Anti-Obesity and Anti-Diabetic Effect of Neoagarooligosaccharides on High-Fat Diet-Induced Obesity in Mice

Abstract

Neoagarooligosaccharides (NAOs), mainly comprising neoagarotetraose and neoagarohexaose, were prepared by hydrolyzing agar with β-agarase DagA from Streptomyces coelicolor, and the anti-obesity and anti-diabetic effects of NAOs on high-fat diet (HFD)-induced obesity in mice were investigated after NAOs-supplementation for 64 days. Compared to the HFD group, the HFD-0.5 group that was fed with HFD + NAOs (0.5%, w/w) showed remarkable reduction of 36% for body weight gain and 37% for food efficiency ratios without abnormal clinical signs. Furthermore, fat accumulation in the liver and development of macrovesicular steatosis induced by HFD in the HFD-0.5 group were recovered nearly to the levels found in the normal diet (ND) group. NAOs intake could also effectively reduce the size (area) of adipocytes and tissue weight gain in the perirenal and epididymal adipose tissues. The increased concentrations of total cholesterol, triglyceride, and free fatty acid in serum of the HFD group were also markedly ameliorated to the levels found in serum of the ND group after NAOs-intake in a dose dependent manner. In addition, insulin resistance and glucose intolerance induced by HFD were distinctly improved, and adiponectin concentration in the blood was notably increased. All these results strongly suggest that intake of NAOs can effectively suppress obesity and obesity-related metabolic syndromes, such as hyperlipidemia, steatosis, insulin resistance, and glucose intolerance, by inducing production of adiponectin in the HFD-induced obese mice.

Inhibitory Effect of Olive Leaf Extract on Obesity in High-fat Diet-induced Mice

“…Taken together, these results suggest that the anti-obesity effects of OLE occur through the control of adipogenesis and thermogenesis in vesical adipose tissue. Recently, hepatic lipid metabolism was shown to influence obesity and may be a therapeutic target (49). Therefore, further studies are needed to evaluate the effects of OLE on liver metabolism and predict the efficacy of OLE in obesity patients.…”

“…Five-week-old male C57BL/6 mice weighing 18-21 g were purchased from Orient Bio (Gyeonggi-do, Korea). All mice were housed in a specific pathogen-free standard room under controlled temperature (21.5-22.3˚C), humidity (47)(48)(49)(50)(51)(52)(53).1%), and light cycle (12:12 h light-dark) conditions; the mice had access to rodent chow and tap water ad libitum for 1 week.…”

Biochemical Characterization of a Novel GH86 ��-Agarase Producing Neoagarohexaose from Gayadomonas joobiniege G7

“…Various biological activities of neoagarooligosaccharides have been described, including melanoma cell whitening [9], skin moisturizing [9], and antibacterial [8], anti-obesity, and antidiabetic effects [10]. In particular, neoagarooligosaccharides, composed mainly of NA4 and NA6, can effectively suppress obesity and obesity-related metabolic syndromes, such as hyperlipidemia, steatosis, insulin resistance, and glucose intolerance [10]. It is thought to suppress these conditions by inducing adiponectin production in high-fat diet-induced obese mice [10].…”

“…In particular, neoagarooligosaccharides, composed mainly of NA4 and NA6, can effectively suppress obesity and obesity-related metabolic syndromes, such as hyperlipidemia, steatosis, insulin resistance, and glucose intolerance [10]. It is thought to suppress these conditions by inducing adiponectin production in high-fat diet-induced obese mice [10]. Because AgaJ5 has a significantly high value of V m a x and produces NA6 as the predominant hydrolysis product, it may be useful to the food, pharmaceutical, and cosmetic industries.…”

“…An understanding of the catabolic enzymes involved in agar degradation is necessary for engineering the bioconversion of agar into industrial chemicals or biofuels. Notably, neoagarooligosaccharides produced by agarase are known to have many biological activities, such as antibacterial activity [8], moisturizing the skin [9], whitening of melanoma cells [9], anti-obesity activity [10], and antidiabetic activity [10].…”