The Effect of water-extract of Epimedium koreanum Nakai on age-related changes of the xenobiotic metabolizing enzyme system in the liver of rats

Epimedium koreanum Nakai(EKN) has traditionally been well-known as a herbal medicine for the promotion of stamina and the improving sexual activity of human in oriental countries including Korea and China. The aim of this study was to investigate the effect of dietary supplementation of EKN water-extract(0.025%,w/v) on age-related change of xenobiotic metabolizing system in rat liver. Long-term supply of the EKN extract to rats did not induce any discernible signs. However, the mass of liver and kidney were slightly increased by the dietary supplementation. Level of cytochrome P450, NADPH cytochrome P450 reductase, P450 dependent ethoxycoumarin O-deethylase benzphetamine N-demethylase and glutathione-S-transferase in liver were decreased with age, but, these activities in 24 months of age were declined more in rats supplied with EKN extract. Level of cytochrome b5 and NADH-cytochrome b5 reductase were also decreased with age, however, there was no significant difference between with and without EKN extract. These results indicate that long-term supplementation of EKN extract to rats from weaning to 24 months may be a burden on the liver function in old age, and may aggregate the decline of xenobiotic metabolizing enzymes activities in old age.