Mechanism of action involved in the hepatoprotective activities of methanol extract of Cassytha filiformis L. aerial parts in CCl4-induced liver damage

Abstract

Cassytha filiformis alcohol decoction is used by traditional healers in Idem-Ogwa, Mbaitoli Local Government Area of Imo State, Nigeria, in the treatment of liver disorders ranging from hepatitis to susceptive poisoning and alcohol intoxication. The methanol extract of the aerial parts of Cassytha filiformis L. was investigated for hepatoprotective activity in rats challenged with carbon tetrachloride (CCl4). Apart from group 1 (normal), all other groups were pre-challenged with a single intraperitoneal injection of 0.7 ml of 20 % (v/v) CCl4 solution in olive oil. Group 2 (negative control) was given distilled water (10 ml kg−1, p.o.). Group 3 were treated with silymarin (35 mg kg−1 p.o.). Groups 4, 5, and 6 received oral treatments of 75, 150, and 300 mg kg−1 of the extract of C. filiformis respectively. All treatments were given by stomach intubation and at 12 h intervals for 7 days. Sodium pentobarbitone-induced sleeping time assay was carried out on the animals at 12 h after the last treatment on day 7 by intraperitoneal administration of Na-pentobarbitone (35 mg kg−1). Serum from individual animal was used to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, total protein and in vitro red blood cell membrane stability. The extract was safe up to 2000 mg kg−1 orally and did not induce overt clinical manifestation or death in rats. The extract significantly (p < 0.01) demonstrated potency at all test doses (75, 150, and 300 mg kg−1) in CCl4-challenged and treated animals when compared with prolonged Na-pentobarbitone-induced sleeping time observed in untreated CCl4-intoxicated rats. The methanol extracts of C. filiformis (150 and 300 mg kg−1) were also able to reduce hepatic tissue injury as revealed by a reduction in the serum levels of AST, ALT, ALP, and total bilirubin significantly (p < 0.05) but increased total serum protein significantly (p < 0.05) relative to values in untreated CCl4-induced liver damaged rats. Exposure of rat erythrocytes to varying saline concentrations (0.2–1.0 mg mL−1) of the extract did not produce observable measured increase in osmotic fragility in the red blood cell membranes. The findings suggest that the methanol extract of the aerial parts of C. filiformis could be useful in protecting hepatocytes from toxins especially from alcohol intoxication.