Evaluation of Hydrogen peroxide Scavenging and Antibacterial activity of successive extracts of Luisia tenuifolia Blume against skin and wound infections

Abstract

Skin and wound infections might trigger severe secondary complications when left untreated. A proper balance between reactive oxygen species generation and antioxidant formation is necessary to achieve redox haemostasis. Luisia tenuifolia Blume (Orchidaceae) has been traditionally applied on cuts, boils and wounds in regions of Western Ghats. The present study was aimed to validate the antioxidant and antibacterial effect of the whole plants of Luisia tenuifolia against five pathogenic bacteria often responsible for skin and wound infections The whole plants of L.tenuifolia, after drying under shade, was pulverised, successively extracted with solvents of different polarity and evaporated to dryness. The hydrogen peroxide scavenging potential of all the four extracts was determined by H2O2 assay. The agar-well diffusion technique was employed for the preliminary screening of antibacterial activity. Further, the minimum inhibitory concentration was determined by broth-dilution assay. Among the four extracts, the ethanol extract of L. tenuifolia exhibited a strong antioxidant activity with an IC50 value of 42.61μg/mL compared to the standard Ascorbic acid (IC50 value of 21.56μg/mL). Moreover, the n-hexane extract was found to be more effective against Staphylococcus aureus whereas the ethanol extract exhibited highest antibacterial effect on Streptococcus oralis, Pseudomonas aeruginosa, Aeromonas hydrophila and Escherichia coli. Furthermore, the ethanol extract was found to be a promising antibacterial candidate with an MIC value of 0.312μg/mL against S.oralis and A.hydrophila. Thus the current study validate the antioxidant and antibacterial potential of L. tenuifolia whole plant extracts and further studies were aimed at identification of active components responsible for the activity.