Amaranth beverage digestion generates bioactive peptides with preliminary antiproliferative activity

Introduction: Dietary proteins from sustainable plant-based sources are important for addressing global nutritional needs while reducing the environmental impact of animal-derived proteins. Amaranth, a protein-rich pseudocereal, represents a promising alternative; however, the contribution of digestion-derived peptides to its biological effects remains underexplored. Materials and methods: This study aimed to evaluate peptides generated by simulated gastrointestinal digestion (SGD) of an amaranth-based beverage (AB). Protein hydrolysis and peptide generation were assessed using proximate analysis, degree of hydrolysis, and electrophoretic and chromatographic techniques. Cytotoxicity (neutral red assay) and apoptosis (Annexin V/propidium iodide) were evaluated in Caco-2 TC7 cells. Additionally, complementary in silico digestion and peptide prediction analyses were performed. Results: SGD resulted in extensive protein hydrolysis, with peptides predominantly <3 kDa. None of the samples reduced cell viability below 50% within the tested range (0.05–1.8 mg/ml). However, the <3 kDa fraction increased the proportion of apoptotic cell levels, whereas SGD-AB and the >3 kDa fraction were associated with predominantly non-apoptotic cell death responses. In silico analysis predicted the release of short peptides (<10 residues) with sequence similarity to peptides previously associated with cellular responses in cancer cell models. Conclusions: These results provide preliminary in vitro evidence suggesting that digestion-derived peptides from amaranth proteins are associated with cellular responses in a Caco-2 TC7 model. Peptide size appears to influence biological activity, supporting further evaluation in other biologically relevant models.