Antidiabetic and antioxidant potency evaluation of different fractions obtained from Cucumis prophetarum fruit

Cucumis prophetarum Linn. (Cucurbitaceae) fruit is used for inflammatory-related problems and is proved to be possessing anticancer and hepatoprotective effects.

The present investigation was to study the effect of different fractions of C. prophetarum on antidiabetic and antioxidant activity.

Aqueous crude extract (CE) of C. prophetarum fruits was fractionated into water soluble fraction 1 (F1), chloroform fraction 2 (F2), basic fraction 3 (F3), and neutral fraction 4 (F4) by acid-base extraction. CE and its fractions at different doses (0.02-0.1 mg/mL) were subjected to antidiabetic (α-amylase and α-glucosidase inhibition assays) and antioxidant (DPPH, superoxide radical scavenging (SO) and metal chelation) evaluation.

F1 exhibited effective antidiabetic activity (p < 0.05) with an IC50 value of 20.6 and 59.9 µg/mL. The activity decreased in the order of CE > F4 > F3 > F2, according to α-amylase assay, which were the same, with the exception of the rank order of F4 and CE, as the α-glucosidase assay. Furthermore, F1 (IC50 = 73 µg/mL) showed better reducing ability than CE >F4 >F2 > F3 (IC50 = 78-272 µg/mL), according to the DPPH assay. In SO and metal chelation assays, F1 showed the highest activity (IC50 = 101 and 147 µg/mL), respectively; the activity decreased in the order of CE >F4 >F3 > F2 (IC50 = 126-469 µg/mL) for SO and 194-944 µg/mL for metal chelation assay.

The results indicate that F1 possesses potent in vitro antidiabetic and antioxidant activities.