Effect of pepper and bismuth subsalicylate on gastric pain and surface hydrophobicity in the rat

Abstract

Background: The mechanism by which dietary pepper causes dyspepsia and epigastric pain is poorly understood, as is the ability of bismuth subsalicylate (BSS) to relieve these symptoms. Aim: To investigate the ability of black pepper, red pepper and BSS to affect gastric surface hydrophobicity and induce/relieve visceral pain in rat model systems. Methods: Fasted rats were administered intragastrically Vivonex containing varying concentrations of either black or red pepper (0-200 mg/mL) and gastric contact angles were read after 1-24 h. Some rats were post-treated with BSS (2.0-17.5 mg/mL) and contact angles were read after 2-18 h. To study pain sensitivity in rats treated with pepper/BSS, we compared tail-flick latencies after the application of radiant heat. Results: Both black and red pepper rapidly (< 1 h) induced a decrease in gastric surface hydrophobicity in a dose-dependent fashion. This spice-induced increase in surface wettability was long-lasting, could be enhanced in the presence of ethanol and reversed by post-treating the rats with BSS. Both black and red pepper induced an increase in pain sensitivity, consistent with the presence of gastric pain, which could also be reversed by post-treating the rats with BSS. Conclusion: Both black and red pepper may induce epigastric pain by removing the stomach's hydrophobic lining and activating intramucosal pain receptors. BSS may provide relief from postprandial dyspepsia by restoring the stomach's non-wettable properties.