Antibacterial effect of flavonoids and diethyl acetate extract from the leaves of hibiscus rosa-sinensis / Syazwan Manshor

The purpose of this study was to investigate the antibacterial activity of flavonoid compound and diethyl acetate extract from Hibiscus rosa-sinensis leaves. The antibacterial activity was evaluated using broth microdilution assay. The extract was provided by Prof Dr Teh Lay Kek, lecturer of Faculty of Pharmacy, UiTM Puncak Alam. The flavonoids selected for this study were tannic acid, gallic acid, ellagic acid, diosmetin and acacetin. Among the flavonoid compounds used, tannic acid had the widest spectrum of activities while diosmin and acacetin had the lowest spectrum of activity. The gram positive bacteria used were Streptococcus agalactiae, Staphylococcus aureus, Straptococcus pyogenes, and Methicillin-resistant Staphylococcus aureus (MRSA). The gram negative bacteria used were Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, and Shigella spp. This study showed that flavonoid compound and diethyl acetate extract from Hibiscus rosa-sinensis had antibacterial activity against selected bacteria.