Studies On The Effects And Mechanisms Of Fucoxanthin And Dietary Fiber From Soybean Dregs On The Prevention Of Obesity

The prevalence of obesity is increasing all over the world, posing a threat to human health. Obesity has close correlation with many chronic diseases, such as diabetes mellitus, cardiovascular diseases, digestive system diseases, respiratory tract diseases and various cancers.Fucoxanthin (Fc) is one of the important marine carotenoids that is characterized by a unique structure including an allenic bond and5,6-monoepoxide, exerting many benefits, such as antiobesity, modulation of glucose, anticancer, antioxidant, angiogenesis, and radical free radical scavenging. Conjugated linoleic acid (CLA), a natural octadecadienoic acid containing conjugated double bond, refers to a group of polyunsaturated fatty acids that exists as the isomer of linoleic acid (LA). CLA possess many beneficial physiologic effects including reducing the development of atherosclerosis, enhancing growth, improving immunity of organisms, decreasing accumulation of body fat, reducing the concentration of triglyceride, anticancer, and improving type II diabetes.The soybean dregs are the byproducts of tofu and soymilk manufacturing, rich in dietary fiber and low-caloric, besides containing nutritional components, such as calcium, phosphorus, ferrum and vitamins, which is beneficial for obesity, diabetes, and cardiovascular diseases. The dietary fiber is called the seventh nutritional element which has significant function to human health. Nowadays, the intake of dietary fiber in China is relatively low, though dietary fiber is rich in soybean dregs (approximately50%-70%of total masses), the application in food industry of soybean dregs is restricted due to the rough taste. The production of soybean dregs is approximately20million tons per year, most of which are used as feed. The part of research the powder of soybean dregs supplemented with the biscuits, which are used to conduct the randomized controlled trial on overweight and obese subjects. The aim of this part was to explore the effects of dietary fiber in soybean dregs on weight loss, fat loss and the improvement of lipid profile.First of all, Fc and Fc plus CLA supplemented in the diet were prepared for Sprague Dawley (SD) rats. Body weight, weight of white fat tissue and liver, histological observation of liver and white adipose tiuuse (WAT), serum lipid profile and the mRNA expression of Adi, leptin, enzymes of lipogenesis, transportation and lipolysis, and UCP2in WAT of SD rats were determined. The results showed that body weight, weight of white fat tissue and liver, and accumulation of hepatic lipid droplets, were significantly decreased by Fc and Fc+CLA. In addition, the mRNA expression of adiponectin, adipose triacylglycerol lipase, carnitine palmitoyltransferase1A was remarkably up-regulated in Fc and Fc+CLA groups. Fc and CLA up-regulated the expression of lipolysis genes, down-regulated the expression of lipogenesis genes, accelerate β-oxidation and the hydrolysis of TG, inhibited the lipogenesis and differentiation of mature adipocytes, thus exerting the effects on antiobesity of high-fat diet-induced rats. In summary, Fc and CLA were beneficial for the antiobesity though exhibiting different mechanisms. The present research provide theoretical and scientific basis for the exploitation of nutraceutical or medicinal food and nutritional evaluation.In the next part, thirty nine overweight and obese college adults (aged19-39y, BMI=23-30kg/m2) were randomly assigned to consume control biscuits or biscuits supplemented with soy fiber for12wks (approximately100g/d). There were significant differences in changes on body weight, body mass index (BMI) and low density lipoprotein cholesterol (LDL-C) between the two groups after12wk intervention. Body weight, body mass index (BMI), waist circumference, diastolic blood pressure, serum levels of total cholesterol, low density lipoprotein cholesterol, glucose, body fat and trunk fat of participants in soy fiber group were decreased significantly over the study period compared with the baseline. Soy fibers may help prevent weight gain by promoting satiety, inhibiting appetite and decreasing spontaneous food intake. Soy fiber might accelerate fecal bile acid excretion and the subsequent increase in conversion of cholesterol to bile acid, finally resulting in a decrease in the serum cholesterol levels. Soy fiber had favorable effects on body weight, blood pressure, fasting lipid levels and body fat in overweight and obese adults.