Valorisation of kitul, an overlooked food plant: Phenolic profiling of fruits and inflorescences and assessment of their effects on diabetes-related targets

Abstract

Caryota urens L. has long been valued as a traditional food, the edible fruits being eaten raw and the inflorescences commonly used on sweet sap and flour production. In the current work, the phenolic profile of methanol extracts obtained from the inflorescences and fruits was unveiled for the first time, nine caffeic acid derivatives being identified and quantified. Since kitul products have been reported for their antidiabetic properties, extracts radical scavenging activity and α-amylase, α-glucosidase and aldose reductase inhibitory activity were assessed. The inflorescences' extract was particularly active against yeast α-glucosidase (IC₅₀ = 1.53 μg/mL), acting through a non-competitive inhibitory mechanism. This activity was also observed in enzyme-enriched homogenates obtained from human Caco-2 cells (IC₅₀ = 64.75 µg/mL). Additionally, the extract obtained from the inflorescences showed no cytotoxicity on HepG2, AGS and Caco-2 cell lines. Our data suggest that C. urens inflorescences can support the development of new functional foods with α-glucosidase inhibitory activity.

Keywords: 3-O-Caffeoylquinic acid (PubChem CID1794427); 3-O-caffeoylshikimic acid (PubChem CID10131826); 4-O-caffeoylquinic acid (PubChem CID9798666); 4-O-caffeoylshikimic acid (PubChem CID49821869);; 5-O-caffeoylquinic acid (PubChem CID5280633); 5-O-caffeoylshikimic acid (PubChem CID5281762); Caffeic acid derivatives; Caryota urens; Diabetes; Functional foods; α-Glucosidase.