Genetic variations and epigenetic modulations in CYP genes: Implications in NSAID-treatment of arthritis patients

CYP2C gene polymorphisms in North African populations

BACKGROUND

Cytochrome P450 is a superfamily of genes generating hemoproteins that metabolize foreign chemicals as well as endogenous compounds, such as steroids. The human CYP2C genes (CYP2C8, CYP2C9, CYP2C18, CYP2C19) cluster on chromosome 10 and metabolize many clinically useful drugs. CYP2C19 and CYP2C9 have been the most studied while CYP2C8 has been studied less frequently. CYP2C18 has been relatively ignored until recently but its importance has begun to be recognized.

METHODS AND RESULTS

We studied the genotypes of 7 pharmacogenetic markers in 3 CYP2C genes: CYP2C19 (rs12248560), CYP2C9 (rs4918758, rs1799853), and CYP2C8 (rs10509681, rs11572103, rs1058930, rs11572080), in one Libyan population and 7 Tunisian populations. Five of the 7 SNPs are in exons and have functional consequences while one intronic SNP is considered to be in close proximity to a regulatory region because of the many studies that report associations with metabolic effects. We carried out principal component analysis (PCA) on the North African populations and 83 other populations from the 1000 Genomes Project and Kidd Laboratory. The geographic clustering observed via PCA was more pronounced when considering multi-SNP haplotype frequencies.

CONCLUSION

This study reveals the intermediate position of North Africans between Europeans and Asians and the varied dissimilarities with other world regions. The genetic variation observed within and between geographic regions have implications for drug metabolism and adverse individual responses to medical treatments.

EIDD-1931 Treatment Tweaks CYP3A4 and CYP2C8 in Arthritic Rats to Expedite Drug Interaction: Implication in Oral Therapy of Molnupiravir

EIDD-1931 is the active form of molnupiravir, an orally effective drug approved by the United States Food and Drug Administration (USFDA) against COVID-19. Pharmacokinetic alteration can cause untoward drug interaction (drug-drug/disease-drug), but hardly any information is known about this recently approved drug. Therefore, we first investigated the impact of the arthritis state on the oral pharmacokinetics of EIDD-1931 using a widely accepted complete Freund's adjuvant (CFA)-induced rat model of rheumatoid arthritis (RA) after ascertaining the disease occurrence by paw swelling measurement and X-ray examination. Comparative oral pharmacokinetic assessment of EIDD-1931 (normal state vs arthritis state) showed that overall plasma exposure was augmented (1.7-fold) with reduced clearance (0.54-fold), suggesting its likelihood of dose adjustment in arthritis conditions. In order to elucidate the effect of EIDD-1931 treatment at a therapeutic regime (normal state vs arthritis state) on USFDA-recommended panel of cytochrome P450 (CYP) enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, and CYP3A4) for drug interaction using the same disease model, we monitored protein and mRNA expressions (rat homologs) in liver tissue by western blotting (WB) and real time-polymerase chain reaction (RT-PCR), respectively. Results reveal that EIDD-1931 treatment could strongly influence CYP3A4 and CYP2C8 among experimental proteins/mRNAs. Although CYP2C8 regulation upon EIDD-1931 treatment resembles similar behavior under the arthritis state, results dictate a potentially reverse phenomenon for CYP3A4. Moreover, the lack of any CYP inhibitory effect by EIDD-1931 in human/rat liver microsomes (HLM/RLM) helps to ascertain EIDD-1931 treatment-mediated disease-drug interaction and the possibility of drug-drug interaction with disease-modifying antirheumatic drugs (DMARDs) upon coadministration. As elevated proinflammatory cytokine levels are prevalent in RA and nuclear factor-kappa B (NF-kB) and nuclear receptors control CYP expressions, further studies should focus on understanding the regulation of affected CYPs to subside unexpected drug interaction.