Phytochemical and in vitro antiplasmodium activities of leaf extracts of Cassia nigricans Vahl. (Caesalpinaceae)

Abstract

The study was aimed at evaluating the phytochemicals, acute toxicity and in vitro antiplasmodium activity of aqueous and chloroform leaf extracts of Cassia nigricans using the basic phytochemical screening, Lorke’s and Candle Jar methods. Steroid glycosides, reducing sugars and alkaloids were detected in both extracts, while saponins and flavonoids were only detected in the aqueous extract. The median lethal dose (LD₅₀) of the aqueous leaf extractwas found to be 471.17mg/kg. The in vitro antiplasmodium screening showed that both extracts have antiplasmodium activity; with chloroform extract having the highest activity at the concentration of 2, 3 and 4 mg/ml which was statistically significant (P<0.05) in comparison with the positive control. The chloroform extract had the most potent half maximal inhibitory concentration (IC₅₀)value of 0.60 mg/ml. It can be concluded that C. Nigricans possess strong antiplasmodium activity and this may accounts for its use in traditional medicine in the management of malaria.

Keywords: Acute toxicity, antiplasmodium, malaria, phytochemicals and traditional medicine