Published online Dec 15, 2003. doi: 10.3748/wjg.v9.i12.2742
Revised: August 12, 2002
Accepted: September 25, 2002
Published online: December 15, 2003
AIM: To investigate the effects of long-term tea polyphenols (TPs) consumption on hepatic microsomal drug-metabolizing enzymes and liver function in rats.
METHODS: TPs were administered intragastrically to rats at the doses of 833 mg·kg-1·d–1 (n = 20) and 83.3 mg·kg-1·d-1 (n = 20) respectively for six months. Controlled group (n = 20) was given same volume of saline solution. Then the contents of cytochrome P450, b5, enzyme activities of aminopyrine N-demethylase (ADM), glutathione S-trasferase (GST) and the biochemical liver function of serum were determined.
RESULTS: The contents of cytochrome P450 and b5 in the livers of male rats in high dose groups (respectively 2.66 ± 0.55, 10.43 ± 2.78 nmol·mg MS pro-1) were significantly increased compared with the control group (1.08 ± 1.04, 5.51 ± 2.98 nmol·mg MS pro- 1; P < 0.01, respectively). The enzymatic activities of ADM in the livers of female rats in high dose groups (0.91 ± 0.08 mmol·mg MS pro-1min-1) were increased compared with the control group (0.82 ± 0.08 mmol·mg MS pro-1·min-1; P < 0.05). The GST activity was unchanged in all treated groups, and the function of liver was not obviously changed.
CONCLUSION: The antidotal capability of rats’ livers can be significantly improved after long-term consumption of TPs. There are differences in changes of drug-metabolizing enzymes between the sexes induced by TPs and normal condition.