Study of antimicrobial properties of six wild vegetables of medicinal value consumed by the Bodos of Assam, India

In the present study, the methanol and aqueous extracts of six wild vegetables viz. Cardamine hirsuta, Tetrastigma angustifolium, Oenanthe javanica, Melothria perpusilla, Stellaria media, and Cryptolepis sinensis consumed by the Bodo tribes of Assam, India were tested for antimicrobial activities against four bacterial strains such as Staphylococcus aureus, Bacillus cereus, Escherichia coli and Proteus vulgaris by disc diffusion method. This study reveals that all the six plant species showed different antimicrobial activities with the highest zone of inhibition (16 mm) in the methanol extracts of S. media and O. javanica against E. coli and P. vulgaris, respectively. The methanol extracts of C. sinensis and M. perpusilla showed the highest zone (15 mm) against S. aureus and B. cereus respectively. However in aqueous extract, the highest zone of inhibition (13 mm) was observed in C. hirsuta, and S. media at 30 mg/mL concentration against E. coli. In this study, the MIC values of aqueous extracts of selected plants ranged from 15 to <30 mg/mL and that of methanol extracts varied from 7.5 to <30 mg/mL, and the MBC values of aqueous extracts varied from 15 to <30 mg/mL and that of methanol extracts ranged from <15 to <30 mg/mL. The results of this study revealed that the methanol extracts of all the selected plants are showing more effective antimicrobial activities in comparison to the aqueous extracts. However, the plants showed comparatively smaller zone of inhibitions in comparison to the standard antibiotics (amoxicillin).