ソバペプチドはDPP-Ⅳ活性を阻害する

抄録

Food proteins and their constituent peptides can impart huge health benefits in addition to their nutritional attributes. Buckwheat flour hydrolysate was studied for its ability to inhibit the activity of dipeptidyl peptidase-IV (DPP-IV); as shown in in-vitro assays, inhibition of this enzyme can be used for the treatment of type II diabetes. Buckwheat flour hydrolysate prepared with Alcalase^® and Flavourzyme^® showed greater DPP-IV inhibitory activity than the control sample. Buckwheat flour hydrolysate was purified using successive column chromatography. The obtained Val–Pro–Leu (VPL) and Val–Pro–Ile (VPI) were identified using LC-Q-TOF. VPL has been used as a commercial inhibitor of DPP-IV, named Diprotin B. VPI, with an IC₅₀ of 18.0 ± 2.4 μM, exhibited approximately 10-fold greater inhibition of DPP-IV than VPL (200.5 ± 7.5 μM). The DPP-IV inhibitory activity of VPI was maintained at approximately 95% after the in vitro gastrointestinal digestion process. These results suggest that the buckwheat flour hydrolysate has potential value in functional food formulations.