Preliminary investigation of the antibacterial activity of Acalypha hispida leaf extracts against local bacterial isolates from skin infections

Acalypha hispida leaf extracts are used locally for the treatment of skin infections. We sought to obtain laboratory-based evidence for this practice by evaluating the antibacterial activity of this extract against local isolates of bacteria obtained from skin lesions and wounds. Aqueous and ethanolic extracts were evaluated using the agar well diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, Escherichia coli, Klebsiella species, and Salmonella typhimurium. S. aureus (ATCC standard and local) and Ps. Aeruginosa isolates were sensitive to all the extracts but one. E. coli (ATCC standard and local), S. enterica serovar typhimurium and Klebsiella species were only sensitive to the soxhlet leaf extracts while S. pyogenes was sensitive to only the ethanolic soxhlet extract. Though there was no statistically significant difference in the antibacterial activity of the 5-days and 14-days neat extracts obtained by soaking in water (p = 0.13) and ethanol (p = 0.08), their antibacterial activity decreased with longer soaking periods. Likewise, there was no significant difference in the antibacterial activity of the neat water and ethanolic soxhlet extracts (p = 0.48). The results show that A. hispida leaf extracts showed some in vitro antibacterial activity and that aqueous extraction using heat would be the preferred option. Keywords: Acalypha hispida, antibacterial, skin infections, aqueous extract, ethanolic extract Nigerian Journal of Health and Biomedical Sciences Vol. 5 (2) 2006: 12-16