Eugenol contributes to decreased expression of rpoD and luxS genes in clinically isolated Helicobacter pylori: An in vitro study using real-time-PCR technique

Abstract

Helicobacter pylori is one of the most significant human pathogens present in the gastric epithelial mucosa of >50 % of the world's population. The luxS and rpoD genes play an essential role in biofilm formation and growth of this bacterium, respectively. This study aimed at the eugenol effect on biofilm formation and the expression level of luxS and rpoD genes by H. pylori using the qRT-PCR technique.A total of the thirty-biopsy specimen were collected from the suspected patients. The samples were analyzed for the isolation of H. pylori. Out of the samples, one isolate of H. pylori was isolated based on the culture in microaerophilic conditions. The results showed that eugenol has an inhibitory effect on H. pylori growth. Semi-quantitative biofilm formation by H. pylori upon exposure to different concentrations of eugenol was evaluated, and quantitative expression of luxS and rpoD genes was investigated using qRT-PCR.Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined at 6.25 and 12.5 mg/ml, respectively. Also, biofilm production was inhibited completely using eugenol at a concentration of 12.5 mg/ml. In general, a decrease of about 4 and 2-fold in the expression of luxS and rpoD genes were observed, post-exposure to eugenol at a concentration of 3.12 mg/ml, respectively. Therefore, it can be concluded that eugenol contributes to decreased expression of luxS and rpoD genes in H. pylori, which may incorporate in biofilm formation by this bacterium.