10.3 cm, 0.73 g and 0.34 g respectively. [ABSTRACT FROM AUTHOR]

The KEAP1‐NRF2 pathway regulates the main inducible cellular response to oxidative and electrophilic stresses. Activating mutations in the KEAP1‐NRF2 pathway occur commonly in human cancer, where they contribute to the formation of aggressive tumours that are associated with a poor prognosis for patients. An important clinical feature of these tumours is their defiance to all current anti‐cancer treatment regimens, highlighting the need for the development of new therapeutic strategies to target NRF2‐activated cancers. In this review, we discuss the mechanisms through which acquired NRF2 hyperactivation can result in resistance of tumours to immune checkpoint inhibitor therapies in addition to classical chemotherapeutics, and propose with examples that using a synthetic lethal strategy mediated by NRF2‐target gene‐dependent bioactivation of prodrugs represents a promising strategy to specifically enhance toxicity to heretofore untreatable NRF2‐hyperactivated human tumours. [ABSTRACT FROM AUTHOR]

Organophosphorus pesticides (OPs) are a chemically diverse class of insecticides that inhibit acetylcholinesterase (AChE). Many OPs require bioactivation to their active oxon form via cytochrome P450 to effectively inhibit AChE. OP toxicity can be mitigated by detoxification reactions performed by carboxylesterase and paraoxonase. The relative extent of bioactivation to detoxification varies among individuals and between species, leading to differential susceptibility to OP toxicity. Because of these species differences, it is imperative to characterize OP metabolism in model systems used to assess OP toxicity. We have shown that the asexual freshwater planarian Dugesia japonica is a suitable model to assess OP neurotoxicity and developmental neurotoxicity via rapid, automated testing of adult and developing organisms in parallel using morphological and behavioral endpoints. D. japonica has two cholinesterase enzymes with intermediate properties between AChE and butyrylcholinesterase that are sensitive to OP inhibition. Here, we demonstrate that D. japonica contains the major OP metabolic machinery to be a relevant model for OP neurotoxicity studies. Adult and regenerating D. japonica can bioactivate chlorpyrifos and diazinon into their respective oxons. Significant AChE inhibition was only observed after in vivo metabolic activation but not when the parent OPs were directly added to planarian homogenate using the same concentrations and timing. Using biochemical assays, we found that D. japonica has both carboxylesterase (24 nmol/(min*mg protein)) and paraoxonase (60 pmol/(min*mg protein)) activity. We show that planarian carboxylesterase activity is distinct from cholinesterase activity using benzil and tacrine. These results further support the use of D. japonica for OP toxicity studies. [ABSTRACT FROM AUTHOR]

The mycotoxin ochratoxin A (OTA) is a contaminant in food that causes nephrotoxicity and to a minor degree hepatotoxicity. Recently, we observed that OTA induces liver damage preferentially to the cytochrome P450 (CYP)-expressing pericentral lobular zone, similar to hepatotoxic substances known to be metabolically toxified by CYP, such as acetaminophen or carbon tetrachloride. To investigate whether CYP influences OTA toxicity, we used a single dose of OTA (7.5 mg/kg; intravenous) with and without pre-treatment with the pan CYP-inhibitor 1-aminobenzotriazole (ABT) 2 h before OTA administration. Blood, urine, as well as liver and kidney tissue samples were collected 24 h after OTA administration for biochemical and histopathological analyses. Inhibition of CYPs by ABT strongly increased the nephro- and hepatotoxicity of OTA. The urinary kidney damage biomarkers kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were increased > 126-fold and > 20-fold, respectively, in mice treated with ABT and OTA compared to those receiving OTA alone. The blood biomarkers of liver damage, alanine transaminase (ALT) and aspartate transaminase (AST) both increased > 21- and 30-fold, respectively, when OTA was administered to ABT pre-treated mice compared to the effect of OTA alone. Histological analysis of the liver revealed a pericentral lobular damage induced by OTA despite CYP-inhibition by ABT. Administration of ABT alone caused no hepato- or nephrotoxicity. Overall, the results presented are compatible with a scenario where CYPs mediate the detoxification of OTA, yet the mechanisms responsible for the pericental liver damage pattern still remain to be elucidated. [ABSTRACT FROM AUTHOR]

Moscatilin, a bioactive ingredient isolated from Dendrobium moscatum, has been demonstrated to have excellent anti‐cancer activity. The goals of the present study were to investigate the metabolic profiles of moscatilin and to identify and characterize its metabolites. In vitro studies were performed by incubating moscatilin (10 μM) with rat, dog, monkey, and human liver microsomes (0.5 mg protein/ml) to generate the metabolites. An analytical method of liquid chromatography combined with hybrid quadrupole orbitrap high‐resolution mass spectrometry in full mass/data‐dependent tandem mass spectrometry scan was utilized to separate and identify the metabolites in accordance with their accurate masses, formulas, and tandem mass spectrometry fragment ions determination. A total of six phase I metabolites were detected and structurally characterized. The phase I metabolic pathways of moscatilin were hydroxylation, demethylation, and dehydrogenation. In glutathione‐supplemented liver microsomes, nine glutathione conjugates were detected and identified. Our results demonstrated that moscatilin was susceptible to bioactivation with the result of ortho quinone and quinone‐methide intermediates. The present study provided an overview of the in vitro metabolic profiles of moscatilin, which will aid in the understanding of the efficacy and safety of this active compound. [ABSTRACT FROM AUTHOR]

[Display omitted] The tripeptide glutathione (GSH) possesses two key structural features, namely the nucleophilic sulfur and the γ-glutamyl isopeptide bond. The former allows GSH to serve as a critical antioxidant and anti-electrophile. The latter allows GSH to translocate throughout the systemic circulation without being degraded. The kidneys exhibit several unique processes for handling GSH. This includes the extraction of 80% of plasma GSH, in part by glomerular filtration but mostly by transport across the basolateral plasma membrane. Studies on the protective effect of exogenous GSH are summarized, showing the different inherent susceptibility of proximal tubular and distal tubular cells and the impact on pathological or disease states, including hypoxia, diabetic nephropathy, and compensatory renal growth associated with uninephrectomy. Studies on mitochondrial GSH transport show the coordination between the citric acid cycle and oxidative phosphorylation in generating driving forces for both plasma membrane and mitochondrial carriers. The strong protective effects of increasing expression and activity of these carriers against oxidants and mitochondrial toxicants are summarized. Although GSH plays a cytoprotective role in most situations, two distinct exceptions to this are presented. In contrast to expectations, overexpression of the mitochondrial 2-oxoglutarate carrier markedly increased cell death from exposure to the nephrotoxic chemotherapeutic drug cisplatin (CDDP). Another key example of GSH serving a bioactivation role in the kidneys, rather than a detoxification role, is the metabolism of halogenated alkenes such as trichloroethylene (TCE). Although considerable research has gone into this topic, unanswered questions and emerging topics remain and are discussed. [ABSTRACT FROM AUTHOR]

Biocompatible and biodegradable foams prepared using the high-pressure foaming technique have been widely investigated in recent decades as porous scaffolds for in vitro and in vivo tissue growth. In fact, the foaming process can operate at low temperatures to load bioactive molecules and cells within the pores of the scaffold, while the density and pore architecture, and, hence, properties of the scaffold, can be finely modulated by the proper selection of materials and processing conditions. Most importantly, the high-pressure foaming of polymers is an ideal choice to limit and/or avoid the use of cytotoxic and tissue-toxic compounds during scaffold preparation. The aim of this review is to provide the reader with the state of the art and current trend in the high-pressure foaming of biomedical polymers and composites towards the design and fabrication of multifunctional scaffolds for tissue engineering. This manuscript describes the application of the gas foaming process for bio-scaffold design and fabrication and highlights some of the most interesting results on: (1) the engineering of porous scaffolds featuring biomimetic porosity to guide cell behavior and to mimic the hierarchical architecture of complex tissues, such as bone; (2) the bioactivation of the scaffolds through the incorporation of inorganic fillers and drugs.

An Al2O3-1 wt.% Ti composite was prepared by powder techniques with the intention of analyzing its mechanical and chemical properties for its possible application as a biomaterial. Alumina was synthesized using the reaction bonding aluminum oxide (RBAO) process. The powders resulting from the milling stage present sizes minor than 1.5 microns. With the help of X-ray diffraction and differential thermal analysis, it was determined that aluminum oxidizes in both solid and liquid states during the RBAO process. It was also found that the alumina formation reaction in this process is completed at 1,100oC. From the measurements of mechanical properties (HV, KIC, E) in the Al2O3-1 wt.% Ti composite, it was determined that these properties are better than the same properties of compact bone. Electrochemical impedance spectroscopy, indicates that additions of 1 wt.% Ti on Al2O3 enhance its corrosion resistance. The bioactivation of a Al2O3-1 wt.% Ti composite was successful using a biomimetic method, because after 21 days, hydroxyapatite begins to proliferate on the surface of the substrate. With all these results it can be commented that it is feasible to use Al2O3-1 wt.% Ti composite in the elaboration of synthetic bone for its application as a biomaterial.

Many nitrosamines are recognized as mutagens and potent rodent carcinogens. Over the past few years, nitrosamine impurities have been detected in various drugs leading to drug recalls. Although nitrosamines are included in a 'cohort of concern' because of their potential human health risks, most of this concern is based on rodent cancer and bacterial mutagenicity data, and there are little data on their genotoxicity in human-based systems. In this study, we employed human lymphoblastoid TK6 cells transduced with human cytochrome P450 (CYP) 2A6 to evaluate the genotoxicity of six nitrosamines that have been identified as impurities in drug products: N-nitrosodiethylamine (NDEA), N-nitrosoethylisopropylamine (NEIPA), N-nitroso-N-methyl-4-aminobutanoic acid (NMBA), N-nitrosomethylphenylamine (NMPA), N-nitrosodiisopropylamine (NDIPA), and N-nitrosodibutylamine (NDBA). Using flow cytometry-based assays, we found that 24-h treatment with NDEA, NEIPA, NMBA, and NMPA caused concentration-dependent increases in the phosphorylation of histone H2A.X (γH2A.X) in CYP2A6-expressing TK6 cells. Metabolism of these four nitrosamines by CYP2A6 also caused significant increases in micronucleus frequency as well as G2/M phase cell-cycle arrest. In addition, nuclear P53 activation was found in CYP2A6-expressing TK6 cells exposed to NDEA, NEIPA, and NMPA. Overall, the genotoxic potency of the six nitrosamine impurities in our test system was NMPA > NDEA ≈ NEIPA > NMBA > NDBA ≈ NDIPA. This study provides new information on the genotoxic potential of nitrosamines in human cells, complementing test results generated from traditional assays and partially addressing the issue of the relevance of nitrosamine genotoxicity for humans. The metabolically competent human cell system reported here may be a useful model for risk assessment of nitrosamine impurities found in drugs. [ABSTRACT FROM AUTHOR]

Biphasic macroporous Hydroxyapatite/β-Tricalcium Phosphate (HA/β-TCP) scaffolds (BCPs) are widely used for bone repair. However, the high-temperature HA and β-TCP phases exhibit limited bioactivity (low solubility of HA, restricted surface area, low ion release). Strategies were developed to coat such BCPs with biomimetic apatite to enhance bioactivity. However, this can be associated with poor adhesion, and metastable solutions may prove difficult to handle at the industrial scale. Alternative strategies are thus desirable to generate a highly bioactive surface on commercial BCPs. In this work, we developed an innovative "coating from" approach for BCP surface remodeling via hydrothermal treatment under supercritical CO2, used as a reversible pH modifier and with industrial scalability. Based on a set of complementary tools including FEG-SEM, solid state NMR and ion exchange tests, we demonstrate the remodeling of macroporous BCP surface with the occurrence of dissolution–reprecipitation phenomena involving biomimetic CaP phases. The newly precipitated compounds are identified as bone-like nanocrystalline apatite and octacalcium phosphate (OCP), both known for their high bioactivity character, favoring bone healing. We also explored the effects of key process parameters, and showed the possibility to dope the remodeled BCPs with antibacterial Cu2+ ions to convey additional functionality to the scaffolds, which was confirmed by in vitro tests. This new process could enhance the bioactivity of commercial BCP scaffolds via a simple and biocompatible approach. [ABSTRACT FROM AUTHOR]

Larval zebrafish is emerging as a new model organism for studying drug-induced liver injury (DILI) with superiorities in visual assessment, genetic engineering as well as high throughput. Metabolic bioactivation to form reactive intermediates is a common event that triggers DILI. This study first addressed the correlation between acetaminophen metabolism and hepatotoxicity in zebrafish larvae (3-day postfertilization) and demonstrated the occurrence of cytochrome P450 enzymes-mediated acetaminophen (APAP) bioactivation at early developmental stage through characterizing the dose-effect (0–1.6 mg/ml) and the time course (0–72 h) of liver injury and metabolism in the AB strain and LiPan transgenic line Tg(lfabp10a: DsRed; elaA:egfp) expressing the liver-specific fluorescent protein. APAP caused multiorgan developmental retardation and elicited dose- and time-dependent hepatotoxicity. Liver imaging revealed significant changes earlier than histological and biochemical measurements. APAP bioactivation in larval zebrafish was first confirmed by the detection of the glutathione conjugate of the reactive intermediate NAPQI (NAPQI-GSH) and subsequent mercapturate derivatives NAPQI-cysteine and NAPQI-N-acetylcysteine after even short (0.5-h postexposure) or low (0.2 mg/ml) APAP exposure. APAP overdose impaired metabolic function, in particular sulfation, whereas facilitated GSH depletion and APAP sulfate excretion. Meanwhile, APAP displayed triphasic accumulation in the larvae, agreeing with fluctuating metabolic capabilities with sulfation dominating the early larval developmental stage. Most importantly, the dose-response effects and time course of APAP accumulation and metabolism agree well with those of the liver injury development. Overall, larval zebrafish has developed mammalian-like metabolic function, enabling it an ideal model organism for high-throughput screening hepatotoxicity and mechanistic study of bioactivation-based DILI. [ABSTRACT FROM AUTHOR]

This study evaluated the surface optimization of β-Ti-40Nb alloy in terms of corrosion and bioactivity properties. Electrochemical anodization at different voltages was used to synthesize (Ti,Nb)O 2 nanostructures (nanopores (NPs)) and (nanotubes (NTs)) on samples' surfaces, allowing the analysis of their influence on performances related to those properties. Then, (Ti,Nb)O 2 NPs and NTs were annealed at 550 °C to crystallize the previously obtained amorphous (Ti,Nb)O 2 into a mixture of anatase and rutile. Also, a pre-calcification process (PC) was applied on annealed (Ti,Nb)O 2 NPs and NTs. SEM micrographs showed the presence of NTs (10 V) and NPs (20 V) after anodization. After annealing, the morphology of (Ti,Nb)O 2 NPs and NTs remained constant for both diameter and length. XRD analysis confirmed that as-anodized amorphous (Ti,Nb)O 2 was crystallized, after annealing, into a mixture of anatase-rutile phases. Corrosion properties were evaluated through the open circuit potential (OCP), potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS). Samples were immersed in a simulated body fluid (SBF) solution for one to 14 days to assess the bioactivity. The bioactivity evaluation was carried out by mass gain. Also, the amount of apatite precipitated on the sample's surface was determined through SEM-EDS. The results showed that PC samples presented similar corrosion properties compared to the annealed samples. However, PC processing improved the bioactivity (apatite formation) of (Ti,Nb)O 2 NTs and NPs modified β-Ti-40Nb alloy. [ABSTRACT FROM AUTHOR]

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Mycotoxins are a threat to human and animal health. Climate change increases their occurrence and our dietary exposure. Although humans and animals are concomitantly exposed to several mycotoxins, their combined effects are poorly characterised. This study investigated the interaction between aflatoxin B1 (AFB1), the most potent natural carcinogen, and deoxynivalenol (DON), which is among the most prevalent mycotoxins. AFB1 is associated with hepatocellular carcinoma through its bioactivation by cytochrome P450 (CYP450) enzymes; while DON induces ribotoxic stress leading to an alteration of intestinal, immune and hepatic functions. Analysis of DNA damage biomarkers γ-H2AX and 53BP1 revealed that DON reduces the genotoxicity of AFB1. This effect was mimicked with cycloheximide (CHX), another ribosome inhibitor; moreover DOM-1, a DON-derivative lacking ribosome inhibition, did not affect DNA damage. Exposure to DON, alone or in combination with AFB1, decreased the protein levels and/or activities of CYP1A2 and CYP3A4 in a time- and dose-dependent manner. A similar reduction of CYP1A2 and CYP3A4 activities was also observed with CHX. Altogether, these results revealed an original interaction between DON and AFB1, DON inhibiting the genotoxicity of AFB1. The underlying mechanism involves ribosome inhibition by DON and the subsequent impairment of CYP450s, responsible for the bioactivation of AFB1. This work highlights the importance of studying mycotoxins not only individually but also in mixture and of considering food contaminants as part of the exposome., 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 Elsevier B.V. All rights reserved.)

Nimbolide is a major furanoid compound isolated from Azadirachta indica. The aim of this study was to characterize the metabolites of nimbolide in rats and to propose the metabolic pathways. The metabolites were generated by incubating nimbolide (10 μM) with rat liver microsomes, nicotinamide adenine dinucleotide phosphate (NADPH), and nucleophiles (glutathione [GSH] or N-acetyl-lysine [NAL]) at 37°C for 60 min. For the in vivo study, nimbolide was intravenously administered to rats at a single dose of 10 mg/kg, and the bile and urine were collected. The metabolites were identified by ultra-high-performance liquid chromatography-quadrupole/orbitrap mass spectrometry (UPLC-Q/Orbitrap-MS) using electrospray ionization in positive ion mode. Totally, nine metabolites were detected, and their identities were characterized by accurate MS and MS/MS data. In GSH-supplemented liver microsomes, GSH conjugation was the primary elimination pathway. The furan ring was bioactivated into cis-butene-1,4-dial that can be trapped by GSH. In NAL-supplemented liver microsomes, two NAL conjugates (M4 and M5) derived from cis-butene-1,4-dial were observed. In rat bile and urine, N-acetyl-cysteine, cysteine-glycine, and GSH conjugate were also found. The current study provides an overview of the metabolism and the bioactivation profiles of nimbolide in rats, which aids in understanding its safety and activity., (© 2024 John Wiley & Sons, Ltd.)

Background: Cross-resistance between pre-emergence herbicides is developing in Australian populations of annual ryegrass (Lolium rigidum Gaud.). A previous study has reported that selection with prosulfocarb (a pro-herbicide requiring bioactivation to its phytotoxic sulfoxide) can decrease metabolic resistance to trifluralin. Metabolism of prosulfocarb and trifluralin was investigated in L. rigidum populations with different levels of resistance to prosulfocarb, trifluralin and also pyroxasulfone, which is detoxified by glutathione (GSH) conjugation., Results: Coleoptiles and radicles of herbicide-treated seedlings responded differently to the same herbicide. Radicles had a lower capacity for bioactivation of prosulfocarb, and this was correlated with a lower ability to metabolise trifluralin within and among populations. Coleoptile resistance to prosulfocarb sulfoxide was negatively correlated with abundance of a major polar metabolite. There was no evidence of GSH conjugation with the sulfoxide, making any potential links between prosulfocarb and pyroxasulfone resistance less obvious., Conclusions: Activation and metabolism of prosulfocarb in L. rigidum is complex and differentially regulated in different tissues. Selection with prosulfocarb may ameliorate trifluralin metabolism in the radicles, but the relationship between prosulfocarb and pyroxasulfone resistance is not GSH-mediated. When applying pre-emergence herbicides, care should be taken with the composition of mixtures and rotations to avoid selection of cross-resistance between pyroxasulfone and prosulfocarb. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Diosbulbin B (DBB), the major component isolated from herbal medicine Dioscorea bulbifera L. (DBL), can trigger severe hepatotoxicity. The previous studies demonstrated that DBB-induced hepatotoxicity is closely relevant to the bioactivation mediated by CYP3A4 and subsequent generation of adducts with cellular proteins. Schisandrol B (SchB), the primary lignan ingredient in herbal medicine Schisandra chinensis (SC), is able to inhibit CYP3A activity. The objective of this study is to investigate the protective effect of SchB against hepatotoxicity induced by DBB and to explore the underlying mechanism. Biochemical and histopathological analysis demonstrated that SchB exerted dose-dependent protective effect against DBB-induced hepatotoxicity. In vitro metabolism assay showed that the formation of pyrrole-glutathione (GSH) conjugates of DBB was inhibited by SchB in a concentration dependent manner, suggesting SchB inhibited the bioactivation of DBB in vitro. Pharmacokinetic studies demonstrated that SchB enhanced C max and AUCs of DBB in mouse blood and liver, resulting in accelerating the accumulation of DBB in the circulation. In addition, pretreatment with SchB alleviated DBB-induced hepatic GSH depletion, obviously facilitated the excretion of DBB in urine, and reduced the urinary excretion of DBB-GSH conjugates, indicating that SchB affected absorption, distribution, metabolism, and excretion (ADME) of DBB by inhibiting the bioactivation of DBB in vivo. In conclusion, our findings demonstrated the amelioration of SchB against DBB-induced hepatotoxicity was correlated with the inhibition of CYP3A4-mediated bioactivation of DBB. Thus, the findings indicated that SchB may serve as a potential candidate drug for the treatment of DBB intoxication., 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 Elsevier Inc. All rights reserved.)

Introduction: Understanding how insects and mites develop resistance to chlorpyrifos is crucial for effective field management. Although extensive research has demonstrated that T. urticae exhibits high resistance to chlorpyrifos, the specific resistance mechanism remains elusive. Investigating this mechanism could provide valuable insights for pest control strategies., Objectives: This study aimed to reveal the mechanism of chlorpyrifos resistance in T. urticae., Methods: The expression level of the CYP392D8 gene in T. urticae strains were analyzed using real- time quantitative PCR and western blot techniques. Functional validation of CYP392D8 was conducted through RNAi and heterogeneous expression. The production of chlorpyrifos-oxon in both resistant and susceptible strains were quantified using LC-MS/MS. Furthermore, the metabolic capabilities of CYP392D8 variants were verified using HPLC-MS and molecular docking., Results: The results showed the expression of CYP392D8 was reduced in some Chinese resistant populations and mites with knocked down CYP392D8 showed decreased susceptibility to chlorpyrifos. Chlorpyrifos-oxon, the active metabolite of chlorpyrifos, was generated when chlorpyrifos was incubated with recombinant CYP392D8 protein in vitro. And a higher efficiency of chlorpyrifos-oxon formation was observed with the CYP392D8-S variant from susceptible mites compared to the CYP392D8-R variant from resistant mites. After treatment with low doses of chlorpyrifos, susceptible mite extracts produced substantial amounts of chlorpyrifos-oxon, while resistant mites only showed trace amounts. In addition, molecular docking studies showed that CYP392D8-S had a higher binding capacity to chlorpyrifos than the CYP392D8-R variant., Conclusion: This study reveals a mechanism of insecticide resistance due to the bioactivation reduction in combination with the sequence variation in a pest mite. These findings provide an important theoretical bias for management strategies of mites in the field and comprehensive control., 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. Production and hosting by Elsevier B.V.)

Wound healing is a dynamic process that requires an optimal extracellular environment, as well as an accurate synchronization between various cell types. Over the past few years, great efforts have been devoted to developing novel approaches for treating and managing burn injuries, sepsis, and chronic or accidental skin injuries. Multifunctional smart-polymer-based dressings represent a promising approach to support natural healing and address several problems plaguing partially healed injuries, including severe inflammation, scarring, and wound infection. Naturally derived compounds offer unique advantages such as minimal toxicity, cost-effectiveness, and outstanding biocompatibility along with potential anti-inflammatory and antimicrobial activity. Herein, the main driving idea of the work was the design and development of konjac glucomannan d-glucono-1,5-lactone (KG) films bioactivated by tannic acid and d-glucono-1,5-lactone (GL) addition. Our analysis, using attenuated total reflectance-Fourier transform infrared, atomic force microscopy, and surface energy measurements demonstrated that tannic acid (TA) clearly interacted with the KG matrix, acting as its cross-linker, whereas GL was embedded within the polymer structure. All developed films maintained a moist environment, which represents a pivotal property for wound dressing. Hemocompatibility experiments showed that all tested films exhibited no hemolytic impact on human erythrocytes. Moreover, the presence of TA and GL enhanced the metabolic and energetic activity in human dermal fibroblasts, as indicated by the MTT assay, showing results exceeding 150%. Finally, all films demonstrated high antibacterial properties as they significantly reduced the multiplication rate of both Staphylococcus aureus and Escherichia coli in bacterial broth and created the inhibition zones for S. aureus in agar plates. These remarkable outcomes make the KG/TA/GL film promising candidates for wound healing applications.