High-carbohydrate high-fat diet–induced metabolic syndrome and cardiovascular remodeling in rats

The prevalence of metabolic syndrome including central obesity, insulin resistance, impaired glucose tolerance, hypertension, and dyslipidemia is increasing. Development of adequate therapy for metabolic syndrome requires an animal model that mimics the human disease state. Therefore, we have characterized the metabolic, cardiovascular, hepatic, renal, and pancreatic changes in male Wistar rats (8-9 weeks old) fed on a high-carbohydrate, high-fat diet including condensed milk (39.5%), beef tallow (20%), and fructose (17.5%) together with 25% fructose in drinking water; control rats were fed a cornstarch diet. During 16 weeks on this diet, rats showed progressive increases in body weight, energy intake, abdominal fat deposition, and abdominal circumference along with impaired glucose tolerance, dyslipidemia, hyperinsulinemia, and increased plasma leptin and malondialdehyde concentrations. Cardiovascular signs included increased systolic blood pressure and endothelial dysfunction together with inflammation, fibrosis, hypertrophy, increased stiffness, and delayed repolarization in the left ventricle of the heart. The liver showed increased wet weight, fat deposition, inflammation, and fibrosis with increased plasma activity of liver enzymes. The kidneys showed inflammation and fibrosis, whereas the pancreas showed increased islet size. In comparison with other models of diabetes and obesity, this diet-induced model more closely mimics the changes observed in human metabolic syndrome.     

高脂高盐饮食对未成年鼠生长及代谢的影响

目的 观察高脂高盐饮食对未成年鼠生长发育、胰岛素敏感性及相关代谢指标的影响. 方法 40只体质量50g左右SD鼠（生长至3周末,刚断乳）随机分为三组：普通饮食组（NC组）12只、高脂组（FC组）14只、高脂高盐组（FSC组）14只,分别给予普通食物、高脂食物、高脂＋高盐食物喂养4周（鼠生长至7周末）,观察三组大鼠体质量、血压及内脏脂肪重量、血脂等,行口服葡萄糖耐量试验及胰岛素释放试验评价血糖及胰岛细胞功能. 结果 FSC组鼠体质量、内脏脂肪、血糖及胰岛素水平均较NC组明显增加,血脂紊乱加重并表现出显著的胰岛素抵抗,差异有统计学意义（均P＜0.05）. 结论 高脂高盐饮食可诱导未成年鼠腹型肥胖、高血压、血脂异常及糖耐量异常.     

Nutrapharmacology of tocotrienols for metabolic syndrome

Metabolic syndrome is defined as a set of health risk factors that are associated with an increased chance of cardiovascular diseases and type 2 diabetes. These include abdominal obesity, hyperglycemia, impaired glucose tolerance, dyslipidemia, and hypertension. Interventions in metabolic syndrome include lifestyle interventions such as a healthy diet using functional foods together with increased physical activity to induce weight loss as the first aim of treatment. Nutraceuticals such as tocotrienols and tocopherols as members of the vitamin E family may be more targeted interventions. This review evaluates the effects of tocotrienols on the risk factors of metabolic syndrome using data from human, animal and in vitro studies. Tocotrienols improved lipid profiles and reduced atherosclerotic lesions, decreased blood glucose and glycated hemoglobin concentrations, normalized blood pressure, and inhibited adipogenesis. The differences in responses between tocopherols and tocotrienols in preventing obesity, diabetes, hypertension, atherosclerosis, ischemia, and inflammation suggest that different receptors or signaling mechanisms may be involved.     

Medium-chain fatty acids: Functional lipids for the prevention and treatment of the metabolic syndrome

Metabolic syndrome is a cluster of metabolic disorders, such as abdominal obesity, dyslipidemia, hypertension and impaired fasting glucose, that contribute to increased cardiovascular morbidity and mortality. Although the pathogenesis of metabolic syndrome is complicated and the precise mechanisms have not been elucidated, dietary lipids have been recognized as contributory factors in the development and the prevention of cardiovascular risk clustering. This review explores the physiological functions and molecular actions of medium-chain fatty acids (MCFAs) and medium-chain triglycerides (MCTs) in the development of metabolic syndrome. Experimental studies demonstrate that dietary MCFAs/MCTs suppress fat deposition through enhanced thermogenesis and fat oxidation in animal and human subjects. Additionally, several reports suggest that MCFAs/MCTs offer the therapeutic advantage of preserving insulin sensitivity in animal models and patients with type 2 diabetes.     

代谢综合征幼鼠血管VEGF和vWF的表达及意义

目的:探讨血管内皮生长因子(VEGF)和血管性假血友病因子(vWF)在代谢综合征(MS)幼鼠血管壁和血清中的表达及意义.方法:3周龄SD大鼠随机分为普通饮食组(NC组)、高脂组(FC组)和高脂+高盐组(FSC组).实验4周末测体质量、腹围、血压、内脏脂肪质量、血脂,行口服葡萄糖耐量试验,计算胰岛素抵抗指数.取腹主动脉免疫组化法检测血管壁VEGF和vWF表达,ELISA方法检测血清VEGF和vWF表达.结果:FSC组体质量、腹围、血压、内脏脂肪、血糖、胰岛素水平均较NC组增加,血脂紊乱加重,并出现胰岛素抵抗.FC组仅体质量、内脏脂肪质量高于NC 组,其他上述指标差异无统计学意义.FSC组血管壁及血清中VEGF和vWF较NC组和FC组均升高.FC组较NC组血管VEGF及血清中VEGF和vWF均升高.结论:VEGF和vWF参与了血管壁的功能紊乱或损伤的病生理改变.     

喂养型代谢综合征小鼠及大鼠模型的建立方法探讨

目的探讨与人类代谢综合征(metabolic syndrome,MS)临床特征相似的啮齿类动物模型的建立方法,考察造模条件,建立经济、简便、稳定可靠的代谢综合征药物筛选模型。方法高热量饲料喂养KM、C57BL/6、BALB/c小鼠6～8wk,喂养Wistar大鼠23wk,动态监测空腹血清总胆固醇(total cholesterol,TC)、低密度脂蛋白胆固醇(low density lipoprotein-cholesterol,LDL-C)、血糖(fasting blood glucose,FBG)、胰岛素(fasting insulin,FINS)含量,计算稳态模型胰岛素抵抗评价指数(homeostasis model assessment of insulin resistance,HOMA-IR)。实验结束时做口服葡萄糖耐量试验(oral glucose tolerance test,OGTT),称取动物内脏脂肪重量(visceral fat mass,VFM)并计算内脏脂肪系数(visceral fat coefficient,VFC)。结果高热量饲料喂养KM、C57BL/6、BALB/c小鼠及Wistar大鼠均表现出TC、LDL-C、FBG增高和葡萄糖耐量减低的糖脂代谢紊乱。高热量饲料使KM鼠形成腹型肥胖和胰岛素抵抗。C57BL/6小鼠未能形成肥胖,BALB/c小鼠形成整体型肥胖。Wistar大鼠形成腹型肥胖,喂养2～6wk形成脂代谢紊乱、10wk后表现出糖代谢紊乱及胰岛素抵抗,且大鼠摄食重量下降,下丘脑神经肽Y含量增加。结论喂养型KM小鼠具有腹型肥胖、糖脂代谢紊乱和胰岛素抵抗的特征,与人类临床特征相似,符合MS定义要求,适于作为MS治疗和干预药物的快速筛选模型。     

Coenzyme Q10 supplementation lowers hepatic oxidative stress and inflammation associated with diet-induced obesity in mice

Background

Diabetes and obesity are metabolic disorders induced by an excessive dietary intake of fat, usually related to inflammation and oxidative stress.

Aims

The aim of the study is to investigate the effect of the antioxidant coenzyme Q10 (CoQ10) on hepatic metabolic and inflammatory disorders associated with diet-induced obesity and glucose intolerance.

Methods

C57bl6/j mice were fed for 8 weeks, either a control diet (CT) or a high-fat diet plus 21% fructose in the drinking water (HFF). CoQ10 supplementation was performed in this later condition (HFFQ).

Results

HFF mice exhibit increased energy consumption, fat mass development, fasting glycaemia and insulinemia and impaired glucose tolerance. HFF treatment promoted the expression of genes involved in reactive oxygen species production (NADPH oxidase), inflammation (CRP, STAMP2) and metabolism (CPT1α) in the liver. CoQ10 supplementation decreased the global hepatic mRNA expression of inflammatory and metabolic stresses markers without changing obesity and tissue lipid peroxides compared to HFF mice. HFF diets paradoxically decreased TBARS (reflecting lipid peroxides) levels in liver, muscle and adipose tissue versus CT group, an effect related to vitamin E content of the diet.

Conclusion

In conclusion, HFF model promotes glucose intolerance and obesity by a mechanism independent on the level of tissue peroxides. CoQ10 tends to decrease hepatic stress gene expression, independently of any modulation of lipid peroxidation, which is classically considered as its most relevant effect.     

Long-term feeding of red algae (Gelidium amansii) ameliorates glucose and lipid metabolism in a high fructose diet-impaired glucose tolerance rat model

This study was designed to investigate the effect of Gelidium amansii (GA) on carbohydrate and lipid metabolism in rats with high fructose (HF) diet (57.1% w/w). Five-week-old male Sprague-Dawley rats were fed a HF diet to induce glucose intolerance and hyperlipidemia. The experiment was divided into three groups: (1) control diet group (Con); (2) HF diet group (HF); and (3) HF with GA diet group (HF + 5% GA). The rats were fed the experimental diets and drinking water ad libitum for 23 weeks. The results showed that GA significantly decreased retroperitoneal fat mass weight of HF diet-fed rats. Supplementation of GA caused a decrease in plasma glucose, insulin, tumor necrosis factor-α, and leptin. HF diet increased hepatic lipid content. However, intake of GA reduced the accumulation of hepatic lipids including total cholesterol (TC) and triglyceride contents. GA elevated the excretion of fecal lipids and bile acid in HF diet-fed rats. Furthermore, GA significantly decreased plasma TC, triglyceride, low density lipoprotein plus very low density lipoprotein cholesterol, and TC/high density lipoprotein cholesterol ratio in HF diet-fed rats. HF diet induced an in plasma glucose and an impaired glucose tolerance, but GA supplementation decreased homeostasis model assessment equation-insulin resistance and improved impairment of glucose tolerance. Taken together, these results indicate that supplementation of GA can improve the impairment of glucose and lipid metabolism in an HF diet-fed rat model.     

来曲唑联合45%高脂饲料诱导生殖内分泌及代谢表型异常的多囊卵巢综合征大鼠模型研究

目的 建立来曲唑联合高脂饲料诱导SD雌性大鼠多囊卵巢综合征（PCOS）内分泌及代谢异常的动物模型。方法 选取18只21日龄雌性大鼠喂养45%高脂饲料16周,第6周龄开始服用来曲唑直至造模结束;8只对照组大鼠常规饲料喂养,第6周龄服用生理盐水。观察阴道涂片及卵巢组织学变化,比较每周体重变化,测定脏器重量、血清睾酮水平、糖耐量、血脂水平、空腹胰岛素以及胰岛素敏感指数。结果 与对照组比较,模型组大鼠体重增加,卵巢、腹股沟脂肪质量增加,子宫、垂体质量及脏器指数显著减少。模型组大鼠卵巢呈多囊样改变,颗粒细胞层减少,白膜增加。模型组大鼠的三酰甘油和低密度脂蛋白升高,糖耐量曲线下面积增加,血清睾酮水平上升,空腹胰岛素水平升高,胰岛素敏感性降低。结论 来曲唑联合高脂饲料可以建立有效的内分泌及代谢表型异常PCOS动物模型。     

Preventive effect of Tinospora cordifolia against high-fructose diet-induced insulin resistance and oxidative stress in male Wistar rats

High intake of dietary fructose exerts a number of adverse metabolic effects. The aim of the present study was to investigate whether aqueous extract of Tinospora cordifolia stem (TCAE) alleviates high-fructose diet-induced insulin resistance and oxidative stress in rats. High-fructose diet (66% of fructose) and TCAE (400 mg/kg/day) were given simultaneously for a period of 60 days. Fructose fed rats showed hyperglycemia, hyperinsulinemia, hypertriglyceridemia, impaired glucose tolerance and impaired insulin sensitivity (P < 0.05). TCAE treatment prevented the rise in glucose levels by 21.3%, insulin by 51.5%, triglycerides by 54.12% and glucose–insulin index by 59.8% of the fructose fed rats. Regarding liver antioxidant status, fructose fed rats showed higher values of lipid peroxidation (91.3%), protein carbonyl groups (44%) and lowered GSH levels (42.1%) and, lowered activities of enzymatic antioxidants, while TCAE treatment prevented all these observed abnormalities. In conclusion, our data indicate the preventive role of T. cordifolia against fructose-induced insulin resistance and oxidative stress; hence this plant could be used as an adjuvant therapy for the prevention and/or management of chronic diseases characterized by hyperinsulinemia, hypertriglyceridemia, insulin resistance and aggravated antioxidant status.     

The effect of obesity and tobacco smoke exposure on inflammatory mediators and matrix metalloproteinases in rat model

Obesity is characterized by hypertrophy of adipose tissue and chronic obstructive pulmonary disease (COPD) by lung damage; both diseases are associated with systemic low-grade inflammation. There are no animal models combining obesity and COPD; therefore, these diseases were induced simultaneously in rats to analyze their effects on the expression of inflammatory mediators and enzymes involved in lung tissue remodeling. Obesity was induced with sucrose (30%) for 4 months concomitant with tobacco smoke exposure (20 cigarettes/day, 5 days/wk) for the last 2 months. Were evaluated: body weight, abdominal fat, dyslipidemia, glucose tolerance test (GTT), histology, inflammatory mediators with qPCR and enzyme-linked immunosorbent assay, matrix metalloproteinases (MMP-2), MMP-9, MMP-12, TIMP-1 and TIMP-2 through qRT-PCR, and MMP-2 and MMP-9 by gelatin zymography. The rats on a sucrose diet exhibited increased body weight, abdominal fat, triglycerides, GTT, and plasma levels of insulin, adiponectin, leptin, resistin, IL-6, IL-1β, tumor necrosis factor-α (TNF-α) and IFN-γ, upregulated lung IL-6, IL-1β, TNF-α and IFN-γ, showing hyperplastic bronchial and alveolar epithelium. The animals exposed to sucrose and tobacco smoke exhibited decreased body weight, abdominal fat and plasma levels of leptin, resistin, IL-1β and IFN-γ, reducing inflammation but showing emphysematous lesions. Expression of gelatinases and MMP-12 augmented in the rats exposed to tobacco smoke alone or combined with sucrose. Zymography showed prominent gelatinases activity in all the experimental groups. These results suggest that simultaneous exposure to sucrose and tobacco smoke decreases inflammation but results in emphysematous lesions similar to those observed with tobacco smoke exposure, suggesting that obesity does not confer any protective effect against lung damage.     

Characterization of vascular complications in experimental model of fructose-induced metabolic syndrome

Vascular dysfunction is an important complication associated with metabolic syndrome (MS). Here we fully characterized vascular complications in a rat model of fructose-induced MS. MS was induced by adding fructose (10%) to drinking water to male Wistar rats of 6 weeks age. Blood pressure (BP) and isolated aorta responses phenylephrine (PE), KCl, acetylcholine (ACh), and sodium nitroprusside (SNP) were recorded after 6, 9, and 12 weeks of fructose administration. In addition, serum levels of glucose, insulin, uric acid, tumor necrosis factor α (TNFα), lipids, advanced glycation end products (AGEs), and arginase activity were determined. Furthermore, aortic reactive oxygen species (ROS) generation, hemeoxygenase-1 expression, and collagen deposition were examined. Fructose administration resulted in a significant hyperinslinemia after 6 weeks which continued for 12 weeks. It was also associated with a significant increase in BP after 6 weeks which was stable for 12 weeks. Aorta isolated from MS animals showed exaggerated contractility to PE and KCl and impaired relaxation to ACh compared with control after 6 weeks which were clearer at 12 weeks of fructose administration. In addition, MS animals showed significant increases in serum levels of lipids, uric acid, AGEs, TNFα, and arginase enzyme activity after 12 weeks of fructose administration. Furthermore, aortae isolated from MS animals were characterized by increased ROS generation and collagen deposition. In conclusion, adding fructose (10%) to drinking water produces a model of MS with vascular complications after 12 weeks that are characterized by insulin resistance, hypertension, disturbed vascular reactivity and structure, hyperuricemia, dyslipidemia, and low-grade inflammation.     

Comparison of the effects of sulforaphane and pioglitazone on insulin resistance and associated dyslipidemia,hepatosteatosis, and endothelial dysfunction in fructose-fed rats

The purpose of this work was to compare the influences of sulforaphane (SFN) to those of the standard insulin sensitizer pioglitazone (PIO) on high fructose diet (HFrD)-induced insulin resistance, dyslipidemia, hepatosteatosis, and vascular dysfunction in rats.Male Sprague Dawley rats (150–200 g) were fed on a standard diet (control) or a high fructose diet (HFrD, 60% w/w fructose) for 60 days. From day 16, two subgroups of HFrD-fed rats received either SFN (0.5 mg/kg/day, orally) or PIO (5 mg/kg/day, orally) along with HFrD until the end of the experiment.Fructose-fed rats showed significant decreases in food intake, body weight and feeding efficiency; effects that were not altered by either treatment. Data from insulin tolerance test (ITT), oral glucose tolerance test (OGTT), and HOMA-IR and HOMA-β indices demonstrated impaired insulin sensitivity and glucose utilization in HFrD-fed rats.SFN and PIO treatments significantly reduced OGTT_AUC (Glass's Delta values = 1.12 and 0.84, respectively), decreased ITT_AUC (Glass's Delta values = 1.05 and 0.71, respectively), significantly diminished HOMA-IR index (by 55.6% and 77.6%, respectively), and increased HOMA-β value (by 1.8 and 1.3 fold, respectively) compared to the HFrD rats. Moreover, SFN and PIO ameliorated hepatic oxidative stress and reduced serum levels of C-reactive protein and lactate dehydrogenase in HFrD-fed rats. Furthermore, SFN and PIO administrations improved insulin resistance-associated heaptosteatosis and enhanced vascular responsiveness to acetylcholine-induced relaxations. However, only SFN was able to enhance serum HDL-C levels in HFrD group.These finding suggests that SFN elicited insulin-sensitizing, hepatoprotective, and vasculoprotective effects in HFrD insulin-resistant rats that were comparable to those exerted by PIO.     

代谢综合征未成年鼠肝脏5α-R1表达及其对肾上腺皮质功能的调控

[摘要]目的:探讨代谢综合征未成年鼠肝脏中皮质醇代谢关键酶5α-还原酶1表达及其对肾上腺皮质功能的影响。方法: 方法:50克左右雄、雌性SD大鼠随机分为3组:普通饮食组(NC组);高脂组(FC组);高脂十高盐组(FSC组)。实验四周末测体重、体长、腹围、血压,观测内脏脂肪重量、血脂、血皮质醇、促肾上腺皮质激素释放激素等,行口服葡萄糖耐量试验及胰岛素释放试验。取肾上腺称重,取新鲜肝组织,测5α-还原酶1mRNA表达水平。结果: 高脂高盐饮食使未成年鼠体重、腹围、血压、内脏脂肪、血糖、胰岛素水平均比普通饮食组显著增加,血脂紊乱加重并表现出显著的胰岛素抵抗。该组肝脏5α-还原酶1 mRNA增加,并与肾上腺重量、血皮质醇及促肾上腺皮质激素释放激素水平显著相关。 结论: 我们成功以高脂高盐饮食诱导了代谢综合征未成年鼠模型,肝脏组织高表达5α-还原酶1可正性调控肾上腺皮质功能。提示针适时适当干预5α-还原酶1表达和活性可能是代谢综合征干预策略之一。     

Obesity decreases the oxidant stress induced by tobacco smoke in a rat model

Obesity and emphysema are associated with low-grade systemic inflammation and oxidant stress. Assuming that the oxidant stress induced by emphysema would be decreased by obesity, we analyzed the oxidant/antioxidant state in a rat model combining both diseases simultaneously. Obesity was induced using sucrose, while emphysema by exposure to tobacco smoke. End-points evaluated were: body weight, abdominal fat, plasma dyslipidemia and malondialdehyde (MDA), insulin and glucose AUC, activities of Mn-superoxide dismutase (Mn-SOD), glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GPx); lung MnSOD and 3-nitrotyrosine (3-NT) immunostaining, and expression of αV and β6 integrin subunits. In rats with obesity, the body weight, abdominal fat, plasma triglyceride levels, glucose AUC, insulin levels, GST activity, and αV and β6 integrin expressions were amplified. The rats with emphysema had lower values of body weight, abdominal fat, plasma insulin, triglycerides and glucose AUC but higher values of plasma MDA, GPx activity, and the lung expression of the αV and β6 integrins. The combination of obesity and emphysema compared to either condition alone led to diminished body weight, abdominal fat, plasma insulin MDA levels, GPx and GST activities, and αV and β6 integrin expressions; these parameters were all previously increased by obesity. Immunostaining for MnSOD augmented in all experimental groups, but the staining for 3-NT only increased in rats treated with tobacco alone or combined with sucrose. Results showed that obesity reduces oxidant stress and integrin expression, increasing antioxidant enzyme activities; these changes seem to partly contribute to a protective mechanism of obesity against emphysema development.     

Effects of guggulsterone isolated from Commiphora mukul in high fat diet induced diabetic rats

Sedentary lifestyle, consumption of energy-rich diet, obesity and longer lifespan are some of the major reasons for the rise of metabolic disorders like type II diabetes, obesity, hypertension and dyslipidemia among people of various age groups. High fat diet induced diabetic rodent models resembling type II diabetic condition in human population were used to assess the anti-diabetic and hypolipidemic activity of guggulsterone (isolated from Commiphora mukul resin). Four groups of rats were fed high fat diet, for 16 weeks. On feeding the normal rats with fat rich diet they showed increased serum glucose, cholesterol and triglyceride levels along with increase in insulin resistance significantly (p < 0.05) in comparison to control animals. Different biochemical parameters like GTT, glycogen content, glucose homeostatic enzymes (like glucose-6-phosphatase, hexokinase), insulin release in vivo and expression profiles of various genes involved in carbohydrate and lipid metabolism clearly demonstrated the hypoglycemic effect of this extract. Guggulsterone demonstrated a differential effect with a significantly improved PPARγ expression and activity in in vivo and in vitro conditions, respectively. However, it inhibited 3T3-L1 preadipocytes differentiation in vitro. The results presented here suggest that the guggulsterone has both hypoglycemic and hypolipidemic effect which can help to cure type II diabetes.     

Effects of antidiabetic drugs in high-fat diet and streptozotocin-nicotinamide-induced type 2 diabetic mice

Based on previously established methods, we developed an easily available type 2 diabetic mouse model that exhibits obesity and insulin resistance. We investigated the effects of several antidiabetic drugs on this new model, which was induced by a high-fat diet in combination with streptozotocin and nicotinamide injection. Male ICR mice were fed a high-fat diet (45% of calories as fat) for 3weeks and then intraperitoneally administered with nicotinamide (1000mg/kg) and streptozotocin (150mg/kg). These diabetic mice exhibited hyperglycemia and glucose intolerance as a result of the loss of early-phase insulin secretion. The mice also developed significant insulin resistance, hyperlipidemia and obesity. A single dose of mitiglinide, glibenclamide, sitagliptin, insulin, metformin and voglibose significantly improved glucose tolerance during a liquid meal tolerance test. Repeated administration of sitagliptin and rosiglitazone also improved hyperglycemia and insulin resistance. These results demonstrate that a high-fat diet combined with nicotinamide and streptozotocin injection induces a diabetic mouse model that replicates the metabolic characteristics of human type 2 diabetes. This diabetic model, which exhibits impaired insulin secretion, glucose intolerance, insulin resistance, and obesity, may be suitable to evaluate antidiabetic agents for the treatment of type 2 diabetes.     

The effect of high-fat diet-induced obesity on cardiovascular toxicity in Wistar albino rats

The consumption of a high-fat diet (HFD) is considered a risk factor for obesity development. Nonetheless, a causal role of dietary fat has never been documented, because of inadequate animal models. In our study, one group of rats was fed with standard rat diet, while other group of rats fed with high-fat diet for 4 weeks. After 4 weeks of feeding, the hemodynamic parameters in the rats fed with HFD were significantly increased as compared with control rats. Rats fed with HFD had elevated levels of serum lipids, insulin, leptin, glucose and apolipoprotein B. Lipid peroxides and caspase-3 levels were increased while serum apolipoprotein A1 and antioxidant enzymes levels in heart tissues were decreased in HFD-induced obesity in rats as compared to normal healthy control rats fed on standard rat pellet diet. This model of diet-induced obesity will be a useful tool for studying the mechanisms by which dietary fat induces the obesity in humans.     

Over-the-counter analgesics normalize blood glucose and body composition in mice fed a high fat diet

Type 2 diabetes (noninsulin-dependent diabetes mellitus) develops from a pre-diabetic condition that is characterized by insulin resistance and glucose intolerance, and is exacerbated by obesity. In this study, we compared the ability of over-the-counter analgesic drugs (OTCAD) [acetaminophen (APAP); ibuprofen (IBU); naproxen (NAP); aspirin (ASA)], to protect against the development of a pre-diabetic state in mice fed a high fat diet. After 10 weeks on the high fat diet, mice had normal fasting blood glucose (FBG) levels, but exhibited impaired glucose tolerance. Treatment with 20 mg OTCADs/kg body weight improved glucose tolerance, with the order of efficacy, APAP=ASA>IBU, while NAP proved ineffective. Mice fed the high fat diet also exhibited increases in weight gain associated with an increase in body fat. OTCADs prevented in part this increase in body fat, in the order of efficacy, APAP=IBU>NAP=ASA. In isolated liver mitochondria, OTCADs inhibited succinate-dependent H2O2 production, while in white adipose tissue, APAP inhibited NADPH-oxidase mediated H2O2 production and lipid peroxidation. Thus, OTCADs diminish pro-oxidant processes that might otherwise exacerbate inflammation and a pre-diabetic state. We conclude that OTCADs, especially APAP and IBU, may be valuable tools to delay or prevent the development of type 2 diabetes from a pre-diabetic condition.