The effects of bitter melon (Momordica charantia) on serum and liver triglyceride levels in rats

Effects of three different varieties (Koimidori, Powerful-Reishi, and Hyakunari) of bitter melon (Momordica charantia) and those of methanol fraction extract of Koimidori variety on serum and liver triglycerides were studied in rats. Feeding of diets containing either bitter melon or various fractions isolated by organic solvents caused no adverse effects on food intake or growth of rats. When the effect of three different varieties of bitter melon was compared, the Koimidori variety was found to be the most effective in lowering hepatic triglyceride levels as compared to the other two varieties, suggesting a variety-dependent difference in their activity. Furthermore, the active component(s) responsible for the liver triglyceride lowering activity of Koimidori variety was assumed to be concentrated in the methanol fraction, but not in other fractions such as the n-hexane, the acetone, or the residual fraction. The triglyceride lowering activity was furthermore confirmed by the dose-dependent reduction of hepatic triglyceride, resulting the lowest level in rats fed 3.0% supplementation. In these experiments, the effects on serum lipids were marginal. The results of the present and previous studies clearly show that bitter melon, especially Koimidori variety, exhibits a potent liver triglyceride-lowering activity.     

Hypolipidaemic effect of fenugreek seeds. A clinical study

The hypolipidaemic effect of fenugreek seeds (Trigonella foenum graecum L.) was evaluated in ten hyperlipidaemic subjects. Isocaloric diets with and without fenugreek were each given for 20 days. Ingestion of experimental diets, containing 100 g of debitterized fenugreek powder, resulted in a significant reduction in the serum total cholesterol, LDL and VLDL cholesterol and triglyceride levels. HDL cholesterol levels were not altered but the ratio with total cholesterol and LDL and VLDL cholesterol were significantly increased. These results indicate the beneficial effect of fenugreek seeds in hyperlipidaemic patients.     

Peucedanum japonicum Thunb inhibits high-fat diet induced obesity in mice

This study examined the antiobese activity of Peucedanum japonicum Thunb (PJT) in mice. In the first experiment, 4-week-old C57BL/6 mice were fed seven different diets containing 15% corn oil and 0-20% PJT powder for 4 weeks. Feeding the 10% and 20% PJT diet suppressed the body weight gain and the accumulation of abdominal and subcutaneous fats. PJT reduced serum and liver levels of triglyceride and serum levels of leptin in a dose-dependent manner. PJT intake decreased the proportion of saturated fatty acids and increased polyunsaturated and n-3 fatty acids in the liver. To obtain more insight into the antiobese activity of PJT, its effect on lipid absorption and enzyme activities related to lipid metabolism was studied in the second experiment. There was an increased faecal excretion of triglyceride in mice fed 5% and 10% PJT diets. Fatty acid synthase activity was decreased while carnitine palmitoyltransferase activity was increased by 10% PJT intake. These findings pointed to the usefulness of PJT for the development of a safe natural agent to reduce obesity or body weight for the first time. The rationale for the lipid lowering mechanism of PJT and the candidate compound responsible for the observations have also been discussed.     

Bitter melon fruit extract has a hypoglycemic effect and reduces hepatic lipid accumulation in ob/ob mice

Bitter melon (Momordica charantia L.) is a vegetable and has been used as traditional medicine. Recently, we reported that bitter melon fruit extracts and its ethyl acetate (EtOAc)‐soluble fraction markedly suppressed the expression of proinflammatory genes, including the inducible nitric oxide synthase gene. However, it is unclear whether bitter melon exhibits antidiabetic effects. In this study, we showed that cucurbitacin B, a cucurbitane‐type triterpenoid, was present in an EtOAc‐soluble fraction and suppressed nitric oxide production in hepatocytes. When the EtOAc‐soluble fraction was administered for 7 days to ob/ob mice, a type 2 diabetes mellitus model, the mice fed with this fraction exhibited a significant decrease in body weight and blood glucose concentrations compared with the mice fed without the fraction. The administration of the fraction resulted in significant increases in serum insulin concentrations and the levels of both insulin receptor mRNA and protein in the ob/ob mouse liver. The EtOAc‐soluble fraction decreased the interleukin‐1β mRNA expression, as well as hepatic lipid accumulation in hepatocytes. Taken together, these results indicate that administration of an EtOAc‐soluble fraction improved hyperglycemia and hepatic steatosis, suggesting that this fraction may be responsible for both the antidiabetic and anti‐inflammatory effects of bitter melon fruit.     

蜘蛛香对高脂血症大鼠血脂及肝功能的影响

目的:探讨蜘蛛香对高脂血症大鼠血脂及肝功能的影响.方法:清洁级SD大鼠,除正常组外,其余各组采用高脂饲料喂养25 d建立高脂血症大鼠模型后,洛伐他汀组按3 mg·kg-1每日ig给予一次洛伐他汀溶液,蜘蛛香醇提物低、中、高3个剂量组每日分别按相当于生药1.25,2.5,5 g·kg-1 ig给药1次,造模各组仍喂食高脂饲料.2周后,检测血清胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)及肝组织TC,TG.结果:高脂饲料诱导后,模型对照组大鼠血清及肝组织中TC,TG,LDL-C较空白对照组显著升高(P＜0.05,P＜0.01),且血清ALT,AST也显著升高(P＜0.05).洛伐他汀,蜘蛛香醇提物给药后,均能显示显著降低血清及肝组织的TG,肝组织中TC及血清中ALT,AST的作用(P＜0.01).结论:蜘蛛香能降低实验性高脂血症大鼠血脂,并能保护高血脂动物的肝功能.     

复合磷脂和大豆磷脂对大鼠血脂和心肌丙二醛及脉搏波的影响

 目的：观察复合碑脂和大豆磷脂对高脂大鼠血脂、心肌丙二醛及脉搏波的影响。方法：在高脂饲料中添加复合磷脂或大豆磷脂饲养大鼠，3周末浏定血脂、心肌丙二醛及脉搏波。结果：复合碑脂和大豆磷脂都能明显降低大鼠血清胆固醉、甘油三脂及低密度脂蛋白胆固醉的含蚤；复合碑脂还可明显降低心肌丙二醛含t，提高尾动脉脉搏波上升支针率，增加降中峡的相对深度。结论：复合碑脂和大豆磷脂都具有降血脂的作用;复合碑脂还具有延缓衷老的作用。     

高效快速降脂动物模型研究

探讨斑马鱼作为降脂药物筛选模型的可行性以及盐酸小檗碱(BBR)对高脂斑马鱼的影响。用含4%胆固醇饲料喂养3月龄斑马鱼0,2,4,8,14,20,25,30 d,检测血清总胆固醇含量的变化;测定对照组、高胆固醇组、0.01%辛伐他汀组、0.1%BBR组和0.2%BBR组斑马鱼血清总胆固醇(TC)、总甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-c)和高密度脂蛋白胆固醇(HDL-c)的水平;RT-PCR检测肝脏HMGCR,LDLR和CYP7A1a mRNA的表达水平;油红O染色检测肝脏中脂肪含量的变化。结果显示4%胆固醇喂养斑马鱼后血清TC水平升高且有时间依赖性,20 d基本达到稳定水平;BBR组斑马鱼血清TC,TG和LDL-c水平显著下降,肝脏HMGCR mRNA的表达下降,LDLR和CYP7A1a mRNA的表达升高,脂肪含量减少。4%胆固醇饲料喂养斑马鱼20 d即可建立高脂斑马鱼模型,研究结果为进一步开展降脂药物的筛选奠定基础。     

苦瓜提取物抑制蛋白质的非酶糖基化

目的:研究苦瓜提取物对蛋白质非酶糖基化终末产物( AGE)生成的抑制作用.方法:体外蛋白质非酶糖基化反应系统中分别加入不同质量浓度的苦瓜提取物(0.01,0.1,1.0 g·L-1)或氮基胍(4 mmol·L-1),在不同时间分别测定蛋白质非酶糖化终末产物的生成量.制备糖尿病小鼠模型,以苦瓜提取物10,30 g·kg-1两个剂量连续ig 14 d,测定苦瓜提取物对糖尿病小鼠血糖以及心、肝、肾组织中AGE含量、超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量的影响.结果:在体外系统中,蛋白糖化产物的生成与孵育时间呈正相关,苦瓜提取物浓度依赖性抑制蛋白糖化终末产物的生成(P＜0.01).动物实验表明苦瓜提取物能抑制血糖升高(P ＜0.05,P＜0.01),改善糖尿病小鼠心、肝、肾组织中AGE含量(P ＜0.05,P＜0.01)、升高SOD活性(P ＜0.05,P＜0.01)和降低MDA含量(P＜0.05,P＜0.01),呈现剂量效果正相关.结论:苦瓜提取物体内体外均可有效抑制蛋白糖化终末产物的生成.     

仙人掌粉对大鼠血脂的调节作用及其机制的探讨

目的:观察仙人掌粉对大鼠血脂的调节作用,并探讨其作用机制。方法:分别以基础饲料、基础饲料加高、中、低剂量仙人掌粉饲喂正常大鼠,观察仙人掌粉对正常大鼠血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL C),低密度脂蛋白胆固醇(LDL C)、动脉硬化指数(AI),血清丙二醛(MDA),超氧化物歧化酶(SOD)等指标的影响。将造模成功的高血脂大鼠随机分为4组:分别为模型对照组和仙人掌粉高、中、低3剂量组,后者按高、中、低3种剂量给予样品。以上各组继续喂饲高脂饲料,3周后分别取血测定上述指标。结果:仙人掌粉对正常大鼠血清TC有降低作用,但与正常饲料组比较无显著差异(P>0.05),对正常大鼠TG,HDL C无影响。能明显降低正常大鼠MDA含量,升高SOD活性,与对照组比较,差异均有显著性意义。对于实验性高脂血症大鼠,仙人掌粉高、中、低3剂量组均能显著降低血清TC,LDL C,AI(P<0.01),TG(P<0.05),且其降脂作用与给药剂量有关。结论:仙人掌粉对正常大鼠及实验性高脂血症大鼠血脂均有调节作用,而对后者作用更为显著。     

Hypocholesterolaemic effect of the oleoresin of Capsicum annum L. in gerbils (Meriones hurrianae Jerdon)

The effect of capsicum oleoresin (CO) on dietary hypercholeterolaemia were observed in male gerbils at a dose of 75 mg/kg body wt/day. The oleoresin reduced serum cholesterol and triglycerides by 70% and 66%, whereas, liver cholesterol and triglycerides were lowered by 70.9% and 68.7% respectively, in comparison with atherogenic fed controls. CO feeding prevented the accumulation of cholesterol and triglycerides in the liver and aorta. The faecal excretion of cholesterol and triglycerides were significantly increased in oleoresin fed gerbils.     

Traditional medicine Taeeumjowitangkagambang exerts antiobesity and hypolipidemic effects via antioxidant enzyme enhancement

Taeeumjowitangkagambang (ETJKB) is a traditional Korean medicine that has been clinically used for obesity with little mechanistic understanding. The present study investigated antiobesity and hypolipidemic effects of ETJKB in high fat diet fed rats as well as a 3T3-L1 pre-adipocyte differentiation model. ETJKB significantly inhibited the lipidogenesis in 3T3-L1 adipocytes in a concentration-dependent manner as well as reduced the cellular adipokine leptin level. Daily oral gavage of ETJKB to rats fed a high fat diet significantly attenuated body weight gain and abdominal and epididymal fat weights. ETJKB treatment also reduced the levels of total cholesterol, low density lipoprotein (LDL) and triglyceride as well as increased high density lipoprotein (HDL) in serum compared with the untreated control. Similarly, the ETJKB treatment decreased the levels of total lipid, triglyceride and cholesterol in liver tissue in high fat diet fed rats. Interestingly, ETJKB significantly increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase in liver tissue, while decreasing the hydroxyl radical, thiobarbituric acid reactive substances (TBARS), carbonyl concentration. An improvement of antioxidant enzymes was associated with improved body weight control and healthier lipid profiles and therefore may play an important role in the antiobesity and hypolipidemic effects of ETJKB.     

Hypolipidaemic Effect of Fenugreek Seeds: a Chronic Study in Non-insulin Dependent Diabetic Patients

The lipid lowering activity of fenugreek seeds ( Trigonella foenum graecum L.) was studied in 60 non-insulin dependent diabetic subjects. Isocaloric diets without and with fenugreek were given for 7 days and 24 weeks respectively. Ingestion of an experimental diet containing 25 g fenugreek seed powder resulted in a significant reduction of total cholesterol, LDL and VLDL cholesterol and triglyceride levels. These results indicate the beneficial effect of fenugreek seeds in diabetic subjects.     

Hypolipidaemic and antioxidant effect of Enicostemma littorale Blume aqueous extract in cholesterol fed rats

Enicostemma littorale aqueous extract (1.5 g/100 g body weight/day, p.o.) was administered to rats along with hypercholesterolaemic diet for 6 weeks and the hypolipidaemic and antioxidant effect was evaluated. Feeding cholesterol increased serum cholesterol, serum triglycerides, LDL, VLDL and decreased HDL levels as compared to normal diet fed rats. Enicostemma littorale treatment increased HDL levels and decreased serum cholesterol, triglyceride, LDL, VLDL, LDL/HDL ratio. In addition, treatment with the extract showed a decrease in activities of erythrocyte catalase, superoxide dismutase and lipid peroxidation levels, with an increase in reduced glutathione levels as compared to cholesterol fed untreated rats. Liver and kidney cholesterol levels and triglyceride levels were also decreased in Enicostemma littorale treated rats. Hepatic HMG CoA reductase activity was significantly reduced in the extract treated hypercholesterolemic rats. Lovastatin was used as a reference drug. The hypolipidaemic and antioxidant effect of Enicostemma littorale aqueous extract in cholesterol fed rats is being reported for the first time.     

化浊解毒方对胰岛素抵抗大鼠脂代谢的影响

目的:探讨化浊解毒方对胰岛素抵抗(IR)大鼠脂代谢的影响。方法:将模型建立成功的胰岛素抵抗大鼠随机分为化浊解毒方组、模型组、空白对照组,每组16只。化浊解毒方组予化浊解毒颗粒按生药3 g/(kg·d)灌胃给药,空白对照组、模型组灌服等体积生理盐水,各组连续做相应处理8周。8周后检测各组大鼠血清甘油三酯(TG)、血清总胆固醇(TC)、游离脂肪酸(FFA)、大鼠肝脏二酰基甘油酰基转移酶2(DGAT2)mRNA表达以及肝脏组织TG含量水平。结果:模型组大鼠血清甘油三酯(TG)、血清总胆固醇(TC)以及游离脂肪酸(FFA)明显高于空白对照组(P<0.01);化浊解毒方组大鼠血清甘油三酯(TG)、血清总胆固醇(TC)以及游离脂肪酸(FFA)显著低于模型组(P<0.01);化浊解毒方组DGAT2mRNA表达较模型组显著降低(P<0.01);化浊解毒方组大鼠肝脏组织TG含量水平明显低于模型组(P<0.01)。结论:化浊解毒方可改善胰岛素抵抗大鼠的脂代谢紊乱,其作用机制可能是通过下调DGAT2基因表达,进而影响TG合成及TG在肝脏组织的蓄积。     

Momordica charantia extract on insulin resistance and the skeletal muscle GLUT4 protein in fructose-fed rats

Aim of the study

We investigated the preventive effect of Momordica charantia Linn. (Cucurbitaceae) fruit, commonly known as bitter melon, on hyperglycemia and insulin resistance in rats fed with a fructose-enriched diet.

Materials and methods

First, rats were divided randomly into two groups: the control group was fed with control diet, whereas the experimental group was fed with a 60% high-fructose diet for 8 weeks. After the first 6 weeks, the fructose-treated rats were further subdivided into six groups and were orally fed with or without Momordica charantia L. or rosiglitazone (ROS) for 2 weeks while rats were still on fructose diet.

Results

We demonstrated that bitter melon was effective in ameliorating the fructose diet-induced hyperglycemia, hyperleptinemia, hyperinsulinemia, and hypertriglyceridemia as well as in decreasing the levels of free fatty acid (FFA) (P < 0.001, P < 0.05, P < 0.05, P < 0.05, P < 0.05, respectively). Bitter melon reversed fructose diet-induced hypoadiponectinemia (P < 0.05), which provides a therapeutic advantage to insulin resistance in improving insulin sensitivity. Additionally, bitter melon decreased the weights of epididymal (P < 0.05) and retroperitoneal white adipose tissue (WAT) (P < 0.05). Bitter melon increased the expression of peroxisome proliferator-activated receptor γ (PPARγ) in white adipose tissue (WAT). Conversely, bitter melon decreased the expression of leptin in WAT. Furthermore, we demonstrate that bitter melon significantly increases the mRNA expression and protein of glucose transporter 4 (GLUT4) in skeletal muscle.

Conclusions

This study demonstrates, for the first time, the beneficial effects of two different extracts of bitter melon on insulin resistance in rats fed a high-fructose diet thereby producing evidence of the role of changes in expression of PPARγ and GLUT4.     

A study on the toxicology of Acacia nilotica

The potential toxicity of Acacia nilotica was investigated in rats maintained on 2% and 8% acacia diet for 2 and 4 weeks. A significant reduction in body weight in all acacia-fed groups and a significant decrease in the levels of hemoglobin, serum total protein and total cholesterol in animals fed 8% acacia diet for up to 4 weeks were observed. These effects were, however, reversed one week after treatment termination. No significant changes in serum parameters of hepatic and renal functions, fasting glucose and triglycerides were observed. Further, no deaths among treated animals and no significant histopathological changes in liver sections were noted. It is concluded that A. nilotica, at 2% and 8% levels, has a low toxicity potential.     

脂肪肝、高脂血症、糖尿病复合动物新模型的建立

[目的]探索建立脂肪肝、高脂血症、糖尿病复合模型。[方法]采用北京鸭,随机分为对照组和模型组。模型组填饲高糖饲料(玉米96.7%、调和油1.9%、食盐1.4%、禽用维生素10g/100kg),100g/(kg.d),观察体质量、血清脂质、血糖、肝脏脂质、肝脏病理形态学等指标。[结果]模型组家鸭体质量、肝指数、血清胆固醇(TC)、甘油三酯(TG)、血糖、肝组织TG均高于空白组,存在大量肝细胞脂肪变性。[结论]家鸭高糖饮食3周可复制脂肪肝、高脂血症、糖尿病复合模型。     

Effect of shosaikoto, daisaikoto and sannoshashinto (traditional Japanese and Chinese medicines) on experimental hyperlipidemia in rats

Effect of Sannoshashinto, Shosaikoto and Diasaikoto, Japanese and Chinese traditional medicinal mixtures (kampohozai), on cholesterol-induced hypercholesterolemia, aging-induced hyperlipidemia and cholesterol turnover were studied in rats. Sannoshashinto, Shosaikoto and Daisaikoto reduced the hypercholesterolemia induced by a high cholesterol diet and Sannoshashinto and Daisaikoto improved the atherogenetic index. Liver total cholesterol as increased by a high cholesterol diet was reduced by all three kampohozai. Furthermore, the increases of serum and liver triglyceride were also inhibited. In an experiment using untreated aging rats, both serum total cholesterol and serum triglyceride levels were increased. The aging-induced increases of serum total cholesterol were inhibited by Sannoshashinto and Daisaikoto and the increases of serum triglyceride were reduced by all three kampohozai. These drugs showed no effect on cholesterol biosynthesis in liver. Sannoshashinto, however, appeared to accelerate the disappearance of cholesterol from blood, while Daisaikoto inhibited the cholesterol absorption from the intestine.     

藏药复方TKF对自发性2型糖尿病小鼠(KK-Ay小鼠)糖代谢的作用研究

目的:研究藏药复方TKF对KK-Ay小鼠的降糖作用。方法:以C57BL/6 J小鼠作为对照组,KK-Ay小鼠随机分为模型组、TKF组(1.125、2.25、4.5g/kg)和格列本脲组5组,连续灌胃35天,检测小鼠体重、空腹血糖、口服糖耐量、血清胰岛素和血脂等指标。结果:TKF 2.25g/kg组从给药7天起即出现空腹血糖的降低,并在给药期间维持在一较低水平,给药35天时TKF各组血清胰岛素水平显著降低,2.25g/kg组血清甘油三酯亦明显降低。结论:TKF具有降低KK-Ay小鼠血糖、血脂和胰岛素水平,改善胰岛素抵抗的作用。