Abstract:
Red yeast rice dietary supplements have been proven to ameliorate hyperglycemia, but the mechanism was unclear. In this work, ankaflavin (AK) and monascin (MS), as typical pigments derived from red yeast rice, were found to exert noteworthy inhibitory ability against α-glucosidase, with an IC50 of 126.5 ± 2.5 and 302.6 ± 2.5 μM, respectively, compared with acarbose (IC50 = 341.3 ± 13.6 μM). They also exhibited mixed-type inhibition of α-glucosidase in vitro and caused fluorescence quenching through the static-quenching process. Molecular-docking studies indicated that AK and MS bind to amino acid residues outside the catalytic center, which induces structural changes in the enzyme, thus influencing its catalytic activity. The anti-glycation ability of Monascus-fermented products was evaluated, and they exhibited a high inhibition rate of 87.1% in fluorescent advanced glycation end-product formation at a concentration of 0.2 mg mL-1, while aminoguanidine showed a rate of 75.7% at the same concentration. These results will be significant in broadening the application scope of Monascus pigments, especially AK and MS, in treating type 2 diabetes.
摘要:
红曲米膳食补充剂已被证明可以改善高血糖症,但机制尚不清楚。在这项工作中,安卡夫拉芬(AK)和单层植物(MS),作为来自红曲米的典型色素,发现对α-葡萄糖苷酶具有显著的抑制能力,IC50为126.5±2.5和302.6±2.5μM,分别,与阿卡波糖相比(IC50=341.3±13.6μM)。它们还在体外表现出对α-葡萄糖苷酶的混合型抑制,并通过静态猝灭过程引起荧光猝灭。分子对接研究表明,AK和MS与催化中心外的氨基酸残基结合,诱导酶的结构变化,从而影响其催化活性。对红曲发酵产物的抗糖基化能力进行了评价,在0.2mgmL-1的浓度下,它们对荧光高级糖基化终产物形成的抑制率为87.1%,而氨基胍在相同浓度下的抑制率为75.7%。这些结果对拓宽红曲色素的应用范围具有重要意义,尤其是AK和MS,治疗2型糖尿病。