No author

Cleistocalyx nervosum var. paniala, Ma-kiang, is a local plant in northern region of Thailand presenting high antioxidant activity in vitro. Our previous study found that 5 g/kg bw of C. nervosum aqueous ex-tract had no acute toxic effect on rat. The present study was designed to determine effect of aqueous extract of C. nervosum on oxidative status in rat liver. Male Wistar rats were divided into 3 groups. Rats in group 1 were received water as a vehicle control, while group 2 and 3 were received 100 and 500 mg/ kg bw of aqueous extract via intragastrium 5 times a week for 4 weeks. At the indicated time, the effect of C. nervosum on oxidative stress and antioxidant system were evaluated. Aqueous extract of C. nervo-sum did not affect the level of total glutathione, glutathione peroxidase and catalase activities. Low dose of C. nervosum (100 mg/kg bw) significantly increased malondialdehyde formation but high dose (500 mg/kg bw) did not. However, 500 mg/kg bw of C. nervosum extract significantly enhanced heme oxy-genase-1 activity. Although the aqueous extract of C. nervosum at low dose exhibited the pro-oxidant effect but at high dose, it reduced oxidative stress in rat liver. In conclusion, the aqueous extract of C. nervosum might show biphasic effect on oxidative status of rat liver