The Effects of Poncirus fructus on Insulin Resistance and the Macrophage-Mediated Inflammatory Response in High Fat Diet-Induced Obese Mice.

Obesity is a chronic low-grade inflammatory condition in which hypertrophied adipocytes and adipose tissue immune cells, mainly macrophages, contribute to increased circulating levels of proinflammatory cytokines. Obesity-associated chronic low-grade systemic inflammation is considered a focal point and a therapeutic target in insulin resistance and metabolic diseases. We evaluate the effect of Poncirus fructus (PF) on insulin resistance and its mechanism based on inflammatory responses in high-fat diet (HFD)-induced obese mice. Mice were fed an HFD to induce obesity and then administered PF. Body weight, epididymal fat and liver weight, glucose, lipid, insulin, and histologic characteristics were evaluated to determine the effect of PF on insulin resistance by analyzing the proportion of macrophages in epididymal fat and liver and measured inflammatory gene expression. PF administration significantly decreased the fasting and postprandial glucose, fasting insulin, HOMA-IR, total-cholesterol, triglycerides, and low-density lipoprotein cholesterol levels. The epididymal fat tissue and liver showed a significant decrease of fat accumulation in histological analysis. PF significantly reduced the number of adipose tissue macrophages (ATMs), F4/80+ Kupffer cells, and CD68+ Kupffer cells, increased the proportion of M2 phenotype macrophages, and decreased the gene expression of inflammatory cytokines. These results suggest that PF could be used to improve insulin resistance through modulation of macrophage-mediated inflammation and enhance glucose and lipid metabolism.

Euphorbia kansui Attenuates Insulin Resistance in Obese Human Subjects and High-Fat Diet-Induced Obese Mice.

BACKGROUND: Obesity is a main cause of insulin resistance (IR), metabolic syndrome, and fatty liver diseases. This study evaluated Euphorbia kansui radix (Euphorbia) as a potential treatment option for obesity and obesity-induced IR in obese human and high-fat diet- (HFD-) induced obese mice. METHODS: In the human study, we analyzed the body weight change of 14 patients who took a single dose of 6 g of Euphorbia powder. In the animal study, male mice were divided into three groups: normal chow, HFD, and Euphorbia (high-fat diet and 100 mg/Kg Euphorbia once per week). Body weight, epididymal fat pad weight, fasting blood glucose, fasting insulin, HOMA-IR, and oral glucose tolerance test were measured. Also, macrophage infiltration and expression of CD68, tumor necrosis factor- (TNF-) α, interferon- (IFN-) γ, and interleukin- (IL-) 6 genes in the liver and adipose tissue were analyzed. RESULTS: The human study showed that Euphorbia has a potential effect on body weight loss. In the in vivo study, body weight, epididymal fat weight, glucose level, IR, expression of CD68, TNF-α, IFN-r, and IL-6 genes, and macrophages in liver and adipose tissue were significantly reduced by Euphorbia. CONCLUSIONS: These results suggest that Euphorbia attenuates obesity and insulin resistance via anti-inflammatory effects.

Effect of Seyoeum on Obesity, Insulin Resistance, and Nonalcoholic Fatty Liver Disease of High-Fat Diet-Fed C57BL/6 Mice.

BACKGROUND: This study was performed to evaluate the effect of Seyoeum (SYE), a novel herbal meal replacement, on insulin resistance and nonalcoholic fatty liver disease (NAFLD) in obese mice fed with a high-fat diet (HFD). METHODS: SYE contained six kinds of herbal powder such as Coix lacryma-jobi, Oryza sativa, Sesamum indicum, Glycine max, Liriope platyphylla, and Dioscorea batatas. Male C57BL/6 mice were divided into four groups: normal chow (NC), HFD, SYE, and HFD plus SYE (HFD + SYE). The mice in groups other than NC were fed HFD for 9 weeks to induce obesity and then were fed each diet for 6 weeks. Clinical markers related to obesity, diabetes, and NAFLD were examined and gene expressions related to inflammation and insulin receptor were determined. RESULTS: Compared with HFD group, body weight, serum glucose, serum insulin, HOMA-IR, total cholesterol, triglyceride, epididymal fat pad weight, liver weight, and inflammatory gene expression were significantly reduced in SYE group. Insulin receptor gene expression increased in SYE group. CONCLUSIONS: Based on these results, we conclude that SYE improved obesity and insulin resistance in high-fat fed obese mice. Our findings suggest that SYE could be a beneficial meal replacement through these antiobesity and anti-insulin resistance effects.