Combined effect of vitamin E and insulin on cataracts of diabetic rats fed a high cholesterol diet

In the present study we investigated the effects of a long-term treatment with vitamin E, an antioxidant vitamin, insulin or their combination on cataracts of streptozotocin (STZ)-induced diabetic rats fed a high cholesterol diet. Each rat was checked for cataracts at 0, 1, 2, 4, 8, 12 and 15 weeks after STZ injection. Cataracts were observed from 8 weeks in the control diabetic rats and their incidence of catarats increased to 100% by 12 weeks. The incidence of cataracts in rats treated with vitamin E, insulin and their combination was first seen at 12 weeks and 56%, 20% and 10%, respectively, at 12 weeks and 78%, 50% and 20%, respectively, at 15 weeks. The preventive effects of either agent alone and their combination on the cataracts were in agreement with those obtained by histopathological evaluation of eyeballs. The combined treatment with both agents markedly improved hyperglycemia, hyperlipidemia and increased serum lipid peroxide levels. These results indicate that the combined treatment with vitamin E and insulin is useful in preventing the development and progression of diabetic cataracts.     

LW-AFC对饮食和链佐星联合诱导糖尿病大鼠的治疗作用

目的评价LW-AFC治疗糖尿病的作用,并探讨其作用特点。方法采用高热量饲料对Wistar大鼠饮食诱导5周,随后一次性ip给予链佐星(STZ)30 mg.kg-1制备糖尿病大鼠模型。7 d后ig给予LW-AFC 0.28,0.56和1.12 g.kg-1,每天1次,连续8周。在给药后2,4,6和8周动态监测大鼠空腹血糖、胰岛素、胰岛素抵抗指数(HOMA-IR)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)和甘油三酯(TG)水平,称量内脏脂肪质量(VFM)并计算内脏脂肪系数(VFC)。采用酶比色法检测血糖、TC和TG,采用清除法检测LDL-C,采用放射免疫分析法检测胰岛素。结果与正常对照组比较,模型组大鼠VFM和VFC显著升高(P<0.01),空腹血糖水平显著升高(P<0.01),胰岛素水平在2和6周明显升高(P<0.05),TC水平在4,6和8周明显升高,LDL-C水平在2,6和8周明显升高(P<0.05),TG水平在2周明显升高。与模型组比较,LW-AFC 0.56和1.12 g.kg-1给药8周可显著降低VFM至17.1±3.0和(16.0±3.6)g,可降低VFC至(4.5±0.6)%和(4.3±0.9)%(P<0.01);LW-AFC 1.12 g.kg-1给药4,6和8周可将空腹血糖水平由19.3±3.1,21.4±7.0和(17.0±4.7)mmol.L-1分别降低至14.2±4.0,11.8±4.9和(11.2±4.9)mmol.L-1;LW-AFC对胰岛素水平无明显影响。HOMA-IR在2～8周明显升高(P<0.01),HOMA-IR降低至17.3±4.8,17.4±6.7和4.1±2.4(P<0.05),LW-AFC 1.12 g.kg-1给药4,6和8周可明显降低TC至2.34±0.22,2.09±0.29和(2.16±0.22)mmol.L-1。LW-AFC 1.12 g.kg-1给药2周可将LDL-C降至(0.41±0.11)mmol.L-1;在6和8周降至0.50±0.10和(0.46±0.08)mmol.L-1。LW-AFC 0.56和1.12 g.kg-1给药2周TG降低至1.9±0.8和(1.8±0.8)mmol.L-1。结论 LW-AFC对糖尿病模型大鼠具有改善腹型肥胖、糖脂代谢紊乱和胰岛素抵抗的作用。     

苦瓜提取物对高脂饲料诱导肥胖大鼠的减肥作用

目的研究苦瓜提取物对高脂膳食诱导肥胖大鼠的减肥作用和可能机制。方法高脂饲料喂养制备肥胖大鼠模型,然后随机分为空白对照组、模型对照组和苦瓜提取物36 g.kg-1治疗组,分别灌胃给予质量分数为0.5%的羧甲基纤维素钠和苦瓜提取物,给药周期为6周,实验过程中每周记录体质量,最后一周测定摄食量,实验结束后检测体内脂肪含量,检测血清高密度脂蛋白(highdensity lipoprotein,HDL)、低密度脂蛋白(low density lipoprotein,LDL)、谷草转氨酶(aspartate ami-no transaminase,AST)和谷丙转氨酶(alanine amino transferase,ALT)水平以及肝脏脂肪病变。结果苦瓜提取物能够在不影响大鼠摄食量的基础上抑制肥胖大鼠的体质量增长速度,降低其体质量和附睾下脂肪量,升高血清中HDL水平,降低血清中AST水平,抑制肝细胞脂肪变性;而对Lee's指数、肠系膜和肾周脂肪量、血清中LDL和ALT水平无明显影响。结论苦瓜提取物具有一定减肥和保肝作用,该作用可能与升高血清HDL水平和降低血清AST水平以及抑制肝细胞脂肪变性有关。     

Ameliorative effect of berberine on endothelial dysfunction in diabetic rats induced by high-fat diet and streptozotocin

Berberine can improve insulin resistance, lower blood glucose, and regulate lipid metabolism disorders which cause endothelial dysfunction, leading to vascular complications of type 2 diabetes mellitus. The aim of the present study was to investigate the effects of berberine on endothelial dysfunction of aortas in type 2 diabetes mellitus rats and its mechanism. Wistar rats were randomly divided into four groups: diabetic rats, control rats, diabetic rats treated with berberine (100 mg/kg), and control rats treated with berberine. The serum fasting blood glucose, insulin, total cholesterol, triglyceride and nitric oxide (NO) levels were tested. Acetylcholine-induced endothelium-dependent relaxation and sodium nitroprusside induced endothelium-independent relaxation were measured in aortas for estimating endothelial function. The expression of endothelial nitric oxide synthase (eNOS) mRNA was measured by RT-PCR, and the protein expressions of eNOS and NADPH oxidase (NOX4) were analyzed by western blot. The results showed that berberine significantly decreased fasting blood glucose, and triglyceride levels in diabetic rats. Berberine also improved endothelium-dependent vasorelaxation impaired in aorta. The expressions of eNOS mRNA and protein were significantly increased, while NOX4 protein expression was decreased in aortas from diabetic rats with berberine treatment. Moreover, serum NO levels were elevated after berberine treatment. In conclusion, berberine restores diabetic endothelial dysfunction through enhanced NO bioavailability by up-regulating eNOS expression and down-regulating expression of NADPH oxidase.     

丹参降尿酸作用初步实验研究

目的研究丹参醇提物对高尿酸血症小鼠尿酸水平的影响,并初步探讨其作用途径。方法腹腔注射黄嘌呤和氧嗪酸钾,诱导小鼠致高尿酸血症,分别给予不同剂量的丹参醇提物,检测小鼠血清尿酸(SUA),尿液尿酸(UUA)及肝脏黄嘌呤氧化酶活性(XOD)。结果丹参中剂量组(DM)和低剂量组(DL)均能显著降低小鼠SUA水平,促进UUA排泄。结论丹参醇提物可通过促进尿酸排泄显著降低小鼠血尿酸水平。     

Anti-inflammatory effect of genistein on non-alcoholic steatohepatitis rats induced by high fat diet and its potential mechanisms

Genistein is a naturally occurring plant-derived phytoestrogen present in the human diet, and is known to possess anti-cancer, anti-oxidant and anti-osteoporosis effects. Anti-inflammatory activity of genistein has been revealed in animal studies. In this paper, we investigated the anti-inflammatory effect of genistein on non-alcoholic steatohepatitis (NASH) rats induced by high fat diet (HFD), and explored its potential mechanisms. Rats were fed with normal chow diet or HFD for 12 weeks with or without low (4 mg/kg/day body weight) or high (8 mg/kg/day body weight) dose of genistein. Serum levels of aminotransferases, thiobarbituric acid-reactive substances (TBARS), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) and transforming growth factor beta (TGF-β(1)) were measured, hepatic inflammation, liver TBARS, IL-6, TNF-α and TGF-β(1) levels were determined, and proteins involved in mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) pathways were assayed. The results showed that the NASH model rats reproduced typical pathogenetic and histopathological features of NASH in human, and genistein administration improved liver function, slowed down NASH progression, decreased the levels of TBARS, TNF-α and IL-6 in serum and liver, as well as inhibited IκB-α phosphorylation, nuclear translocation of NF-κB p65 subunit, and activation of c-Jun N-terminal kinase (JNK). In conclusion, genistein may be a promising drug to inhibit the inflammatory process and prevent liver damage in patients with NASH.     

Cardiotoxicity in rats induced by methidathion and ameliorating effect of vitamins E and C

We have examined the effect of subchronic methidathion (MD) administration on heart damage, and have evaluated possible ameliorating effects of a combination of vitamins E and C against MD toxicity. The experimental groups were: control group, rats treated with 5 mg/kg MD and rats treated with 5 mg/kg body weight MD plus vitamin E and vitamin C (MD+Vit). The groups were given MD by gavage 5 days a week for four weeks at a dose level of 5 mg/kg/day (MD and MD+Vit) by using corn oil as the vehicle. Vitamin E and vitamin C were injected at doses of 50 mg/kg i.m. and 20 mg/kg i.p., respectively, after the treatment with MD in the MD+ Vit group. The levels of malondialdehyde (MDA) were determined in the heart tissue, and the levels of cardiac troponin I (TnI) in serum. An autoanalyser was used to determine the serum activities of cholinesterase (ChE). Histopathological examination was carried out in the heart tissue. MDA significantly increased in the MD group as compared to controls (P <0.01). When MD was given concurrently with vitamins E and C, the increase in MDA was significantly less (P <0.01). ChE activity significantly decreased in the MD group as compared to controls (P <0.01). When MD was given concurrently with vitamins E and C, the decrease in ChE activity was significantly higher (P <0.05). The serum TnI levels significantly increased in the MD group as compared to controls (P <0.01). When MD was given concurrently with vitamins E and C, the increase in the serum TnI was significantly less (P <0.01). MD caused the diffuse loss of striation and myocytolysis of the cardiomyocytes, whereas the combination of vitamins E and C caused a significant decrease in these effects of MD. In conclusion, subchronic MD administration caused heart damage and, in addition, treatment with a combination of vitamins E and C after the administration of MD reduced heart damage caused by MD.     

酮替芬对高糖高脂饮食诱导肥胖模型大鼠的减肥作用简

目的：探讨酮替芬对高糖高脂饮食诱导的大鼠肥胖模型的减肥作用及其机制。方法：SD大鼠随机分成肥胖模型组、酮替芬干预组和正常对照组,肥胖模型组和酮替芬干预组以高糖高脂饲料饲喂,正常对照组以基础饲料饲喂,酮替芬干预组每天灌胃给予酮替芬0．09mg／kg,持续12周。称重,计算Lee’s指数,检测空腹血糖（FBG）、空腹胰岛素（FINS）、瘦素（LEP）、游离脂肪酸（FFA）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL—C）、白介素-6（IL-6）、肿瘤坏死因子-α（TNF—α）;检测白色脂肪解偶联蛋白2（UCP2）mRNA的表达。结果：酮替芬明显降低肥胖模型大鼠的体质量及Lee’S指数（P〈0．05）,降低FBG、FINS和LEP水平（P〈0．05）,降低FFA、TG和LDL—C水平（P〈0．05）和IL-6、TNF—α水平（P〈0．05）,而增加UCP2mRNA的表达水平（P〈0．05）。结论：酮替芬能够降低肥胖模型大鼠炎症介质和游离脂肪酸水平,减轻高胰岛素血症和高瘦素血症,促进脂肪组织能量代谢,实现减肥作用。     

Combined effect of probucol and insulin on cataracts of diabetic rats fed a high cholesterol diet

We investigated the effects of long-term treatment with probucol, a hypolipidemic agent with antioxidative action, insulin, or their combination on cataracts of streptozotocin-induced diabetic rats fed a high cholesterol diet. Each rat was checked for cataracts at 0, 1, 2, 4, 8, 12 and 15 weeks after streptozotocin injection. Cataracts were observed from 8 weeks in untreated hypercholesterolemic and diabetic rats and the incidence of catarats increased to 100% by 15 weeks. The incidence of cataracts in rats treated with probucol, insulin and their combination was first seen at 12, 12 and 15 weeks, respectively, and was 86%, 63% and 33%, respectively, at 15 weeks. The preventive effects of both agents alone and their combination on the cataracts were confirmed by histopathological evaluation of eyeballs. The combined treatment with both agents markedly improved hyperglycemia, hyperlipidemia and increased serum lipid peroxide levels. These results indicate that the combined treatment with probucol and insulin is useful in preventing the development and progression of diabetic cataracts.     

维生素E对氯丁二烯所致大鼠肝损害的预防作用

给大鼠ｉｇ维生素Ｅ１５０ｍｇ·ｋｇ－１·ｄ－１，３０ｍｉｎ后ｉｐ氯丁二烯（ＣＢＤ）８０ｍｇ·ｋｇ－１·ｄ－１，持续３ｗｋ，能明显防止由单独ｉｐＣＢＤ而引起的肝细胞色素Ｐ４５０，氨基比林脱甲基酶活性的降低及肝内脂质过氧化产物丙二醛含量升高；还可使线粒休与微粒体α－生育酚含量大幅度升高，并使肝受损指标血清甘胆酸含量下降，病理所见肝细胞变性坏死亦明显减轻。离休肝细胞以ＣＢＤ染毒发现，胞内游离钙浓度明显升高，并有明显的剂量依赖关系。     

阿托伐他汀对高脂饮食大鼠非酒精性脂肪性肝炎的影响

目的观察阿托伐他汀对高脂饮食大鼠非酒精性脂肪性肝炎(NASH)的影响。方法将23只SD大鼠随机分为三组:正常对照组(NC组,8只)、高脂饲养模型组(HF组,7只)和高脂饲养+阿托伐他汀组(HF+AT组,8只)。观察大鼠血清及肝脏各指标的变化,RT-PCR分别检测肝组织核转录因子κB(NF-κB)、肿瘤坏死因子α(TNF-α)及过氧化物酶体增生物激活受体γ(PPARγ)mRNA表达。结果与HF组相比,HF+AT组大鼠血清相关指标明显改善,肝组织脂肪变性及炎症活动得以减轻,肝脏NF-κB及TNF-αmRNA表达降低,PPARγmRNA表达增加(P<0.05或P<0.01)。结论阿托伐他汀能减轻高脂诱导的模型大鼠NASH。     

Vascular wall damage in rats induced by methidathion and ameliorating effect of vitamins E and C

We examined the effect of subacute methidathion (MD) administration on vascular wall damage and evaluated the ameliorating effects of combination of vitamins E and C against MD toxicity. The experimental groups were: rats treated with corn oil (control group), rats treated with 5 mg/kg MD (MD), and rats treated with 5 mg/kg body weight MD plus vitamin E and vitamin C (MD+Vit). The groups were given MD by gavage on 5 days a week for 4 weeks at a daily dose 5 mg/kg (MD and MD+Vit) using corn oil as the vehicle. Vitamins E and C were injected at doses of 50 mg/kg intramuscularly and 20 mg/kg intraperitoneally, respectively, after the treatment with MD in the MD+Vit group. The levels of malondialdehyde (MDA) were determined in the aortic tissue. Histopathological examination was examined in the thoracic aortic tissue. MDA levels were higher in the MD group than the control group and lower in the MD+Vit group than MD group. MD administration led to irregulation, prominent breaks, and fragmentation of the elastic fibers but decrease in the irregulation and fragmantation of the elastic fibers with the combination of vitamins E and C in MD-treated rats. In conclusion, it is likely that subacute MD administration caused vascular wall damage, and that treatment with a combination of vitamins E and C after the administration of MD can reduce vascular wall damage caused by MD.     

Cyclophosphamide effect on ultrastructural myocardial changes in rats on low-magnesium diet.

Intraperitoneal cyclophosphamide administration to a total dose of 225 mg/kg body weight during six weeks produced in rat myocardial fibres evident focal degenerative changes in all organelles, and, fairly frequently, significant damage even up to necrosis. The experiment showed that in rats on low-magnesium diet cyclophosphamide produced more intense and more extensive changes than in rats receiving only cyclophosphamide. The extent of the lesions produced with low and high doses of cyclophosphamide was compared and it was observed that the lesions increased with an enlargement of doses of the drug.     

Endometrial damage and apoptosis in rats induced by dichlorvos and ameliorating effect of antioxidant vitamins E and C

We aimed to investigate the effect of subchronic administration of dichlorvos (DDVP) on endometrium and to evaluate ameliorating effects of a combination of Vitamins E and C against DDVP toxicity in the rat. Three groups of rats were used in the experiment. The first group was treated with 4 mg/kg DDVP; the second group was treated with 4 mg/kg body weight DDVP plus Vitamins E and C (DDVP + Vit); the third group was given only corn oil (control). DDVP and DDVP + Vit groups were given DDVP by gavage 5 days a week for 4 weeks at a dose level of 4 mg/kg day by using corn oil as the vechicle. Vitamins E and C were injected at doses of 50 mg/kg i.m. and 20 mg/kg body weight i.p. Histopathological and immunohistochemical examinations for caspase-3 and caspase-9 were accomplished in the endometrium. The level of malondialdehyde (MDA) increased significantly in the DDVP group compared with the control group (p < 0.05). MDA significantly decreased in the DDVP + Vit group compared with the DDVP group (p < 0.05). Administration of Vitamins E and C along with DDVP significantly reduced the histopathological changes and the extent of apoptosis. In conclusion, subchronic DDVP administration caused endometrial damage and that treatment with a combination of Vitamins E and C reduced endometrial damage caused by DDVP.     

Endometrial damage and apoptosis in rats induced by dichlorvos and ameliorating effect of antioxidant Vitamins E and C

We aimed to investigate the effect of subchronic administration of dichlorvos (DDVP) on endometrium and to evaluate ameliorating effects of a combination of Vitamins E and C against DDVP toxicity in the rat. Three groups of rats were used in the experiment. The first group was treated with 4 mg/kg DDVP; the second group was treated with 4 mg/kg body weight DDVP plus Vitamins E and C (DDVP + Vit); the third group was given only corn oil (control). DDVP and DDVP + Vit groups were given DDVP by gavage 5 days a week for 4 weeks at a dose level of 4 mg/kg day by using corn oil as the vechicle. Vitamins E and C were injected at doses of 50 mg/kg i.m. and 20 mg/kg body weight i.p. Histopathological and immunohistochemical examinations for caspase-3 and caspase-9 were accomplished in the endometrium. The level of malondialdehyde (MDA) increased significantly in the DDVP group compared with the control group (p < 0.05). MDA significantly decreased in the DDVP + Vit group compared with the DDVP group (p < 0.05). Administration of Vitamins E and C along with DDVP significantly reduced the histopathological changes and the extent of apoptosis. In conclusion, subchronic DDVP administration caused endometrial damage and that treatment with a combination of Vitamins E and C reduced endometrial damage caused by DDVP.     

Crocetin improves the insulin resistance induced by high-fat diet in rats

BACKGROUND AND PURPOSE: The amelioration of insulin resistance by treatment with crocetin is closely related to the hypolipidaemic effect. The present study is designed to clarify the insulin-sensitizing mechanism of crocetin by elucidating the mechanism of regulation of lipid metabolism by crocetin. EXPERIMENTAL APPROACH: Rats given a high-fat diet were treated with crocetin for 6 weeks before hyperinsulinaemic-euglycaemic clamp. 14C-palmitate was used as tracer to track the fate of non-esterified fatty acids or as substrate to measure beta-oxidation rate. Triglyceride clearance in plasma and lipoprotein lipase activity in tissues were tested. Content of lipids in plasma and tissues was determined. Real-time PCR was used to assay the level of mRNA from genes involved in non-esterified fatty acid and triglyceride uptake and oxidation. KEY RESULTS: Crocetin prevented high-fat-diet induced insulin resistance (increased clamp glucose infusion rate), raised hepatic non-esterified fatty acid uptake and oxidation, accelerated triglyceride clearance in plasma, enhanced lipoprotein lipase activity in liver, and reduced the accumulation of detrimental lipids (DAG and long-chain acyl CoA) in liver and muscle. Genes involved in hepatic lipid metabolism which are regulated by peroxisome proliferator-activated receptor-alpha, were modulated to accelerate lipid uptake and oxidation. CONCLUSIONS AND IMPLICATIONS: Through regulating genes involved in lipid metabolism, crocetin accelerated hepatic uptake and oxidation of non-esterified fatty acid and triglyceride, and reduced lipid availability to muscle, thus decreasing lipid accumulation in muscle and liver, and consequently improving sensitivity to insulin.     

Hyperlipidemia induced by a cholesterol-rich diet aggravates necrotizing pancreatitis in rats

The aim of the present study was to investigate whether hyperlipidemia can cause acute pancreatitis or alter its severity. Male Wistar rats were fed a 3% cholesterol-enriched diet or a normal diet for 16 weeks. Edematous and necrotizing pancreatitis was induced with 3x75 mug/kg body weight of cholecystokinin s.c. and 2x2 g/kg body weight of L-arginine i.p., respectively, in separate groups of normal and hyperlipidemic rats. The severity of the pancreatitis was assessed. We studied the influence of hyperlipidemia on the formation of oxygen-derived free radicals, endogenous scavengers, nitric oxide synthases (NOS), peroxynitrite (ONOO(-)), heat shock protein 72 (HSP72) and nuclear factor-kappa B (NF-kappaB) activation in the pancreas during acute edematous and necrotizing pancreatitis. Hyperlipidemia did not worsen edematous, but aggravated necrotizing pancreatitis. The cholesterol-enriched diet significantly reduced the catalase and Mn-superoxide dismutase (SOD) and constitutive NOS (cNOS) activities and increased the inducible NOS (iNOS) in the pancreas relative to those in the rats on the normal diet. The pancreatic nitrotyrosine level, as a marker of ONOO(-), and the NF-kappaB DNA-binding activity in the pancreas, were significantly elevated in the cholesterol-fed rats. The pancreatic HSP72 expression during necrotizing pancreatitis was not influenced by the hyperlipidemia. The pancreatic Mn-SOD, Cu, Zn-SOD, glutathione peroxidase, total glutathione and cNOS activities were significantly reduced, while the catalase, iNOS and NF-kappaB DNA-binding activities were significantly increased in the animals with necrotizing pancreatitis on the cholesterol diet as compared with those with pancreatitis and receiving the normal diet. Hyperlipidemia induced with this cholesterol-enriched diet leads to decreases in endogenous scavenger and cNOS activities, results in iNOS and NF-kappaB activation and stimulates ONOO(-) generation in the pancreas, which may be responsible for the aggravation of acute necrotizing pancreatitis.     

Hypolipaemic effect and inhibition of lipid peroxidation by glunicate in rats on atherogenic diet

The antiatherosclerotic profile of nicotinic acid and of its new water-insoluble derivative was studied in an 8-day experiment in rats. Both drugs lowered plasma triglyceride levels significantly, while other lipoprotein parameters were unaffected. Circulating immune complex levels were decreased with lysosomal membrane permeability by both drugs. Glunicate proved to be a powerful antioxidant with regard to enzymatic lipid peroxidation when studied in the liver microsomal system. The relevance of these findings to the antiatherosclerotic effect of the drugs and the biological significance of antioxidant treatment is discussed. On the basis of these data glunicate seems to be a promising new therapeutic tool against atherosclerosis and merits further study.     

The effect of tryptophan supplementation on autotomy induced by nerve lesions in rats.

Rats were fed an artificial diet containing either their normal, or five times their normal, daily requirement of tryptophan for up to five weeks and were tested in an animal model of deafferentation pain, nerve lesion-induced autotomy. In this model one of the hind limbs of the animal was denervated, and the extent to which the animal attacked its denervated paw was assessed. Rats receiving the high-tryptophan diet showed significantly lower levels of autotomy, compared to rats fed the control diet. 5-Hydroxytryptamine and 5-hydroxyindoleacetic acid in the brain and spinal cord were significantly elevated in rats receiving the high-tryptophan diet, indicating that the supplemented diet produced a chronic increase in CNS indoleamine metabolism. Currently there is no accepted pharmacological treatment of deafferentiation pain. Our results suggest that tryptophan should be tested in phantom limb pain and other deafferentation pain syndromes.