Anti-atherosclerotic effect of traditional fermented cheese whey in atherosclerotic rabbits and identification of probiotics

BACKGROUND Traditional fermented cheese whey (TFCW), containing probiotics, has been used both as a dairy food with ethnic flavor and a medicine for cardiovascular disease, especially regulating blood lipid among Kazakh. We therefore investigated anti-atherosclerotic effects of TFCW in atherosclerotic rabbits and identified lactic acid bacteria (LAB) and yeasts in TFCW. METHODS Atherosclerotic rabbits were induced by administration of atherosclerotic diet for 12 weeks and divided randomly into three groups and treated for 4 weeks with Simvastatin (20 mg/kg) or TFCW (25 mg/kg) and (50 mg/kg). In addition, a normal control group and an atherosclerotic group were used for comparison. All drugs were intragastrical administered once daily 10 mL/kg for 4 weeks. Body weight (BW), lipid profiles, C-reactive protein (CRP), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were tested and theromatous plaques and the number of foam cells and infiltrating fibroblast cells in the thoracic aorta endothelium was evaluated by hematoxylin and eosin stainin. LAB and yeasts were isolated and purified by conventional techniques and identified using morphological and biochemical properties as well as gene sequences analysis. RESULTS After 4 weeks of treatment, high and low dose TFCW decreased serum TC, TG, LDLC, CRP, VCAM-1 and ICAM-1 (P < 0.05) compared to atherosclerotic group, and increased HDL-C (P < 0.05) compared to normal controls. Histological analysis showed TFCW reduced VCAM-1 expression and formation of atheromatous plaques on the aortic endothelium of atherosclerotic rabbits. CONCLUSION Seven classes of LBA from two different genera including Lactobacillus brevis, Lactobacillus kefianofaciens, Lactobacillus helveticus, Lactobacillus Casei, Lactobacillus plantarum, Lactobacillus kefiri and Lactococcus lactic as well as 2 classes of yeasts from two different genera including Saccharomyces unisporus and Issatchenkia orientalis were isolated and identified from TFCW. In summary, TFCW, containing 7 classes of LBA and 2 classes of yeasts, has significant anti-atherosclerotic potential in atherosclerotic rabbits and may modulate lipid metabolism and protect aorta in the atherosclerotic condition, which might be related to various probiotics acting through reducing the CRP, VCAM-1 and ICAM-1 levels and protecting the aortic endothelium.