Protective effects of certoparin sodium, a low molecular weight heparin derivative, in experimental atherosclerosis

Acyclic Isoprenoid Attenuates Lipid Anomalies and Inflammatory Changes in Hypercholesterolemic Rats

The present study was aimed to explore the antihyperlipidemic and anti-inflammatory effect of acyclic isoprenoid on high fat diet fed rats. Hypercholesterolemia was induced by the diet comprising of the normal rat chow 84.3%, lard 5%, yolk powder 10%, cholesterol 0.2% and 0.5% bile salt were fed to the rats for the period of 8 weeks. The results showed that abnormally elevated levels of plasma lipid profiles. Three different doses of acyclic isoprenoid (20, 40 and 80 mg/kg b.w/day) were administered orally to hypercholesterolemia suffering rats for the period of 30 days. Among these three doses of acyclic isoprenoid, the dose 80 mg/kg b.w. was significantly decreased the plasma lipid profiles when compared to other two doses. The effect produced by acyclic isoprenoid (80 mg/kg b.w) was comparable to that of simvastatin. Therefore, 80 mg/kg b.w was fixed as a effective dose and used for further analyses. Acyclic isoprenoid administration reinstated the elevated levels of cardiac and inflammatory markers in both blood and serum of hypercholesterolemic rats. In addition, acyclic isoprenoid administration decreased activity of 3-hydroxy 3-methyl-glutaryl-CoA reductase and increased the activity of lecithin cholesterol acyl transferase. These findings suggest that the administration of acyclic isoprenoid was potentially ameliorated the cardiac marker enzymes and inflammatory markers in addition to its antihypercholesterolemic effect.

Anti-GRP78 autoantibodies induce endothelial cell activation and accelerate the development of atherosclerotic lesions

The 78-kDa glucose-regulated protein (GRP78) is an ER molecular chaperone that aids in protein folding and secretion. However, pathological conditions that cause ER stress can promote the relocalization of GRP78 to the cell surface (csGRP78), where it acts as a signaling receptor to promote cancer progression. csGRP78 also possesses antigenic properties, leading to the production of anti-GRP78 autoantibodies, which contribute to tumor growth. In contrast, the presence and role of anti-GRP78 autoantibodies in atherosclerosis is unknown. Here, we show that atherosclerotic-prone ApoE-/- mice develop circulating anti-GRP78 autoantibodies that bind to csGRP78 on lesion-resident endothelial cells. Moreover, GRP78-immunized ApoE-/- mice exhibit a marked increase in circulating anti-GRP78 autoantibody titers that correlated with accelerated lesion growth. Mechanistically, engagement of anti-GRP78 autoantibodies with csGRP78 on human endothelial cells activated NF-κB, thereby inducing the expression of ICAM-1 and VCAM-1, a process blocked by NF-κB inhibitors. Disrupting the autoantibody/csGRP78 complex with enoxaparin, a low-molecular-weight heparin, reduced the expression of adhesion molecules and attenuated lesion growth. In conclusion, anti-GRP78 autoantibodies play a crucial role in atherosclerosis development, and disruption of the interaction between anti-GRP78 autoantibodies and csGRP78 represents a therapeutic strategy.

Impact of coagulation function and anticoagulation therapy on liver fibrosis

Liver cirrhosis and its complications, including esophageal and gastric variceal bleeding, hepatic encephalopathy, and ascites, can cause serious harm to human health. Therefore, treatment of liver fibrosis is key to the prevention and treatment of liver cirrhosis. In order to treat liver fibrosis to reduce human suffering, medical experts and scholars have performed many clinical and animal studies to find safe, efficient and reliable drugs to slow the progression of hepatic fibrosis and even reverse the liver function. This review introduces the definition of liver fibrosis in China and other countries, discusses the effect of coagulation on the process of liver fibrosis and various anticoagulation therapies for liver fibrosis, and summarizes the advantages, disadvantages, and side effects of different anticoagulants in the prevention and treatment of liver fibrosis.

An experimental evaluation of the anti-atherogenic potential of the plant, Piper betle, and its active constitutent, eugenol, in rats fed an atherogenic diet

Hypercholesterolemia is a major risk factor for systemic atherosclerosis and subsequent cardiovascular disease. Lipoperoxidation-mediated oxidative damage is believed to contribute strongly to the progression of atherogenesis. In the current investigation, putative anti-atherogenic and antioxidative properties of an ethanolic extract of Piper betle and of its active constituent, eugenol, were sought in an experimental animal model of chronic hypercholesterolemia. Atherogenic diet-fed rats that received either Piper betle extract orally (500mg/kg b.wt) or eugenol orally (5mg/kg b.wt) for 15days (commencing 30days after the atherogenic diet had been started) exhibited the following variations in different parameters, when compared to atherogenic diet-fed rats that received only saline: (1) significantly lower mean levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol and very low density lipoprotein cholesterol in both serum and hepatic tissue samples; (2) lower mean serum levels of aspartate amino-transferase, alanine amino-transferase, alkaline phosphatase, lactate dehydrogenase and lipid-metabolizing enzymes (lipoprotein lipase, 3-hydroxy-3-methyl-glutaryl-CoA reductase; (3) significantly lower mean levels of enzymatic antioxidants (catalase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase) and non-enzymatic antioxidants (reduced glutathione, vitamin C and vitamin E) and significantly higher mean levels of malondialdehyde in haemolysate and hepatic tissue samples. Histopathological findings suggested a protective effect of the Piper betle extract and a more pronounced protective effect of eugenol on the hepatic and aortic tissues of atherogenic diet-fed (presumed atherosclerotic) rats. These results strongly suggest that the Piper betle extract and its active constituent, eugenol, exhibit anti-atherogenic effects which may be due to their anti-oxidative properties.

Pyrroloquinoline quinone (PQQ) has potential to ameliorate streptozotocin-induced diabetes mellitus and oxidative stress in mice: A histopathological and biochemical study

Enhanced oxidative stress and hyperglycemia are associated with diabetes mellitus (DM). As pyrroloquinoline quinone (PQQ) is known to protect cells from oxidative stress, the present study was undertaken to reveal the hitherto unknown effects of PQQ in DM and associated problems in different tissues. Forty two mice were randomly divided into six groups. Group I receiving only citrate buffer served as the normal control, while group II animals were injected with citrate buffer and PQQ at 20 mg/kg for 15 days and served as test drug control. Animals of groups III-VI were rendered diabetic by single dose of streptozotocin (STZ, 150 mg/kg body weight), following which PQQ at a dose of 5, 10 and 20 mg/kg, was injected to the animals of group IV, V and VI respectively for 15 days. At the end, alterations in serum indices such as glucose, different lipids, insulin, amylase, urea, uric acid, serum glutamate pyruvate transaminase and serum glutamate oxaloacetate transaminase; tissue antioxidants and histopathological alterations in liver, kidney and pancreas were evaluated. STZ-treated animals developed oxidative stress as indicated by a significant increase in tissue lipid peroxidation (LPO) and lipid hydroperoxide, serum glucose, total cholesterol, triglyceride and urea, with a parallel decrease in the levels of serum insulin and tissue antioxidants. When diabetic animals received different doses of PQQ, these adverse effects were ameliorated. However, 20 mg/kg of PQQ appeared to be most effective. Findings revealed for the first time that PQQ has the potential to mitigate STZ-induced DM and oxidative damage in different organs of mice, suggesting that it may ameliorate diabetes mellitus and associated problems.

Antihypercholesterolemic and Antioxidative Potential of an Extract of the Plant, Piper betle, and Its Active Constituent, Eugenol, in Triton WR-1339-Induced Hypercholesterolemia in Experimental Rats

Hypercholesterolemia is a dominant risk factor for atherosclerosis and cardiovascular diseases. In the present study, the putative antihypercholesterolemic and antioxidative properties of an ethanolic extract of Piper betle and of its active constituent, eugenol, were evaluated in experimental hypercholesterolemia induced by a single intraperitoneal injection of Triton WR-1339 (300 mg/kg b.wt) in Wistar rats. Saline-treated hypercholesterolemic rats revealed significantly higher mean blood/serum levels of glucose, total cholesterol, triglycerides, low density and very low density lipoprotein cholesterol, and of serum hepatic marker enzymes; in addition, significantly lower mean serum levels of high density lipoprotein cholesterol and significantly lower mean activities of enzymatic antioxidants and nonenzymatic antioxidants were noted in hepatic tissue samples from saline-treated hypercholesterolemic rats, compared to controls. However, in hypercholesterolemic rats receiving the Piper betle extract (500 mg/kg b.wt) or eugenol (5 mg/kg b.wt) for seven days orally, all these parameters were significantly better than those in saline-treated hypercholesterolemic rats. The hypercholesterolemia-ameliorating effect was better defined in eugenol-treated than in Piper betle extract-treated rats, being as effective as that of the standard lipid-lowering drug, lovastatin (10 mg/kg b.wt). These results suggest that eugenol, an active constituent of the Piper betle extract, possesses antihypercholesterolemic and other activities in experimental hypercholesterolemic Wistar rats.

Protective role of phytosterol esters in combating oxidative hepatocellular injury in hypercholesterolemic rats

The aim of the present study is to evaluate the effect of eicosapentaenoic acid-docosahexaenoic acid (EPA-DHA) rich sterol ester and A-linolenic Acid (ALA) rich sterol ester on the atherogenic disturbances in hypercholesterolemic atherogenic animals. Six groups of male Wistar rats were employed in this study, wherein five groups were fed with a high cholesterol diet (stock diet supplemented with 1% cholesterol) for 30 days, among which, two groups of rats were also treated with EPA-DHA rich sterol ester in two doses (25 and 50 mg/rat/day, oral gavage) and two groups were treated with ALA rich sterol ester also in two doses (25 and 50 mg/rat/day, oral gavage). The remaining one group served as control. Abnormal increases in the levels of malondialdehyde, as well as depressed antioxidants status, were observed in hepatic tissue of hypercholesterolemic control group. Hypercholesterolemia induced abnormal elevation in the activities of marker enzymes in liver (aspartate transaminase, alanine transaminase and alkaline phosphatase) and was accompanied by increased hepatic cholesterol level and altered fatty changes in the histology of liver. These changes were restored partially in the groups administered with lower doses (25 mg/rat/day) of sterol esters. However, the higher doses (50 mg/rat/day) of sterol esters almost ameliorated the hypercholesterolemic-oxidative changes in the hypercholesterolemic rats. The results of this study present oxidative injury induced by hypercholesterolemic diet and administration of the treatment with higher doses of sterol esters afforded sound protection against lipemic-oxidative injury.

Anthocyanin-rich red cabbage (Brassica oleracea L.) extract attenuates cardiac and hepatic oxidative stress in rats fed an atherogenic diet

BACKGROUND

Oxidative stress induced by reactive oxygen species plays an important role in the aetiology of several diseases including atherosclerosis and coronary heart disease. Anthocyanin-rich extracts have been shown to possess a variety of therapeutic roles, including antioxidant, cardioprotective and hepatoprotective properties. The present inventory was undertaken to evaluate the protective role of anthocyanin-rich red cabbage extract (ARCE) on an atherogenic (ATH) diet-induced hypercholesterolaemia and related cardiac and, hepatic oxidative stress in rats.

RESULTS

ARCE (100 mg kg(-1) body weight) treatment of rats fed the ATH diet significantly prevented elevation in serum and tissue lipids, circulating levels of cardiac and hepatic damage markers, and resulted in excretion of lipids through faeces. Also, the ARCE extract significantly attenuated alterations in the cardiac and hepatic antioxidants and lipid peroxidation, and histopathological changes in cardiac and hepatic tissue.

CONCLUSION

Thus, the present study provides the first scientific evidence for a protective role of ARCE against ATH diet-induced hypercholesterolaemia and cardiac and hepatic oxidative stress.

Rho kinase inhibition by fasudil exerts antioxidant effects in hypercholesterolemic rats

1. The inhibition of Rho kinase (ROCK) ameliorates many cardiovascular dysfunctions, but the role of ROCK in oxidative stress in hypercholesterolemic rats has not been explored. The aim of the current study was to investigate the antioxidant effects and the potential related mechanisms of fasudil, a selective ROCK inhibitor, in high-cholesterol diet (HCD)-induced hypercholesterolemic rats. 2. Hypercholesterolemia was induced in rats by feeding with a HCD for 4 weeks. Starting from day 15, physiological saline (1 mL/100 g) or ROCK inhibitor, fasudil (10 or 30 mg/kg), was injected intraperitoneally for another 14 days. 3. The results showed that fasudil significantly suppressed ROCK activity, potently elevated the activities of antioxidant enzymes and the expression of endothelial nitric oxide synthase, as well as the concentration of nitric oxide in the serum and cardiac tissue. In addition, fasudil notably suppressed the extent of lipid peroxidation and attenuated the histopathological changes in the heart and liver of hypercholesterolemic rats. 4. These antioxidant effects of fasudil suggest that ROCK activation is involved in oxidative stress in hypercholesterolemic rats.

Evaluation of antioxidative and anti-inflammatory potential of hesperidin and naringin on the rat air pouch model of inflammation

BACKGROUND

Anti-inflammatory and antioxidative potential of hesperidin and naringin was carried out considering the rat air pouch model of inflammation.

METHODS

Reference dose of hesperidin (H) or naringin (N) or indomethacin (I) was administered to the rat air pouches. The pouches were induced by injecting sterile air into the intra-scapular region of the rats followed by carrageenan (AP + C) administration. Rats injected only with air (AP) served as controls.

RESULTS

The AP + C group, showed an increase in the exudate lipid peroxidation (LPO), reduced glutathione (GSH), TNF-α, activity of catalase (CAT), total leukocytes and neutrophils along with tissue edema and infiltration of inflammatory cells. Increases in tissue nitrite, LPO, GSH, SOD (superoxide dismutase) and CAT were recorded. Increased CAT and SGPT with concomitant decrease in ALP were observed in serum. When treated with indomethacin (AP + C + I), all the alterations in the exudate, tissue and serum shifted towards normalcy, except LPO in exudate and nitrite in tissue, while, hesperidin (AP + C + H) or naringin (AP + C + N) treatment normalized all the alterations.

CONCLUSION

It seems that both naringin and hesperidin are anti-inflammatory and antioxidative in nature, but hesperidin proved to be better than indomethacin and naringin because of more pronounced pharmacological actions without tissue toxicity.

Nigella sativa thymoquinone-rich fraction greatly improves plasma antioxidant capacity and expression of antioxidant genes in hypercholesterolemic rats

The antioxidant activities of the thymoquinone-rich fraction (TQRF) extracted from Nigella sativa and its bioactive compound, thymoquinone (TQ), in rats with induced hypercholesterolemia were investigated. Rats were fed a semipurified diet supplemented with 1% (w/w) cholesterol and were treated with TQRF and TQ at dosages ranging from 0.5 to 1.5 g/kg and 20 to 100 mg/kg body wt, respectively, for 8 weeks. The hydroxyl radical (OH(.))-scavenging activity of plasma samples collected from experimental rats was measured by electron spin resonance. The GenomeLab Genetic Analysis System was used to study the molecular mechanism that mediates the antioxidative properties of TQRF and TQ. Plasma total cholesterol and low-density-lipoprotein cholesterol levels were significantly decreased in the TQRF- and TQ-treated rats compared to untreated rats. Feeding rats a 1% cholesterol diet for 8 weeks resulted in a significant decrease in plasma antioxidant capacity, as measured by the capacity to scavenge hydroxyl radicals. However, rats treated with TQRF and TQ at various doses showed significant inhibitory activity toward the formation of OH(.) compared to untreated rats. Upon examination of liver RNA expression levels, treatment with TQRF and TQ caused the up-regulation of the superoxide dismutase 1 (SOD1), catalase, and glutathione peroxidase 2 (GPX) genes compared to untreated rats (P<0.05). In support of this, liver antioxidant enzyme levels, including SOD1 and GPX, were also apparently increased in the TQRF- and TQ-treated rats compared to untreated rats (P<0.05). In conclusion, TQRF and TQ effectively improved the plasma and liver antioxidant capacity and enhanced the expression of liver antioxidant genes of hypercholesterolemic rats.

The Effect of Combined Treatment with Niacin and Chromium (III) Chloride on the Different Tissues of Hyperlipemic Rats

We investigated the effects of a combined treatment with chromium (Cr) and niacin on the spleen, tongue, and lens tissues in terms of lipid peroxidation (LPO), glutathione (GSH), serum catalase (CAT), lactate dehydrogenase (LDH), serum cholesterol, and total lipid levels in normal and hyperlipemic rats. In this study, female 1-year-old Swiss albino rats were used. The rats were randomly divided into four groups. Group I rats (control) were fed with standard pellet chow. Group II rats were fed a lipogenic diet in which 2% cholesterol, 0.5% cholic acid, and 20% sunflower oil were added and were given 3% alcoholic water for 60 days. Group III rats were fed with the same lipogenic diet and were treated with a dose of 250 microg/kg body weight CrCI3 x 6H2O and 100 mg/kg body weight niacin, for 45 days, by gavage. The rats in group IV were fed with pellet chow and treated with 250 microg/kg body weight CrCI3 x 6H2O and 100 mg/kg body weight niacin, by gavage, for 45 days. After 2 weeks, the animals showed symptoms of hyperlipemia. On the 60th day, tissue and blood samples were taken. We have observed decreased CAT activity and GSH levels, increased LDH activity, cholesterol, total lipid, and LPO levels in hyperlipemic rats. Niacin and Cr administration to hyperlipemic rats increased tissue GSH levels and CAT activity and decreased tissue LPO levels and LDH activity, cholesterol, and total lipid levels compared with hyperlipemic rats. We conclude that the administration of a combination of niacin and chromium has a protective effect against oxidative damage to tongue, lens, and spleen tissues as a result of hyperlipemia.

Possible amelioration of atherogenic diet induced dyslipidemia, hypothyroidism and hyperglycemia by the peel extracts of Mangifera indica, Cucumis melo and Citrullus vulgaris fruits in rats

Hitherto unknown efficacy of the peel extracts of Mangifera indica (MI), Cucumis melo (CM) and Citrullus vulgaris (CV) fruits in ameliorating the diet-induced alterations in dyslipidemia, thyroid dysfunction and diabetes mellitus have been investigated in rats. In one study, out of 4 different doses (50-300 mg/kg), 200 mg/kg of MI and 100 mg/kg for other two peel extracts could inhibit lipidperoxidation (LPO) maximally in liver. In the second experiment rats were maintained on pre-standardized atherogenic diet CCT (supplemented with 4% cholesterol, 1% cholic acid and 0.5% 2-thiouracil) to induce dyslipidemia, hypothyroidism and diabetes mellitus and the effects of the test peel extracts (200 mg/kg of MI and 100 mg/kg for CM and CV for 10 consecutive days) were studied by examining the changes in tissue LPO (in heart, liver and kidney), concentrations of serum lipids, thyroid hormones, insulin and glucose. Rats, treated simultaneously with either of the peel extracts reversed the CCT-diet induced increase in the levels of tissue LPO, serum lipids, glucose, creatinine kinase-MB and decrease in the levels of thyroid hormones and insulin indicating their potential to ameliorate the diet induced alterations in serum lipids, thyroid dysfunctions and hyperglycemia/diabetes mellitus. A phytochemical analysis indicated the presence of a high amount of polyphenols and ascorbic acid in the test peel extracts suggesting that the beneficial effects could be the result of the rich content of polyphenols and ascorbic acid in the studied peels.

Atherogenic diet induced diabetes mellitus: involvement of thyroid hormones

An investigation was made to reveal the possible involvement of thyroid hormones in the progression of diabetes mellitus in response to an atherogenic diet; CCT (4% cholesterol, 1% cholic acid and 0.5% 2-thiouracil). Following the intake of CCT diet for 14 consecutive days a decrease in the serum levels of insulin, both the thyroid hormones, triiodothyronine (T(3)) and thyroxine (T(4)); hepatic glycogen content, hepatic type-1 iodothyronine 5'-mono-deiodinase (5'D) and serum alpha-amylase activities were observed, while there was an increase in the levels of serum glucose and nitrite and in lipid peroxidation of heart, liver and kidney tissues as well as in serum. However, simultaneous administration of L-thyroxine (500 microg/kg/day, s.c.) to CCT-diet fed animals resulted in the amelioration of all the aforesaid adverse changes including that of serum glucose, insulin, alpha-amylase, hepatic glycogen content and nitrite levels, suggesting the involvement of thyroid hormones in the progression of CCT-diet induced diabetes mellitus.

Protective effect of lupeol and its ester on cardiac abnormalities in experimental hypercholesterolemia

Hyperlipidemia is a major risk factor for the premature development of coronary heart disease and it has been shown to increase the incidence of myocardial ischemia and cardiac events. Pentacyclic triterpenes possess antiatherosclerotic, antioxidant, anti-inflammatory and cytoprotective effects. To study the effect of plant derived triterpene, lupeol and its ester lupeol linoleate, on lipid status and biochemical changes on heart tissue, male albino Wistar rats were fed high-cholesterol diet (normal rat chow supplemented with 4% cholesterol and 1% cholic acid; HCD) for 30 days. There was a significant (p<0.001) increase in the levels of total cholesterol, triglycerides and phospholipids along with augmented activities of lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase in the heart tissue. Triterpenes treatment reduced the above alterations produced in hypercholesterolemic rats. The transmembrane enzymes, namely Na(+), K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase showed a decrease in their activities. Triterpenes treatment reversed these levels, prevented the hypertrophic cardiac histology and restored the normal ultrastructural architecture. In conclusion, lupeol and lupeol linoleate intervention minimized the lipid abnormalities and abnormal biochemical changes induced by HCD fed rats. This shows that triterpenes possess cardioprotective effects which will be beneficial in hypercholesterolemic condition. Out of these two triterpenes tested, lupeol linoleate appeared to be even more effective than lupeol.

Cardio-protective role of terazosin is possibly mediated through alteration in thyroid function

An investigation was made to reveal the possible involvement of thyroid hormones, if any, in terazosin (an alfa-1 adrenergic receptor blocker) induced alterations in tissue lipid peroxidation (LPO) and in the concentration of different serum lipids. We determined the impact of terazosin on the changes in hypercholesterolemic (CCT) diet induced thyroid dysfunction; cardiac, renal and hepatic LPO and on serum glucose concentration in female Wister rats. Simultaneously levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), creatinine, alkaline phosphatase (ALP) activity, hepatic glycogen synthesis and total daily food consumption were studied as supporting parameters. While a decrease in the level of serum thyroid hormones, HDL-C and in hepatic glycogen content, was observed in CCT diet fed animals; it increased the concentration of other serum lipids, glucose and creatinine; ALP activity; tissue and serum LPO. However, following terazosin administration for 15 days to CCT diet fed animals, status of thyroid hormones and all other thyroid dependent parameters were reversed suggesting that the drug might be acting through an alteration in the thyroid functions.

The Effects of Combined Treatment with Niacin and Chromium on the Renal Tissues of Hyperlipidemic Rats

In this study, 12 months old female Swiss albino rats were used. They were randomly divided into four groups. The animals of group I were fed with pellet chow. Group II were fed with pellet chow and treated with 250 microg/kg CrCl3 x 6H2O and 100 mg/kg niacin for 45 days. Group III were fed a lipogenic diet consisting of 2% cholesterol, 0.5% cholic acid and 2% sunflower oil added to the pellet chow, and given 3%alcoholic water for 60 days. Group IV were fed with the same lipogenic diet for 60 day sand treated by gavage technique to rats at a dose of 250 micro/kg CrCl3 x 6H2O and 100 mg/kg niacin for 45 days, 15 days after experimental animals were rendered hyperlipidemic. At the 60th day, renal tissue and blood samples were taken from the animals. The sections were examined under light and electron microscopy. The degenerative changes were much more in the hyperlipidemic rats than the control group. The changes in renal tissue were also observed in hyperlipidemic animals given niacin and chromium. In the hyperlipidemic rats, renal glutathione levels decreased and renal lipid peroxidation levels, and serum urea and creatinine levels were increased. But, renal glutathione levels increased and lipid peroxidation levels and serum urea and creatinine levels decreased in hyperlipidemic rats given niacin and chromium. The purpose of this study was to investigate whether a protective effect of a combination of niacin and chromium is present on the renal tissue of hyperlipidemic rats or not. In conclusion, we can say that niacin and chromium do not have a protective effect on the morphology of the renal tissue of hyperlipidemic rats, except a protective effect on their biochemical parameters.

Mitigating role of lupeol and lupeol linoleate on hepatic lipemic-oxidative injury and lipoprotein peroxidation in experimental hypercholesterolemia

In the present study, the role of pentacyclic triterpenes, lupeol and its ester lupeol linoleate, was studied in relation to hepatic oxidative abnormalities and lipoprotein peroxidation in hypercholesterolemic rats. Hypercholesterolemia was induced in male Wistar rats by feeding them with high cholesterol diet (4% cholesterol + 1% cholic acid; HCD) for 30 days. Pentacyclic triterpenes, lupeol and lupeol linoleate were supplemented (50 mg/kg body wt/day) during the last 15 days. After the experimental period, there was a significant depression in hepatic activities of antioxidant enzymes, SOD (38.39%), CAT (25.03%) and GPx (30.26%) along with a marked fall in the levels of non-enzymic antioxidant molecules GSH (31.39%), vitamin C (46.07%) and vitamin E (42.28%), with a concomitant increase (p<0.001) in lipid peroxidation and in the activities of serum alkaline phosphatase, lactate dehydrogenase and aminotransferases when compared to controls. Treatment with triterpenes decreased lipid peroxidation and reverted the activities of antioxidants (p<0.001 and p<0.01) and marker enzymes to near control. Histopathological findings further confirmed the hepatoprotective nature of triterpenes by showing the normal architecture in treated rats, as against the fatty cellular changes in HCD fed rats. Further, the susceptibility of apo-B containing lipoprotein to oxidation by copper and Fenton's reagent was increased in in vitro condition in HCD fed rats, whereas the lipoproteins were less susceptible to oxidation in triterpenes treated animals. Therefore, it may be concluded that lupeol and its ester afford protection against the hepatic abnormalities and lipoprotein peroxidation in hypercholesterolemic rats.

Protective role of eicosapentaenoate-lipoate (EPA-LA) derivative in combating oxidative hepatocellular injury in hypercholesterolemic atherogenesis

The aim of the present study is to evaluate the effect of eicosapentaenoic acid (EPA), dl-alpha-lipoic acid (LA) and eicosapentaenoate-lipoate (EPA-LA) derivative on the atherogenic disturbances in hypercholesterolemic atherogenic animals. Eight groups of male Wistar rats were employed in this study, wherein four groups were fed with a high cholesterol diet (rat chow supplemented with 4% cholesterol and 1% cholic acid; HCD) for 30 days, among which, three groups of rats were also treated with either EPA (35 mg/kg body weight/day, oral gavage), LA (20 mg/kg body weight/day, oral gavage) or EPA-LA derivative (50 mg/kg body weight/day, oral gavage) commencing from 16th day of the experimental period. The remaining four groups served as control and EPA, LA and EPA-LA derivative treated drug controls. Abnormal increases in the levels of malondialdehyde, protein carbonyl and 8-hydroxy-2-deoxyguanosine, as well as depressed antioxidants status, were observed in hepatic tissue of HCD fed rats. HCD induced abnormal elevation in the activities of hepatic lactate dehydrogenase, aminotransferases and alkaline phosphatase (ALP) and was accompanied by increased hepatic cholesterol level and altered fatty changes in the histology of liver. These changes were restored partially in the EPA and LA administered groups. However, the combined derivative EPA-LA almost ameliorated the hypercholesterolemic-oxidative changes in the HCD fed rats. The results of this study present oxidative injury induced by hypercholesterolemic diet and administration of the combination treatment of EPA-LA afforded sound protection against lipemic-oxidative injury.

Biochemical evaluation of the inflammatory changes in cardiac, hepatic and renal tissues of adriamycin-administered rats and the modulatory role of exogenous heparin-derivative treatment

The aim of the present work is to evaluate the role of a heparin derivative, low molecular weight heparin (LMWH), certoparin on the inflammatory changes in adriamycin (ADR) cytotoxicity on a biochemical basis. Male Wistar rats (140+/-10g) were divided into four groups: untreated control, ADR group (a single dose intravenous injection of 7.5 mg/kg ADR), LMWH control (300 microg/(day rat) s.c. for 1 week) and ADR plus LMWH group (7.5 mg/kg ADR on day 1 of study period followed by LMWH treatment, 300 microg/(day rat) commencing on day 8 and continued for 1 week). At the end of the 2-week experimental period, biochemical assessment of the inflammatory status was carried out in the plasma, cardiac, hepatic and renal tissues. Increased concentrations of plasma C-reactive protein (CRP) and fibrinogen indicated severe inflammation in the ADR cytotoxic rats. These acute-phase inflammatory markers diminished significantly in the LMWH treated group, when compared with the cytotoxic group (p<0.001). Tissue damage was marked by elevated levels of plasma and tissue hexose, hexosamine, hexuronic acid and sialic acid, which were reversed on LMWH administration (p<0.001). The activities of lysosomal enzymes was measured in the experimental groups, and it was observed that the ADR induced rats showed a marked increase in the enzymic activities, while LMWH treated rats revealed normal activities. The present study throws light on the inflammatory changes in the ADR-challenged heart, liver and kidney tissues, and projects the biochemical basis for the anti-inflammatory property of the LMWH, certoparin.

Beneficial cardio-renovascular effects of a low-molecular-weight heparin-derivative on adriamycin-induced glycosaminoglycanuria and tissue lipid abnormalities

The present work includes a study on the glycosaminoglycanuric condition induced by adriamycin (ADR, a chemotherapeutic agent) and the accompanying secondary hyperlipidemia, wherein the treatment with a low-molecular-weight heparin-derivative (LMWH), certoparin, is evaluated for its protective role (if any) on these parameters. Two groups of male albino rats of the Wistar strain (140+/-10 g) received a single intravenous injection of adriamycin (7.5 mg/kg), and one of these groups was treated with a low-molecular-weight heparin-derivative (Certoparin Sodium, Troparin; 300 microg/day/rat s.c.), commencing on day 8, for a week. Urinary total glycosaminoglycans excretion of the untreated ADR-induced group was found to increase on the 8th and the 15th days of observation, when compared with the controls. The LMWH treatment commencing on day 8 resulted in minimising the glycosaminoglycans (GAGs) excretion by day 15 (p<0.001). Plasma, cardiac, hepatic and renal lipids (cholesterol, triglycerides and phospholipids) showed a sharp increase in the pathologic group, along with a rise in plasma LDL and VLDL cholesterol and drop in HDL cholesterol levels, paralleled by abnormal activities of the enzymes involved in lipid metabolism. LMWH treated group showed a normalised lipid profile and the activities of the lipid-metabolising enzymes was close to that of controls. It is concluded herein that adriamycin administration resulted in severe nephropathy manifested by increased glycosaminoglycanuria and abnormal lipid metabolism, and that LMWH treatment afforded substantial protection by restoring glomerular structure and function, and normalised the plasma and tissue lipid levels, lipoprotein profile and the activities of lipid-metabolising enzymes.

Atheroprotective effect of exogenous heparin-derivative treatment on the aortic disturbances and lipoprotein oxidation in hypercholesterolemic diet fed rats

BACKGROUND

The present work explores the myriad of biochemical and cellular changes that are featured in the early stages of atherosclerosis; if unchecked these changes lead to the complicated atherosclerotic plaque formation. The influence of a low-molecular-weight heparin derivative on the aortic aberrations and lipoprotein oxidation has been assessed in an experimental model of hypercholesterolemic atherogenesis.

METHODS

Two groups of male Wistar rats (140+/-10 g) were fed a hypercholesterolemic atherogenic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil; CCT diet) for 2 weeks; one of these groups received LMWH (Certoparin) treatment of 300 microg/day/rat, s.c. for 7 days. An untreated control and a LMWH drug control group were also included.

RESULTS

Abnormal increase in the aortic lipids -glycosaminoglycans levels (p<0.001) in CCT-diet fed group was circumvented by the exogenous glycosaminoglycan (LMWH) treatment (p<0.001). The escalation of oxidative stress (markers-lipid peroxidation and thiol levels, superoxide dismutase and catalase activities) in the atherogenic aorta was minimised by LMWH treatment. Further, an increased susceptibility of the apo B-containing lipoproteins (LDL+VLDL) to oxidation in vitro, induced by copper ions and Fenton's reagent, was observed in the untreated CCT diet fed group. This paper reports the favorable modulation of these oxidative changes by LMWH administration. Vascular protection by LMWH is further substantiated by the normal aortic histologic findings as against the appearance of foam cells in the untreated atherogenic group.

CONCLUSION

The exogenous heparin-derivative (LMWH) treatment attempted in this experimental model of hypercholesterolemic atherogenesis affords substantial protection against abnormal levels of aortic lipids and glycosaminoglycans, aortic oxidative stress and also stunts the lipoprotein peroxidative process, thereby proving its multi-faceted anti-atherogenic effects.

Effect of hypercholesterolemia on inducible nitric oxide synthase expression in a rat model of elevated intraocular pressure

PURPOSE

This study was performed to examine the effect of hypercholesterolemia on inducible nitric oxide synthase (NOS-2) expression and oxidative tissue injury in an experimental rat model of elevated IOP.

METHODS

Wistar rats were maintained on either regular chow or a high-cholesterol diet for 24 weeks. Intraocular pressure (IOP) was elevated in hypercholesterolemic rats by unilaterally cauterizing three episcleral vessels. Rats were divided into four experimental groups as follows; hypercholesterolemia, hypercholesterolemia+elevated IOP, elevated IOP and control. NOS-2 distribution, lipid peroxidation and retinal nerve fiber layer (RNFL) thickness was evaluated in all experimental groups at the end of 24 weeks.

RESULTS

Light microscopic evaluation of retinas in hypercholesterolemic rats revealed breaks and discontinuation in focal areas in the outer nuclear layer (ONL). NOS-2 positive staining was observed throughout the outer plexiform layer (OPL), inner plexiform layer (IPL) and ganglion cell layer (GCL) in rats with elevated IOP and/or hypercholesterolemia. Calculated values of RNFL thickness in hypercholesterolemic rats were significantly higher than those in the control and elevated IOP group. Vitreous malondialdehyde (MDA) levels detected in elevated IOP (3.51+/-0.31 nmol/mg protein) and hypercholesterolemia+elevated IOP (5.14+/-1.28 nmol/mg protein) groups were significantly higher than those detected in hypercholesterolemic (1.92+/-1.43 nmol/mg protein) and control (1.89+/-0.24 nmol/mg protein) groups.

CONCLUSION

The presented data confirms hypercholesterolemia as a risk factor in the development of glaucomatous optic neuropathy (GON) and suggests that increased circulating cholesterol may exacerbate disease progression by inducing NOS-2 expression and elevating oxidant tissue injury.

A study of unfractionated and low molecular weight heparins in a model of cholestatic liver injury in the rat

Forty-eight rats with biliary obstruction induced by double ligation and section of the common bile duct were randomly and blindly assigned to receive subcutaneous injection of either conventional heparin sodium (1000IU kg(-1)), three already marketed low molecular weight heparin (LMWH) preparations: nadroparin (1000 anti-Xa IU kg(-1)), tinzaparin (1000 anti-Xa IU kg(-1)), enoxaparin (180 anti-Xa IU kg(-1)) or saline. Drugs were administered once a day, starting 7 days after surgery and continued for 3 weeks. At the end of the treatment period, rats were killed and analyzed for blood biochemistry and liver pathology. Liver fibrosis was assessed by image analysis. Data indicated that treatment with nadroparin decreased plasma total bilirubin, serum alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT) levels by 80.3, 70.7 and 42%, compared with bile duct ligated (BDL) control values. The reduction in plasma total protein observed in BDL controls was prevented by nadroparin. Enoxaparin-treated rats showed significant reduction in plasma total bilirubin and alanine aminotransferase levels by 32.5 and 38.4% versus BDL controls. Liver necrosis evaluated histologically was significantly reduced in the nadroparin- and enoxaparin-treated rats. Morphometric analysis showed significant reduction in fibrosis on nadroparin and enoxaparin treatment: area of fibrosis: 1.66 +/- 0.17% and 14.03 +/- 1.1% versus 18.94 +/- 2.4% (P<0.05); nadroparin and enoxaparin versus BDL control. By contrast, neither conventional heparin nor tinzaparin prevented the bile duct ligation-induced liver damage as indicated by increased plasma aminotransferases, ALP and GGT concentrations and the histological evidence of necrosis. Total serum bilirubin was increased by 27.5% in rats treated with conventional heparin, while ALP and GGT levels were 38.6 and 31.4% higher after tinzaparin treatment versus BDL controls. Significant increase in the area of fibrosis was observed after tinzaparin treatment compared to BDL control group. Results suggest a beneficial effect for nadroparin and enoxaparin in the therapy of patients with obstructive jaundice or cholestatic liver disorders. The present data from bile duct ligated rats suggest an antifibrotic effect for nadroparin and enoxaparin.