Phytochemical characterization and bioactivity of Chamaecrista nomame (Siebold) H. Ohashi: bridging korean ethnic food tradition and modern functional science

Abstract Chamaecrista nomame (Siebold) H. Ohashi ( C. nomame ) has a long-standing history of consumption in East Asia, particularly in Korea and Japan, as a traditional functional tea. Traditionally, the aerial parts are dried, roasted, and prepared as a hot-water infusion, serving as a conventional daily beverage valued for its health-promoting properties. This study aimed to scientifically evaluate the potential anti-obesity, anti-diabetic, and anti-inflammatory activities of C. nomame extracts, bridging its ethnobotanical use with modern functional science. Hot water and 40% ethanol extracts were prepared, and their bioactivities were assessed through pancreatic lipase, α-glucosidase, and nitrite scavenging assays. Although both extracts exhibited bioactivities, the 40% ethanol extract consistently demonstrated significantly higher potency than the hot-water extract across all assays. Notably, within the in vitro enzyme inhibition model, the 40% ethanol extract (200 µg/mL) exhibited over 90% inhibition of α-glucosidase, demonstrating a substantial inhibitory capacity. The extract also demonstrated substantial lipase inhibitory and nitrite scavenging activities, suggesting its potential role in regulating lipid digestion and inflammatory responses. Molecular docking analysis further supported these findings, revealing that luteolin, a major constituent, possessed favorable binding affinities toward α-glucosidase, lipase, and inducible nitric oxide synthase, with the strongest interaction observed for α-glucosidase (− 8.4 kcal/mol). These results provide scientific evidence supporting the traditional use of C. nomame as a Korean ethnic food resource and highlight its potential as a natural functional ingredient for the management of metabolic and inflammatory disorders.