Anti-infective potential of a quorum modulatory polyherbal extract (Panchvalkal) against certain pathogenic bacteria

Anti-infective potential of a polyherbal ayurvedic formulation namely panchvalkal was assayed against three pathogenic bacteria. This formulation was found to exert quorum-modulatory effect on Chromobacterium violaceum , Serratia marcescens , and Staphylococcus aureus at 250-750 μg/mL. Besides altering production of the quorum sensing-regulated pigments in these bacteria, the test formulation also had in vitro effect on antibiotic susceptibility, catalase activity and hemolytic potential of the pathogens. In vivo assay confirmed the protective effect of this panchvalkal formulation on Caenorhabditis elegans , when challenged with the pathogenic bacteria. Repeated exposure of S. aureus to panchvalkal did not induce resistance in this bacterium. To the best of our awareness, this the first report on quorum-modulatory potential of panchvalkal formulation, validating the anti-infective potential and moderate prebiotic property of this polyherbal preparation.