Study on Effects and Mechanism of Saponins of Sea Cucumber on Lipid Metabolism
|School||Ocean University of China|
|Course||Of Food Science|
|Keywords||Holothurian glycosides Non - alcoholic fatty liver Obesity Insulin Resistance Sterol regulatory element binding protein Peroxisome proliferator-activated receptor Microsomal triglyceride transfer protein Pancreatic lipase Adiponectin|
The sea cucumber saponins the sea cucumber secondary metabolites, is an important one of the active ingredients of the sea cucumber. Studies have confirmed that the sea cucumber saponins have antifungal, improve immunity, anti-tumor effects, but have not yet found the reported relating to the regulation of lipid metabolic activity. In this experiment, the low-value sea cucumber for raw materials, the regulatory role of sea cucumber saponins on lipid metabolism, focus on the improvement of the role of non-alcoholic fatty liver disease (NAFLD), and weight loss, and its mechanism of action at the molecular level systems research, and provide a scientific basis for improving the value of the use of low-value sea cucumber as well as the development of new health food. Sea cucumber contains saponins, polysaccharides, polar lipids, collagen and other active substances, but there are research is basically to stay at the level of the entire parameter differences of these active ingredients in improving lipid metabolism is unclear. This article first compares the differences of whole ginseng, saponins, polysaccharides, collagen peptides, residues, and in addition to saponins residues components on lipid metabolism results show that the sea cucumber saponins and polysaccharides can effectively inhibit the accumulation of body fat, decreased serum and liver lipid content is a the sea cucumber major lipid-lowering active ingredients, both effects are better than the whole parameters, better than polysaccharides and saponins. In view of the above results, the follow-up study selected holothurian glycosides depth research priorities, the impact of the mechanisms of lipid metabolism in rats. The results found that the sea cucumber saponins can significantly inhibit pancreatic lipase activity, hinder exogenous fat digestion and absorption; while inhibition of fatty acid synthase (FAS) and stearoyl CoA desaturase (SCD) vitality, thus weakening the endogenous lipogenesis. The sea cucumber saponins play through these two ways to reduce the accumulation of body fat activity. This paper further studied the sea cucumber saponins improvement of NAFLD. By studying the characteristics and mechanisms of orotic acid induced NAFLD model, it is found that the model is suitable for the study of NAFLD. The research results show that the sea cucumber saponins orotic acid induced NAFLD, cucumber saponins can significantly reduce blood lipid levels, and has significantly reduced the effect of liver triglyceride (TG) and cholesterol (TC) content, and show some dose-dependent effect, suggesting that it have a good preventive therapeutic effect of NAFLD. In order to elucidate the sea cucumber saponins molecular mechanism of prevention to improve fatty liver, the experiments from both fatty acid synthesis and fatty acid p-oxidation are discussed. The results show that the sea cucumber saponins can inhibit the key rate-limiting enzyme in fatty acid de novo synthesis process, such as FAS, malic acid enzyme (ME), glucose-6 - phosphate dehydrogenase (G6PDH) vitality; Real-time PCR detection FAS, ME, G6PDH transcription factor sterol regulatory element binding protein (SREBP-1c) mRNA expression also significantly reduced. In addition, after feeding sea cucumber saponins key enzyme in fatty acid β-oxidation CPT vitality improved significantly; simultaneously CPT-1, CPT-2, ACO and its transcription factor PPARα mRNA expression showed the same upward trend. The above results show that the sea cucumber saponins decomposition of gene expression by inhibiting SREBP-1c in liver fat synthesis regulation gene expression, as well as to improve the PPARα-mediated fat in the liver, and thus play a role to improve NAFLD. The results also show that the cucumber saponins inhibit SREBP-2 and HMG-CoA reductase gene expression, inhibition of hepatic cholesterol synthesis pathway, thereby reducing hepatic TC content to improve with NAFLD. Finally, cucumber saponins weight loss as well as the prevention of type 2 diabetes, compared with the common ginsenosides. The use of a high-fat diet induced obesity with insulin resistance in a mouse model of sea cucumber saponins and ginsenosides on glucose metabolism and fat metabolism. The results show that the cucumber saponins inhibit weight gain, reduce body fat accumulation, demonstrated excellent weight loss effects, in addition to effectively reducing the levels of blood lipids and liver fat. The detected serum adiponectin levels significantly increased after feeding sea cucumber saponins prompted its lipid-lowering effect may be caused by the fatty acid β-oxidation by the AMP-activated protein kinase (AMPK) signaling pathway activated by adiponectin and PPARα activation related to the strength. In addition, the oral glucose tolerance test, sea cucumber saponins can improve impaired glucose tolerance, and reduce serum insulin levels observed sea cucumber saponins can play its effect on the prevention of type 2 diabetes by improving insulin sensitivity. In this thesis, for the first time to carry out the activity of sea cucumber saponins regulation of lipid metabolism system discussed, and its mechanism of action. Carry out the study of the sea cucumber saponins lipid-lowering activity, abundant sea cucumber field of study, and some scientific basis for the depth of the development and utilization of the sea cucumber. Sea cucumber saponins as a safe and effective lipid-lowering functional components, related to the prevention and treatment of diseases of lipid metabolism disorders caused by high cholesterol, NAFLD, obesity and insulin resistance provide a new way for its application in functional foods or drugs laid the theoretical foundation.