Lipid Lowering Activity of Guggulsterone from Commiphora mukul in Hyperlipaemic Rats

The lipid lowering action of guggulsterone, the active constituent of guggulipid, has been studied in triton and cholesterol fed hyperlipaemic rats. Serum lipids were found to be lowered by guggulsterone (50 mg/kg, b.w.) in triton WR-1339 induced hyperlipaemia. Chronic feeding of this drug (5 mg/kg, b.w.) in animals simultaneously fed with cholesterol (25 mg/kg, b.w.) for 30 days, caused lowering in the lipid and apoprotein levels of very low density and low density lipoproteins in experimental animals. Guggulsterone activates lipolytic enzymes in plasma and liver as well as stimulated receptor mediated catabolism of low density lipoprotein. The hypolipidaemic activity of this drug is mediated through inhibition of hepatic cholesterol biosynthesis, increased faecal bile acid excretion and enhanced plasma lecithin:cholesterol acyltransferase activity.     

Terminalia arjuna: an Ayurvedic Cardiotonic,Regulates Lipid Metabolism in Hyperlipaemic Rats

The lipid lowering action of the bark powder of Terminalia arjuna (T. arjuna ) has been studied in triton and cholesterol fed rats. Serum lipids were found to be lowered by T. arjuna (100 mg/kg, b.w.) in triton induced hyperlipaemia. Chronic feeding of this powder (100 mg/kg, b.w., p.o.) in animals simultaneously fed with cholesterol (25 mg/kg, b.w.) for 30 days, caused lowering in lipids and protein levels of β-lipoproteins followed by an increase in high density lipoprotein-cholesterol compared with the cholesterol fed groups. T. arjuna alters lipolytic activities in plasma, liver, heart and adipose tissues of hyperlipaemic rats. The lipid lowering action of this natural product is mediated through inhibition of hepatic cholesterol biosynthesis, increased faecal bile acid excretion and enhanced plasma lecithin:cholesterol acyltransferase activity and stimulation of receptor mediated catabolism of low density lipoprotein.     

Hypolipedaemic activity of picroliv in albino rats

The hypolipidaemic action of picroliv, a standarized preparaton from Picrorhiza kurrooa, has been studied in normal as well as in triton- and cholesterol-fed rats. Serum lipids were found to be lowered by picroliv (25 mg/kg b.w.) in triton WR-1339-induced hyperlipaemia. Chronic feeding of this drug (6 mg/kg b.w.) in normal rats and in animals simultaneously treated with cholesterol (25 mg/kg b.w.) for 30 days caused lowering in the lipid and protein levels constituting β-lipoproteins followed by an increase in high density lipoprotein cholesterol in experimental animals. Picroliv alters lipolytic activities in plasma, liver, heart an adipose tissues and stimulated receptor mediated catabolism of low density lipoprotein. The lipid lowering action of the natural product is mediated through inhibition of cholesterol biosynthesis in liver, increased faecal bile acid excretion and enhanced plasma lecithin: cholesterol acyltransferase activity.     

Hypolipidaemic activity of methanol extract of Aleurites moluccana

The lipid-lowering action of the leaves of the Aleurites moluccana methanol extract was studied in Triton W-1339 and high-fat-diet fed rats. The serum lipids (total cholesterol, LDL- and HDL-cholesterol and triglycerides) and body weight were found to be lowered by A. moluccana (300 mg/kg, b.w.) in rats with Triton-induced hypercholesterolaemia and on a hyperlipaemic diet. The results suggest that the lipid lowering action of this natural product is mediated through inhibition of hepatic cholesterol biosynthesis and reduction of lipid absorption in the intestine.     

Hypolipidemic activity of Anethum graveolens in rats

The aerial parts of Anethum graveolens (dillweed) are used in Iran as a hypolipidemic agent. The scientific basis for its use has yet to be established. In this study the hypolipidemic activity of dill powder and its essential oil (its most important fraction) were evaluated in male Wistar rats (180 +/- 20 g) fed a high cholesterol diet. Anethum graveolens essential oil (AGEO) was prepared by hydrodistillation and analysed using GC/MS. AGEO had a yield of 2% and GC/MS analysis showed that alpha-phellandrene (32%), limonene (28%) and carvone (28%) were its major components. Daily oral administration of AGEO to rats at doses of 45, 90 and 180 mg/kg for 2 weeks significantly and in a dose-dependent manner reduced total cholesterol, triglyceride and low density lipoprotein cholesterol (LDL-C). AGEO also increased significantly high density lipoprotein cholesterol (HDL-C). Anethum graveolens powder when added to the diet of animals showed similar effects on serum lipids. It is concluded that Anethum graveolens has significant lipid lowering effects and is a promising cardioprotective agent.     

Antiamnesic potential of Murraya koenigii leaves

Murraya koenigii leaves commonly known as curry patta are added routinely to Indian gravy and vegetarian dishes as a favorite condiment. The effects of Murraya koenigii leaves (MKL) on cognitive functions, total serum cholesterol level and brain cholinesterase activity in young and aged mice fed orally with a diet containing 2%, 4% and 8% w/w of MKL for 30 days consecutively, were investigated. The memory scores were measured using various exteroceptive and interoceptive behavioral models. The MKL diets produced a significant dose-dependent improvement in the memory scores of young and aged mice and significantly reduced the amnesia induced by scopolamine (0.4 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.). Also, brain cholinesterase activity and total cholesterol levels were reduced by the MKL diets. The underlying mechanism of action for the observed nootropic effect may be attributed to pro-cholinergic activity and a cholesterol lowering property. Therefore, it would be worthwhile to investigate specifically the therapeutic potential of MKL in the management of Alzheimer patients.     

Lipid lowering effect of S-methyl cysteine sulfoxide from Allium cepa Linn in high cholesterol diet fed rats

The lipid lowering action of S-methyl cysteine sulfoxide (SMCS) isolated from Allium cepa Linn (family: Liliaceae) was investigated in Sprague-Dawley rats fed on 1% cholesterol diet, in comparison to the hypolipidemic drug gugulipid. Administration of SMCS at a dose of 200mg/kg body weight for 45 days ameliorated the hyperlipidemic condition. The lipid profile in serum and tissues showed that concentrations of cholesterol, triglyceride and phospholipids were significantly reduced when compared to their untreated counterparts. The total lipoprotein lipase activity in the adipose tissue was decreased with also a decrease in the free fatty acid levels in serum and tissues. The activities of the lipogenic enzymes glucose 6-phosphate dehydrogenase and malic enzyme as also of HMG CoA reductase in the tissues remained low on treatment indicating that both the drugs did not favor lipogenesis and cholesterogenesis in the hyperlipidemic animals. The fecal excretion of bile acids and sterols was further increased upon treatment with the drugs. The results are directive to that both gugulipid and SMCS cause reduction of endogenous lipogenesis, increase catabolism of lipids and subsequent excretion of metabolic by-products through the intestinal tract. However, gugulipid is a better drug than SMCS at a low dose of 50mg/kg body weight.     

Effect of mangiferin on hyperglycemia and atherogenicity in streptozotocin diabetic rats

In the present study, the effect of mangiferin (a xanthone glucoside, isolated from the leaves of Mangifera indica) on the atherogenic potential of streptozotocin (STZ)-diabetes was investigated. In addition, the effect of mangiferin on oral glucose tolerance in glucose-loaded normal rats was also determined. The chronic intraperitoneal (i.p.) administration of mangiferin (10 and 20 mg/kg) once daily (o.d.) for 28 days exhibited antidiabetic activity by significantly lowering fasting plasma glucose level at different time intervals in STZ-diabetic rats. Further, mangiferin (10 and 20 mg/kg, i.p.) showed significant antihyperlipidemic and antiatherogenic activities as evidenced by significant decrease in plasma total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) levels coupled together with elevation of high-density lipoprotein cholesterol (HDL-C) level and diminution of atherogenic index in diabetic rats. In addition, the chronic administration of mangiferin (10 and 20 mg/kg, i.p.) for 14 days significantly as well as markedly improved oral glucose tolerance in glucose-loaded normal rats suggesting its potent antihyperglycemic activity. The accumulating evidences suggest that both pancreatic and extrapancreatic mechanisms might be involved in its antidiabetic or antihyperglycemic action. In conclusion, the present study demonstrates that mangiferin possesses significant antidiabetic, antihyperlipidemic and antiatherogenic properties thus suggesting its beneficial effect in the treatment of diabetes mellitus associated with hyperlipidemia and related cardiovascular complications.     

Effect of silibinin and vitamin E on restoration of cellular immune response after partial hepatectomy

Our aim was to study the antioxidant and immunomodulatory effect of silibinin and vitamin E on the early postoperative course in rats that had undergone a partial hepatectomy (PHX). Male Wistar rats that were treated with silibinin (50 mg/b.w.kg i.p.) and/or vitamin E (500 mg/b.w.kg p.o.) were randomised to undergo 70% PHX. At 72 h after operation, Concanavalin A (Con-A) induced lymphocyte proliferation, and lipopolysaccharide (LPS) induced interleukin-1 (IL-1) mitogenicity and tumour necrosis factor-alpha (TNF-alpha) cytotoxicity were measured in the spleen. In addition, total free radical scavenger capacity of the liver was analysed. In PHX animals, Con-A induced lymphocyte proliferation was significantly decreased, and both LPS induced IL-1 and TNF-alpha activity were significantly increased as compared to Sham treated animals. Treatment with silibinin and vitamin E synergistically restored both lymphocyte proliferation (P<0.01) and cytokine activity (P<0.001) in PHX animals. In addition, silibinin and vitamin E synergistically (P<0.001) restored total hepatic free radical scavenger capacity as well as serum levels of AST and gammaGT, that were all markedly decreased in PHX animals. Our results suggest that preoperative treatment with silibinin and/or vitamin E modulates the cellular immunoresponse and restores impaired liver function following PHX, presumably through their antioxidant capacity. This may explain their beneficial effects on the postoperative course of liver repair.     

Anti-inflammatory, analgesic and antipyretic effects of methanol extract from Bauhinia racemosa stem bark in animal models

In this study, the anti-inflammatory, analgesic, and antipyretic effects of 50, 100 and 200 mg/kg body weight of methanol extract obtained from Bauhinia racemosa stem bark, the so-called MEBR, were investigated. The effects of MEBR on the acute and chronic phases of inflammation were studied in carrageenan, dextran and mediators (histamine and serotonin)-induced paw oedema and cotton pellet-induced granuloma, respectively. Analgesic effect of MEBR was evaluated in acetic acid-induced writhing and hotplate tests. Antipyretic activity of MEBR was evaluated by yeast-induced hyperpyrexia in rats. The anti-oedema effect of MEBR was compared with 10 mg/kg of indomethacin orally. In acute phase of inflammation, a maximum inhibition of 44.9, 43.2, 44.8 and 45.9% (P<0.001) was noted at the dose of 200 mg/kg b.w. after 3h of treatment with MEBR in carrageenan, dextran, histamine and serotonin-induced paw oedema, respectively. Administration of MEBR (200 mg/kg b.w.) and indomethacin (10 mg/kg b.w.) significantly (P<0.05) decreased the formation of granuloma tissue induced by cotton pellet method at a rate of 50.4 and 56.2%, respectively. The extract also inhibited peritoneal leukocyte migration in mice. The MEBR also produced significant (P<0.01) analgesic activity in both models. Further, the MEBR potentiated the morphine- and aspirin-induced analgesic in mice. Treatment with MEBR showed a significant (P<0.01) dose-dependent reduction in pyrexia in rats. The results suggest that MEBR possess potent anti-inflammatory, analgesic and antipyretic activity.     

Screening for antihyperglycaemic activity in several local herbs of Malaysia

Screening of aqueous extract of Phyllantus niruri (PL), Zingiber zerumbet (ZG), Eurycoma longifolia (TA-a and TA-b) and Andrographis paniculata (AP) to determine their blood glucose lowering effect were conducted in normoglycaemic and Streptozotocin-induced hyperglycaemic rats. Significant reduction in blood glucose level at 52.90% was shown when hyperglycaemic rats were treated with 50 mg/kg body weight (BW) aqueous extract of AP. This effect is enhanced when freeze-dried material was used, where 6.25 mg/kg BW gave 61.81% reduction in blood glucose level. In the administration of TA-a and TA-b, positive results in hyperglyacaemic rats were only obtained when 150 mg/kg BW of the aqueous extract was used. No significant reduction in blood glucose level were shown in hyperglycaemic rats treated with PL and ZG at all concentrations used (50, 100 and 150 mg/kg BW). In normoglycaemic rats, no significant reduction was noted when all the same extracts were used.     

Hypolipidemic activity of aqueous extract of Withania coagulans Dunal in albino rats

Administration of an aqueous extract of fruits of Withania coagulans (1 g/kg; p.o.) to high fat diet induced hyperlipidemic rats for 7 weeks, significantly reduced elevated serum cholesterol, triglycerides and lipoprotein levels. This drug also showed hypolipidemic activity in triton induced hypercholesterolemia. The histopathological examination of liver tissues of treated hyperlipidemic rats showed comparatively lesser degenerative changes compared with hyperlipidemic controls. The hypolipidemic effect of W. coagulans fruits was found to be comparable to that of an Ayurvedic product containing Commiphora mukkul.     

Effect of different fractions of Swertia chirayita on the blood sugar level of albino rats

A 95% ethanol extract and four fractions of Swertia chirayita were tested for blood sugar lowering activity in rats when given orally at 250 mg/kg. The hexane fraction caused maximum lowering although the ethanol extract was clearly active. Of the four dose levels of the hexane fraction tested, 250 mg/kg was found to produce the optimum effect and 300 mg/kg did not evoke a better response. The optimum dose produced significant lowering of blood sugar in fed, glucose-loaded and tolbutamide-pretreated animal models, but not in fasted rats.     

Improvement of insulin resistance by miracle fruit (Synsepalum dulcificum) in fructose-rich chow-fed rats

In an attempt to probe a new target to improve insulin resistance, miracle fruit (Synsepalum dulcificum) was employed to investigate the effect on insulin resistance induced by fructose-rich chow in rats. Single oral administration of the powder of this miracle fruit decreased the plasma glucose in a dose-dependent manner for 150 min in rats fed fructose-rich chow for 4 weeks. Insulin action on the glucose disposal rate was measured using the glucose-insulin index, the value of the areas under the curve of glucose and insulin during the intraperitoneal glucose tolerance test. Oral administration of miracle fruit (0.2 mg/kg) to fructose-rich chow fed rats, three times daily for 3 days, reversed the raised value of the glucose-insulin index, indicating that miracle fruit has the ability to improve insulin sensitivity. The plasma glucose lowering action of tolbutamide, induced by secretion of endogenous insulin, is widely used to characterize the formation of insulin resistance. The time for the loss of the plasma glucose lowering response to tolbutamide (10.0 mg/kg, i.p.) in fructose-rich chow fed rats was markedly delayed after treatment with miracle fruit compared with the vehicle-treated group. Thus providing supportive data that oral administration of miracle fruit could delay the development of insulin resistance in rats. Also, the in vivo insulin sensitivity was markedly raised by miracle fruit. In conclusion, the results suggest that miracle fruit may be used as an adjuvant for treating diabetic patients with insulin resistance because this fruit has the ability to improve insulin sensitivity.     

Antidiabetic and antioxidant effects of oleanolic acid from Ligustrum lucidum Ait in alloxan‐induced diabetic rats

The present study evaluated the antidiabetic and antioxidant effects of oleanolic acid (OA) from Ligustrum lucidum Ait (LLA) in alloxan‐induced diabetic rats. OA in the alloxan‐induced diabetic rats showed significant hypoglycemic activity by lowering blood glucose (at doses of 60 and 100 mg/kg for 40 days). The levels of serum total cholesterol (TC), triglycerides (TG) and low‐density lipoprotein cholesterol (LDL‐c) in the OA‐treated diabetic rats were lower, and the high‐density lipoprotein cholesterol (HDL‐c) level was higher than in the control diabetic rats. A significant reduction in the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) levels of diabetic rats following OA treatment was also observed. Furthermore, OA treatment decreased the malondialdehyde (MDA) level, but increased superoxide dismutase (SOD) and glutathione peroxidase (GSH‐px) activities of the liver and kidney in diabetic rats. These results indicate that OA could protect the liver function avoiding alloxan‐induced damage; OA had hypoglycemic, hypolipidemic and antioxidant efficacy in the diabetic rats. The antioxidant ability of OA might be one of the mechanisms of its hypoglycemic and hypolipidemic effects. Copyright © 2009 John Wiley & Sons, Ltd.     

Gastroprotective effect of swallow root (Decalepis hamiltonii) extract: possible involvement of H(+)-K(+)-ATPase inhibition and antioxidative mechanism

The present study reports the antiulcer potentials of aqueous extract of swallow root (Decalepis hamiltonii Wight & Arn, SRAE) belonging to the family Asclepiadaceae. Swim stress-induced ulcers with an ulcer index (UI) of 6.0+/-0.01 was protected up to 43% and 72% at 100 and 200mg/kg b.w. of SRAE, respectively, similar to protection offered by ranitidine (79%) at 30mg/kg b.w. Depletion in antioxidant enzymes and increased Thiobarbituric Acid Reactive Substances (TBARS) were observed in ulcer-induced rats while SRAE fed rats showed normal levels. SRAE also normalized approximately 3.1 and 2.4 folds of increased H(+)-K(+)-ATPase and gastric mucin, respectively, in ulcerous animals, similar to the levels found in healthy controls. SRAE also possessed reducing power, free radical scavenging ability with an IC(50) of 0.17microg/mL gallic acid equivalent (GAE), comparable to that of BHA (IC(50)-0.08microg/mL). DNA protection up to 80% at 0.2microg was also observed. Toxicity studies indicated no lethal effects in rats fed up to 5g/kg b.w. Antioxidant, proton pump inhibition as well as boosting of gastric mucin effects of SRAE have been implicated to be responsible for antiulcer property of SRAE.     

Effect of ethanolic extract of Zingiber officinale on dyslipidaemia in diabetic rats

The lipid lowering and antioxidant potential of ethanolic extract of Zingiber officinale Roscoe (family, Zingiberaceae) was evaluated in streptozotocin (STZ)-induced diabetes in rats. Ethanolic extract of Zingiber officinale (200 mg/kg) fed orally for 20 days produced, significant antihyperglycaemic effect (P < 0.01) in diabetic rats. Further, the extract treatment also lowered serum total cholesterol, triglycerides and increased the HDL-cholesterol levels when compared with pathogenic diabetic rats (P < 0.01). STZ-treatment also induced a statistically significant increase in liver and pancreas lipid peroxide levels (P < 0.01) as compared to normal healthy control rats. Zingiber officinale extract treatment lowered the liver and pancreas thiobarbituric acid reactive substances (TBARS) values (P < 0.01) as compared to pathogenic diabetic rats. The results of test drug were comparable to gliclazide (25 mg/kg, orally), a standard antihyperglycaemic agent. The results indicate that ethanolic extract of Zingiber officinale Roscoe can protect the tissues from lipid peroxidation. The extract also exhibit significant lipid lowering activity in diabetic rats. The present study is the first pilot study to assess the potential of Zingiber officinale in diabetic dyslipidaemia.     

Shengmai San reduces hepatic lipids and lipid peroxidation in rats fed on a high-cholesterol diet

Shengmai San (SMS), which is comprised of the medicinal herbs of Panax ginseng C.A. Meyer, Schisandra chinensis Baill., and Ophiopogon japonicus Ker-Gawl (2:1:2)., is a traditional Chinese medicine being used for treating coronary heart disease. The aim of this study was to investigate the effects of SMS on the plasma and liver lipids, lipid peroxidation and antioxidant systems in liver and heart of cholesterol-fed rats. Rats were fed on a high-cholesterol (0.5%) diet (control group), high-cholesterol diet containing 2% SMS (2% SMS group) and 4% SMS (4% SMS group) for four weeks. The oxidative stress marker (thiobarbituric acid reactive substances, TBARS) and antioxidant defense systems including glutathione (GSH), glutathione peroxidase (GSH-Px), glutathione-S-transferase (GST) and superoxide dismutase (SOD) activities in rat liver and heart were evaluated. Results showed that rats fed with SMS-containing diet had reduced the H(2)O(2)-induced erythrocytes susceptibility to hemolysis, and 4% SMS feeding rats had higher plasma GSH concentration compared to the animals fed with the control diet. However, SMS had no effect on plasma lipids (total cholesterol, triglyceride and high-density lipoprotein cholesterol) and TBARS concentration. On the other hand, rats fed with the 4% SMS diet reduced the hepatic cholesterol and triglyceride contents. Fecal bile acid excretion was significantly increased in rats fed with the SMS-containing diet. Higher hepatic GSH and lower TBARS concentrations were observed in rats fed with the 4% SMS diet compared with the rats fed with the control diet. No significant difference in activities of GSH-Px, GST and SOD was found in liver and heart after the SMS treatment. Results from this study indicate that the SMS may reduce hepatic lipids and lipid peroxidation in rats.     

Effect of traditional herbal medicine, shakuyaku-kanzo-to on total and free serum testosterone levels

The effect of the traditional herbal medicine, Shakuyaku-Kanzo-To (SK), which contains Shakuyaku (S) and Kanzo (K) in equal amounts, on serum testosterone levels was investigated in androgen-sterilized rats. They were given orally SK [0, 22.5, 45, 90 and 180 mg/kg body weight (b.w.)] and S or K (0, 11.25, 22.5, 40 and 90 mg/kg b.w.) in 2 ml of water daily for 2 weeks. Dose-dependent decreases in free serum testosterone (T) levels were found in the administration of SK. Total serum T levels in the administration of SK and S decreased in a dose-dependent manner. K decreased total serum T levels slightly in 11.5 and 22.5 mg/kg doses but showed the dose-dependent increase in much higher doses, the extent of which was much less than that of the decrease in S. Serum estradiol/T (E2/T) ratios were significantly elevated in 45 to 180 mg/kg doses of SK, 90 mg/kg dose of S and 11.25 to 90 mg/kg doses of K. Serum LH and FSH levels were not changed by SK, S and K. Oophorectomized rats were similarly given SK (0, 90 and 180 mg/kg b.w.) and S or K (the half doses of SK). There were no changes in serum T, LH and FSH levels in all given doses. Thus, one of the mechanisms for SK to lower serum T levels is the direct action on the ovary to stimulate the aromatase activity, resulting in decreasing the T secretion and this is the additive effects of S and K.     

Hypoglycaemic activity of Anthocleista vogelii (Planch) aqueous extract in rodents

The hypoglycaemic effect of Anthocleista vogelii was studied in mice, rats and rabbits. Aqueous extract of the plant obtained by infusion from finely pulverized root was used. The extract (100, 400 and 800 mg/kg) induced significant hypoglycaemic activity in a dose-related fashion at 2 h after oral administration in mice and rats with ED₂₅ of 250 mg/kg and 350 mg/kg respectively. The extract (800 mg/kg, orally) similarly induced statistically significant lowering of blood glucose levels at 8 h in normoglycaemic rabbits. The extract (400 mg/kg and 800 mg/kg, orally) also caused reduction of blood glucose levels in alloxan-induced diabetic animals. The results of this study indicate that the aqueous extract of the roots of Anthocleista vogelii possess favourable hypoglycaemic activity both in normo and hyperglycaemic animals compared to chlorpropamide as a standard.