BACKGROUND : Bacterial infections of the gastrointestinal tract (GIT) cause vomiting, diarrhoea and even systemic disease. There
is a need for the development of natural products into alternative and safer medicines.
OBJECTIVES : This study evaluated the anti-microbial activity of extracts prepared from berries, leaves,bark and roots of the edible
plant Grewia flava.
METHODS : The anti-bacterial activity was evaluated by the broth microdilution method. Anti-oxidant activity of the most active
extracts was performed by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The cytotoxicity of the extracts was determined using
the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.
RESULTS : The acetone extracts of the leaves and roots showed the best activity with MIC values as low as 0.03 mg/mL against
Staphylococcus aureus and Salmonella typhimurium and 0.07 mg/mL against Bacillus cereus, Escherichia coli and Staphylococcus aureus.
Quantitative analysis of the scavenging ability showed that acetone extracts exhibited good free radical scavenging activity in a
dose-dependent manner. The berries extract had the highest LC50 (lowest toxicity) of 551.68 68 μg/mL.
CONCLUSION : Acetone extract of leaves and roots of Grewia flava contain anti-microbial and anti-oxidant compounds and could
therefore be used as a natural product with little toxicity to host cells.