Hartanti Lanny, Yonas Stefania Maureen Kasih, Mustamu Josianne Jacqlyn, Wijaya Sumi, Setiawan Henry Kurnia, Soegianto Lisa
Faculty of Pharmacy, Widya Mandala Catholic University Surabaya, Raya Kalisari Selatan 1, Pakuwon City, Surabaya 60112, Indonesia.
Heliyon. 2019 Apr 9;5(4):e01485. doi: 10.1016/j.heliyon.2019.e01485. eCollection 2019 Apr.
Bay leaf, one of the plants in Indonesia that has been shown to have activities to reduce cholesterol in the blood. HMG-CoA Reductase inhibition is one of many mechanisms in lowering the level of cholesterol in the blood. Here, we reported the inhibitory activity of HMG-CoA Reductase of bay leaves ethanol extracts that we suspected to be the mechanism of action of bay leaves in reducing cholesterol in the blood. In this research we also investigated the correlation between the inhibitory activities, the total phenol content and antioxidant activities of bay leaves () ethanol extracts.
The inhibitory activity of HMG-CoA Reductase was determined kinetically at 340 nm using simvastatin as positive control. scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP), and beta-carotene method were used to determine the antioxidant activities. The total phenolic content was determined by Folin-Ciocalteu's method.
The IC of bay leaves ethanolic extract obtained by percolation and soxhlet extraction method towards HMG-CoA Reductase enzyme activity were 49.50 ± 0.700 μg/mL and 15.50 ± 0.707 μg/mL, respectively, while the IC of simvastatin was 0.00238 ± 0.00004 μg/mL. The antioxidant activity and total phenolic content of bay leaves ethanolic extract obtained by Soxhlet extraction method was higher compared to the percolation method (DPPH and beta-carotene assay results). The 3D linear analysis showed that there was a high correlation between the inhibition activities of HMG-CoA Reductase pattern of both extract types and the total phenol pattern and also the antioxidant pattern of these extracts.
The result showed that the bay leaves ethanolic extract have a potent activity to reduce the cholesterol serum level by inhibition of HMG-CoA Reductase activity. The activity was due to the phenolic compounds in the extracts as well as the antioxidant activity of the extracts.
月桂叶是印度尼西亚的一种植物，已被证明具有降低血液中胆固醇的活性。HMG-CoA还原酶抑制是降低血液中胆固醇水平的众多机制之一。在此，我们报道了月桂叶乙醇提取物对HMG-CoA还原酶的抑制活性，我们怀疑这是月桂叶降低血液中胆固醇的作用机制。在本研究中，我们还研究了月桂叶乙醇提取物的抑制活性、总酚含量和抗氧化活性之间的相关性。
以辛伐他汀为阳性对照，在340nm处动力学测定HMG-CoA还原酶的抑制活性。采用2,2-二苯基-1-苦基肼（DPPH）清除试验、铁离子还原抗氧化能力（FRAP）和β-胡萝卜素法测定抗氧化活性。总酚含量采用福林-酚法测定。
通过渗漉法和索氏提取法得到的月桂叶乙醇提取物对HMG-CoA还原酶活性的IC50分别为49.50±0.700μg/mL和15.50±0.707μg/mL，而辛伐他汀的IC50为0.00238±0.00004μg/mL。索氏提取法得到的月桂叶乙醇提取物的抗氧化活性和总酚含量高于渗漉法（DPPH和β-胡萝卜素测定结果）。三维线性分析表明，两种提取物类型的HMG-CoA还原酶抑制活性模式与总酚模式以及这些提取物的抗氧化模式之间存在高度相关性。
结果表明，月桂叶乙醇提取物具有通过抑制HMG-CoA还原酶活性来降低血清胆固醇水平的有效活性。该活性归因于提取物中的酚类化合物以及提取物的抗氧化活性。
