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).