Antidiabetic activity of Cassia javanica flowers through in vitro inhibitory evaluation of α-amylase, α-glucosidase and its antiglycation property.

Diabetes is a group of metabolic diseases that affect millions of people globally. Cassia javanica L. (Fabaceae), a tree native to Asia and present in Brazil, is used in folk medicine to treat diabetes and as a laxative. We evaluated the in vitro antidiabetic potential of ethanol extract, fractions and compounds isolated from the plant's flowers. The extract underwent liquid-liquid extraction with hexane, dichloromethane (FDCj) and ethyl acetate. FDCj showed activity against pancreatic α-amylase (IC50 0.3 μg mL-1, triticum: 0.2 μg mL-1), α-glucosidase (58.6%, acarbose: 98.6%) and strong antiglycation activity (>94.6%). Chromatography allowed the isolation of kaempferol, rhein, engeletin and afzelin, showing antiglycation activity (62.6-100%) and kaempferol stood out in inhibiting α-amylase (IC50 0.04 μg mL-1). The results corroborate the traditional use of C. javanica in the treatment of diabetes and are the first study with biological activity of compounds isolated from this species.