Potential Inhibitors of the Activity of the Cholesterol-Ester Transfer Protein

New Cholesteryl Ester Transfer Protein from Indonesian Herbal Plants as Candidate Treatment of Cardiovascular Disease

BACKGROUND: There is a strong negative relationship between high-density lipoprotein cholesterol (HDL-C) and the risk of cardiovascular disease (CVD). Cholesterol ester transfer protein (CETP) is a glycoprotein transporter that transfers cholesterol esters to very low-density lipoprotein and low-density lipoprotein cholesterol (LDL-C). The CETP inhibitor is a new strategy against CVD because of its ability to increase HDL-C. Various Indonesian plants have not been optimally used, and in silico phytochemical screening of these plants showing potential as CETP inhibitors is still limited. AIM: This study for exploring Indonesian phytochemicals as CETP inhibitors for new CVD treatments. METHODS: We screened 457 phytochemicals registered in the herbal database and met Lipinski’s rule of five. Their molecular structures were downloaded from the PubChem database. The three-dimensional structures of CETP and dalcetrapib (the CETP inhibitor standard) were obtained from a protein data bank (http://www.rcsb.org/pdb/) with the 4EWS code and ZINC database with the ZINC03976476 code, respectively. CETP–dalcetrapib binding complexes were validated 5 times using AutoDock Vina 1.1.2 software. Interactions between CETP and phytochemicals were molecularly docked with the same software and visualized using Pymol 1.8× software. RESULTS: Dalcetrapib had a docking score of −9.22 kcal/mol and bound to CETP at Ser230 and His232 residues. The 11 phytochemicals had lower binding scores than dalcetrapib, but only L-(+)-tartaric acid, chitranone, and oxoxylopine could interact with CETP at the Ser230 residue. These are commonly found in Tamarindus indica, Plumbago zeylanica, and Annona reticulata, respectively. CONCLUSION: L-(+)-Tartaric acid, chitranone, and oxoxylopine show potential as CETP inhibitors in silico.

Daily intake of up to two eggs for 11 weeks does not affect the cholesterol balance of Chinese young adults

Approximately 90% of the cholesterol content of the body is derived from de novo synthesis and the enterohepatic circulation. As numerous studies have shown previously, one egg per day intake has little impact of cholesterol balance in human body. Therefore, this study assumed that intake of up two eggs a day has little effect on biomarkers of cardiovascular diseases (CVDs) risk in Chinese young adults. With the increase in egg intake, total cholesterol, low‐density lipoprotein cholesterol (LDL‐C), high‐density lipoprotein cholesterol (HDL‐C), and choline all increased among all the groups as the study progressed from autumn to winter (p < .05). However, there were no differences in the plasma triglycerides, LDL‐C/HDL‐C ratio, glucose, liver enzymes, C‐reactive protein, and urinary microalbumin during the diet periods. Subjects who ate eggs at breakfast felt less hungry and more satisfied, which were relative with decreased fasting plasma ghrelin level (p < .05). Furthermore, egg‐derived cholesterol appeared to upregulate the mRNA levels of low‐density lipoprotein receptor and lecithin–cholesterol acyltransferase, and downregulate cholesteryl ester transfer protein and flavin‐containing monooxygenase 3 mRNA levels in isolated peripheral blood mononuclear cells. These results demonstrate that intake of up to two eggs a day had little effect on biomarkers of CVDs in young, healthy Chinese college students and provided useful evidence for the dietary guidelines regarding egg consumption.

Pathophysiological potential of lipid hydroperoxide intermembrane translocation: Cholesterol hydroperoxide translocation as a special case

Peroxidation of unsaturated phospholipids, glycolipids, and cholesterol in biological membranes under oxidative stress conditions can underlie a variety of pathological conditions, including atherogenesis, neurodegeneration, and carcinogenesis. Lipid hydroperoxides (LOOHs) are key intermediates in the peroxidative process. Nascent LOOHs may either undergo one-electron reduction to exacerbate membrane damage/dysfunction or two-electron reduction to attenuate this. Another possibility is LOOH translocation to an acceptor site, followed by either of these competing reductions. Cholesterol (Ch)-derived hydroperoxides (ChOOHs) have several special features that will be highlighted in this review. In addition to being susceptible to one-electron vs. two-electron reduction, ChOOHs can translocate from a membrane of origin to another membrane, where such turnover may ensue. Intracellular StAR family proteins have been shown to deliver not only Ch to mitochondria, but also ChOOHs. StAR-mediated transfer of free radical-generated 7-hydroperoxycholesterol (7-OOH) results in impairment of (a) Ch utilization in steroidogenic cells, and (b) anti-atherogenic reverse Ch transport in vascular macrophages. This is the first known example of how a peroxide derivative can be recognized by a natural lipid trafficking pathway with deleterious consequences. For each example above, we will discuss the underlying mechanism of oxidative damage/dysfunction, and how this might be mitigated by antioxidant intervention.