1 research outputs found
Anti-α-glucosidase and Anti-dipeptidyl Peptidase-IV Activities of Extracts and Purified Compounds from Vitis thunbergii var. <i>taiwaniana</i>
Ethanol extracts (Et) from the stem
(S) and leaf (L) of Vitis thunbergii var. <i>taiwaniana</i> (VTT) were used to investigate
yeast α-glucosidase and porcine
kidney dipeptidyl peptidase-IV (DPP-IV) inhibitory activities. Both
VTT-Et showed complete α-glucosidase inhibition at 0.1 mg/mL;
VTT-S-Et and VTT-L-Et showed 26 and 11% DPP-IV inhibition, respectively,
at 0.5 mg/mL. The VTT-Et interventions (20 and 50 mg/kg) resulted
in improvements in impaired glucose tolerance of diet-induced obese
rats. (+)-Hopeaphenol, (+)-vitisin A, and (−)-vitisin B were
isolated from the ethyl acetate fractions of S-Et and showed yeast
α-glucosidase inhibition (IC<sub>50</sub> = 18.30, 1.22, and
1.02 μM) and porcine kidney DPP-IV inhibition (IC<sub>50</sub> = 401, 90.75, and 15.3 μM) compared to acarbose (6.39 mM)
and sitagliptin (47.35 nM), respectively. Both (+)-vitisin A and (−)-vitisin
B showed mixed noncompetitive inhibition against yeast α-glucosidase
and porcine kidney DPP-IV, respectively. These results proposed that
VTT extracts might through inhibitions against α-glucosidase
and DPP-IV improve the impaired glucose tolerance in diet-induced
obese rats