The Bioavailability and Biological Activities of Phytosterols as Modulators of Cholesterol Metabolism.

Xiang Li,Yan Xin,Taiping He,Pavel Marozik,Honghui Guo,Yuqian Mo

doi:10.3390/molecules27020523

Abstract

Phytosterols are natural sterols widely found in plants that have a variety of physiological functions, and their role in reducing cholesterol absorption has garnered much attention. Although the bioavailability of phytosterols is only 0.5–2%, they can still promote cholesterol balance in the body. A mechanism of phytosterols for lowering cholesterol has now been proposed. They not only reduce the uptake of cholesterol in the intestinal lumen and affect its transport, but also regulate the metabolism of cholesterol in the liver. In addition, phytosterols can significantly reduce the plasma concentration of total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C), with a dose-response relationship. Ingestion of 3 g of phytosterols per day can reach the platform period, and this dose can reduce LDL-C by about 10.7%. On the other hand, phytosterols can also activate the liver X receptor α-CPY7A1 mediated bile acids excretion pathway and accelerate the transformation and metabolism of cholesterol. This article reviews the research progress of phytosterols as a molecular regulator of cholesterol and the mechanism of action for this pharmacological effect.

Highlights

Phytosterols, encompassing plant sterols and stanols, are natural steroids that are widely found in different parts of plants and are an important part of plant cell membranes
To better understand the molecular mechanisms by which phytosterols affect cholesterol absorption and metabolism, this review focuses on recent clinical trials involving phytosterol interventions and, using non-alcoholic fatty liver disease (NAFLD) and cardiovascular diseases (CVDs) as examples, explores the protective role of phytosterols, including the modulation of exogenous cholesterol absorption and endogenous cholesterol synthesis
In order to maintain liver cholesterol homeostasis, dietary intake of phytosterols leads to a decrease in intestinal cholesterol absorption, which will later cause a compensatory increase in the synthesis of endogenous cholesterol in the body

Summary

Introduction

Phytosterols, encompassing plant sterols and stanols, are natural steroids that are widely found in different parts of plants (including roots, stems, leaves, flowers, fruits, and whole grasses) and are an important part of plant cell membranes. The physiological functions of phytosterols can be reflected in many aspects, such as an antioxidant function [5], anti-inflammatory and antipyretic effects [6], and a hormone-like effect [7] Their most remarkable function is to reduce the absorption of cholesterol as well as the concentration of LDL-C [8,9]. In addition to the above physiological functions, phytosterols play many other roles in promoting human health They can improve insulin resistance [11] and lipid metabolism [12], and can reduce cancer risk [13], Alzheimer’s disease [14], as well as the risk of atherosclerosis related CVDs [15]. The main phytosterols are β-sitosterol, campesterol, and stigmasterol, and the content of these three sterols can reach more than 80%. Considering the health-promoting effects of phytosterols, people can increase phytosterols intake by consuming phytosterolrich foods or dietary supplements, especially for people with hypercholesteremia and high dietary cholesterol intakes

Bioavailability of Phytosterols

Participants in the intervention

Phytosterols Regulate Liver Cholesterol Metabolism

Conclusions