In vitro antibacterial activity of gels with different papain concentrations

Abstract

The papain is a proteolytic enzyme from papaya, Carica papaya Linn., and it is so used in food, cosmetic and pharmaceutical industry. The aim of this study was to determine in vitro antibacterial activity of gels with different papain concentrations against standard bacteria: Staphylococcus aureus (ATCC 6538) and Echerichia coli (ATCC 10538), as well as 04 hospital Pseudomonas aeruginosa. Aliquots of 2.0ml from bacterial inocula (0.5 McFarland scale) were seeded in duplicate onto Petri plates’ surface. The papain gels with different concentrations were dropped onto culture medium surface by the drop technique and the incubation realized at 35ºC for 24 hours. The results of antibacterial activity were obtained by measuring of growth inhibition halos around the drops of papain gels. Only the papain gel 10% was able to inhibit S. aureus and 2 P. aeruginosa growth. In conclusion, according to literature the papain has action on dead tissues, but only the gel formulation 10% presented in vitro antibacterial activity. So, before using any substance or product against microorganisms it is necessary to know if it really has antimicrobial activity.