The aim of the present study was to characterize the antimicrobial properties of various crude extracts of the Cassia spectabilis leaf against bacteria and yeast. Acetone, n-hexane, dichloromethane, ethyl acetate and methanol extracts of C. spectabilis leaves were evaluated in vitroagainst Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram negative bacteria (Escherichia coli, Salmonella typhi and Pseudomonas aeroginosa) and yeast (Candida albicans). The Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC) and Minimum Fungicidal Concentration (MFC) were determined using micro dilution assay. Methanol showed the highest yield (14.12%) followed by dichloromethane (8.37%), acetone (6.66%), ethyl acetate (4.76%) and n-hexane (1.80%). Acetone and methanol crude extracts showed a good antimicrobial activity with MIC values ranging from 0.625 to 2.5 mg mL-1 and MBC or MFC values ranging from 1.25 to 5 mg mL-1. The MIC, MFC and MBC values of these extracts were 10 to 80 times less potent than standard antimicrobial drugs, amoxilin and miconazole nitrate.
N. Krishnan, S. Ramanathan, S. Sasidharan, V. Murugaiyah and S.M. Mansor, 2010. Antimicrobial Activity Evaluation of Cassia spectabilis Leaf Extracts. International Journal of Pharmacology, 6: 510-514.