Microbial evaluation of Limnophila rugosa Roth. (Merr) leaf.

Background: Limphonia rugosa Roth. (Merr.), family-Scrophulariaceae is considered as a botanical source of classical Ayurvedic drug Bhringaraja by the traditional practitioners of Odisha and is being used for the management of various disorders.

Aim: To study the antimicrobial activity of leaf of L. rugosa.

Materials And Methods: Methanol extract of L. rugosa leaf (LRLM) has been studied, at various (5, 25, 50, 100, 250 μg/ml) dilutions, against medically important human pathogenic bacteria (two Gram-positive Staphylococcus aureus, Streptococcus pyogenes and two Gram-negative-Escherichia coli, Pseudomonas aeruginosa) and two fungal strains (Aspergillus niger, A. clavatus, Candida albicans) by using the agar disc diffusion method. A zone of inhibition of extract was compared with that of different standards such as ampicillin, ciprofloxacin, norfloxacin and chloramphenicol for antibacterial activity and nystatin and griseofulvin for antifungal activity.

Results: The antibacterial and antifungal activities of the LRLM increased linear with the increase in concentration of extracts. When compared with standard drugs, the results revealed that, for bacterial activity S. pyogenes and S. aureus were more sensitive and in fungal activity C. albicans was more inhibited. The range of growth inhibition zone for all the sensitive bacteria was 11-20 mm and 13-19 mm for fungal strains.

Conclusion: Methanolic extract of L. rugosa leaf is having antibacterial and antifungal activities.