Statistical Optimization of Terminalia chebula Fruit Extraction for Improved Antibacterial Activity Against Odour-Causing Bacteria

Abstract

The antibacterial effect of plant extract majorly depends on the process parameters of herbal extraction. In this aspect, this study is focused on optimizing the extraction conditions for better performance after application. The effects of variables like extraction time, sonication time and the extraction temperature were taken as key parameters. The Box and Behnken design was adopted to study the effects of these parameters on the effectiveness of extraction in terms of the in vitro antibacterial activity of treated textile (in zone of inhibition) against odour-causing bacterial strains. The response surface methodology results showed that the increment in the extraction time from 12 h to 36 h increases the antibacterial activity. The extraction temperature has a very little effect on the efficacy against the selected strains. The increment in the temperature after 39 °C reduces the activity considerably. The effect of sonication time plays a vital role in the dissolvability of the active substance. The regression coefficient values (r2) of 82.27, 80.6, 77.51 and 45.11% are obtained, respectively, for Corynebacterium sp (MTCC 8730), Bacillus licheniformis (MTCC 429), Micrococcus luteus (ATCC 49732) and Corynebacterium acnes (MTCC1951). The optimized extraction parameters for improved antibacterial properties are identified: methanol with 29.1 h of immersion, 30 min of sonication period and 35 °C of extraction temperature. At optimized condition, the zone of inhibition values is predicted as 10.94, 31.87, 24.33 and 40.44 mm, respectively, for the above-mentioned strains.