An in vitro efficacy validation of mangrove associates

Objective:To investigate the in vitro antimicrobial potential of mangrove associates against a battery of human and shrimp pathogenic bacteria and to elucidate its antimicrobial principles.Methods:In the present study,12 species of mangrove associates collected from the Kollam(southwest coast of India)vicinity were extracted in different organic solvents of increasing polarity.The resultant extracts obtained from the respective species were examined for the antimicrobial activity against a panel of shrimp and human pathogens by agar diffusion assay.Results:Of the 12 species evaluated,three species of mangrove associates[Calophyllum inophyllum(C.inophyllum),Cerbera odollam and Dalbergia candenatensis]were found to be active.The broadest and highest rank of activity was observed in the crude extract of C.inophyllum.Amongst the pathogens tested,shrimp pathogenic Vibrios were the most sensitive organisms while human pathogens were found to be a bit resistant.In the present study,ethyl acetate was found to be the best solvent for extracting antimicrobial metabolites.The bioactive principles present in the crude extract of C.inophyllum were chemically elucidated by gas chromatography-mass spectrometer.The gas chromatography-mass spectrometer studies revealed the presence of two principal compounds such as 1-Dimethyl(phenyl)silyloxyhexadecane(24.73%)and β-d-Mannofuranoside,O-geranyl(50%)which might play functional role in the chemical defense against microbial invasion.Conclusions:Based on the overall findings,it could be inferred that the mangrove associate C.inophyllum is a promising candidate for the development of plant-based human and veterinary grade antibiotics in future.