Advances in research on hypolipidemic mechanism of phytosterols / 中国中药杂志

Hyperlipidemia,as one of the severe risk factors of cardiovascular disease,could easily trigger atherosclerosis,coronary heart disease,peripheral vascular disease,pancreatitis,etc.,and could also increase the incidence of type 2 diabetes and fatty liver disease. Improving dyslipidemia could slow down the progression of atherosclerosis and reduce the risk of coronary heart disease. This is of great importance for prevention and treatment of cardiovascular disease. Phytosterols are natural active ingredients in plants. Many researches have shown that phytosterols have significant lipid-lowering activity,which could effectively lower blood cholesterol and triglyceride levels. Foods containing phytosterols have been widely used as therapeutic diets for improving dyslipidemia. In the early years,it was believed that the lipid-lowering effect of phytosterols was achieved by competitively inhibiting the absorption of dietary cholesterol in the intestine since phytosterols had similar chemical structures with cholesterol. In further researches in recent years,more progress has been made in the lipid-lowering mechanisms of phytosterols. In this paper,PubMed and Web of Science were used to review the cholesterol-lowering and triglyceride-lowering mechanisms of phytosterols according to the available data published,so as to use phytosterols more rationally in clinical application to improve hyperlipidemia and other induced diseases.

Protective effect of eicosapentaenoic acid-docosahexaenoic acid and α–linolenic acid rich phytosterol ester on brain antioxidant status and brain lipid composition in hypercholesterolemic rats.

With a view to investigate the ameliorative effects of sitosterol esters against degenerative effects of hypercholesterolemia brain antioxidant enzyme assays, brain lipid profile, brain phospholipid compositional change and brain neurotransmitter concentrates (glutamic acid, asparctic acid, glycine) were measured in hypercholesterolemic rats. The results indicated that phytosterol esters have a role in countering hypercholesterolemia-related changes in the brain by decreasing the cholesterol levels, increasing the phospholipid levels and increasing the level of antioxidant enzymes. The results suggest that phytosterol esters may be of therapeutic significance and may offer new and effective options for the treatment of hypercholesterolemia-induced changes in the brain.

Impact of quality of dietary fat on serum cholesterol and coronary heart disease: Focus on plant sterols and other non-glyceride components.

Elevated serum low density lipoprotein (LDL) cholesterol is a strong risk factor for coronary heart disease; dietary as well as therapeutic regimens target reduction of serum LDL cholesterol to decrease the morbidity and mortality of coronary heart disease. The fatty acid composition of dietary fat has a marked impact on serum LDL cholesterol and other risk factors of dietrelated chronic diseases (metabolic syndrome, diabetes and coronary heart disease). Besides fatty acids, which constitute >95% of their content, fats in foods contain other fat-soluble chemicals collectively called non-glyceride components. Sterols are a major part of the non-glyceride components of fats in plant foods and get concentrated in vegetable oils. Current evidence suggests that properly solubilized plant sterols or stanols incorporated in ester or free form in various food formulations effectively restrict the absorption of both dietary and biliary cholesterol causing 10%–14% reduction in serum LDL cholesterol in normal, hyperlipidaemic and diabetic subjects. The carotenoid-lowering effect of foods enriched with plant sterols can be corrected by increasing the intake of foods rich in carotenoids. The use of foods enriched with plant sterols as a part of a heart-healthy diet is recommended only after consulting a clinician. Recent studies strongly suggest that even smaller amounts of sterols available from natural plant foods and vegetable oils are important dietary components for lowering serum LDL cholesterol. Furthermore, some of the other non-glyceride components of food fats have one or more of the following functions—vitamin activity, serum LDL cholesterol-lowering and antioxidant activity. Since the hypocholesterolaemic and antioxidant effects of a combination of the non-glyceride components may be more than their individual effects, increasing dietary plant sterols and nonglyceride components from natural plant foods and vegetable oils could provide an additional dietary means for prevention/ correction of dyslipidaemia and increasing the antioxidant potential of human diets. The food-based dietary guidelines recommended to ensure an optimal fat quality in the diet of Indians provide high levels of natural plant sterols and other health-promoting non-glyceride components in addition to adequate absolute levels of individual fatty acids and their optimal balance. National policies to promote these dietary guidelines may contribute to the prevention of coronary heart disease and other diet-related chronic diseases.