Effect ofDangguiandHonghuaon Cytochrome P450 1A2, 2C11, 2E1 and 3A1 mRNA Expression in Liver of Rats

As alternative medicines or dietary supplements, herbal medicines have received increasing interest in recent years. Danggui and Honghua are two of the most popular traditional Chinese herbal medicines. However, little is known about the pharmacokinetics interactions between Danggui/Honghua and prescription drugs. Therefore, the present study was undertaken to investigate the effect of Danggui or Honghua on the gene expression of cytochrome P450 (CYP) using reverse- transcriptase-polymerase chain reaction (RT-PCR) in Wistar rats. Commercial Danggui (0.35 and 0.7 g/kg, twice a day), Honghua (0.35 g/kg or 0.7 g/kg, twice a day) or water (control group) were given to rats (3 rats for each group) for 5 consecutive days. Treatment of rats with 0.7 and 1.4 g/kg per day Danggui or Honghua for 5 days caused mild to strong increase of CYP 3A1 and decrease of CYP 2E1 RNA expression. However, only Honghua (0.7 and 1.4 g/kg per day) induced the increase of CYP 1A2 RNA expression, while CYP 2C11 RNA was unaffected by both Danggui and Honghua. These data demonstrated that Danggui or Honghua affected the expression of hepatic CYP isoforms in the rats; they elevated CYP 1A2 and 3A1 RNA expression but inhibited CYP 2E1 RNA expression. Such alterations may change the therapeutic actions of the drugs metabolized primarily by P450 system when they are co-administered to people with Danggui or Honghua. Therefore, patients should be cautioned about the potential drug-herb interactions between Danggui or Honghua and prescription drugs that were metabolized by CYP1A2, 2E1 and 3A1 isoforms.