Artichoke leaf extract reduces oxidative stress and lipoprotein dyshomeostasis in rats fed on high cholesterol diet

Hypercholesterolemia and lipid peroxidation play complementary role in atherosclerosis. Artichoke leaf extract (ALE) is rich in natural antioxidants and has a cholesterol‐reducing effect. However, there is no study investigating the effect of ALE on lipid levels and lipid peroxidation in experimental hypercholesterolemic conditions. Rats were fed on 4% (w/w) cholesterol and 1% (w/w) cholic acid supplemented diet for 1 month. ALE (1.5 g/kg/day) was given by gavage during the last 2 weeks. Serum lipid composition, malondialdehyde (MDA) and diene conjugate (DC) levels and plasma antioxidant activity (AOA) were measured. In addition, endogenous DC and copper‐induced MDA levels were determined in apo B‐containing lipoproteins (LDL+VLDL fraction). Serum cholesterol and triglyceride levels and the ratio of cholesterol to HDL‐cholesterol decreased due to ALE treatment in rats fed on HC diet. Significant decreases in serum MDA and DC levels and increases in plasma AOA were detected in serum in ALE‐treated hypercholesterolemic rats. Endogenous DC and copper‐induced MDA levels were also lower in LDL+VLDL fraction due to ALE‐treatment in hypercholesterolemic rats. Our results indicate that ALE may be useful for the prevention of hypercholesterolemia‐induced pro‐oxidant state in LDL+VLDL fraction and the reduction of increased serum cholesterol and triglyceride levels. Copyright © 2009 John Wiley & Sons, Ltd.     

Effect of fruits of Moringa oleifera on the lipid profile of normal and hypercholesterolaemic rabbits

Rabbits were fed Moringa oleifera (200mg/kg/day, p.o.) or lovastatin (6mg/kg/day, p.o.) in banana pulp along with standard laboratory diet and hypercholesterolaemic diet for 120 days. Moringa oleifera and lovastatin were found to lower the serum cholesterol, phospholipid, triglyceride, VLDL, LDL, cholesterol to phospholipid ratio and atherogenic index, but were found to increase the HDL ratio (HDL/HDL-total cholesterol) as compared to the corresponding control groups. Treatment with M. oleifera or lovastatin in normal rabbits decreased the HDL levels. However, HDL levels were significantly increased or decreased in M. oleifera- or lovastatin-treated hypercholesterolaemic rabbits, respectively. Lovastatin- or M. oleifera-treated hypercholesterolaemic rabbits showed decrease in lipid profile of liver, heart and aorta while similar treatment of normal animals did not produce significant reduction in heart. Moringa oleifera was found to increase the excretion of faecal cholesterol. Thus, the study demonstrates that M. oleifera possesses a hypolipidaemic effect.     

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.     

Hypolipidaemic activity of Helicteres isora L. bark extracts in streptozotocin induced diabetic rats

In this study, the hypolipidaemic effect of an aqueous extract of the bark of Helicteres isora was investigated in streptozotocin (STZ)-induced diabetic rats. Administration of the bark extract of Helicteres isora (100 and 200 mg/kgb.w.) for 21 days resulted in significant reduction in serum and tissue cholesterol, phospholipids, free fatty acids and triglycerides in STZ diabetic rats. In addition to that, significant (p<0.05) decrease in high-density lipoprotein (HDL) whereas significant increase (p<0.05) low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) were observed in STZ diabetic rats, which were normalized after 21 days of bark extract treatment. The bark extract at a dose of 200 mg/kgb.w. showed much significant hypolipidaemic effect than at the dose of 100 mg/kgb.w.     

Hypolipidemic effect of Glycine tomentella root extract in hamsters

The influence of the aqueous crude extract of Glycine tomentella root (Leguminosae) on lipid metabolism was investigated in hyperlipidemic hamsters. It was found that the administration of the G. tomentella extract (GTE) leads to a decrease of high serum cholesterol and triglyceride levels induced by high-fat diet. The GTE also increased serum high-density lipoprotein (HDL) cholesterol and decreased serum low-density lipoprotein (LDL) cholesterol. The reduction of serum triglyceride levels was accompanied by a significant decrease in the hepatic triglyceride content, while the cholesterol content was not changed. The results indicate that GTE is definitely an anti-hyperlipidemic agent, at least, in animals.     

Glucose lowering effect of aqueous extract of Enicostemma littorale Blume in diabetes: a possible mechanism of action

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycemia. Enicostemma littorale Blume is a small herb and recently we have reported its blood glucose lowering potential in alloxan induced diabetic rats. A single dose of aqueous extract of E. littorale (15 g dry plant equivalent extract per kg) had shown significant increase in the serum insulin levels in alloxan-induced diabetic rats at 8 h. The insulinotropic action of aqueous extract of E. littorale was further investigated using rat pancreatic islets. Extract has the potential to enhance glucose-induced insulin release at 11.1 mM glucose from isolated rat pancreatic islets and was partially able to reverse the effect of diazoxide (0.25 mM). Incubation with Ca(2+) chelator (EGTA) and Ca(2+) channel blocker (nimodipine) did not affect the glucose-induced insulin release augmented by the extract. Above results suggest the glucose lowering effect of aqueous extract of E. littorale to be associated with potentiation of glucose-induced insulin release through K(+)-ATP channel dependent pathway but did not require Ca(2+) influx.     

Hypolipidaemic and antiatherosclerotic effects of oral Gymnema sylvestre R. Br. Leaf extract in albino rats fed on a high fat diet

Gymnema sylvestre R. Br. leaf extract (25–100 mg/kg) when orally administered to experimentally induced hyperlipidaemic rats for 2 weeks, reduced the elevated serum triglyceride (TG), total cholesterol (TC), very low-density lipoprotein (VLDL)-and low-density lipoprotein (LDL)-cholesterol in a dose-dependent manner. The decreased serum high-density lipoprotein (HDL)-cholesterol and antiatherogenic index (AAI) in hyperlipidaemia were also reversed towards normalization. The ability of this extract (at 100 mg/kg) to lower TG and TC in serum and its antiatherosclerotic potential were almost similar to that of a standard lipid lowering agent—clofibrate.     

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 activity of aqueous Ocimum basilicum extract in acute hyperlipidaemia induced by triton WR-1339 in rats and its antioxidant property

Hyperlipidaemia, atherosclerosis and related diseases are becoming a major health problem in developing countries. Ocimum basilicum is one of the medicinal plants widely used in Morocco to reduce plasma cholesterol and to reduce the risk of atherosclerosis-related diseases. However, mechanisms underlying the reported hypolipidaemic effect of this plant have not been investigated. This study evaluates the lipid lowering effect of aqueous Ocimum basilicum extract in Triton WR-1339-induced hyperlipidaemic rats. Hyperlipidaemia was developed in animals by intraperitoneal injection of Triton (200 mg/kg). After injection of Triton the animals were divided into three treatment groups: hyperlipidaemic, hyperlipidaemic plus herb extract and hyperlipidaemic plus fenofibrate treated rats. At 7 h after the Triton injection, levels of plasma cholesterol, triglycerides and LDL-cholesterol in rats treated also with the Ocimum basilicum extract (0.5 g/100 g body weight) were, respectively, 50%, 83% and 79% lower than Triton-treated rats and HDL-cholesterol was 129% higher than in rats given Triton alone. At 24 h following Ocimum basilicum administration, total cholesterol, triglycerides and LDL-cholesterol levels decreased by 56%, 63% and 68%, respectively, in comparison with the Triton treated group and HDL-cholesterol was not increased significantly. The hypolipidaemic effect exerted by Ocimum basilicum extract was markedly stronger than the effect induced by fenofibrate treatments. Further it was demonstrated that Ocimum basilicum aqueous extract displayed a very high antioxidant power. These results indicate that Ocimum basilicum extract may contain hypolipidaemic and antioxidant substances and its use as a therapeutic tool in hyperlipidaemic subjects may be of benefit and encourage further investigation in this field.     

Reduction of plasma cholesterol by Curcuma comosa extract in hypercholesterolaemic hamsters.

The influence of the extract of Curcuma comosa Roxb. (Zingiberaceae) on lipid metabolism was investigated in hypercholesterolaemic hamsters. Intragastric administration of the ethyl acetate extract of C. comosa rhizome (0-500 mg/kg per day) to hypercholesterolaemic animals for 7 days decreased both plasma triglyceride and cholesterol levels in a dose-dependent manner. The reduction of plasma cholesterol levels was accompanied by a significant increase in the hepatic cholesterol content while the triglyceride content was not significantly changed. The increase of the hepatic cholesterol content was brought about by an expansion of the free cholesterol pool which specifically augments biliary cholesterol excretion. The C. comosa extract also increased plasma high density lipoprotein (HDL)-cholesterol and decreased plasma low density lipoprotein (LDL)-cholesterol. These results suggest that the C. comosa extract exerts a hypolipidaemic action by acceleration of lipid mobilization from extrahepatic tissue to the liver which subsequently increases excretion of cholesterol via the bile for excretion.     

翻白草水提液对2型糖尿病胰岛素抵抗大鼠糖脂代谢的影响

目的:观察翻白草水提取物对2型糖尿病胰岛素抵抗大鼠糖脂代谢的影响.方法:采用3周龄Wistar大鼠,高脂喂养16周加腹腔小剂量注射链脲佐菌素(STZ)的方法建立2型糖尿病胰岛素抵抗(IR)动物模型,随机分为4组:翻白草高、低剂量组(400,200 mg?kg-1)、吡格列酮组(4.05 mg?kg-1)及模型组,每组7只.另取标准饲料喂养大鼠7只为正常组.比较各药物干预4周后对2型糖尿病IR大鼠空腹血糖(FBG)、甘油三酯(TG)、胆固醇(TC)、低密度脂蛋白(LDL-C)、高密度脂蛋白(HDL-C)及游离脂肪酸(FFA)影响.结果:翻白草提取物和西药组均可显著降低大鼠FBG,TG,TC,LDL,FFA水平,升高HDL水平(P＜0.05).结论:翻白草对2型糖尿病胰岛素抵抗大鼠的空腹血糖及血脂水平有一定调节作用.     

Antihypercholesterolaemic and antioxidant activity assessment of some plants used as remedy in Turkish folk medicine

Ethanolic and aqueous extracts from five plant species used in Turkish traditional medicine were evaluated for in vivo hypercholesterolaemic and antioxidant activities: Agrostemma githago L., Potentilla reptans L., Thymbra spicata var. spicata L., Urtica dioica L. and Viscum album var. album L. We assayed the effects of the administration of plant extracts on serum total cholesterol, triglyceride, HDL-C, LDL-C, glucose, AST and ALT concentrations in mice fed with cholesterol-rich diet. In addition, plasma TAA, MDA and NO(x) levels in the same animals were assayed. All the aqueous plant extracts did not affect the serum cholesterol concentration. However, the ethanolic extracts of Agrostemma githago, Thymbra spicata and Viscum album decreased the serum cholesterol concentration in the mice fed with high-cholesterol diet without inducing any gastric damage. The ethanolic extracts of Thymbra spicata, Viscum album, Potentilla reptans and Urtica dioica and the aqueous extract of Agrostemma githago increased the serum HDL concentration, whereas the ethanolic extracts of Agrostemma githago, Thymbra spicata, Viscum album and Urtica dioica decreased the serum LDL-C concentration. Thymbra spicata and Viscum album were observed to decrease the serum triglyceride concentration. Among the plant extracts studied, the ethanolic extracts of Thymbra spicata significantly decreased the MDA level in mice. The ethanolic extract of Potentilla reptans increased in NO(x). None of these plants showed statistically prominent activity on plasma TAA. Results of the present study indicated that the ethanolic extracts of Agrostemma githago, Thymbra spicata and Viscum album showed potent hypocholesterolaemic activity in the mice fed with a diet containing high-cholesterol.     

Studies on the preventive effect of Spirulina maxima on fatty liver development induced by carbon tetrachloride, in the rat

The aim of the present work was to assess if the feeding of either the oil extract of Spirulina maxima or of its defatted fraction would prevent fatty liver development, induced in rats by a single intraperitoneal dose of carbon tetrachloride (CCl4). Liver and serum lipids were evaluated 4 days after treatment with this agent. Concentration of liver lipids did not differ in rats fed on a purified diet either without or with one of the fractions of Spirulina, except for total cholesterol, which showed a slight increase in the group receiving the oil extract of Spirulina. However, after CCl4 treatment, liver total lipids and triacylglycerols were significantly lower in rats fed on a diet containing any fraction of Spirulina (defatted or the oil fraction) than in rats without Spirulina in their diet. Furthermore, the increased liver cholesterol values, induced by CCl4 treatment, were not observed in rats receiving Spirulina. In addition, rats receiving whole Spirulina in their diet and treated only with the vehicle showed an increase in the percentage of HDL values. The changes in VLDL and LDL induced by CCl4 treatment were not observed in the whole Spirulina group. Furthermore, after CCl4 treatment the values of the liver microsomal thiobarbituric acid-reactive substances were lower in the whole Spirulina group than in the control group. These results support the potential hepatoprotective role of Spirulina.     

Hypolipidaemic Activity in Rats of Bergenin,the Major Constituent of Flueggea microcarpa

Oral administration of bergenin, isolated from the leaves of Flueggea microcarpa, to hyperlipidaemic rats for 14 days significantly decreased serum total lipid without much change in serum cholesterol and triglycerides. However, after 21 days of administration, the serum cholesterol, triglycerides, low-density lipoprotein (LDL)—and very low-density lipoprotein (VLDL)—cholesterol levels were significantly reduced while the serum high-density lipoprotein (HDL)-cholesterol level was elevated. Bergenin-treated animals also showed a significant decrease in atherogenic index.     

The hypolipidaemic activity of aqueous Erica multiflora flowers extract in Triton WR-1339 induced hyperlipidaemic rats: a comparison with fenofibrate

In the present study, an aqueous extract from Erica multiflora L. (Ericaceae) flowers was evaluated for its hypocholesterolaemic and hypotriglyceridaemic activities using Triton WR-1339 induced hyperlipemic rats as experimental model. Hyperlipideamia was developed by intraperitonial injection of Triton (200mg/kg body weight). The animals were divided into control (CG), hyperlipidaemic (HG), hyperlipidaemic plus herb extract (HG+EmE) and hyperlipidaemic plus fenofibrate (HG+FF) treated groups. Intragastric administration of Erica multiflora extract (0.25 g/100g body weight) to the rats caused a significant decrease on their plasma lipid levels (quantified using enzymatic kits). At 7h after treatment, plasma total cholesterol, triglycerides and LDL-cholesterol were decreased by 47%, 95% and 67%, respectively, but the change of HDL-cholesterol level was not significant. However, the hypolipidaemic effect of fenofibrate was limited to triglycerides and LDL-cholesterol, which were lowered by about 92% and 41%, respectively. At 24h after treatment, Erica multiflora extract reduced plasma total cholesterol by 68.5% and triglycerides by 91%. HDL-cholesterol was not significantly increased and LDL-cholesterol was lowered by 80.5%. In fenofibrate treated rats, only plasma triglyceride concentrations were lowered by 82%, while the other lipid parameters were not significantly changed indicating that this aqueous herb extract may contain products that lower plasma lipid concentrations and might be beneficial in treatment of hyperlipideamia.     

Hypolipidaemic activity of seaweed from Karachi coast

During the present study, ethanol extracts of five seaweed species Solieria robusta, Iyengaria stellata, Colpomenia sinuosa, Spatoglossum asperum and Caulerpa racemosa at 10 mg/ 200 g body weight were tested for their hypolipidaemic activity. All the species significantly decreased the serum total cholesterol, triglyceride and low density lipoprotein cholesterol levels in normal, triton-induced and diet-induced hyperlipidaemic rats. Solieria robusta was found to be the most effective in reducing the lipid profile, particularly in diet-induced hyperlipidaemic rats. A beneficial effect of the ethanol extract of S. asperum was also found on cardiac and liver enzymes in diet-induced hyperlipidaemic rats.     

Hypotensive, hypolipidemic, and vascular protective effects of Morus alba L. in rats fed an atherogenic diet

Morus alba L. has been used in traditional Chinese medicine and almost all parts of this plant are useful in cardiovascular, liver and spleen disorders. The present study was designed to investigate the inhibitory effect of a water extract from Morus alba L. (WMA) on vascular dysfunction in rat models fed a high fat and high cholesterol diet. Male rats were fed an atherogenic diet consisting of food with 7.5% cocoa butter and 1.25% cholesterol, with or without 100 or 200 mg/day/kg WMA, for 14 weeks. Chronic treatment with low (100 mg/kg/day) or high (200 mg/day/kg) doses of WMA markedly attenuated hypertension and the impairments of acetylcholine-induced relaxation of aortic rings in rats fed an atherogenic diet. WMA reduced intima/media thickness in rats fed an atherogenic diet. WMA improved plasma levels of triglyceride (TG) and augmented plasma levels of high-density lipoprotein (HDL) and plasma low-density lipoprotein (LDL), but did not affect blood glucose levels. Interestingly, WMA suppressed increased cell adhesion molecules such as E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intracellular adhesion molecule-1 (ICAM-1) expression in the aorta. Taken together, these results suggested that Morus alba L. could improve an atherogenic diet-induced hypertension, hyperlipidemia, and vascular dysfunction through inhibition of cell adhesion molecules expression and induction of vascular relaxation.     

荞秸果胶对高脂血症大鼠调脂作用的实验研究

用不同剂量的荞秸果胶给高脂血症大鼠灌胃,结果表明,荞秸果胶呈剂量依赖性地明显降低肝胆固醇、血清总胆固醇（ＴＣ）、低密度脂蛋白胆固醇（ＬＤＬＣ）、高密度脂蛋白亚组分３胆固醇（ＨＤＬ３Ｃ）及血清甘油三酯的含量。可明显提高血清高密度脂蛋白亚组分２胆固醇（ＨＤＬ２Ｃ）的含量、提高ＨＤＬＣ／ＴＣ、ＨＤＬＣ／ＬＤＬＣ、ＨＤＬ２Ｃ／ＨＤＬＣ及ＨＤＬ２Ｃ／ＨＤＬ３Ｃ。     

Preliminary studies on Campomanesia xanthocarpa (Berg.) and Cuphea carthagenensis (Jacq.) J.F. Macbr. aqueous extract: weight control and biochemical parameters

An infusion of Campomanesia xanthocarpa Berg. (Myrtaceae) leaves (Guabiroba) and the herb Cuphea carthagenensis (Jacq.) J.F. Macbr. (Lythraceae) (Sete-sangrias) is traditionally used in the South of Brazil to treat high levels of cholesterol and triglycerides. The effects of the aqueous extracts of these herbs were investigated in rats fed on a high calorie diet. Chronic treatment with the Guabiroba aqueous extract induced a significant reduction in weight gain in the rats, compared to the control group. Also, biochemical analysis showed that this treatment reduced the glycemia, while no effects on lipidic levels were observed. The biochemical analysis of the animals treated with Sete-sangrias aqueous extract showed no effect on glucose and triglyceride levels, while chronic treatment with the Sete-sangrias aqueous extract induced a significant reduction in plasma cholesterol in rats.     

Effect of an indigenous herbal compound preparation 'Trikatu' on the lipid profiles of atherogenic diet and standard diet fed Rattus norvegicus

Combating heart disease is one of the challenging problems of biomedical science today. Towards this goal an indigenous preparation 'Trikatu' (a herbal combination containing Piper longum (fruit), Piper nigrum (fruit) and Zingiber officinale (rhizome) dry powder) was fed to normal and cholesterol fed male Rattus norvegicus to ascertain its efficacy as a hypolipidaemic agent. Its effects on body weight, blood and tissue (aortic, cardiac and hepatic) lipids--total, free and esterified cholesterol, low density lipoprotein(LDL) and high density lipoprotein(HDL) cholesterol, triglycerides and phospholipids--and the atherogenic index were measured. It was found that 'Trikatu' by virtue of its ability to reduce triglycerides and LDL cholesterol and to increase HDL cholesterol can reduce the risk of hyperlipidaemia and atherosclerosis. Hence 'Trikatu' can be used as a potent hypolipidaemic agent and it can reduce the atherosclerosis associated with a high fat diet.