Cytotoxic and growth inhibitory activity of aqueous extracts of root and leaf of <i>Rhaphiostylis beninensis</i> Planch ex Benth and <i>Pyrenacantha staudtii</i> Engl (Icacinaceae)

Abstract

The aqueous extract of the root and leaf of Rhaphiostylis beninensis Planch ex Benth and Pyrenacantha staudtii Engl, both belonging to the family Icacinaceae were investigated for their claimed anti-tumour activity using simple bench top assays. The cytotoxic activity was evaluated within the concentration range of 1-20µg/ml using the tadpole mortality test, while the growth inhibitory activity was investigated within the concentration range of 1-30mg/ml using the Sorghum bicolor seed growth inhibitory test. At a concentration of 20µg/ml, aqueous extracts of the root and leaf of  Rhaphiostylis beninensis was observed to effect a mortality of 100 and 80% respectively, while aqueous extract of the root and leaf of  Pyrenacantha staudtii, at same concentration, effected mortality of 70 and
93% respectively. Nil mortality was observed in the control setup, while at other concentrations varying degrees of mortality was observed. All the extracts produced varying degrees of inhibition of growth in the emerging radicle of the seed of Sorghum bicolor. The results obtained suggest that these plants may probably have constituents with anti-tumour activities that merit further investigation using other test systems.

Keywords: Rhaphiostylis beninensis; Pyrenacantha staudtii; Icacinaceae; Cytotoxic; Growth inhibition