Cholesterol-Lowering Effect of Beta Glucan Extracted from Saccharomyces cerevisiae in Rats

Abstract

Glucans are present in fungi, plants, algae, and bacteria. β-Glucan, one of the major cell wall components of Saccharomyces cerevisiae, has been found to enhance immune functions. Glucans are glucose polymers with an α- or β-type glycosidic chain. The role of (1→3)-β-D-glucan is in the maintenance of yeast cell wall shape and rigidity. Studies reveal that soluble glucans can lower total cholesterol and LDL levels in patients with hypercholesterolemia. The important benefit of β-glucan is to improve the immune system and to decrease cholesterol levels in the blood. Several studies have reported the benefits of β-glucan as: antiseptic, antioxidant, anti-aging, immune system activators, protection against radiation, anti-inflammatory, anti-diabetic, anti-cholesterol etc. In this research S. cerevisiae was cultured in yeast extract–peptone–glucose (YPG) broth medium to produce beta-glucan. Cells were harvested at the stationary phase, washed, and disrupted by means of sonication method. The obtained cell walls were used to prepare alkali-soluble β-glucan (glucan-S1). In this regard, 2% sodium hydroxide (NaOH) and 3% acetic acid were used in alkaline–acid extraction, respectively.Potential use of beta-glucan extract as an anticholesterol agent was tested using Sprague dawley strain rats. The experiments were divided into eight groups with four replicates: Group I (normal control), group II (fed with cholesterol without beta-glucan), group III (fed with cholesterol + atorvastatin), group IV (fed with cholesterol + β-glucan standard), group V–VIII (fed of cholesterol + β-glucan of S. cerevisiae with each dose of 10, 20, 30, and 40 mg / BW. Rats were fed with cholesterol for 14 days, except for group I. Analysis of blood was carried out to determine total cholesterol, triglycerides, and malondialdehyde.The results showed that beta-glucan crude obtained from S. cerevisiae cultures was 6.890g.L−1. Βeta-glucan extract of S. cerevisiae can reduce total cholesterol approaching normal values at doses of 10 mg of 32.79 % (blood plasma) and 33.71 % (in the liver). The extract was capable of reducing triglyceride levels in a dose of 10 mg of beta-glucan 64.43 % (blood plasma) and at a dose 30 mg of beta-glucan 19.45 % (liver). Beta-glucan treatment at a dose of 40 mg can reduce MDA levels of 45.22 % (blood plasma) and 42.64 % (liver).

Effects of Glucan and Vitamin D Supplementation on Obesity and Lipid Metabolism in Diabetic Retinopathy

“…An additional study found that β-glucan treatment reduced the inflammation induced by a high cholesterol diet [ 35 ]. In a rat experimental model, β-glucan reduced total cholesterol, triglyceride, and malondialdehyde levels up to 42% [ 36 ]. In men, long-term clinical studies using soluble forms of β-glucans demonstrated decreased blood cholesterol in hypercholesterolemic patients [ 37 - 39 ].…”

Beta Glucan: Supplement or Drug? From Laboratory to Clinical Trials

“…Lim et al [89] applied glucans from yeast-like fungus Aureobasidium pullulans to a hamster experimental animal model of hyperlipemia induced by a high-fat diet. In a rat experimental model, glucan reduced total cholesterol by 32% triglyceride by 64%, and malondialdehyde levels by 45% [90]. Moreover, in a study carried out by the current authors, yeast-derived glucan #300 markedly lowered total cholesterol levels in mice with experimentally-induced hypercholesterolemia [69].…”

β-Glucan Metabolic and Immunomodulatory Properties and Potential for Clinical Application

“…The synthesis of bile acids occurs in the liver, in a series of reactions that convert hydrophobic cholesterol into a water-soluble compound, thus representing the primary pathway for cholesterol catabolism [ 59 , 60 ]. The formation of primary bile acids is primarily catalysed by the cytochrome P450 enzyme 7-α hydroxylase (CYP7A1) [ 61 ].…”