Antioxidant, hepatoprotective and nephroprotective activities of Gazania rigens against carbon tetrachloride-induced hepatotoxicity and nephrotoxicity in rats

Objective: The current study investigated the efficacy of total ethanolic extract and various fractions of Gazania rigens to protect against carbon tetrachloride-induced liver and kidney damage in rats and evaluated their antioxidant activity. Methods: The antioxidant activity of the total extract and fractions (petroleum ether, ethyl acetate, and aqueous) of Gazania rigens was examined using 2,2'-diphenyl-1-picrylhydrazyl radical scavenging and phosphomolybdate assays, and their total phenolic and flavonoid contents were determined. The hepatoprotective and nephroprotective potentials were studied at a dose of 300 mg/kg for six consecutive days followed by induction of hepatorenal injury using carbon tetrachloride single dose (1.5 mL/kg, 1:1 v/v in olive oil, intraperitoneal) the next day. Results: The results revealed the potent hepato- and nephroprotective effects of ethyl acetate and aqueous fractions by significantly (P< 0.01 or P < 0.001) reducing the serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, creatinine, urea, triglycerides, cholesterol, and lactate dehydrogenase, along with elevated serum albumin levels. The improvement of hepatic and renal antioxidant capacities and catalase activities, together with the prominent reduction of hepatic and renal malondialdehyde contents, were confirmed by histopathological examination. Conclusion: The potent hepatoprotective and nephroprotective effects of the total extract and different fractions of Gazania rigens may be attributed to the presence of highly phenolic and flavonoid compounds along with their complementary antioxidant scavenging properties.