PHYTOCHEMISTRY, TOXICITY AND IN VITRO ANTITRYPANOSOMAL EFFICACY OF CRUDE AQUEOUS EXTRACT OF GUIERA SENEGALENSIS STEM BARK

Abstract

The crude aqueous extract of Guiera senegalensis stem bark was evaluated for its phytochemistry, acute toxicity and in vitro antitrypanosomal efficacy in this study. Tests for alkaloids, flavonoids, tannins, phlabotannins, saponins, steroids, cardenolides, terpenoids, cardiac glycosides, and anthraquinones were conducted. A total of 15 albino rats of both sexes were used and grouped into 5 (A to E) of 3 rats each. Groups A-D were intraperitoneally treated with graded doses of 100, 200, 400, 800mg/kg body weight of the crude aqueous extract of G. senegalensis stem bark. Group E was treated with Physiological Saline Solution serving as the control. All groups were observed for 24 hours for clinical signs and death to determine the median lethal dose (LD₅₀). An in vitro experiment was carried out with 2 drops of blood from a donor rat added to 5 ml of phosphate buffer glucose solution out of which 0.2ml was finally used at 40, 20, 10, 5, 2.5, 0.625, 0.313, 0.156 and 0.078 concentrations of the extract. The phytochemical screening for bioactive substances had tannins, terpenoids, alkaloids, flavonoids, saponins, anthraquinones and cardiac glycosides.  Phlabotannins and cardenolides were not detected. The clinical signs observed were sluggishness, awkward posture, loss of appetite, starry hair coat and terminal death within 24 hours with LD₅₀ value of 600mg/kg. The in vitro antitrypanosomal efficacy of the extract showed 100% inhibition of motility against Trypanosoma brucei at 20mg/ml. In conclusion, the crude aqueous extract of G. senegalensis stem bark contains phytochemical components that exhibit inhibitory trypanosomal activity.