Cannabidiol restores intestinal barrier dysfunction and inhibits the apoptotic process induced by Clostridium difficiletoxin A in Caco-2 cells

Background Clostridium difficiletoxin A is responsible for colonic damage observed in infected patients. Drugs able to restore Clostridium difficiletoxin A-induced toxicity have the potential to improve the recovery of infected patients. Cannabidiol is a non-psychotropic component of Cannabis sativa,which has been demonstrated to protect enterocytes against chemical and/or inflammatory damage and to restore intestinal mucosa integrity.Objective The purpose of this study was to evaluate (a) the anti-apoptotic effect and (b) the mechanisms by which cannabidiol protects mucosal integrity in Caco-2 cells exposed to Clostridium difficiletoxin A.Methods Caco-2 cells were exposed to Clostridium difficiletoxin A (30 ng/ml), with or without cannabidiol (10−7–10−9 M), in the presence of the specific antagonist AM251 (10−7 M). Cytotoxicity assay, transepithelial electrical resistence measurements, immunofluorescence analysis and immunoblot analysis were performed in the different experimental conditions.Results Clostridium difficiletoxin A significantly decreased Caco-2 cells’ viability and reduced transepithelial electrical resistence values and RhoA guanosine triphosphate (GTP), bax, zonula occludens-1 and occludin protein expression, respectively. All these effects were significantly and concentration-dependently inhibited by cannabidiol, whose effects were completely abolished in the presence of the cannabinoid receptor type 1 (CB1) antagonist, AM251.Conclusions Cannabidiol improved Clostridium difficiletoxin A-induced damage in Caco-2 cells, by inhibiting the apoptotic process and restoring the intestinal barrier integrity, through the involvement of the CB1 receptor.