出版社：The International Institute for Science, Technology and Education (IISTE)
摘要：Higher plants, as source of medicinal compounds, have continue to play a significant role in the maintenance of health for centuries, especially in developing countries. Plant such as Andrographis paniculata extracts have been utilised for the treatment of many diseases including diarrhoea and upper respiratory tract infections. The aim of this study was to screen the phytochemical constituents and prophylactic antibacterial anti-bacterial effect of methanol, ethyl acetate, ethanol: water (1:1 v/v) and aqueous extracts on Staphylococcus aureus, Staphylococcus typhemorium, Staphylococcus epidermidis and Escherichia coli respectively. The highest zone of growth inhibition (14 and 10 mm) observed by ethyl acetate and methanol extacts at the lowest concentration of 0.625 mg/mL, against S.aureus ATCC 9144, respectively. The ethanol: water (1:1 v/v) and aqueous exhibited no activity against the tested pathogenes as compared with the standard ampicillin (2.9 mm) at lowest concentration. Both ethyl acetate and methanol extracts indicated a lower MIC value of 1.25, and 0.625 mg/mL respectively against gram-negative bacteria ( E.coli ), while higher MIC values of 2.5 mg/ml against gram-positive bacteria ( S.aureus and S.typhii ) was observed. The methanol and aqueous extracts showed lower MIC values of 0.625 mg/mL against E. coli (indicating better activity) than ethanol: water (1:1 v/v) against both gram -ve bacteria ( S. epidermidis and E. coli ). However, all the extracts have lower MIC values of 0.625 mg to 1.25 mg against gram -ve bacteria ( S.epidermidis and E.coli ). The result showed a better activity of the extracts against gram -ve bacteria, which are significantly important in causing common problems of bacterial infections in hospitals causing many diseases such as respiratory tract infections.
关键词：key words; Bacteria; minimum inhibitory concentration; zone of growth inhibition; Andrographis paniculata
