Casein-Based Nanocarriers for Myricetin Delivery: Enhancement of Apoptosis and Inhibition of Angiogenesis in Gastric Adenocarcinoma Cells

• Casein-based nanocarriers were successfully developed to enhance myricetin solubility, stability, and cellular delivery. • Myricetin nanoencapsulation significantly increased the cytotoxicity against AGS gastric cancer cells in a dose-dependent manner while showing no cytotoxic potential against normal cells. • M-CNPs induced pronounced apoptosis confirmed by AO/PI staining, cell-cycle arrest, Annexin V flow cytometry, and caspase-associated gene activation. • M-CNPs markedly inhibited angiogenesis in the CAM assay, accompanied by significant VEGFR downregulation. The challenges of conventional chemotherapy's side effects highlight the need for new treatments. Phytochemicals like myricetin show promise in cancer therapy, but their bioavailability is limited due to poor solubility and rapid clearance, requiring nanocarriers for improved delivery. This study focused on synthesizing and characterizing myricetin-encapsulated casein nanoparticles (M-CNPs) and evaluating their effects on angiogenesis and pro-apoptotic activities in human gastric adenocarcinoma (AGS) cells. M-CNPs were characterized using Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). Cytotoxicity was assessed via MTT assay, and cell cycle and apoptosis studies were conducted using flow cytometry and AO/PI staining. Key gene expression, including Caspase 3, Caspase 9, and MMP-2, was analyzed by real-time PCR. The anti-angiogenic effects of M-CNPs were evaluated using the chick chorioallantoic membrane (CAM) assay. The results showed that M-CNPs are spherical, averaging 75.38 nm in size with a polydispersity index of 0.31, indicating uniformity in particle distribution. MTT analysis revealed a dose-dependent reduction in AGS cell viability, while AO/PI staining and flow cytometry confirmed that M-CNPs induce apoptosis and cell cycle arrest. Gene expression analysis indicated upregulation of Caspase 3 (p>0.05) and downregulation of MMP-2 (p≤0.05). The CAM assay demonstrated significant anti-angiogenic effects and downregulated VEGFR expression (p≤0.05). These findings suggest that M-CNPs could be an effective cancer treatment by enhancing myricetin bioavailability and targeting multiple pathways.