Effects of Sho-saiko-to extract and its components, Baicalin, baicalein, glycyrrhizin and glycyrrhetic acid, on pharmacokinetic behavior of salicylamide in carbon tetrachloride intoxicated rats

To elucidate the effects of Sho-saiko-to extract and its components, baicalin, baicalein, glycyrrhizin and glycyrrhetic acid, against the effects of longer periods of acute hepatic injury induced by CCl4, we measured serum ALT activity in male Wistar rats for five days after ip administration Of CCl4 (0.2 ml/kg), and examined the daily changes of the pharmacokinetic behavior of salicylamide (SAM) for five days. Serum ALT activity rose to a maximum level within a day after administration Of CCl4 and then decreased to the control level after three. Sho-saiko-to extract and its components could suppress this acute change in serum ALT activity to less than 50% Of CCl4 alone. However, the pharmacokinetics of SAM showed that liver function recovers in a biphasic manner, so that plasma clearance (CL) decreased significantly at days I and 3 after administration Of CCl4 (P < 0.05). We concluded that the CL change at day I corresponds to the acute action of CCl4 intoxication, and that the change at day 3 is effect of physiologically reduced liver function due to the liver regeneration for tissue repair after the CCl4 hepatic injury. Sho-saiko-to extract and its components were shown to suppress acute hepatic injury induced by CCl4, and to bring about an early recovery in liver function. (C) 2004 Elsevier Ltd. All rights reserved.