Antiobesity Effect of Flaxseed Polysaccharide via Inducing Satiety due to Leptin Resistance Removal and Promoting Lipid Metabolism through the AMP-Activated Protein Kinase (AMPK) Signaling Pathway

Abstract

Obesity is a metabolic syndrome worldwide that causes many chronic diseases. Recently, we found an antiobesity effect of flaxseed polysaccharide (FP), but the mechanism remains to be elucidated. In this study, rats were first induced to develop obesity by being fed a high-fat diet. The obese rats were then fed a control diet, AIN-93M (group HFD), or a 10% FP diet (group FPD). The body weight, body fat, adipose tissue and liver sections, serous total triglycerides, levels of fasting blood glucose in serum, serous insulin, inflammatory cytokines in serum, and serous proteins within the leptin−neuropeptide Y (NPY) and AMP-activated protein kinase (AMPK) signaling pathway were determined and analyzed. FP intervention significantly reduced body weight and abdominal fat from 530 ± 16 g and 2.15% ± 0.30% in group HFD to 478 ± 10 g and 1.38% ± 0.48% in group FPD, respectively. This effect was achieved by removing leptin resistance possibly by inhibiting inflammation and recovering satiety through the significant downregulation of NPY and the upregulation of glucagon-like peptide 1. Adiponectin was then significantly upregulated probably via the gut−brain axis and further activated the AMPK signaling pathway to improve lipid metabolism including the improvement of lipolysis and fatty acid oxidation and the suppression of lipogenesis. This is the first report of the proposed antiobesity mechanism of FP, thereby providing a comprehensive understanding of nonstarch polysaccharides and obesity.

Flaxseed Polysaccharide Altering Colonic Gene Expression of Lipid Metabolism and Energy Metabolism in Obese Rat

“…In the previous research, we had found axseed polysaccharides (FP) had an anti-obesity effect via promoting lipid metabolism, inducing satiety and regulating the intestinal ora [9][10]. However, as a polysaccharide, FP can not directly enter the body to play a role, so we speculate that it can promote weight loss through the interaction with intestinal ora, change the gene expression of intestinal epithelial tissue, and induce the metabolism of fat and energy in vivo.…”

“…Caused by the complex interactions between genes and environmental factors, including food components, diet and/or way of life, obesity is one of the most serious public health challenges facing the world [1]. Over 340 million children and adolescents aged [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] in 2016, as well as an estimated 38.2 million children under the age of 5 years in 2019, were overweight or obese [2]. Developing from an imbalance between energy expenditure and energy intake, obesity is a risk factor for the development of several clinical conditions, such as diabetes, cancers and cardiovascular disease [3].…”

Behavior of Non‐Digestible Polysaccharides in Gastrointestinal Tract: A Mechanistic Review of its Anti‐Obesity Effect

“…NDPs can regulate the secretion of GI hormones such as GLP-1, PYY, Cholecystokinin (CCK) and ghrelin to control the uptake of food. A recent study found that a NDP from flaxseed contributed to satiety through up-regulation of GLP-1, which might further increase the level of adiponectin and promote lipid metabolism via AMP-Activated Protein Kinase (AMPK) regulation [13]. Several studies also have demonstrated that NDPs intake is positively associated with the level of PYY [103,104] and CCK [105].…”

Current Evidence to Propose Different Food Supplements for Weight Loss: A Comprehensive Review

“…Many flaxseed components may have positive effects on weight management: lignans are reported to reduce visceral fat and increase fat oxidation and adiponectin levels in mice [278], but their supplementation alone was not shown to be effective in improving body composition in humans [277]; soluble fiber, which represent up to 27% of flaxseed weight, may induce a feeling of fullness, delay gastric emptying and increase SCFA concentration in the gut, inducing satiety and promoting weight loss via GI hormones release [279]. Furthermore, ALA has been shown to increase adipose leptin expression in animal models [280] and flaxseed polysaccharides have been able to induce satiety improving leptin resistance together with enhancing lipolysis and suppressing lipogenesis through the AMPK signaling pathway [281]. Lastly, ALA metabolism products, eicosapentaenoic acid and docosahexaenoic acid, were able to induce adipocytes apoptosis, suppress appetite and enhance fat oxidation and energy expenditure in animal models, while human studies confirmed its potential benefit only in combination with exercise and hypocaloric diets [282].…”