Toxicological Evaluation of Aspilia Africana Leaf Extracts in Mice

Abstract

Problem statement: The degree of toxicity of crude extracts of Aspilia Africana (Bush marigold) leaf on the basis of routes and dosages of administration were investigated. 204 healthy, male Swiss albino mice (20-25g) were used in three consecutive studies. Approach: In the first and second study, oral and intraperitoneal doses of 100, 500, 1000, 2000 and 4000 mg kg^-1 body weight of aqueous, chloroform or ethanolic extract were administered to mice. 0.2 mL of distilled water was given to the control group as placebo. Mortality and behavioural changes were monitored at 1, 2, 4, 6, 24, 48 and 96 h post administrations. In the third study, higher doses of 4,000, 8,000, 12,000, 16,000 and 20,000 mg kg^-1 body weight aqueous or ethanolic extract were orally administered to fresh groups of mice. Results: Results revealed that the degree of toxicity of Aspilia africana leaf was extractant, dose and route of exposure responsive. Signs of behavioral toxicity; nervous and respiratory disorders and piloerections fluctuated in mice. Results indicated that the medium Lethal Dose (LD₅₀) was greatest for the aqueous extract and least for the chloroform extract. Oral exposure had significantly greater LD₅₀ (p<0.001, Av. value = 8,194.84 mg kg^-1) compared to intraperitoneal exposure with an average of 232.55 mg kg-¹. Conclusion: These findings support the common practice of oral administration of either aqueous or ethanolic extract of Aspilia africana as a medicinal decoction in herbal medicine. The study concludes that oral administration of up to 10,000 mg kg^-1 body weight of aqueous and ethanolic extracts of Aspilia africana leaf are safe for human and animal use.