Abstract:
Ageratum conyzoides is a common annual herbaceous weed with long history of traditional medicinal use in many countries especially in the tropical regions. The leaves extract is used in eastern Nigeria to treat malaria. This study is aimed to establish the pharmacological basis for the apparent antimalarial activity of Ageratum conyzoides. Aqueous extract (AE) of leaf of A. conyzoides was by obtained by cold maceration while methanol leave extract was by Soxhlet extraction. The crude methanol extract (ME) was fractionated into n-hexane (HF), chloroform (CF) and methanol (MF) fractions. Phytochemical tests and toxicity tests were done. The antiplasmodial activity of the aqueous extract as well as the methnolic extracts were screened by in vivo model in mice infected with Plasmodium berghei using 4-day suppression test. The aqueous extract of A. conyzoides exhibited significant (p < 0.05) and dose dependent antiplasmodial activity. All the fractions showed significant (p < 0.05), but varying levels of antiplasmodial activity. The phytochemical screening of the extracts revealed the presence of alkaloids, glycosides, flavonoids, saponins, tannins, reducing sugar, proteins, carbohydrates, resins. The LD50 was estimated to be greater than 5000 mg/kg, p.o in mice. The results suggest that leaves extracts and fractions of Ageratum conyzoides possesses significant antimalarial activity.
