Pharmacokinetics of isoniazid in Wistar rats exposed to ethanol

Abstract Tuberculosis treatment consists of a drug combination, where isoniazid is the core drug and alcoholism is a factor highly related to poor patient compliance with the therapy. CYP2E1 is an enzyme involved both in the metabolism of ethanol and in the formation of hepatotoxic compounds during the metabolism of isoniazid. The shared metabolism pathway accounts for the possibility of pharmacokinetic interaction in cases of concomitant alcohol use during tuberculosis treatment. The aim of this study was to evaluate the effect of repeated exposure of Wistar rats (males, 250 g, n=6) to ethanol on the pharmacokinetics of a single dose of isoniazid in combination with pyrazinamide and rifampicin (100 mg/kg, 350 mg/kg and 100 mg/kg, respectively). An animal group received the combination of drugs and ethanol and was compared to a control group, which received the combination of drugs without exposure to ethanol. The plasma concentrations of isoniazid were determined by a UHPLC/UV bioanalytical method that was previously validated. Biochemical markers of liver function were measured to assess potential damage. A lower elimination half-life of isoniazid was observed in the ethanol group than in the control group (t1/2 0.91 h versus 1.34 h). There was no evidence of hepatotoxicity through the biomarker enzymes evaluated. The results allow us to infer that although there are no biochemical changes related to liver damage, there is a slight influence of ethanol exposure on the pharmacokinetic profile of isoniazid. This change may have a relevant impact on the efficacy of isoniazid in the outcome of tuberculosis treatment.

Extracts of Poria cocos polysaccharides improves alcoholic liver disease in mice via CYP2E1 and NF-κB inflammatory pathways / 中国中药杂志

The present study investigated the effect of extract of Poria cocos polysaccharides(PCP) on cytochrome P450 2 E1(CYP2 E1) and nuclear factor κB(NF-κB) inflammatory signaling pathways in alcoholic liver disease(ALD) mice and explored its protective effect and mechanism. Sixty male C57 BL/6 N mice of SPF grade were randomly divided into a control group, a model group, a positive drug group(bifendate, 200 mg·kg~(-1)), and high-(200 mg·kg~(-1)) and low-dose(50 mg·kg~(-1)) PCP groups. Gao-binge mo-del was induced and the mice in each group were treated correspondingly. Liver morphological and pathological changes were observed and organ index was calculated. Serum levels of alanine aminotransferase(ALT) and aspartate aminotransferase(AST) were detected. Malondialdehyde(MDA) and superoxide dismutase(SOD) in liver tissues were detected by assay kits. The levels of interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) were detected by ELISA. The activation of macrophages was observed by immunofluorescence staining and protein expression of CYP2 E1, Toll-like receptor 4(TLR4), NF-κB p65, and phosphorylated NF-κB p65(p-NF-κB p65) were analyzed by Western blot. The ALD model was properly induced. Compared with the model group, the PCP groups significantly improved the pathological injury of liver tissues. Immunofluorescence staining revealed that compared with the model group, the groups with drug intervention showed decreased macrophages in liver tissues. Additionally, the PCP groups showed reduced ALT, AST, MDA, IL-6, and TNF-α(P<0.05), and potentiated activity of SOD(P<0.01). PCP extract has the protective effect against alcoholic liver injury in mice, and the underlying mechanism may be related to the regulation of the expression of CYP2 E1 and inhibition of TLR4/NF-κB inflammatory signaling pathway to reduce oxidative stress and inflammatory injury, thereby inhibiting the development of ALD.