Effects of Aqueous Extract of Annona muricata Leaves on Cyanide –induced Toxicity in New Zealand Rabbits

Abstract

Aqueous extract from Annona muricata leaves was investigated for its ameliorative effect on cyanide- induced toxicity in New Zealand Rabbits of weights 1200g-1800g. Four groups of rabbits (four per group) were used in a 28 day study. Group A served as the experimental control, groups B and C were given 400 ppm of cyanide salt (KCN) incorporated in the feed; this was done by dissolving the salt in water and then mixed with the feed in a ratio of 10:1 in addition to daily oral administration of Annona muricata extract (150mg/kg body weight and 300mg/kg body weight respectively). Group D was given only 400 ppm of cyanide salt (KCN) supplemented feed. Oxidative stress was evaluated by liver and kidney superoxide dismutase, catalase, and malondialdehyde. Administration of the aqueous extract of Annona muricata leaves for 21days significantly (P<0.05) ameliorated the changes in the biochemical parameters induced by cyanide when compared to the cyanide treated group. There was significant increase in the activity of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST); while alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) activities in the liver were not altered significantly when compared to the control but significantly different(P>0.05) from the untreated group. However, the activities of catalase (CAT) and superoxide dismutase were significantly reduced (P<0.05) in both the liver and the kidney. Increasing the dose of the extract (from 150mg/kg body weight to 300mg/kg body weight) resulted in significant decrease (P>0.05) in catalase activity but increase in MDA concentration. The concentrations of total protein as well as MDA of the liver were improved to levels that were not significantly different from the control. This suggested that aqueous extract of Annona muricata leaves might have a protective action against cyanide-induced hepatotoxicity arising from its bioactive constituents
Keywords: Annona muricata, cyanide, antioxidants, liver function enzymes, hepatotoxicity