A practical approach to control glycemia in diabetes is to use plant natural products that delay hydrolysis of complex sugars and promote the diminution of the release of glucosyl units into the blood plasma. Polyphenolics have been described as being effective in inhibiting amylases and α-glucosidases. Grape pomace is an important sub product of the wine industry, still rich in many compounds such as polyphenolics. In this context, the purpose of this study was to search for possible effects of a grape pomace extract on salivary and pancreatic α-amylases and α-glucosidase, as well as on intestinal glucose absorption. The Merlot grape pomace extract (MGPE) was prepared using a hydroalcoholic mixture (40% ethanol + 60% water). In vitro inhibition was quantified using potato starch (for amylases) and maltose (for α-glucosidase) as substrates. In vivo inhibition was evaluated by running starch and maltose tolerance tests in rats with or without administration of MGPE. Ranking of the extract compounds for its affinity to the α-amylases was accomplished by computer simulations using three different programs. Both α-amylases, pancreatic and salivary, were inhibited by the MGPE. No inhibition on α-glucosidase, however, was detected. The IC₅₀ values were 90 ± 10 μg/mL and 143 ± 15 μg/mL for salivary and pancreatic amylases, respectively. Kinetically this inhibition showed a complex pattern, with multiple binding of the extract constituents to the enzymes. Furthermore, the in silico docking simulations indicated that several phenolic substances, e.g., peonidin-3-O-acetylglucoside, quercetin-3-O-glucuronide and isorhamnetin-3-O-glucoside, besides catechin, were the most likely polyphenols responsible for the α-amylase inhibition caused by MGPE. The hyperglycemic burst, an usual phenomenon that follows starch administration, was substantially inhibited by the MGPE. Our results suggest that the MGPE can be adequate for maintaining normal blood levels after food ingestion.

控制糖尿病中血糖的一种实用方法是使用植物天然产物，该产物可延缓复合糖的水解并促进减少葡萄糖基单元向血浆中的释放。多酚已被证明可有效抑制淀粉酶和α-葡萄糖苷酶。葡萄渣是葡萄酒工业的重要副产品，仍然富含多种化合物，例如多酚。在这种情况下，本研究的目的是寻找葡萄渣提取物对唾液和胰α-淀粉酶和α-葡萄糖苷酶以及肠道葡萄糖吸收的可能作用。使用水醇混合物（40％乙醇+ 60％水）制备Merlot葡萄渣提取物（MGPE）。体外抑制作用以马铃薯淀粉（淀粉酶）和麦芽糖（α-葡萄糖苷酶）为底物进行定量。通过在给予或不给予MGPE的大鼠中进行淀粉和麦芽糖耐受性测试来评估体内抑制作用。通过使用三种不同程序的计算机模拟，完成了提取化合物对α-淀粉酶亲和力的排名。MGPE抑制胰腺和唾液的α-淀粉酶。然而，未检测到对α-葡萄糖苷酶的抑制。唾液和胰淀粉酶的IC ₅₀值分别为90±10μg/ mL和143±15μg/ mL。从动力学上讲，这种抑制表现出复杂的模式，提取物成分与酶具有多重结合。此外，计算机对接模拟表明，除了儿茶素外，几种酚类物质，例如peonidin-3- O-乙酰葡萄糖苷，槲皮素-3- O-葡萄糖醛酸苷和异鼠李素-3- O-葡萄糖苷是引起α-淀粉酶抑制的最可能多酚由MGPE。MGPE基本上抑制了淀粉摄入后的高血糖爆发现象。我们的结果表明，MGPE足以保持食物摄入后的正常血液水平。