The Antioxidative and Antilipidemic Effects of Different Molecular Weight Chitosans in Metabolic Syndrome Model Rats

The effect of high and low molecular weight chitosans (HMC, 1000 kDa, LMC, 30 kDa) on oxidative stress and hypercholesterolemia was investigated using male 6-week-old Wistar Kyoto rats as a normal model (Normal-rats) and spontaneously hypertensive rat/ND mcr-cp (SHP/ND) as a metabolic syndrome model (MS-rats), respectively In Normal-rats, the ingestion of both chitosans over a 4 week period resulted in a significant decrease in total body weight (BW), glucose (Cl), triglyceride (TG), low density lipoprotein (LDL) and serum creatinine (Cre) levels The ingestion of both chitosans also resulted in a lowered ratio of oxidized to reduced albumin and an Increase in total plasma antioxidant activity In addition to similar results in Normal-rats, the ingestion of only HMC over a 4 week period resulted in a significant decrease in total cholesterol levels in MS-rats Further, the ingestion of LMC resulted in a significantly higher antioxidant activity than was observed for HMC in both rat models In in vitro studies, LMC caused a significantly higher reduction in the levels of two stable radicals, compared to HMC, and the effect was both dose- and time-dependent The findings also show that LDL showed strong binding in the case of HMC These results suggest that LMC has a high antioxidant activity as well as antilipidemic effects, while HMC results in a significant reduction in the levels of pro-oxidants such as LDL in the gastrointestinal tract, thereby inhibiting the subsequent development of oxidative stress in the systemic circulation in metabolic model rats