Abstract: The ultrasonic extraction process of purple sweet potato leaves was optimized and the protective effect of the extract on  CCl₄-induced acute hepatic injury of mice was investigated.The extraction process was optimized by orthogonal test with three factors (ethanol concentration,ultrasonic power,and ultrasonic time) and three levels.The hydroxyl radical scavenging rate was used as investigation index.The protective effect of different doses (0.1 g/kg,0.3 g/kg) of purple sweet potato leaves extract on hepatic injury was investigated by the establishment of acute hepatic injury model using  CCl₄.The results showed that the optimal extraction conditions were as follows:ethanol concentration of 70%,ultrasonic power of 400 W,ultrasonic time of 17 min.Compared with the model group,purple sweet potato leaves extract decreased the activities of serum ALT and hepatic MDA concentration,increased the activities of hepatic SOD and the level of hepatic GSH,and obviously relieved damage degree of liver tissue in the hepatic injury mice.These results indicated that purple sweet potato leaves extract had protective effect on CCl₄-induced acute hepatic injuries of mice.

Key words: purple sweet potato leaves, hydroxyl radical, ultrasonic extract, hepatic injury