In vitro comparison of the effect of shallot extract and chlorhexidine mouthwash on oral pathogens

Chlorhexidine is the most common mouthwash that we can compare the effect of new products with it as a gold standard. This study is designed to compare the effects of shallot extract with chlorhexidine on oral pathogens. The water extract of shallot was mixed with ethyl acetate in 50: 50 proportions for a period of 24 h; the upper organic layer was separated and dried in a rotary evaporator, dissolved in methanol and subjected to antimicrobial activity. The tested bacteria were Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius and Lactobacillus casei. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of shallot extract and chlorhexidine were measured by E test and tube dilution method respectively. The growth of all tested microorganisms was stopped by shallot extract. The least MIC of shallot extract was for S. mutans, 0.4 mu g/ml and the most was for L. casei, 1.4 mu g/ml. The MIC of chlorhexidine for these bacteria was 0.62 and 5 mu g/ml respectively. Regarding the results, shallot extract has good effects on oral pathogens as compared with chlorhexidine and can be used as a new mouthwash but its side effects must be investigated.