多谷物配方米多酚和肌醇提取物体外降血糖活性分析

In vitro Hypoglycemic Activities of Polyphenols and Inositol Extracts from Multi-grain Formula Rice

摘要:

谷物和豆类中含有丰富的降血糖活性物质。为了探究谷物和豆类中活性物质的降血糖机制，该研究对一款由绿豆、苦荞、黑米、血糯米、燕麦胚芽米和白米复配而成的多谷物配方米（Multi-grains Formula, MGF）中的降血糖活性物质进行了研究。对MGF进行高温空气流化和蒸煮后，提取其中多酚和肌醇物质得到富含多酚和肌醇提取液（Polyphenols and Inositol Extracts, PIEs），并评估PIEs 体外降血糖活性。LC-MS和HPLC分析表明，PIEs中主要的活性物质成分为芦丁、异牡荆素、山奈酚-3-O-芸香糖苷、槲皮素、肌-肌醇和D-手性肌醇。未经过高温空气流化但经蒸煮处理后的MGF PIEs对α-淀粉酶的抑制作用最强，其IC50值为17.07 mg/mL，而经过高温空气流化和蒸煮处理的MGF PIEs对α-葡萄糖苷酶的抑制活性最高，其IC50值为0.51 mg/mL。同时，无论蒸煮与否，高温空气流化后的MGF PIEs对Caco-2单层细胞葡萄糖转运具有更强的抑制作用，在60 min时细胞葡萄糖转移率低于50%，在120 min时低于65%。MGF PIE还表现出较强的抗糖基化率，最高达69.79%。相关性分析表明多酚和肌醇含量与降血糖活性之间的显著相关性，其中类黄酮含量表现出的相关性最强。该研究为谷物饮食在预防糖尿病代谢疾病方面提供了一定的理论依据。

Abstract:

Cereals and beans are abundant in hypoglycemic active substances. In order to explore the hypoglycemic mechanism of active substances in cereals and beans, the hypoglycemic active substances in a multi-grains formula (MGF) rice composed of mung bean, Tartary buckwheat, black rice, black sticky rice, oat germ rice and white rice were investigated in this study. Polyphenols and inositol extracts (PIEs) were obtained by extracting polyphenols and inositol from the MGF after hightemperature air fluidization (HTAF) and steaming, and the in vitro hypoglycemic activity of PIEs was evaluated. LC-MS and HPLC analyses revealed that the main active substances in PIEs were rutin, isovitexin, kaempferol-3-O-rutinoside, quercetin, myo-inositol and D-chiro-inositol. The MGF PIEs subjected to steaming in the absence of high-temperature air fluidization exhibited the strongest inhibitory effect against α-amylase, with the IC50 value being 17.07 mg/mL, whilst the MGF PIEs after high-temperature air fluidization and steaming exhibited the highest inhibitory activity on α-glucosidase, with the IC50 value being 0.51 mg/mL. Meanwhile, in the absence or presence of steaming, the MGF PIEs subjected to HTAF exhibited a stronger inhibitory effect on glucose transport in a Caco-2 cell monolayer with a cell glucose transfer rate lower than 50% at the 60th min and lower than 65% at the 120th min. Furthermore, MGF PIEs showed a strong anti-glycosylation effect, with the highest anti-glycosylation rate up to 69.79%. Correlation analysis revealed a significant correlation between the polyphenols and inositol contents, and the hypoglycemic activity, with the flavonoids content exhibiting the strongest correlation. This study provides a theoretical basis for the application of cereal diet in preventing diabetic metabolic diseases.