Daidzein nanosuspension combined with 5-fluorouracil induces apoptosis and alleviate inflammation in Caco-2 colorectal adenocarcinoma cells

Colorectal cancer is the third most common malignancy worldwide and the second most common cause of cancer deaths. Alternative treatment strategies, including nano-based formulations, show remarkable promise to improve the efficacy of chemotherapy. The soy isoflavone daidzein has attracted attention for its anti-cancer activity. The aim of this study was to investigate the effects of daidzein nanosuspension with 5-fluorouracil on apoptosis and inflammation induced in human colorectal adenocarcinoma cells (Caco-2). Cytotoxicity, total antioxidant/oxidant status (TAS, TOS), and the expression of proteins associated with apoptosis and inflammation were analyzed by the MTT, ELISA and qRT-PCR, respectively. Daidzein nanosuspension showed a strong cytotoxicity (IC₅₀ = 240.3 μM for daidzein, IC₅₀ = 35.34 μM for daidzein nanosuspension) compared to daidzein. The combination of 5-fluorouracil and daidzein nanosuspension treatment showed a synergistic antiproliferative effect without increasing oxidative stress. The combination showed a significant increase in p53 levels and a significant decrease in Bcl-2, IL-6, TNF-α and MMP-9 levels. qRT-PCR results showed that the combinations of daidzein and DZ-NS with 5-FU regulated these parameters in Caco-2 cells. In conclusion, daidzein nanosuspension with 5-fluorouracil treatment reduced the proliferation and inflammation and increased apoptosis of Caco-2 cells without oxidative stress. The current study shows that this combination also elucidates several signaling pathways, including effects on oxidative stress, apoptosis, and inflammation. The integration of this nanotechnology approach into traditional chemotherapy will form the basis of an innovative strategy.