Antimicrobial Activity of Six Different Parts of the Plant Citrus medica Linn.

Introduction: Antimicrobial activity of fruit juice and ethanolic extracts of root, leaf, bark, peel and pulp of citron (Citrus medica Linn., Rutaceae) was examined against seven bacteria (Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus vulgaris), two fungi (Aspergillus flavus and A. niger) and a yeast Candida albicans of clinical origin. Methods: The level of antimicrobial effects was established using an in vitro disc diffusion method; minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were determined by standard agar dilution method. Results: All extracts and fruit juice showed varied level of antibacterial activity against one or more test bacteria. Antifungal activity was shown by only root extract and fruit juice while C. albicans was resistant to all tested plant samples. Broad spectrum antimicrobial activity was shown by fruit juice (MIC <1% to 3.5% and MBC 1% to 7% v/v) and fruit pulp (MIC 25 mg/ml and MBC 30 to 75 mg/ml). Root extract was found highly potent with MIC as small as 0.5 mg/ml and MBC 1 mg/ml against S. aureus. Among all tested plant samples leaf and peel extracts have shown less antimicrobial activity. Conclusion: It is concluded that fruit juice and juiceless fruit pulp extract have shown broad antimicrobial activity while root extract was very effective against some tested microorganisms.