ANTITRYPANOSOMAL ACTIVITIES OF SOME SELECTED NIGERIAN ETHNOMEDICINAL PLANTS

Résumé

The phytochemical components and antitrypanosomal activities of four selected Nigerian plants (Pterocarpus  santalinoides leaves, Picrlima nitida seeds, Dacyroedes edulis stem bark and Terminalia catappa leaves) were investigated. Phytochemistry was determined following standard methods while antitrypanosomal activity was determined via the in vitro assay using five different concentrations (4, 2, 1, 0.25 and 0.0625 mg/ml) of the plant extracts. Concentrations of P. santalinoides hydroethanol leaf extract (PSHELE) were further incubated for 60 minutes, inoculated in mice for the infectivity test and monitored for 21 days. Phytochemical studies revealed the presence of flavonoids, tannins, carbohydrate and reducing sugar in PSHELE; flavanoids, tannins, alkaloids, carbohydrate and reducing sugars in P. nitida hydroethanol seed extract; alkaloids, reducing sugars, steroids, tannins and saponins in T. catappa hydroethanol leaf extract, and alkaloids, phenols, flavonoids, tannins, cardiac glycosides and reducing sugars in D. edulis hydroethanol stem bark extract. P. santalionides hydroethanol leaf extract exhibited strong in vitro antitrypanosomal activity followed by P. nitida hydroethanol seed extract (PNHESE) with IC50 of 0.011 and 0.022 mg/ml respectively. Following infectivity test, none of the PSHELE concentrations was able to exhibit loss of infectivity following incubation for 60 minutes. Though, a concentration-dependent prolongation of the pre-patent period was observed. It was therefore concluded that PSHELE and PNHESE possess antitrypanosomal activities and could serve as a potential candidate for development of new lead against African trypanosomosis.