Beneficial effects of Chlorella on glucose and lipid metabolism in obese rodents on a high-fat diet

Background: Obesity-induced glucose and lipid metabolism disorders have become risk factors for lifestyle diseases. Powderized Parachlorella beijerinckii (BP) and its hot water extract (BCEx) are believed to be useful for preventing common diseases such as hypertension, arteriosclerosis, and hyperlipidemia. The present study investigated how chlorella components influence common diseases in obese mice and rats on a high-fat diet. Methods: We fed C57BL/6J mice a high-fat diet containing 5% BP, and then weighed their organs, tested their glucose tolerance and insulin sensitivity, and analyzed their serum. Further, we fed Sprague-Dawley rats with a high-fat diet containing 1% BCEx, and then weighed their organs and analyzed their serum parameters. Results: BP administration had no effect on high-fat diet-induced obesity. However, compared with high-fat diet group, BP group had improved glucose tolerance and insulin sensitivity and inhibited the hypertrophic growth of visceral fat cells. In addition, BP group had improved serum adiponectin, leptin and monocyte chemoattractant protein-1 (MCP-1) levels. The MCP-1 expression level at epididymal fat was decreased at BP group. BCEx administration reduced amount of peritesticular fat and serum triglyceride (TG) levels. Conclusions: The results suggest that the antihyperinsulinemic effects of BP are due to the modulation of adipose tissue hypertrophy and adipocytokine secretion. BCEx inhibited the accumulation of visceral fat and serum TG. The study showed that BP and BCEx improve glucose and lipid metabolism disorders caused by a high-fat diet. (C) 2013 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.