Extraction and pharmacological evaluation of flavonoids of sida acuta Burm. f.

Abstract

Background: Flavonoids are group of polyphenolic compounds which are known to have medicinal properties and play a major role in the successful medicinal treatments from ancient times. Aims: The present study is conducted to evaluate the antimicrobial activity of free and bound flavonoids of Sida acuta Burm. f. Materials and Methods: The disc diffusion assay was performed against three bacteria (Escherichia coli, Staphylococcus aureus and Proteus mirabilis) and two fungi (Aspergillus flavus and Aspergillus niger). Minimum inhibitory concentrations were evaluated by the micro broth dilution method, while minimum bactericidal/fungicidal concentrations were carried out by subculturing the relevant samples. Total activity was also calculated for the extracts, to relate minimum inhibitory concentration of the extract with its amount isolated from 1 g of dried plant material. Statistical Analysis: All the values of the results of disc diffusion assay were expressed as means of three replicates ± standard error means. Results: The flavonoid extracts showed only antibacterial activity, but were inactive against the tested fungi. Free flavonoids from roots and bound flavonoid from stems exhibited antibacterial activity against all tested bacteria. S. aureus was the most susceptible microorganism which was sensitive toward 6 extracts out of 7 active extracts followed by P. mirabilis (5 extracts) and E. coli (3 extracts), respectively. Conclusion: The antibacterial flavonoids from S. acuta could be used in developing novel antibacterial drugs. Key words: Antimicrobial activity, flavonoid, sida acuta, total activity