Department of Food Engineering and Technology, School of Engineering, Tezpur University, 784 028, India.
Department of Molecular Biology and Biotechnology, School of Sciences, Tezpur University, 784 028, India.
Int J Biol Macromol. 2020 Dec 1;164:1328-1341. doi: 10.1016/j.ijbiomac.2020.07.196. Epub 2020 Jul 26.
Tocotrienols (T3) are vitamin E components that inhibit 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), a primary target for cholesterol management. T3 was extracted from rice bran (RBE) using ultrasonic energy keeping solute: solvent ratio, power and time on specific energy and T3 concentration as responses as per Box-Behnken Design. The lowest specific energy (52.38 ± 0.14 J mL) uptake by the sample was most effective in enhancing the concentration of T3 in RBE (199.34 ± 0.63 μg mL). In vitro HMGR kinetics and in silico binding interactions of the identified α-, δ- and γ-T3 fractions were studied. Enzyme kinetic studies revealed an uncompetitive mode of inhibition by α-T3, γ-T3, and RBE and a mixed mode of inhibition for δ-T3. γ-T3 showed lowest IC concentration (11.33 μg mL) followed by α-T3 (16.73 μg mL), RBE (20.45 μg mL) and δ-T3 (23.16 μg mL). Molecular docking studies highlighted the hydrogen bonding of δ-T3 with Gln766 and α- and γ-T3 with Met655 and Val805 amino acid residues at the NADPH binding site of HMGR. Results indicate the potential use of T3 enriched RBE optimally extracted using ultrasound as potent HMGR inhibitor.
生育三烯酚（T3）是维生素 E 的组成部分，可抑制 3-羟基-3-甲基戊二酰辅酶 A 还原酶（HMGR），这是胆固醇管理的主要靶点。采用超声能量从米糠（RBE）中提取 T3，保持溶剂比、功率和时间不变，以特定能量和 T3 浓度为响应，根据 Box-Behnken 设计进行实验。样品吸收的最低特定能量（52.38±0.14 J mL）对提高 RBE 中 T3 浓度最有效（199.34±0.63 μg mL）。研究了鉴定的α-、δ-和γ-T3 馏分的体外 HMGR 动力学和计算机模拟结合相互作用。酶动力学研究表明，α-T3、γ-T3 和 RBE 通过非竞争性抑制模式抑制 HMGR，而 δ-T3 通过混合抑制模式抑制 HMGR。γ-T3 显示出最低的 IC 浓度（11.33 μg mL），其次是 α-T3（16.73 μg mL）、RBE（20.45 μg mL）和 δ-T3（23.16 μg mL）。分子对接研究突出了 δ-T3 与 Gln766 以及 α-T3 和 γ-T3 与 HMGR 的 NADPH 结合位点的 Met655 和 Val805 氨基酸残基的氢键作用。结果表明，T3 富集的 RBE 可作为潜在的 HMGR 抑制剂，最佳提取方法是超声提取。
