Evaluation of betanin-encapsulated biopolymeric nanoparticles for antitumor activity via PI3K/Akt/mTOR signaling pathway

Cancer nanotheranostic components are useful in monitoring drug delivery and potency against tumor cells. Current chemotherapeutic agents exhibit severe side effects and requires the urgency for discovery of potent therapeutic nano-drugs. So, this study focuses on evaluating the antitumor activity of chitosan nanoparticles encapsulating betanin (CSNPs-BET) against breast cancer (MDA-MB-231) cells. CSNPs-BET were prepared using the ionic gelation method and characterized for their size, polydispersity index (PDI), zeta potential, and surface morphology. Antitumor activity of CSNPs-BET and standard drug, doxorubicin (DOX), was evaluated using MTT, cell migration and gene expression assays. The entrapment efficiency of CSNPs-BET was in the approximate range of 88–91%. The sustained in vitro betanin release pattern was observed under different conditions. Chitosan nanoparticles encapsulated with and without betanin reduced the cell viability in MDA-MB-231 cells with IC₅₀ values of 3.974 µg/mL and 7.994 µg/mL, respectively. Further, the treatment of MDA-MB-231 with CSNPs-BET with different concentrations significantly reduced the levels of PI3K (**P = 0.0016), Akt (**P = 0.0014) and mTOR (****P < 0.0001) as compared to control. Inhibition of PI3K and downstream molecules Akt and mTOR by CSNPs-BET resulted in cell proliferation inhibition and cell cycle arrest. Furthermore, CSNPs-BET treated MDA-MB-231 cells probed the significant two-dimensional migration of cells vs. control. Our study findings suggest that nano-scale formulation can improve systematic toxicity and cell proliferation inhibitory activity against cancer cells. In conclusion, the CSNPs-BET improved MDA-MB-231 cells death and depicts promising nano-therapy for breast cancer.