Unravelling the In Vitro and In Vivo Anti-Helicobacter pylori Effect of Delphinidin-3-O-Glucoside Rich Extract from Pomegranate Exocarp: Enhancing Autophagy and Downregulating TNF-α and COX2

Abstract

Fruits containing antioxidants, e.g., anthocyanins, exhibit antimicrobial activities. The emergence of drug resistance represents a major challenge in eradicating H. pylori. The current study aims to explore the effect of pomegranate exocarp anthocyanin methanol extract (PEAME) against H. pylori isolates recovered from antral gastric biopsies. The UPLC-PDA-MS/MS and 1H NMR analyses indicated delphinidin-3-O-glucoside as the major anthocyanin in the extract. The PEAME showed activity against all tested resistant isolates in vitro recording minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 128 and 256 µg/mL, respectively. In vivo investigation included evaluation of the rat gastric mucosa for malondialdehyde (MDA), catalase activity, COX2, TNF-α, and key autophagy gene expression. The combination of pomegranate with metronidazole markedly reduced the viable count of H. pylori and the level of COX2, with alleviation of H. pylori-induced inflammation and oxidative stress (reduction of MDA, p-value < 0.001; and increase in catalase activity, p-value < 0.001). Autophagy gene expression was significantly upregulated upon treatment, whereas TNF-α was downregulated. In conclusion, we comprehensively assessed the effect of PEAME against H. pylori isolates, suggesting its potential in combination with metronidazole for eradication of this pathogen. The beneficial effect of PEAME may be attributed to its ability to enhance autophagy.