Protective effect of ethanolic extract of Cucurbita maxima (PUMPKIN) leaf on acetaminophen-induced acute liver toxicity

Ethanolic extract of dried leaves of Cucurbita maxima (Pumpkin) were screened for their phytochemical composition. The in vitro antioxidant property was determined by assessing the free radical (DPPH) scavenging activity. Twenty rats divided into four groups were used for this study with group 4 pre- treated with the extract and later intoxicated with 2 g/kg single dose of acetaminophen. The hepatoprotective effect of the extract was determined by measuring the liver function parameters, liver antioxidant enzyme activities and the rats liver histological micrograph. The ethanolic extract was found to be a rich source of bioactive compounds and showed a direct variation in in vitro free radical (DPPH) scavenging property. DPPH scavenging property increases as the concentration of the extract increases from 0.03 to 0.12 mg/l (8.9 - 64.2%) but dropped sharply to 52.2% at a concentration of 0.5 mg/l. A 400 mg/kg daily pre-treatment (for seven days) with ethanolic leaf extract of the plant was able to offer protection to the hepatic cells of the rats. This was evidenced in the significant (p<0.05) reduction of the activities of alanine aminotransferase (ALT) from 117.30±57.50 to 31.26±11.22 µ/l and alkaline phosphatase (ALP) from 209.80±67.00 µ/l to 172.00±30.31 µ/l, significant (p<0.05) increase of the activities of glutathione peroxidase (GPx) from 115.60±10.03 to 235.45±43.52 µ/mg, superoxide dismutase (SOD) from 0.02±0.01 to 0.09±0.05 U/mg and catalase (CAT) from 2.50±2.60 to 10.23±5.05 U/mg in the test group when compared with the negative control. Also, the lobular architecture of the hepatocytes was well-preserved in the test group. Based on the experimental results obtained here, C. maxima has an important role in medicine as it plays a role in scavenging free radicals, stimulating activities of antioxidant enzymes and preserving the liver architecture, thereby protecting the liver against acetaminophen-induced liver toxicity.