Kato-Schwartz Camila Gabriel, Corrêa Rúbia Carvalho Gomes, de Souza Lima Diego, de Sá-Nakanishi Anacharis Babeto, de Almeida Gonçalves Geferson, Seixas Flavio Augusto Vicente, Haminiuk Charles W I, Barros Lillian, Ferreira Isabel C F R, Bracht Adelar, Peralta Rosane Marina
Department of Biochemistry, and Post-graduate Program of Food Science, State University of Maringa, Parana 87020-900, Brazil.
Program of Master in Science, Technology and Food Safety, Cesumar Institute of Science Technology and Innovation (ICETI), University Center of Maringa (UniCesumar), Parana 87050-390, Brazil; Centro de Investigação de Montanha (CIMO), Instituto Politécnico de Bragança, Campus de Santa Apolónia, 5300-253 Bragança, Portugal.
Food Res Int. 2020 Nov;137:109462. doi: 10.1016/j.foodres.2020.109462. Epub 2020 Jun 20.
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 IC 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.
控制糖尿病患者血糖的一种实用方法是使用植物天然产物，这些产物可延缓复合糖的水解，并促进葡萄糖基单元向血浆中的释放减少。多酚类物质已被描述为对抑制淀粉酶和α-葡萄糖苷酶有效。葡萄皮渣是葡萄酒行业的一种重要副产品，仍富含许多化合物，如多酚类物质。在此背景下，本研究的目的是探究葡萄皮渣提取物对唾液淀粉酶、胰腺淀粉酶和α-葡萄糖苷酶以及肠道葡萄糖吸收的可能影响。梅洛葡萄皮渣提取物（MGPE）采用水醇混合物（40%乙醇 + 60%水）制备。以马铃薯淀粉（用于淀粉酶）和麦芽糖（用于α-葡萄糖苷酶）为底物，对体外抑制作用进行定量。通过在给予或不给予MGPE的大鼠中进行淀粉和麦芽糖耐量试验，评估体内抑制作用。使用三个不同程序通过计算机模拟完成提取物化合物对α-淀粉酶亲和力的排序。MGPE对胰腺淀粉酶和唾液淀粉酶均有抑制作用。然而，未检测到对α-葡萄糖苷酶的抑制作用。唾液淀粉酶和胰腺淀粉酶的IC值分别为90±10μg/mL和143±15μg/mL。从动力学角度来看，这种抑制呈现出复杂的模式，提取物成分与酶存在多重结合。此外，计算机模拟对接表明，除儿茶素外，几种酚类物质，如芍药色素-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MGPE引起α-淀粉酶抑制作用最可能的多酚类物质。淀粉摄入后常见的高血糖峰值被MGPE显著抑制。我们的结果表明，MGPE足以在进食后维持正常血糖水平。
