Functional Comparison of High and Low Molecular Weight Chitosan on Lipid Metabolism and Signals in High-Fat Diet-Fed Rats.

Shing-Hwa Liu,Meng-Tsan Chiang,Ching-Ming Shi,Chen-Yuan Chiu

doi:10.3390/md16080251

Abstract

The present study examined and compared the effects of low- and high-molecular weight (MW) chitosan, a nutraceutical, on lipid metabolism in the intestine and liver of high-fat (HF) diet-fed rats. High-MW chitosan as well as low-MW chitosan decreased liver weight, elongated the small intestine, improved the dysregulation of blood lipids and liver fat accumulation, and increased fecal lipid excretion in rats fed with HF diets. Supplementation of both high- and low-MW chitosan markedly inhibited the suppressed phosphorylated adenosine monophosphate (AMP)-activated protein kinase-α (AMPKα) and peroxisome proliferator-activated receptor-α (PPARα) protein expressions, and the increased lipogenesis/cholesterogenesis-associated protein expressions [peroxisome proliferator-activated receptor-γ (PPARγ), sterol regulatory element binding protein-1c and -2 (SREBP1c and SREBP2)] and the suppressed apolipoprotein E (ApoE) and microsomal triglyceride transfer protein (MTTP) protein expressions in the livers of rats fed with HF diets. Supplementation with both a low- and high-MW chitosan could also suppress the increased MTTP protein expression and the decreased angiopoietin-like protein-4 (Angptl4) expression in the intestines of rats fed with HF diets. In comparison between low- and high-MW chitosan, high-MW chitosan exhibits a higher efficiency than low-MW chitosan on the inhibition of intestinal lipid absorption and an increase of hepatic fatty acid oxidation, which can improve liver lipid biosynthesis and accumulation.

Highlights

People who eat a Western pattern of diet, which is generally characterized by high calories, high protein, high fat and high salt, and have a low physical activity level tend to become obese and increase the risk of suffering the metabolic syndrome [1]
The final body weight was markedly higher in the HF diet-fed group than in the normal control (NC) group, which could not be reversed by both low- and high-molecular weight (MW)
The relative adipose tissue weight showed no significant difference between the HF diet-fed + low- or high-MW chitosan group and the HF diet-fed group, high-MW chitosan could reduce the weight of peripheral adipose tissue weight compared to the normal control group (Table 1)

Summary

Introduction

People who eat a Western pattern of diet, which is generally characterized by high calories, high protein, high fat and high salt, and have a low physical activity level tend to become obese and increase the risk of suffering the metabolic syndrome [1]. Obesity is one of the risk factors for the occurrence of cancer, cardiovascular disease, and diabetes. There are 39% of women and 39% of men aged ≥18 overweight and 18% of overweight or obese children and adolescents in 2016 [2]. Insulin resistance and dyslipidemia induced by obesity and diabetes are risk factors for the occurrence of nonalcoholic. Mar. Drugs 2018, 16, 251; doi:10.3390/md16080251 www.mdpi.com/journal/marinedrugs. Mar. Drugs 2018, 16, 251 fatty liver disease (NAFLD) [3,4].

Methods

Results

Discussion

Conclusion