Inhibitory and inductive effects of 4- or 5-methyl-2-mercaptobenzimidazole, thyrotoxic and hepatotoxic rubber antioxidants, on several forms of cytochrome P450 in primary cultured rat and human hepatocytes.

ABSTRACT: Effects of 4-methyl-2-mercaptobenzimidazole (4-MeMBI) and 5-methyl-2- mercaptobenzimidazole (5-MeMBI) on cytochrome P450 (CYP) activity were examined in primary cultured rat hepatocytes. Hepatocytes from male Wistar rats were cultured in the presence of 4-MeMBI or 5-MeMBI (0-400 μM), and the activity of CYPs 3A2/4 (48 and 96 h) and 1A1/2 (48 h) was determined by measuring the activity of testosterone 6β-hydroxylation and 7-ethoxyresorufin O-deethylation, respectively. As a result, 4-MeMBI and 5-MeMBI (≥12.5 μM) inhibited CYP3A2 activity. On the other hand, 4-MeMBI (≥25 μM) and 5-MeMBI (≥100 μM) induced CYP1A1/2 activity, being consistent with the previous in vivo results. In a comparative metabolism study using primary cultured human hepatocytes from two Caucasian donors, 4-MeMBI an

SUBMITTER: Miyajima A 

PROVIDER: S-EPMC7451710 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature