Isolation of Antidiabetic Principle from Fruit Rinds ofPunica granatum

Abstract

Present study was aimed to isolate and evaluate the antidiabetic activity of phytoconstituents from fruit rinds ofPunica granatum. With the above objectives Valoneic acid dilactone (VAD) was isolated from methanolic fruit rind extracts ofPunica granatum(MEPG) and confirmed by1H-NMR,13C-NMR, and mass spectral data. Antidiabetic activity was evaluated by Aldose reductase,α-amylase and PTP1B inhibition assays inin vitroand Alloxan-induced diabetes in rats was used as anin vivomodel. In bioactivity studies, MEPG and VAD have showed potent antidiabetic activity inα-amylase, aldose reductase, and PTP1B inhibition assays with IC50values of 1.02, 2.050, 26.25 μg/mL and 0.284, 0.788, 12.41 μg/mL, respectively. Furthermore, in alloxan-induced diabetes model MEPG (200 and 400 mg/kg, p.o.) and VAD (10, 25, and 50 mg/kg, p.o.) have showed significant and dose dependent antidiabetic activity by maintaining the blood glucose levels within the normal limits. Inline with the biochemical findings histopathology of MEPG (200 and 400 mg/kg, p.o.), VAD (10, 25, and 50 mg/kg, p.o.), and glibenclamide (10 mg/kg, p.o.) treated animals showed significant protection against alloxan-induced pancreatic tissue damage. These findings suggest that MEPG and VAD possess significant antidiabetic activity in bothin vitroandin vivomodels.