The Ameliorative Effect of COST on Diet-Induced Lipid Metabolism Disorders by Regulating Intestinal Microbiota.

BACKGROUND: Chitosan oligosaccharides, with an average molecular weight ≤ 1000 Da (COST), is a natural marine product that has the potential to improve intestinal microflora and resist lipid metabolism disorders. METHODS: First, by establishing a mice model of lipid metabolism disorder induced by a high fat and high sugar diet, it is proven that COST can reduce lipid metabolism disorder, which may play a role in regulating intestinal microorganisms. Then, the key role of COST in the treatment of intestinal microorganisms is further confirmed through the method of COST-treated feces and fecal bacteria transplantation. CONCLUSIONS: intestinal microbiota plays a key role in COST inhibition of lipid metabolism disorder induced by a high fat and high sugar diet. In particular, COST may play a central regulatory role in microbiota, including Bacteroides, Akkermansia, and Desulfovibrio. Taken together, our work suggests that COST may improve the composition of gut microbes, increase the abundance of beneficial bacteria, improve lipid metabolism disorders, and inhibit the development of metabolic disorders.

Advances in the preparation and assessment of the biological activities of chitosan oligosaccharides with different structural characteristics.

Chitosan oligosaccharides (COSs) are widely used biopolymers that have been studied in relation to a variety of abnormal biological activities in the food and biomedical fields. Since different COS preparation technologies produce COS compounds with different structural characteristics, it has not yet been possible to determine whether one or more chito-oligomers are primarily responsible for the bioactivity of COSs. The inherent biocompatibility, mucosal adhesion and nontoxic nature of COSs are well documented, as is the fact that they are readily absorbed from the intestinal tract, but their structure-activity relationship requires further investigation. This review summarizes the methods used for COS preparation, and the research findings with regard to the antioxidant, anti-inflammatory, anti-obesity, bacteriostatic and antitumour activity of COSs with different structural characteristics. The correlation between the molecular structure and bioactivities of COSs is described, and new insights into their structure-activity relationship are provided.

The effects of COST on the differentiation of 3T3-L1 preadipocytes and the mechanism of action.

The objectives of this study were to explore the effect of COST (one thousand Da molecular weight chitosan oligosaccharide) on the differentiation of 3T3-L1 preadipocytes and to determine the mechanism of action. 3T3-L1 preadipocytes were used as the target cells, and the induction of the methods for the differentiation of 3T3-L1 preadipocytes was based on classic cocktails. The MTT assay was used to filtrate the concentration of COST. On the 6th day of induced-differentiation, the differentiation of 3T3-L1 cells was detected by Oil Red O staining. The expression of PPARγ and C/EBPα mRNA was determined using real-time fluorescence quantitative PCR (Q-PCR). COST inhibited 3T3-L1 preadipocyte differentiation in a dose-dependent manner and decreased lipid accumulation. At the molecular level, the expression of the transcription factors, PPARγ and C/EBPα, was reduced by COST during adipogenesis. These results indicate that COST effectively inhibited the differentiation of 3T3-L1 preadipocytes. The mechanism is related to the down-regulation expression of PPARγ and C/EBPα.