Co-Exposure to Lunasin and Other Drugs as a Potential Chemopreventive Strategy Against Breast and Colon Cancers: A Review.

More than 20 years after the discovery of lunasin, a clear shift in lunasin research is observable-from an initial focus on its direct in vitro anticancer effects toward strategies aimed at improving its bioavailability and repositioning it as a potential adjunct in cancer therapy. Lunasin, a soy-derived bioactive peptide, has been extensively studied for its antineoplastic properties. However, its limited oral bioavailability restrains its efficacy in clinical trials. Therefore, recent research on lunasin points towards the possibility of using it as an adjunct in cancer treatment, rather than as a stand-alone nutraceutical in humans. In preclinical models, in vitro and in vivo, lunasin can enhance the effects of standard anticancer drugs in breast and colon cancers. Research suggests that lunasin can potentiate the effects of drugs, such as tamoxifen, aspirin, cisplatin, and oxaliplatin, by sensitizing cancer cells to apoptosis, modulating cell cycle progression, reducing metastatic potential, and attenuating drug-resistance pathways, including PI3K/Akt, FAK/MAPK1/NF-κB, and integrin-mediated signaling. In combination with those drugs, lunasin exerts significant anticancer effects at concentrations substantially lower than those proven as effective in monotherapy, suggesting a potential role in dose reduction in conventional agents and, subsequently, mitigation of their adverse effects. Although the enhanced effect of those combinations has been shown in preclinical models, there is a distinct lack of human clinical trials in this matter. Available evidence supports a promising concept of lunasin as a molecular "priming" agent that might complement cytotoxic therapies rather than replace them. This combination-oriented paradigm may represent a shift in lunasin research and offer a novel direction for the use of bioactive peptides in precision oncology; however, further studies exploring this possibility, including human clinical trials, are needed to elucidate lunasin's role in nutraceutical-assisted cancer therapy.