Protective effect of cannabinoids on gastric mucosal lesions induced by water immersion restrain stress in rats

This study aimed to determine the impact of cannabinoid agonists and antagonists on the mucosal lesion progress in the stomach induced by water-immersion restraint stress (WIRS).    Rats subjected to WIRS for 4 hr were treated with Dimethyl sulfoxide (DMSO), CBR1 agonist (NADA 1 mg/kg), CBR1 antagonist (Rimonabant 1 mg/kg), CBR2 agonist (GW405833 1 mg/kg) or CBR2 antagonist (AM630 1 mg/kg SC) 30 min before WIRS. Microscopic lesions, oxidative stress, inflammatory cytokines biomarkers, and (Myeloperoxidase) MPO in gastric tissues were determined. Results indicated development of severe gastric lesions with a substantial increase in the contents of (nitric oxide) NO, (malondialdehyde) MDA,  (interleukin-1 beta) IL-1β, MPO, (tumor necrosis factor-alpha) TNF-α, and a significant fall in the content of GSH and the activity of  PON-1 after WIRS. Treatment with NADA and AM630 protected gastric tissues against ulcers as demonstrated by a decrease in the contents of MDA, TNF-α, MPO, and IL-1β along with an increase in the content of PON-1 activity and GSH in the stomach tissues. On the other hand, treatment with SR141716A or GW405833 showed no protective effects on ulcers development. It seems that cannabinoids exert their antioxidant potential and anti-inflammatory effects against  WIRS-induced gastric ulcers by activation of CB1R.