Chemical composition and antimicrobial activity of different root extracts of Hermannia geniculata against human pathogens of medical importance

[摘要] Hermannia geniculata has been used widely as traditional medicine for treatmentagai nst infectious human pathogens. The aim of the study was to determine the antibacterialand anti fungal activities of H. geniculata root extracts and their fractio ns against 16 microbialstrains. The dried plant materials were extracted separately in 150 ml of methanol, acetone,ethanol, water and 150 ml (50/50) of hydro-ethanol. Acetone extract inhibited the growth ofmicroorganisms with minimum inhibitory concentration (MIC) values of 1.56 mg/ml againstall the tested strains except for Salmonella typhimurium and Candida rugosa at theconcentration of 6.25 mg/ml. The ethanol, hydro-ethanol and methanol extracts inhibitedbacterial growth with MIC values ranging from3. l 3 mg/ml to 12.50 mg/ml, while water extracthad MIC of 12.50 mg/ml against all tested bacterial and fungal strains. Acetone extract hadmaximum bactericidal concentration (MBC) values ranging from 1.56 to 3.13 mg/ml againstmost microorganisms. Butanol fraction of acetone extract had MIC of 0.78 mg/ml againstStaphylococcus aureus (OK.2b) and Staphylococcus a11re11s (ATCC 6538), whilst the ethylacetate had the lowest MBC of 1.56 mg/ ml against S. aureus (OK.lb), S. aureus (ATCC 6538),and Streptococcus .faecalis. The extracts and their respective fractions displayed similarinhibitory properties which are indica tions that either the crude extract or their fractions couldbe used to manage infections assoc iated with bac teria and fungi.

[发布机构] University of the Free State