Phytochemical Screening and Stability Studies on the Antimicrobial Activities of the Leaf Extracts of Alchornea cordifolia (Schum. & Thonn.) Muell. Arg. (Euphorbiaceae)

Abstract

The phytochemical screening of the water, methanol and ethyl acetate extracts of Alchornea cordifolia leaf using standard biochemical methods revealed the presence of tannins, saponin, flavonoid, alkaloid, glycoside and phenol. The antimicrobial activity of the water, methanol and ethyl
acetate extracts of the Alchornea cordifolia leaf against Pseudomonas aeruginosa (isolate), Pseudomonas aeruginosa ATCC 10145, Stapylococcus aureus (isolate), Stapylococcus aureus ATCC 12600, Escherichia coli (isolate), Escherichia coli ATCC 11775, Candida albicans (isolate) and Candida albicans ATCC 18804 using agar well diffusion and agar dilution methods was studied after a period of six months under different storage conditions. The antimicrobial activities of extracts stored in closed cupboard were relatively constant when compared with the fresh extracts, except methanol extract, which showed lower Minimum Inhibitory Concentrations against Candida albicans after six months. However exposure to light decreased the antimicrobial activities of the extracts with decrease in the diameter of zones of inhibition. The pH of the extract remained stable at 11.0 – 11.5. The implications of these findings in the use of Alchornea cordifolia leaf are discussed.