Quercetin Suppresses Gastric Cancer Progression Through Inhibition of Cell Proliferation, Migration, and Tumor Growth

Background and Objectives: Quercetin, a widely distributed flavonoid in medicinal plants, exhibits potent anti-cancer effects across various malignancies. However, its pharmacological activity in gastric cancer remains insufficiently characterized. To investigate the anti-proliferative, pro-apoptotic, anti-migration, and anti-tumor effects of Quercetin against gastric cancer using in vitro (human gastric adenocarcinoma cell line [AGS], human gastric carcinoma cell line [MKN-45]) and in vivo xenograft models. Materials and Methods: Cell viability, apoptosis, migration, and invasion assays were performed following Quercetin treatment (0–200 μM). A nude mouse xenograft model was induced by subcutaneous inoculation of MKN-45 cells, followed by oral Quercetin treatment (50 or 100 mg/kg/day). Tumor growth, inflammatory cytokines, and oxidative stress biomarkers were evaluated. Results: Quercetin reduced the viability of AGS and MKN-45 cells in a dose-dependent manner, with IC50 values of 46.3 and 52.7 μM, respectively. Apoptosis significantly increased under Quercetin treatment, while migration and invasion were markedly inhibited. In vivo, Quercetin suppressed tumor growth by up to 57.3% compared with controls and significantly reduced serum tumor necrosis factor-alpha, interleukin-6, interleukin-1β, and improved oxidative stress biomarkers. Conclusion: Quercetin exerts strong therapeutic potential against gastric cancer by inhibiting proliferation, migration, and tumor progression, supporting its development as a natural product-based anti-cancer candidate.