Assessment of antimicrobial activity of Catechu and its dyed substrate

The present study was undertaken to evaluate the antimicrobial activity of catechu in solution and % microbial reduction of dyed wool samples against Escherichia con MTCC 443, Staphylococcus aureus MTCC 902, Candida albicans ATCC 10261 and Candida tropicalis ATCC 750, by using micro-broth dilution method, disc diffusion assay and growth curve studies. The dye showed the maximum antimicrobial activity at 20% w/v, inhibiting the microbial growth by more than 90%. In the next set of the experiments the antimicrobial activity of the dye was compared on woollen yarn alone and on pre-mordanted samples. The reduction in antimicrobial activity was observed when mordanted samples were examined. K/S. CIELab values and fastness properties of the dyed samples were assessed. The structural morphology of woollen yarn was also evaluated using scanning electron microscopy (SEM). Haemolytic activity on human erythrocytes was studied to exclude possibility of further associated cytotoxicity. The observed antimicrobial characteristics and negligible cytoxicity of catechu indicate that the dye might be a promising antimicrobial agent for developing bioactive textile materials and clothing. (C) 2011 Elsevier Ltd. All rights reserved.