Protective Role of <i>Carissa edulis </i>Ethanolic Extract Against Dimethoate-induced Hepatotoxicity in Guinea Pigs.

Carissa edulis (CE) (Apocynaceae) is distributed in tropical Africa and Asia and commonly used in folk medicine to treat many diseases such as headache, cough, rheumatism and fever. The purpose of this study was to evaluate the protective role of ethanolic extract of CE, a medicinal plant locally called "Al-Arm" in Yemen, against liver injury induced by dimethoate (DM) intoxication in male guinea pigs.Animals were divided randomly into 5 groups and kept at 5 animals per group. The first group was served as a control group and administered with vehicle orally; the group II administered with DM (14 mg kg-1; 1/25 LD50) orally. Animals of group III, IV and V were administered with 100 mg kg-1 of CE extract, 200 mg kg-1 of CE extract and 100 mg kg-1 Liv-52 orally half hour before DM administration, respectively. All the previous administrations were repeated daily for 21 days. Data were analyzed by one-way ANOVA using SPSS.The DM caused a statistically significant increase in the serum level of liver enzymes (AST, ALT, ALP) when compared to control animals, whereas CE and Liv-52 pre-treatment to the DM-intoxicated animals resulted in a significant normalization of the activities of enzymes. Similarly, a significant increase in lipid peroxidation (LPO) level, while induced significant decreases in the activities of liver catalase (CAT) and glutathione-S-transferase (GST). In contrast, co-administration of CE and Liv-52 to DM-treated animals restored most of these biochemical parameters to nearly normal levels. Histopathological examination of intoxicated animals showed many tissues alterations such as; vasodilation, hemorrhage, cytoplasmic vacuolization, inflammation and nuclear pyknosis indicating liver damage, while the animals received CE or Liv-52 showed less pathological effects when compared to animals treated with DM alone.The biochemical and histological results confirmed the hepatoprotective effect of ethanolic extract of CE against DM-induced hepatotoxicity in male guinea pigs.