Prebiotic and antioxidant effects of the extracts from fruits and flowers of Cereus hildmannianus

Cereus hildmannianus is a species with various nutritional and medicinal properties; however, the fruits and flowers have scarcely been explored. In this regard, the study investigated the bioproduction of total sugar content (TSC), total phenolic content (TPC), and total flavonoid content (TFC), antioxidant [DPPH - 2,2-diphenyl-1-picrylhydrazyl and ABTS - 2,2'-azino-bis-(-3-ethylbenzothiazoline-6-sulfonic acid)], iron chelation, and prebiotic activities of methanolic extracts from fruits (epicarps - EE, mesocarps - ME) and flowers (sepals - SE, petals - PE) of C. hildmannianus. The chemical profiles of the extracts were determined by ultra-high-performance liquid chromatography coupled with mass spectrometry. The highest accumulations of TSC were observed in the ME (64%), while the SE also had a high TFC (17 µg QE per mg DW; QE - quercetin equivalents, DW - dry weight) and the EE had a high TPC (646 µg GAE per mg DW; GAE - gallic acid equivalents). A total of 24 compounds (phenolic and organic acids; and glycosylated flavonoids) were putatively identified. The greatest antioxidant activities were obtained with the PE (DPPH: 199 µmol Trolox per mg DW; and ABTS: 59 µmol Trolox per mg DW), while the highest prebiotic effect was obtained with ME and EE regarding both fermentability and production of lactic and acetic acids by multiple species of Lactobacillus and Bifidobacterium. These promising results of bioactive compounds in the fruits and flowers of C. hildmannianus have potential applications for food and pharmaceutical purposes.