Hepatotoxicity of the methanol extract of Carica papaya (Paw-Paw) seeds in wistar rats

Abstract

Activity of Carica papaya Linn, (commonly known as paw-paw) seed extract in liver physiology of albino (Wistar) rats was studied. The MeOH extract of C. papaya seeds were Soxhlet extracted. Tolerated doses of C. papaya were estimated in acute toxicity studies and administered orally, single or repeated doses, for 30 days to adult male rats weighing between 190 and 200 g, which were divided into four groups of five rats per group. Group 1 received 10 mg/kg; group 2 received 50 mg/kg; group 3 received 200 mg/kg; group 4 received normal saline (1 ml/rat) as control. Twenty-four hours after treatments, the animals of all groups were sacrificed and blood samples collected by heart puncture into centrifugal tubes. The blood samples were allowed to coagulate before centrifuged at 400 rpm at 4°C for 15 min to separate the serum for enzyme assays. A portion of liver was cut off and fixed in 10% normal saline. The result showed that C. papaya seed extract treatments caused elevation of rat serum levels of acid phosphatase (ACP), alkaline phosphatase (ALP), and aspartate amino transferase (AST). Also revealed was mild to severe metaplasia of hepatocytes in a dose-related manner as well as proliferation of Kupfer cells and hepatic cells cirrhosis. These biochemical and pathological changes indicated liver cell damage and malfunction. These results, therefore, suggest that seeds of C. papaya should be used in herbal medicine with care to avoid toxicity. © 2005 Taylor & Francis Ltd.