In vitro evaluation of capsaicin inhibitory effects on zonula occludens toxin in vibrio cholerae ATCC14035 strain

Background: Cholera is one of the most potent diarrheal diseases that is characterized by massive watery stools, frequently accompanied by vomiting and can lead to hypovolemic shock and acidosis. It is caused by certain strains of Vibrio cholerae species which can also cause mild or in apparent infections. The aim of this study was to evaluate Capsaicin, as a potential inhibitor of zonula occludens toxin production in V. cholerae ATCC 14035. Methods: MIC of capsaicin was determined by Broth Microdilution method according to CLSI guidelines. The zot gene expression level was analyzed using real-time RT–PCR. Results: In MIC test, we found 100 μg mL −1 of capsaicin as the highest concentration that did not affect the bacterial growth; however, zonula occludens toxin (zot) gene expression of the tested strain was significantly inhibited by capsaicin in a dose-dependent manner at sub-bacteriocidal concentrations. The recA gene did not show any significant difference in its expression with or without capsaicin. Conclusion: Capsaicin is one of the active compounds of red chili that can drastically suppress zot gene expression and shows promising inhibitory effect against V. cholerae zot production. Thus, routine intake of red chili, which is easily available and inexpensive, may be an alternative approach to prevent and control symptoms of cholera.