Morin treatment modulates MAPK/Nrf2/STAT-3 pathways, improving viability in H. pylori-infected gastric cells

Helicobacter pylori infection is a primary risk factor for gastric cancer (GC) and chronic gastritis, yet its precise molecular mechanisms remain incompletely understood. Current eradication therapies face increasing antimicrobial resistance, necessitating novel therapeutic strategies. Oxidative stress and inflammation in gastric epithelial cells (GECs) are critical drivers of H. pylori-associated pathology. The MAPK/Nrf2/STAT-3 pathways are central to cellular defense against stress and inflammation, making their modulation a promising approach to mitigate H. pylori-induced damage.

This in vitro study investigated the effects of morin on H. pylori-infected human gastric epithelial cells (GES-1). Cells were infected with H. pylori (ATCC 49503, MOI 100:1) and subsequently treated with 40 µM morin for 24 hours. Key outcomes assessed included cell viability via MTT assay, intracellular ROS production using DCFH-DA, and oxidative DNA damage via comet assay. Biochemical assays quantified glutathione (GSH) and malondialdehyde (MDA) levels. Protein expression of MAPK/Nrf2/STAT-3 pathway members was analyzed by Western blot, and gene expression by RT-PCR. Molecular docking was also performed to predict morin's binding affinity to pathway proteins. The study used n=3 biological replicates per group, applying a Q=0.25 false discovery rate threshold for hypothesis generation.

Morin treatment significantly improved cell viability and reduced markers of oxidative stress in H. pylori-infected GES-1 cells. Compared to infected untreated controls, morin-treated cultures showed:

Higher MTT-detectable viability (85% vs. 45%; q=0.042)

Intracellular ROS levels were significantly lower (q=0.021), accompanied by reduced oxidative DNA damage (q=0.018). Biochemical analysis revealed higher GSH levels and lower MDA levels in morin-treated cells. Mechanistically, morin treatment led to lower phosphorylation levels of several MAPK family members, including ERK, JNK, and p38, as well as PI3K/AKT and STAT3/EGFR proteins. Conversely, total Nrf2 protein expression was higher, with a concomitant upregulation of HMOX1 and NQO1 mRNA. Molecular docking predicted binding interactions between morin and MAPK, STAT3, and Nrf2 pathway proteins, though these computational findings require experimental validation.