Metabolite characterization and evaluation of the antioxidant, cytotoxic, and immunomodulatory effects of tiger nuts (Cyperus esculentus L.)

The increasing prevalence of non-communicable diseases (NCDs) and the global demand for sustainable nutritional sources highlight the need to explore underutilized food plants with functional properties. In this context, Cyperus esculentus L. var. sativus (tiger nut) is a promising tuber due to its nutritional richness and bioactive potential. However, studies associating its metabolomic profile and biological activities remain limited. This study aimed to characterize the nutritional and metabolomic composition of tiger nuts cultivated in Brazil and to evaluate their antioxidant, cytotoxic, and immunomodulatory activities in vitro. Proximate composition revealed high levels of carbohydrates (34.89%), lipids (26.73%), and dietary fiber (23.12%), with moderate protein content (6.04%). Total phenolic content reached 239.46 ± 18.38 mg GAE g -1 of extract. HPLC-ESI-MS/MS analysis revealed 35 annotated compounds, including phenolic acids, amino acids, and lipid-derived metabolites, with a predominance of oleic, linoleic, palmitic, and stearic acids. The extract exhibited strong antioxidant activity with concentration-dependent radical scavenging effects (IC 50 = 2.05 ± 0.10 mg mL -1 for ABTS and 3.77 ± 0.73 mg mL -1 for DPPH). Biological assays demonstrated low cytotoxicity in THP-1-derived macrophages and HT-29 cells, while VERO cells were more sensitive at higher concentrations. The extract modulated reactive oxygen species production without inducing oxidative stress and increased IL-10 levels and regulation of IL-6, IL-1β, and IL-8 depending on cell type and concentration. These findings indicate that tiger nuts have potential as a functional food ingredient for the prevention and management of NCD-related mechanisms.