Acute toxicity study of crude methanol leaf extract of Ficus exasperata Vahl on male Wistar albino rats

Abstract

There is an increase in demand for the use of traditional folk medicine globally due to their low cost, efficacy and easy accessibility especially for people living in developing countries. This study was carried out to assess the acute toxicity as well as the LD₅₀ of Ficus exasperata Vahl in male Wistar albino rats. Lorke’s method was adopted for the determination of the LD₅₀ of the crude methanol leaf extract of plant. The extract administration was in two phases. In phase one, doses of 10, 100 and 1000 mg/kg body weight of rats was administered while in phase two, 1500, 3000 and 5000mg/kg body weight of rats was orally administered. Behavioral changes, signs of toxicity and mortality were observed from the point of administration to 24 hours in the first phase only and 14 days in the second phase included. The qualitative phytochemicals screening revealed the presence of alkaloids, tannins, flavonoids, cardiac glycosides, saponins and steroids. Signs of toxicity observed in the rats administered with 1000mg/kg body weight of rats were uneasiness, sluggishness and dizziness after 24 hours of observation. However death was not recorded in all the groups after 14 days of administration. There was dose dependent increase in the level of the selected liver enzymes assayed (AST and ALT) across all the groups. Liver malondialdehyde concentration in the rats administered higher doses differed significantly (p < 0.05) when compared with the control group. From our study, crude methanol leaf extract of Ficus exasperata vahl possess medicinally important phytochemicals and the acute toxicity studies revealed that the extracts has LD₅₀ above 5000mg/kg because no death was recorded. However, the results of the liver enzymes and lipid peroxidation suggested that prolonged use of the extract may cause damage to the liver and some vital organs. It is recommended that a long-term study such as sub-chronic toxicity studies should be conducted to know the long term effect of the leaf extract of Ficus exasperata Vahl.