Preventive And Therapeutic Effects Of Chitosan And Its Derivatives On Obese Rats

In this paper, two kinds of chitosan derivatives O-carboxymethyl-chitosan(OCMCs) and (2-hydroxyl-3-dimethyl long chain ammonium) propyl chitosan(N-C₁₆QCs) were synthesized by chemical modification. The structure, crystallability and electrical charge characters were characterized by FTIR, XRD and zeta(ζ) potential. The absorbability of these derivatives on lipin in edible oil and biliary acid were studied by in vitro digesition model. Moreover, the effect of these chitosan derivatives on obese rats was observed by the precation and treatment methods respectively.Results show that the crystallabilities of OCMCs and N-C₁₆QCs are decreased significantly as the changing of the molecular structure in chitosan, and the electrical charge for the N-C₁₆QCs is highly cationic(ζ=+36.1mV), whereas OCMCs is anionic(ζ=-31.82 mV). It is certainly testified that we perepared two chitosan derivatives successfully by chemical modification. In vitro test, these derivatives have the potential absorbability on the fat and the biliary acid, the ratio of the OCMCs and N-C₁₆QCs to biliary acid comes to 21.58%, 44.87% respectively. Results of animal experiment show that the two chitosan derivatives could significantly decrease the body weight, body fat content and increase the feces fat excretion. Compared to the fat model group, the reduction of the body weight is about 10% and the maximum body fat content is 31.33%. Meanwhile, the blood lipoprotein content have droped in a certain extent and blood leptin level have droped significantly, the maximum effect of OCMCs and N-C₁₆QCs on the blood leptin is 54.82% and 64.17% respectively. The FFA content have decreased in the blood serum, liver and kidney of the obese rats, its maximum reduction was 78.72%, 66.42% and 83.03% respectively. In the test of the superoxide dismutase (SOD) and malondialdehyde(MDA), the OCMCs and N-C₁₆QCs have the mild peroxidatively effect on the rats induced by hyperlipid-diet. Finaly, we have observed the change of liver tissue morphology and find that OCMCs and N-C₁₆QCs are both improved the fatty liver of the obese rats induced by hyperlipid-diet.