Bitter Melon Powder Protects against Obesity-associated Fatty Liver Disease by Improving Colonic Microenvironment in Rats with High-fat Diet-induced Obesity

This study explored how bitter melon powder （BMP） alters the colonic microenvironment during the development of obesity-associated fatty liver in rats. We observed that BMP effectively inhibited the body weight gain and lipid accumulation in the liver, ameliorated glucose intolerance, and increased the colon weight after an 8-week treatment compared to that in the high-fat diet （HFD） group. BMP significantly decreased fecal water toxicity towards HT-29 cells, as revealed by the cell counting kit （CCK）-8 assay results, and the mRNA expression of Toll-like receptor 4 （TLR4） in colon mucosa. Additionally, gut permeability in the BMP group was restored to normal levels. Finally, BMP alleviated the inflammatory state of the rat colon mucosa and liver tissues as well as the systemic inflammation.

Effects of Maternal Linseed Oil Supplementation on Metabolic Parameters in Cafeteria Diet-induced Obese Rats

Because linseed oil may influence maternal and fetal metabolisms, we investigated its role in the modulation of lipid metabolism in cafeteria diet-induced obese rats and their offspring. Female Wistar rats were fed control or cafeteria food, which were either supplemented or not supplemented with linseed oil （5%） for I month before and during gestation. At parturition, serum and tissue lipids and enzyme activities were analyzed. Cafeteria diet induced adverse metabolic alterations in both mothers and offspring. Linseed oil improved metabolic status. In conclusion, linseed oil displayed health benefits by modulating tissue enzyme activities in both obese mothers and their newborns.

Comparative study on the difference of obesity model induced by two kinds of high fat diet in Sprague-Dawley rats

Objective: To explore the differences of obese Sprague-Dawley(SD)rats model induced by lard oil high-fat(HF)diet or purified HF diet. Methods: SD weanling rats were randomly divided into three groups: D1 group,where rats were fed by lard oil HF diet;D2 group,where rats were fed by purified HF diet;C group,where rats were fed on chow. After 12 weeks,diet-induced obesity rat(stop 33% based on weight)were selected for further study,and the rest rats from group D1 and D2 were excluded. The food intake and weight were weighted daily and weekly,respectively. The subcutaneous,visceral and total fat contents of rats was measured by 256-row CT scan and the Lee index was calculated accordingly. The kidney,liver,testis,spleen and heart were weighted respectively. Serum leptin and insulin levels were quantified. The pathology in liver and adipose tissues were analyzed by HE staining. Oral glucose tolerance test(OGTT)was used to compare the glucose tolerance ability. Serum total cholestero(lT-CHO),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),triglyceride(TG)and inflammatory cytokines IL-6,TNF-α were detected as well. Results: After 12 weeks,the body weight,subcutaneous fat,visceral fat,total fat mass,wet weight of liver,kidney and heart,area under blood glucose curve and the levels of serum insulin,leptin,T-CHO,LDL-C,TG,IL-6 and TNF-α in group D2 were significantly increased compared to those of group C and group D1. HDL-C of group D2 was markedly lower than that in group C(P<0. 05). The visceral fat,total fat content and HDL-C in group D1 were significantly different from those of group C(P<0. 05). Steatosis and enlarged adipocyte were found in the livers of rats in group D1 and D2,and the lesions were more significant in group D2. Conclusion: Purified HF diet was more effective in inducing metabolic abnormalities,steatosis,peripheral chronic inflammation in obese SD rat models. But lard oil HF diet was more economical when only inducing visceral steatosis was required.

Changes of Neuronal Activities after Gut Electrical Stimulation with Different Parameters and Locations in Lateral Hypothalamus Area of Obese Rats

This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area（LHA） in obese rats in order to find the optimal stimulation parameter and location. Eight gastric electrical stimulations（GES） with different parameters were performed and the neuronal activities of gastric-distension responsive（GD-R） neurons in LHA were observed. The effects of stimulations with 8 parameters were compared to find the optimal parameter. Then the optimal parameter was used to perform electrical stimulation at duodenum and ileum, and the effects of the duodenal and ileac stimulation on the GD-R neurons in LHA were compared with the gastric stimulation of optimal parameter. The results showed that GES with the lowest energy parameter（0.3 ms, 3 mA, 20 Hz, 2 s on, 3 s off） activated the least neurons. The effects of GES with other parameters whose pulse width was 0.3 ms were not significantly different from those of the lowest energy parameter. Most gastric stimulations whose pulse width was 3 ms activated more LHA neurons than the smallest energy parameter stimulation, and the effects of those 3 ms gastric stimulations were similar. Accordingly, the lowest energy parameter was recognized as the optimal parameter. The effects of stimulations with the optimal parameter at stomach, duodenum and ileum on the LHA neuronal activities were not different. Collectively, gastrointestinal electrical stimulation（GIES） with relatively large pulse width might have stronger effects to the neuronal activities of GD-R neurons in LHA of obese rats. The effects of the GIES at different locations（stomach, duodenum and ileum） on those neurons are similar, and GES is preferential because of its easy clinical performance and safety.

Effect of mango seed kernel extract on the adipogenesis in 3T3-L1 adipocytes and in rats fed a high fat diet

Mangoes (Mangifera indica L.) are one of the most important tropical foods. The seed is one of the main by-products of mango processing. Therefore, it is important to find an economically viable use for this waste (e.g., as a food additive or supplement with high nutraceutical value). We investigated the anti-obesity effects of mango seed kernel extract with hot water (MSKE-W) in 3T3-L1 adipocytes and in a high fat diet (HFD)-induced obesity rat model. MSKE-W caused a significant decrease in the activity of glycerol 2-phosphate dehydrogenase in 3T3-L1 adipocytes without eliciting cell cytotoxicity and inhibited cellular lipid accumulation through down-regulation of transcription factors such as PPARγ and C/EBPα. In the animal model, rats fed an HFD containing 1% MSKE-W gained less weight than rats fed an HFD alone. The visceral fat mass in rats fed an HFD containing 1% MSKE-W tended to be lower than that in rats fed an HFD alone. Furthermore, histological examination of rat livers from an HFD showed steatohepatitis. However, rats on an HFD containning 1% MSKE-W showed no histopathological changes in liver tissue. Our results indicate that MSKE-W influences anti-obesity effects, both in vitro and in vivo, and suggest that MSKE-W provides a novel preventive potential against obesity.

Calorie control increased vaspin levels of serum and periepididymal adipose tissue in diet-induced obese rats in association with serum free fatty acid and tumor necrosis factor alpha

Background Vaspin was recently identified as a novel adipokine that is predominantly secreted from adipose tissue and exerts insulin-sensitizing effects. This study was undertaken to elucidate the regulative effects of calorie control on the expression of vaspin and its potential mechanism.Methods Diet-induced obese Sprague Dawley （SD） rats were adopted as experimental models and accepted interventions of various ingestions and pioglitazone. Various differentiated stages of cultured 3T3-L1 cells were dealt with pioglitazone or TNFα in vitro for 48 hours to further verify findings in animal experiments.Results The rats were successfully induced into an obese experimental model with hyperinsulinemia, hyperlipidemia, and increased serum free fatty acid and TNFa by 12-week high-fat diet. It was found that depending on whether the rats were fed by a high-fat diet or a basal diet, there was extremely higher vaspin in the periepididymal fat pad than in subcutaneous adipose tissues by 16 weeks. Vaspin in sera and the periepididymal fat pad was much lower in rats with a high-fat diet than those with a basal diet （all P 〈0.05）, but vaspin in subcutaneous fat tissues was prone to increase in rats with a high-fat diet. A 4-week calorie restriction or pioglitazone on the obese rats resulted in a partial recovery of vaspin levels in sera and periepididymal adipose tissues, especially the latter revealed a more obvious superiority and increased vaspin levels of subcutaneous adipose. Surprisingly, the treatment of 4-week high-fat diet on non-obese rats did not significantly depress vaspin of sera and periepididymal adipose tissues. However, it is unknown if re-feeding generated the effect on vaspin levels of obese and non-obese rats on sera or adipose tissues. The correlation analysis showed that vaspin levels of serum and periepididymal fat tissues were negatively correlated with serum FFA, TNFα and insulin; meanwhile, there was a positive correlation between serum vaspin and vaspin of periepididymal fat tissues. Pioglitazone enhanced vaspin levels in cultured 3T3-L1 cells and supernatant in various differentiated stages, and this effect became more and more obvious along with the change of preadipocytes into mature fat cells. Administration of TNFα caused suppression on vaspin expression in differentiated stages of 3T3-L1 cells.Conclusions The present data indicated that a long-term high-fat diet could induce obesity metabolic syndrome in SD rats and finally lead to lower vaspin of sera and periepididymal fat, while pioglitazone and chronic calorie-control ingestion could enhance the production of vaspin. It was undoubtedly demonstrated that vaspin expression was strongly associated with insulin sensitivity, serum FFA, and TNFα.

基于下丘脑瘦素受体介导的JAK2/STAT3通路探讨穴位埋线治疗食源性肥胖大鼠的中枢机制

【目的】观察穴位埋线对食源性肥胖(DIO)大鼠体质量、脂代谢、血清瘦素和下丘脑瘦素受体(LepR)介导的Janus激酶2(JAK2)/信号转导和转录激活因子3(STAT3)通路mRNA及蛋白表达的影响。【方法】将40只雄性SD大鼠随机分成正常组10只和造模组30只。采用高脂饮食诱导建立DIO大鼠模型。造模成功后将成模大鼠随机分为模型组、埋线组和埋线+AG490(JAK2/STAT3通路阻断剂)组,每组10只。埋线组、埋线+AG490组于造模成功后第1、8、15、22天进行埋线,穴位选取中脘、水道、天枢、脾俞、胃俞、三焦俞,共治疗4次,埋线+AG490组穴位埋线治疗期间每天腹腔注射AG4901 mg/kg;正常组和模型组仅抓取固定。治疗前后测量体质量。治疗后检测脂代谢指标甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)以及血清瘦素水平,实时定量聚合酶链反应(RT-PCR)法检测下丘脑LepR、JAK2、STAT3的mRNA表达,Western Blot法检测下丘脑LepR、JAK2、STAT3的蛋白表达。【结果】治疗前,与正常组比较,模型组、埋线组、埋线+AG490组体质量均升高(P<0.01),与模型组比较,埋线组、埋线+AG490组体质量无显著性差异(P>0.05)。治疗后,与正常组比较,模型组体质量,瘦素及TG、TC、LDL-C水平升高,LepR、JAK2、STAT3 mRNA及蛋白表达水平降低(均P<0.01);与模型组比较,埋线组体质量,瘦素及TG、TC、LDL-C水平降低,LepR、JAK2、STAT3 mRNA及蛋白水平升高(均P<0.01);与埋线+AG490组比较,埋线组体质量,瘦素及TG、TC、LDL-C水平降低,LepR、JAK2、STAT3 mRNA及蛋白水平升高(P<0.05或P<0.01)。【结论】穴位埋线对DIO大鼠具有良好的减重降脂作用,其中枢机制可能与下调血清瘦素水平,激活下丘脑LepR介导的JAK2/STAT3通路有关。

肥胖大鼠模型的建立及其脂代谢相关分子机制研究

目的建立饮食诱导的肥胖(diet-induced obesity,DIO)大鼠模型并初步探讨其发病的分子机制。方法用脂肪含量30%的高脂饲料饲喂雄性SD大鼠25周,观察大鼠体重、Lee's指数、肝组织病理改变,检测大鼠空腹血糖及空腹血清胰岛素水平,并通过real-time PCR,检测成模大鼠肝脏中乙酰辅酶A羧化酶(ACC)、脂肪酸合酶(FAS)、激素敏感酯酶(HSL)以及固醇调节元件结合蛋白-1c(SREBP-1c)的表达变化。结果高脂饲料饲喂6周后,DIO组大鼠体重、Lee's指数均显著增加;25周后肝脏脂肪异常蓄积,出现中重度脂肪肝,空腹血糖及胰岛素水平显著升高,出现明显的胰岛素抵抗。肝脏中ACC、FAS和HSL表达显著增加,SREBP-1c表达水平达到正常组的2.56倍,两组间差异极其显著。结论成功建立了DIO大鼠模型,通过检测脂代谢相关基因的表达水平,初步阐释了营养性肥胖的发生与脂代谢变化之间的关系,SREBP-1c,ACC,FAS和HSL参与了DIO的形成,从而初步揭示了脂代谢变化与营养性肥胖的发生的关系。

补脾与醒脾药物抗DIO大鼠肥胖疗效及对脂肪激素和炎症因子的影响

目的:观察补脾、醒脾药物对饮食诱导肥胖(DIO)大鼠肥胖疗效及对脂肪激素和炎症因子的影响。方法:Wister大鼠120只,制作DIO大鼠40只和肥胖抵抗(DIO-R)大鼠10只,DIO大鼠分为DIO模型组、西布曲明组、醒脾组、补脾气组4组,分别以0.9%氯化钠溶液、西布曲明、醒脾药物、补脾气药物灌胃,空白对照组与DIO-R组予0.9%氯化钠溶液。灌胃16周,测量肥胖程度及脂肪含量。取血测定胰岛素抵抗指数(IR)、血糖、甘油三酯、胆固醇,肿瘤坏死因子(TNF-α)、脂联素(adiponectin)。取脂肪匀浆测定TNF-α、脂联素等有关脂肪激素和炎症因子。结果:DIO模型组体质量、体质量指数、脂肪系数、IR明显升高(P<0.01);血糖、血脂有增高趋势;血清和脂肪中脂联素下降(P<0.05),血清和脂肪中TNF-α升高(P<0.05,P<0.01)。经药物干预后,西布曲明组体重指数下降(P<0.05),脂肪匀浆TNF-α明显降低(P<0.01)。醒脾组血清和脂肪匀浆中TNF-α减低(P<0.05,P<0.01),血清脂联素升高(P<0.05)。补脾气组治疗后体质量、体质量指数、血糖和IR明显降低(P<0.01),血清和脂肪匀浆中TNF-α减低(P<0.05,P<0.01)、脂联素明显升高(P<0.01)。结论:补脾药物能抑制高脂饲料诱导的肥胖和胰岛素抵抗,优于醒脾药物,其机制与促进脂肪脂联素分泌,降低TNF-α水平有关。"脾气亏虚"是肥胖的病机关键之一。

补脾与醒脾药物对饮食诱导肥胖大鼠瘦素抵抗的调节作用

目的观察补脾、醒脾药物对饮食诱导肥胖(DIO)大鼠肥胖及瘦素抵抗的影响。方法 Wister大鼠120只,制作DIO大鼠40只和DIO-R大鼠10只,DIO大鼠分为DIO模型组、西布曲明组、醒脾组、补脾气组4组,分别以生理盐水、西布曲明、醒脾药物(藿香、佩兰、高良姜)、补脾气药物(白术、云苓、黄芪)灌胃,空白对照组与DIO-R组予生理盐水。灌胃16周后,测定体重,神经肽(NPY)、血清和脂肪匀浆中瘦素(leptin),脂肪匀浆中细胞因子转录负调节因子(SOCS-3)。结果 DIO模型组与DIO-R组比较,体重、NPY明显升高,血清和脂肪匀浆瘦素降低(P<0.05),SOCS-3升高(P<0.05,P<0.01)。药物干预后,各药物组体重有所下降。补脾气组治疗后体重、体重差值、NPY(P<0.01)、SOCS-3水平(P<0.05)减低,血清和脂肪匀浆瘦素水平升高(P<0.01),且在体重减低,血清瘦素升高方面明显优于西布曲明和醒脾组。结论 DIO大鼠存在瘦素抵抗,补脾药物能减轻肥胖,提高瘦素水平,抑制瘦素抵抗。