Relationship between the risk of idiosyncratic drug toxicity and formation and degradation profiles of acyl-glucuronide metabolites of nonsteroidal anti-inflammatory drugs in rat liver microsomes

Preclinical evaluation of chemically reactive metabolites and mitigation of bioactivation in drug discovery

The formation of reactive metabolites (RMs) is thought to be one of the pathogeneses for some idiosyncratic adverse drug reactions (IADRs) which are considered one of the leading causes of some drug attritions and/or recalls. Minimizing or eliminating the formation of RMs via chemical modification is a useful tactic to reduce the risk of IADRs and time-dependent inhibition (TDI) of cytochrome P450 enzymes (CYPs). The RMs should be carefully handled before making a go-no-go decision. Herein, we highlight the role of RMs in the occurrence of IADRs and CYP TDI, the risk of structural alerts, the approaches of RM assessment at the discovery stage and strategies to minimize or eliminate RM liability. Finally, some considerations for developing a RM-positive drug candidate are suggested.

Trends and challenges in phytotherapy and phytocosmetics for skin aging

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Free radicals, oxidative stress, and inflammation contribute to the etiology of most chronic diseases.

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Natural products can be incorporated into cosmetics, cosmeceuticals, and nutricosmetics to tackle inflammation-related diseases.

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The use of alternative green extraction solvents such as natural deep eutectic solvents and electrochemically reduced water is trending.

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Delivery systems are important for the enhancement of the bioavailability, stability, solubility, and controlled release profile of the bioactives.

Oxidative stress and inflammation mostly contribute to aging and age-related conditions including skin aging. The potential of natural products in the form of naturally-derived cosmetics, cosmeceuticals, and nutricosmetics have, however, not been fully harnessed. This review, thus, critically analyzes the potential roles of natural products in inflammation-related skin aging diseases due to the increasing consumers’ concerns and demands for efficacious, safe, natural, sustainable, and religiously permitted alternatives to synthetic products. The information and data were collated from various resources and literature databases such as PubMed, Science Direct, Wiley, Springer, Taylor and Francis, Scopus, Inflibnet, Google, and Google Scholar using relevant keywords and Medical Subject Headings (MeSH). The role of green extraction solvents as promising alternatives is also elucidated. The potential enhancements of the bioavailability, stability, solubility and controlled release profile of the bioactives using different delivery systems are also presented. The current potential global market value, motivators, drivers, trends, challenges, halal, and other regulatory certifications for cosmeceuticals and nutricosmetics are equally discussed. The adoption of the suggested extractions and delivery systems would enhance the stability, bioavailability, and target delivery of the bioactives.

Species differences in liver microsomal hydrolysis of acyl glucuronide in humans and rats

Acyl glucuronides (AGs) are known as one of the causes of idiosyncratic drug toxicity (IDT). Although AGs can be enzymatically hydrolysed by β-glucuronidase and esterase, much information on their characteristics and species differences is lacking. This study was aimed to clarify species differences in AG hydrolysis between human and rat liver microsomes (HLM and RLM).To evaluate the AG hydrolysis profile, and the contribution of β-glucuronidase and esterase towards AG hydrolysis in HLM and RLM, nonsteroidal anti-inflammatory drugs (NSAIDs) were used. AGs were incubated with 0.1 M Tris-HCl buffer (pH 7.4) and 0.3 mg/mL HLM or RLM in the absence or presence of β-glucuronidase inhibitor, D-saccharic acid 1,4-lactone (D-SL) and esterase inhibitor, phenylmethylsulfonyl fluoride (PMSF).AGs of mefenamic acid (MEF-AG) and etodolac (ETO-AG) showed significantly higher AG hydrolysis rates in RLM than in HLM. Esterases were found to serve as AG hydrolases dominantly in HLM, whereas both esterases and β-glucuronidase equally contribute to AG hydrolysis in RLM. However, MEF-AG and ETO-AG were hydrolysed only by β-glucuronidase.We demonstrated for the first time that the activity of AG hydrolases towards NSAID-AGs differs between humans and rats.