Antimicrobial activity of select edible plants from Odisha, India against food-borne pathogens

The anti-microbial activity of crude extracts (hexane, acetone, ethanol, and aqueous) of 46 edible plants from Odisha, India, was studied using a broth microdilution assay against 8 common food-borne pathogens (Gram-positive: Bacillus cereus, Streptococcus faecalis, Listeria innocua, Micrococcus luteus, and Gram-negative: Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Shigella sonnet). In total, 46 plant species belonging to 31 families were tested, from which 10 plants (22%) showed broad-spectrum in vitro antimicrobial activity (inhibiting at least two Gram-positive and Gram-negative species), while 28 (60%) exhibited narrow-spectrum activity against only Gram-positive -, and 2 (4%) against only Gram-negative bacteria. The Gram-positive pathogens were thus clearly more susceptible to most extracts compared to Gram-negative species. Selected active plant extracts were tested for their cytotoxicity against rhabdosarcoma (RD) and Vero cell lines. Selected extract (s) were further subjected to Thin layer chromatography (TLC) to determine their phytochemical profile; the extracts were largely distinguished by the presence of different phytoconstituents like phenols, flavonoids, tannins, saponins, steroids and terpenes. This preliminary antimicrobial screening showed that some edible Indian plants with antibacterial properties have potential as herbal preservatives in the food industry, and perhaps also as alternative therapeutic agents, particularly against food-borne bacterial diseases.