Metabolite Profiling and Bioactive Characterization of Stingless Bee Propolis Extracts: Implications for Functional Food Valorization

Propolis is a resinous matrix generated as a by-product of stingless bee apiculture. Its biochemical complexity makes it a candidate for agrifood waste valorization into functional food ingredients. This study evaluated the metabolite composition and in vitro biological activity of methanolic propolis extracts from four stingless bee species (Trigona clypearis, T. drescheri, T. sarawakensis, and T. terminata). Metabolomic profiling was conducted via Ultra High-Performance Liquid Chromatography-High Resolution Mass Spectrometry (UHPLC-HRMS). The functional health properties were quantified using the MTT cytotoxicity assay on the WiDr colorectal carcinoma cell line. Extracts from T. clypearis, T. drescheri, and T. terminata demonstrated bioactive suppression of cell viability with IC50 values of 230.8, 290.7, and 388.8 µg/mL, respectively. T. sarawakensis exhibited an IC50 > 1,000 µg/mL. Variable Importance in Projection (VIP) analysis identified 2,6-Dimethyl-y-pyrone, 5-OxoETE, 1,3,7-Trihydroxy-6-methoxy-4,5-diisoprenylxanthone, and ethyl oleate as primary differentiating metabolites across the extracts. The bioactivity of T. clypearis correlates with higher relative concentrations of ethyl oleate, betaine, and glycitein. The entomological origin of propolis determines its metabolic profile. Methanolic extracts from specific Trigona species exhibit measurable in vitro bioactivity, providing a biochemical basis for their valorization as functional food components