The Identification of Putative Antitrypanosomal Compounds in Tridax procumbens Extracts.

Abstract

The therapeutic potential of Tridax procumbens extracts were screened for antitrypanosomal properties in mice. Whole T. procumbens was sequentially extracted with hexane, ethyl acetate, methanol and water. The extracts obtained were intraperitoneally administered at doses of 100, 200, 300 and 400mg/kg body weight respectively for 14 consecutive days.to test for antitrypanosomal activity in mice infected with Trypanosoma brucei brucei. The ethyl acetate and methanol extracts gave a mean survival of 11.7 ± 5.4 and 14.3 ± 10.2 days respectively (P<0.05) when compared to untreated control. Phytochemical screening revealed the presence of steroids, saponins, tannins, alkaloids, flavonoids, phenols and carbohydrate in the crude methanol extract and phenols, flavonoids and steroids in the crude ethyl acetate extract. The bioassay-guided fractionation of the crude ethyl acetate and methanol extracts gave 12 and 11 fractions respectively. Fraction 11 of ethyl acetate exhibited better antitrypanosomal activities than fraction 7 of methanol which was significantly different from thier crude extract counterparts and the untreated controls (P≤ 0.05). Thin layer chromatographic (TLC) profile of the active ethyl acetate fraction 11 showed 3 spots, with preparative TLC band 2 producing highest antitrypanosomal effects. The TLC profile showed the presence of phenolic compounds. The spectrum of 13C and 1H NMR indicates the presence of sugars, fatty acids and phenolic related compounds namely cathechin, 3, 7 dihydroxyflavone, 3 – hydroxyflavone and quercetin. Although the demonstrated antitrypanosomal activities are insufficient, synthetic and/or chemical modification of detected phenolic compounds may generate effective antitrypanocidal drugs with novel modes of action.