A new exploration of Dregea volubilis flowers: Focusing on antioxidant and antidiabetic properties

Flowers of Dregea volubilis (Family: Apocynaceae) are commonly consumed as seasonal vegetable in India but not yet evaluated for its health beneficiary effects. In the present study, the hydroalcoholic flower extract of D. volubilis (DVHA) was evaluated for antioxidant and antidiabetic activities in vitro. With high contents of phenolics (39.82 ± 1.22 mg GAE/g) and flavonoids (27.50 ± 0.87 mg QE/g), DVHA showed potential antioxidant activity for scavenging DPPH radical (IC50, 237.86 ± 1.05 μg/mL), hydroxyl radical (IC50, 170.67 ± 0.98 μg/mL), superoxide radical (IC50, 219.07 ± 1.25 μg/mL), nitric oxide radical (IC50, 196.38 ± 1.49 μg/mL) and ferric reducing antioxidant power (176.47 ± 3.18 μmol Fe2 +/g), total antioxidant capacity (39.68 ± 1.62 mg GAE/g) along with remarkable inhibitory effects on α-glucosidase (IC50, 3780.09 ± 21.19 μg/mL) and α-amylase (IC50, 360.68 ± 1.26 μg/mL). The characterization of the extract was evaluated by FT-IR and UHPLC analysis. The liquid chromatography study led to the identification and quantification of six compounds viz. gallic acid (412.36 ± 2.29 μg/g), ferulic acid (162.72 ± 0.89 μg/g), rutin (386.25 ± 2.00 μg/g), ellagic acid (208.8 ± 2.00 μg/g), quercetin (306.85 ± 2.24 μg/g) and cinnamic acid (213.71 ± 2.14 μg/g). The results explain the therapeutic potentialities of D. volubilis flowers as a potential source of natural antioxidants for use in food and pharmaceutical industries along with their possible applications to control postprandial hyperglycaemia.