[In vitro Comparison of antimicrobial activity and cytotoxic effects of Listerine and Irsha mouthwashes]

Irsha is an Iranian sample of Listerine mouthwash. To date biologic effects of Irsha and Listerine have not been compared. This study compared the antimicrobial and cytotoxic effects of Listerine and Irsha mouthwashes. In this in vitro study, antimicrobial effects of 5 dilutions of Irsha and Listerine, on the 0.5 MacFarlnd concentrations of five bacterial strains [Streptococcus mutans, Streptococcus Sangius, Enterococcus Fecalis, Candida albicans and Escherichia coli] were assessed at different times. Each test was repeated three times, with distilled water as control. For cytotoxic effect, more than 100000 cells of KB [epithelial cell], J774.A1[macrophage], Saos-2 [osteoblast] and MRF [fibroblast] were cultured and incubated for 72 hours in different dilutions of the two mouthwashes [0.5, 1, 5, 10%]. After incubation, the cells were washed and stained with MTT for 45 minutes. The results were recorded with ELISA READER and analyzed with SPSS 18 software, using ANOVA, Tukey test and one-way ANOVA. Statistical significance was defined at p value < 0.05. The cytotoxic effects of various dilutions of Listerine and Irsha mouthwashes were not significantly different [p value > 0.05]. In terms of antimicrobial activity, in dilutions of 100% and 50% of Listerine none of the five bacterial strains grew. However, at the same dilutions [100% and 50%] of Irsha, only three strains did not grow. According to the results, antimicrobial activity of Listerine is probably better than Irsha, but cytotoxic effects of Listerine and Irsha mouthwashes were not different