Antimicrobial and anthelmintic Evaluation of Nigerian Euphorbiaceae Plants 3: Acalypha wilkesiana

Abstract

Methanolic extracts of leaf, stem and root of Acalypha wilkesiana were investigated with the goal of establishing its acclaimed potency as an anthelmintic and antimicrobial agent. Antimicrobial assay was carried out using the agar cup plate diffusion method. The extracts were tested against 8 human pathogenic microorganisms (5 bacteria and 3 fungi). The leaf and stem methanol extracts exhibited antibacterial and antifungal activities. The leaf methanol extract showed antibacterial activity against all the test organisms namely, Staphylococcus aureus, Bacillus subtilis, Salmonella typhii, Eschericia coli and Pseudomonas aeruginosa and displayed marked antifungal properties against Aspergillus niger, Candida albicans and Dermatophyte sp. exhibiting higher antifungal activity than the reference drug tioconazole. The methanolic extract of the stem on the other hand inhibited the growth of all the test microorganisms except Salmonella typhii and Dermatophyte sp. and displayed greater antibacterial activity with two of the microorganisms namely, Bacillus subtilis and Escherichia coli than the reference compound ampicillin. Antibacterial and antifungal activity was concentration- dependent except for Dermatophyte sp where activity was independent of extract concentration. All the extracts exhibited in vitro anthelmintic activity against Fasciola gigantica, Taenia solium and Pheritima pasthuma. T. solium was most sensitive to the ethyl acetate extract of the leaf while P. pasthuma was more sensitve to most of the extracts than the reference compound, piperazine citrate. The extracts contain important secondary metabolites - cardiac glycosides, tannins, saponins and alkaloids. These results justify the ethnomedicinal uses of the plant.