Hepatoprotective activity of aqueous root extract of carica papaya against paracetamol-induced hepatotoxicity in wistar rats

Background: Liver is prone to many diseases due to its role in metabolism and detoxification of various exogenous and endogenous compounds. Drug-induced liver damage represents a serious clinical problem in the world. Objective: To evaluate the potential hepatoprotective activity of the aqueous root extract of Carica papaya against paracetamol-induced hepatotoxicity in Wistar rats. Methods: Animals were pre-treated once daily for seven days before induction of hepatotoxicity. Five groups of rats were used. Groups 1 (normal control) and group 2 (negative control) received orally distilled water for seven days. Group 3 (positive control) received orally silymarin at 50 mg/kg body weight for 7 days. Groups 4 and 5 were treated orally with aqueous root extract of Carica papaya (100 and 200 mg/kg body weight, respectively) for seven days. Hepatotoxicity was induced on the seventh day in all the group animal except group 1, by oral administration of paracetamol, 500 mg/kg body weight. On the eighth day, blood was collected and serum markers such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase, total bilirubin and total protein were measured. The liver from rat was also collected and subjected to histopathological analysis. Results: Hepatotoxicity induced with paracetamol resulted in a significant increase in aminotransferase, alanine aminotransferase and alkaline phosphatase levels, and a decrease in total protein level. Rats pre-treated with Carica papaya extract and silymarin exhibited decrease in serum enzymes and total bilirubin levels, and increase in total protein level. However, these changes were not significant. Histopathological analysis of liver sections of paracetamol intoxicated rats showed necrosis, significant steatosis and congestion, while those of pre-treated rats with Carica papaya extract and silymarin exhibited moderate steatosis, congestion and inflammation. Conclusion: The aqueous root extract of Carica papaya exhibits only moderate hepatoprotective effect against a high dose of paracetamol-induced hepatotoxicity.