Introduction: In the context of the global threat of antimicrobial resistance (AMR)
among bacterial pathogens against conventional bactericidal antibiotics, investigation on complementary/
alternative approaches to manage bacterial infections is warranted. The present study
aimed at investigating the anti-pathogenic potential of Phyllanthus emblica seed extract (PESE)
against four different pathogenic bacteria.
Methods: Hydroalcoholic extract of P. emblica seeds was tested for its possible in vitro quorummodulatory
potential against Chromobacterium violaceum, Serratia marcescens, Pseudomonas
aeruginosa, and Staphylococcus aureus through broth dilution assay. In vivo efficacy of PESE
was assayed employing Caenorhabditis elegans as the model host for these four pathogens.
Results: PESE was found to exert in vitro quorum-modulatory effect on C. violaceum, S. marcescens,
P. aeruginosa, and S. aureus at ≥50 μg/mL. This extract could curb the haemolytic activity
of all the four test bacteria by 23-65%, inhibit biofilm formation, and was also able to modulate
their antibiotic susceptibility (AS) and catalase activity. Susceptibility of P. aeruginosa and S.
aureus to lysis by human serum was enhanced under the influence of this extract by 23% and
49%, respectively. Repeated exposure of both these notorious pathogens to PESE did not induce
resistance in them. In vivo assay confirmed the anti-virulence effect of this extract in the C. elegans
host, wherein the nematode host challenged with the PESE-treated pathogenic bacteria
scored better survival. PESE also displayed notable prebiotic potential by promoting the growth of
three probiotic strains.
Conclusion: To the best of our awareness, this is the first report on the quorum-modulatory potential
of P. emblica seed extract, validating its anti-infective potential and prebiotic property.