Polytechnic of Coimbra, Coimbra Agriculture School, 3045-601 Coimbra, Portugal.
Faculty of Pharmacy, University of Coimbra, Azinhaga de Santa Comba, 3000-548 Coimbra, Portugal.
Molecules. 2022 Oct 28;27(21):7338. doi: 10.3390/molecules27217338.
Dyslipidemias are one of the risk factors for cardiovascular diseases, the leading cause of death and hospitalization worldwide. One way to control cholesterol levels is to control the exogenous cholesterol intake in the body. Natural polyphenolic compounds, namely theaflavins from plant extracts such as black tea, showed the ability to inhibit the formation of the micellar structure, essential for the absorption of cholesterol in the intestine. There are several methodologies to determine this effect, many of which are expensive and time-consuming. Due to these facts, the main purposes of this work were to optimize an inexpensive colorimetric method to study, in vitro, the micellar solubility of cholesterol and applied it to plant extracts. In this work, leaf extracts, its phenolic fractions, and flavonoids were evaluated. The non-delipidified infusion (CcI) obtained a maximum percentage of micelle destruction of 59.22% for a concentration of 50 μg/mL and the delipidified infusion (CcdI) obtained a maximum percentage of micelle destruction of 58.01% for a concentration of 200 μg/mL. In the case of the fraction of phenolic acids (CcPAs), 23.85% of maximum micellar destruction was recorded for the concentration of 100 μg/mL, while for the fraction of flavonoids (CcF), the micellar destruction was 92.74% at 1 μg/mL, and for the tannin fraction (CcT) of 99.45% at 25 μg/mL. Luteolin presented a percentage of micelle destruction of 94.83% in the concentration of 1 ng/mL, followed by luteolin-7--glucoside with 93.71% and luteo-lin-6--glucoside with 91.26% at the concentrations of 25 ng/mL and 50 ng/mL, respectively. These results suggest the capability of polyphenols from to prevent the cholesterol absorption in the gut by micellar destruction, and its contribution for cholesterol-lowering activity.
血脂异常是心血管疾病的危险因素之一，也是全球范围内导致死亡和住院的主要原因。控制胆固醇水平的一种方法是控制体内外源性胆固醇的摄入。天然多酚化合物，即来自植物提取物（如红茶）的茶黄素，显示出抑制胶束结构形成的能力，而胶束结构对于胆固醇在肠道中的吸收至关重要。有几种方法可以确定这种效果，其中许多方法既昂贵又耗时。由于这些事实，这项工作的主要目的是优化一种廉价的比色法来研究胆固醇的胶束溶解度，并将其应用于植物提取物。在这项工作中，评估了叶提取物、其酚类部分和类黄酮。非脱脂蛋白浸出液（CcI）在 50μg/mL 浓度下获得了 59.22%的最大胶束破坏百分比，脱脂蛋白浸出液（CcdI）在 200μg/mL 浓度下获得了 58.01%的最大胶束破坏百分比。对于酚酸部分（CcPAs），在 100μg/mL 浓度下记录到最大胶束破坏的 23.85%，而对于黄酮部分（CcF），在 1μg/mL 时胶束破坏为 92.74%，对于单宁部分（CcT）则为 25μg/mL 时的 99.45%。木犀草素在 1ng/mL 浓度下的胶束破坏百分比为 94.83%，其次是木犀草素-7--葡萄糖苷，在 25ng/mL 和 50ng/mL 浓度下分别为 93.71%和 91.26%，木犀草素-6--葡萄糖苷。这些结果表明，来自 的多酚具有通过胶束破坏防止胆固醇在肠道吸收的能力，并且对降低胆固醇活性有贡献。
