Favourable modulation of the inflammatory changes in hypercholesterolemic atherogenesis by a low-molecular-weight heparin derivative

Exercise reduces hyperlipidemia-induced kidney damage in apolipoprotein E-deficient mice

Hyperlipidemia is a risk factor of kidney damage that can lead to chronic kidney disease. Studies have shown that exercise reduces kidney damage; however, the specific mechanisms underlying the protective effects of exercise remain unclear. For 12 weeks, 8-week-old male apolipoprotein E-deficient (ApoE^-/-) mice were randomly divided into four treatment groups (n=7/group) as follows: Mice fed a normal diet (ND group); mice fed a ND and exercised (ND + E group); mice fed a high-fat diet (HD group); and mice fed a HD and exercised (HD + E group). Exercise training consisted of swimming for 40 min, 5 days/week. Metabolic parameters, such as low-density lipoprotein-cholesterol, total cholesterol and creatinine levels were higher in the ApoE^-/- HD mice compared with those in the ApoE^-/- HD + E mice. Serum levels of glutathione peroxidase and superoxide dismutase were significantly decreased in the HD group compared with those in the HD + E group. Significant pathological changes were observed in the HD + E group compared with in the HD group. Immunohistochemistry and immunoblotting revealed increased levels of oxidative stress (nuclear factor erythroid-2-related factor 2) and fibrosis (Smad3 and TGF-β) markers in the ApoE^-/- HD group; however, the expression levels of these markers were significantly decreased in the ApoE^-/- HD + E group. Furthermore, NF-κB expression in the HD + E group was significantly lower compared with that in the HD group. These results suggested that exercise may exert protective effects against kidney damage caused by hyperlipidemia.

Straight to the heart: Pleiotropic antiarrhythmic actions of oral anticoagulants

Mechanistic understanding of atrial fibrillation (AF) pathophysiology and the complex bidirectional relationship with thromboembolic risk remains limited. Oral anticoagulation is a mainstay of AF management. An emerging concept is that anticoagulants may themselves have potential pleiotropic disease-modifying effects. We here review the available evidence for hemostasis-independent actions of the oral anticoagulants on electrical and structural remodeling, and the inflammatory component of the vulnerable substrate.

Ameliorative effect of biofabricated ZnO nanoparticles of Trianthema portulacastrum Linn. on dermal wounds via removal of oxidative stress and inflammation

An impediment in the process of wound healing can be attributed to reactive oxygen species and inflammation. The curative efficacy of green synthesized Trianthema portulacastrum Linn. zinc oxide nanoparticles (ZnOTP) was investigated in the present study for evaluation of their wound healing potential in rodents. Total phenolic and flavonoid content of ZnOTP was determined, and antioxidant potential was evaluated by the DPPH method. In vitro anti-inflammatory activity of ZnOTP was evaluated by membrane stabilization and albumin denaturation, along with proteinase inhibitory assays. The synthesized ZnOTP were characterized by UV-Visible spectroscopy, Fourier transform infrared (FT-IR) studies, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray (EDX) studies. The wound healing potential of ZnOTP was monitored by excision and incision wound models. Analyses confirmed the formation of spherical nanoparticles of 10-20 nm size along with strong signals of zinc and oxygen atoms. Significant results (p < 0.05) of wound contraction rate, epithelialization and histopathology of the healed tissues of rats confirmed the promising wound healing property of ZnOTP. In addition, inflammatory markers, biochemical estimation such as the hydroxyproline content of granulation tissue, and the profile of antioxidant enzymes also supported the wound healing potential of ZnOTP. The present study advocated the attenuation of wounds via antioxidant and anti-inflammatory activities of a green synthesized nano-ointment.

Attenuation of dermal wounds via downregulating oxidative stress and inflammatory markers by protocatechuic acid rich n-butanol fraction of Trianthema portulacastrum Linn. in wistar albino rats

Oxidative stress and inflammation contribute as a key factor for retarding the process of dermal wound healing. Trianthema portulcastrum Linn. (TP) leaves reported to possess antioxidant, antifungal, anti-inflammatory and antibacterial properties, which could make TP a promising wound healing agent. The current study was aimed to estimate the antioxidant potential of the fractionated hydroethanolic extract of TP leaves and evaluate wound healing activity by excision and incision wound models along with the assessment of possible underlying mechanism. Ethyl acetate, chloroform and n-butanol fractions of the hydroethanolic extract of TP leaves were examined for in vitro antioxidant ability by DPPH method. Strongest antioxidant activity bearing n-butanol fraction (nBuTP) was further analyzed quantitatively by High Performance Liquid Chromatography coupled with Diode Array Detector (HPLC-DAD). Wound healing potential of nBUTP using excision and incision wound model was studied. Wistar albino rats were randomly divided into four groups, containing six animals in each group; group I served as control treated with simple ointment base, group II was standard group, treated with povidone-iodine ointment USP (5%), group III treated with nBuTP 5% w/w ointment, and group IV treated with nBuTP 10%w/w ointment. All the groups were topically applied their respective ointments, once daily, till the complete healing achieved. Wound healing was assessed by analyzing % wound closure, hydroxyproline content, epithelialization period, tensile strength, enzymatic antioxidative status and inflammatory markers. Total phenolic and flavonoid content of the extract was estimated to be 112.32±1.12 and 84.42±0.47mg/g, respectively. HPLC-DAD of nBuTP confirmed the presence of chlorogenic acid (20.74±0.03), protocatechuic acid (34.45±0.02mg/g), caffeic acid (4.31±0.03mg/g) and ferulic acid (1.43±0.01mg/g). 5% and 10%w/w nBuTP ointment significantly accelerated the wound healing process dose-dependently in both wound models, evidenced by the faster rate of wound contraction, epithelialization, increased hydroxyproline content, high tensile strength, increased antioxidant enzyme activity, decreased the level of inflammatory markers compared to the control group. Histopathological studies also revealed the dose-dependant amelioration of wound healing by re-epithelialization, collagenation and vascularization of wounded skin sample in nBuTP treated groups. These results implicate potential medicinal value of nBuTP to heal dermal wounds.

Effects of nutritional and excessive levels of selenium on red blood cells of rats fed a high cholesterol diet

In this study, we investigated the effects of selenium (Se) on the properties of erythrocytes and atherogenic index in the presence and absence of high cholesterol diet (HCD). The effect of selected two different doses (1 μg and 50 μg Se/kg/body weight) on HCD-induced oxidative stress was investigated. The hemolysis of the erythrocytes of the HCD rats as well as by high levels of selenium or their combination was markedly increased. Likewise, atherogenic index and plasma glutathione peroxidase (GPx) activity were significantly increased in the same groups of rats compared to control ones. In contrast, paraoxonase activity, glutathione levels and protein thiol levels, catalase, GPx, and superoxide dismutase activities were significantly decreased in rats that received the HCD, high selenium dose, or their combination. Malondialdehyde and protein carbonyl levels in the plasma and red blood cells were significantly increased by HCD and high selenium dose administration. Co-administration of selenium at low dose with or without an HCD restored all of the investigated parameters to near-normal values. The results of this study suggest that excess selenium administration with HCD worsens the atherogenic index and enhances formation of oxidized red blood cells. At dosage levels in the nutritional range such as 1 μg Se/kg body weight, selenium ameliorates the atherogenic index and preserves the antioxidant capacity of the erythrocytes.

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.

A novel phytochemical, digoxigenin-3-O-rutin in the amelioration of isoproterenol-induced myocardial infarction in rat: a comparison with digoxin

INTRODUCTION

The commonly used cardiac glycoside, digoxin (DIG), has a narrow therapeutic window. Although some investigations were made to counteract its toxic effects, no alternate phytochemical is available till date that is more potent and safer than DIG.

AIMS

Our main aim was to isolate a novel cardenolide from the seeds of Trigonella foenum graceium and to evaluate its relative potential in comparison to that of DIG.

EXPERIMENTAL DESIGN

In one experiment effects of the isolated compound at 2.5, 5.0, and 10 mg/kg (p.o.) were evaluated in isoproterenol (ISO)-induced cardiovascular problems in rats. As the test drug (TDR) reversed most of the ISO-induced changes, it was subjected to the phytochemical analyses and was identified as digoxigenin-3-O-rutin. In another experiment effects of DIG and rutin (Rtn) were compared with those of TDR or DIG alone. The hydroxyl radical scavenging activity was also measured by electron spin resonance (EPR).

RESULTS

digoxigenin-3-O-rutin at 10 mg/kg markedly reduced the ISO-induced increase in cardiac lipid peroxidation and in the levels of serum creatinine phosphokinase-MB, glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, lactate dehydrogenase, and creatinine. It also reversed the ISO-induced changes in the cardiac histomorphology. Interestingly TDR appeared to be more effective than DIG alone or DIG and Rtn in combination.

CONCLUSION

The newly isolated digoxigenin-3-O-rutin appears to be more potent and safe than digoxin. Its higher efficacy could be due to its structural specificity and might have been mediated through its better free radical scavenging action.

Anti-inflammatory effects of low molecular weight heparin derivative in a rat model of carrageenan-induced pleurisy

Low molecular weight heparin derivatives are characterized by low anti-coagulant activity and marked anti-inflammatory effects that allow for these molecules to be viewed as a new class of non-steroidal anti-inflammatory drugs (NSAIDs). We show here that K5NOSepiLMW, an O-sulphated heparin-like semi-synthetic polymer of the D-glucuronic acid-N-acetyleparoson disaccharide unit with low molecular weight, has marked anti-inflammatory effects in a rat model of acute inflammation, the carrageenan-induced pleurisy, commonly used to test NSAID efficacy. A 30-min. pre-treatment with K5NOSepiLMW (0.1, 0.5 and 1 mg/kg b.wt., given intrapleurally) attenuated the recruitment of leucocytes in the lung tissue and the pleural exudate, inhibited the induction of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2), thereby abating the generation of nitric oxide and pro-inflammatory prostaglandins such as PgE(2) and PGF(1alpha), reduced the inflammation-induced nitroxidative lung tissue injury, as shown by tissue thiobarbituric acid-reactive substances and nitrotyrosine, and blunted the local generation of cytokines such as interleukin-1beta and tumour necrosis factor-alpha. All these parameters were markedly increased by intrapleural carrageenan in the absence of any pre-treatment. The anti-inflammatory action of K5NOSepiLMW is specific, as judged by the lack of therapeutic effects of B4/110, a biologically inactive cognate polysaccharide, given in the place of the authentic molecule. Moreover, K5NOSepiLMW showed similar effects as celecoxib (1 mg/kg b.wt), a COX-2 inhibitor and well-known NSAID. This study provides further insight into the mechanisms underlying the beneficial effects of heparin derivatives in inflammation and identifies K5NOSepiLMW as a novel, promising anti-inflammatory drug.

Anti-inflammatory effects of low molecular weight heparin derivative in a rat model of carrageenan-induced pleurisy

Low molecular weight heparin derivatives are characterized by low anti-coagulant activity and marked anti-inflammatory effects that allow for these molecules to be viewed as a new class of non-steroidal anti-inflammatory drugs (NSAIDs). We show here that K5NOSepiLMW, an O-sulphated heparin-like semi-synthetic polymer of the D-glucuronic acid-N-acetyleparoson disaccharide unit with low molecular weight, has marked anti-inflammatory effects in a rat model of acute inflammation, the carrageenan-induced pleurisy, commonly used to test NSAID efficacy. A 30-min. pre-treatment with K5NOSepiLMW (0.1, 0.5 and 1 mg/kg b.wt., given intrapleurally) attenuated the recruitment of leucocytes in the lung tissue and the pleural exudate, inhibited the induction of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2), thereby abating the generation of nitric oxide and pro-inflammatory prostaglandins such as PgE(2) and PGF(1alpha), reduced the inflammation-induced nitroxidative lung tissue injury, as shown by tissue thiobarbituric acid-reactive substances and nitrotyrosine, and blunted the local generation of cytokines such as interleukin-1beta and tumour necrosis factor-alpha. All these parameters were markedly increased by intrapleural carrageenan in the absence of any pre-treatment. The anti-inflammatory action of K5NOSepiLMW is specific, as judged by the lack of therapeutic effects of B4/110, a biologically inactive cognate polysaccharide, given in the place of the authentic molecule. Moreover, K5NOSepiLMW showed similar effects as celecoxib (1 mg/kg b.wt), a COX-2 inhibitor and well-known NSAID. This study provides further insight into the mechanisms underlying the beneficial effects of heparin derivatives in inflammation and identifies K5NOSepiLMW as a novel, promising anti-inflammatory drug.

Low-molecular-weight heparin inhibition in classical complement activation pathway during pregnancy

INTRODUCTION

Low-molecular-weight heparin is used clinically for the prevention of pregnancy complications associated with prothrombotic disorders, particularly anti-phospholipid syndrome. Nevertheless, recent studies have suggested that heparin may exert direct effects on the placental trophoblast, independently of its anticoagulant activity. In addition, heparin prevents complement activation in vivo and protects mice from pregnancy complications.

MATERIALS AND METHODS

The inhibition of the classical complement activation pathway by heparin was analyzed by means of in vitro assays and in pregnant women receiving prophylaxis with therapeutic doses (40 mg/day) of subcutaneous low molecular weight heparin by haemolysis of antibody-sensitized sheep erythrocytes (CH(50) assay).

RESULTS

The specific interaction between low-molecular-weight heparin and the C1q subunit of the C1 complex of the complement cascade allowed the isolation of a small subpopulation of heparin ( 8.03+/-1.20 microg %), with an anti-activated factor X activity more than four times greater than the starting material. This subpopulation could be responsible for the in vitro inhibition of the classical complement activation pathway evaluated by the total haemolysis of antibody-sensitized sheep erythrocytes. About 60 microg/ml of low molecular weight heparin was needed to achieve 50% of haemolysis. The detection of the classical complement pathway inhibition in pregnant women treated with heparin required a first activation with aggregated human IgG.

CONCLUSIONS

We concluded that the interaction between low-molecular-weight heparin and C1q could be relevant not only in the complement-dependent, but also in the complement-independent inflammation mechanisms responsible for the prevention of pregnancy loss.

Anti-atherogenic effects of centipede acidic protein in rats fed an atherogenic diet

AIM OF THE STUDY

To investigate the effects of centipede acidic protein (CAP) on atherosclerotic rats and the mechanisms involved.

MATERIALS AND METHODS

Male Sprague-Dawley rats were randomly divided into five groups: control, atherosclerotic, low-dose CAP (L-CAP), high-dose CAP (H-CAP) and simvastatin group (n=12 in each group). Atherosclerotic model was established by a single dose of vitamin D(3) and an atherogenic diet. Rats of H-CAP and simvastatin groups simultaneously received CAP or simvastatin daily for 6 weeks. At the completion of the experiment, the changes in lipid profile, hemorrheology, nitric oxide (NO), endothelin-1 (ET-1), malondialdehyde (MDA) and superoxide desmutase (SOD) were measured, and the histological changes in aorta and liver were observed.

RESULTS

Treatment of atherosclerotic rats with either low or high doses of CAP led not only to significant decreases in plasma total cholesterol, triglyceride, low density lipoprotein and increase in plasma high density lipoprotein, but also to improvement of the hemorrheologic abnormalities. On the other hand, CAP suppressed the lipid peroxidation, regulated the levels of ET-1 and NO. From the histopathological examination, treatment with CAP ameliorated the pathological changes in thoracic aorta and liver in atherosclerotic rats.

CONCLUSIONS

These results suggest that CAP significantly suppress the development of atherosclerosis, improves the hemorrheological disturbances and histopathological changes in the atherogenic diet fed rat model. These effects may partly attribute to reverse of dyslipidemia, inhibition of lipid peroxidation, regulation of NO and ET-1 system.

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.

Effect of sulphated polysaccharides on erythrocyte changes due to oxidative and nitrosative stress in experimental hyperoxaluria

Kidney stones are known to haunt humanity for centuries and increase in oxalate is a predominant risk factor for stone formation. The present study was initiated with a notion to study the oxidative and nitrosative stress on erythrocytes under oxalate stress and the putative role of sulphated polysaccharides. Hyperoxaluria was induced in two groups by the administration of 0.75% ethylene glycol in drinking water for 28 days and one of them was treated with sulphated polysaccharides from Fucus vesiculosus from the 8th day to the end of the experimental period of 28 days at a dose of 5 mg/kg body weight subcutaneously. Control and drug control (sulphated polysaccharides alone) were also included in the study. Glycolic and glyoxylic acid levels of urine were analyzed as an index of hyperoxaluria. The plasma enzymic markers of cellular integrity, redox status of red blood cells, osmotic fragility, and (14)C-oxalate binding were investigated. Urine and plasma nitric oxide metabolites, expression of inducible nitric oxide synthase protein, and mRNA were assessed in kidney to evaluate the nitrosative stress. Increased levels of glycolic and glyoxylic acid in urine indicated the prevalence of hyperoxaluria in ethylene glycol-administered groups. Plasma aspartate and alanine transaminase were not altered, but alkaline phosphatase and lactate dehydrogenase of hyperoxaluric group were increased indicating tissue damage. Activities of antioxidant enzymes were decreased, whereas erythrocyte membrane lipid peroxidation was increased in hyperoxaluric rats. Moreover, an altered fragility with an increase in oxalate binding activity was observed in hyperoxaluric group. Increase in nitric oxide metabolites levels in urine and plasma along with an increase in expression of inducible nitric oxide synthase protein and mRNA in kidney were observed in hyperoxaluric rats. Administration of sulphated polysaccharides to hyperoxaluric rats averted the abnormal increase in urinary glycolic and glyoxylic acid levels and enzyme activities, decreased lipid peroxidation, and increased the activities of antioxidant enzymes. Furthermore, increased nitrosative stress accompanying hyperoxaluria was also normalized on sulphated polysaccharides treatment. To conclude, sulphated polysaccharide administration was able to maintain the integrity of erythrocyte membrane and decrease the damage to erythrocytes in hyperoxaluria.

Gene expression profiling of long-term changes in rat liver following burn injury

The inflammatory response initiated upon burn injury is also associated with extensive metabolic adjustments. While there is a significant body of literature on the characterization of these changes at the metabolite level, little is known on the mechanisms of induction, especially with respect to the role of gene expression. We have comprehensively analyzed changes in gene expression in rat livers during the first 7 d after 20% total body surface area burn injury using Affymetrix microarrays. A total of 740 genes were significantly altered in expression at 1, 2, 4, and 7 d after burn injury compared to sham-burn controls. Functional classification based on gene ontology terms indicated that metabolism, transport, signaling, and defense/inflammation response accounted for more than 70% of the significantly altered genes. Fisher least-significant difference post-hoc testing of the 740 differentially expressed genes indicated that over 60% of the genes demonstrated significant changes in expression either on d 1 or on d 7 postburn. The gene expression trends were corroborated by biochemical measurements of triglycerides and fatty acids 24 h postburn but not at later time points. This suggests that fatty acids are used, at least in part, in the liver as energy substrates for the first 4 d after injury. Our data also suggest that long-term regulation of energy substrate utilization in the liver following burn injury is primarily at the posttranscriptional level. Last, relevance networks of significantly expressed genes indicate the involvement of key small molecules in the hepatic response to 20% total body surface area burn injury.

Antihyperlipidemic effect of Aronia melanocarpa fruit juice in rats fed a high-cholesterol diet

Aronia melanocrpa fruit juice (AMFJ) used in our experiment was very rich in phenolic substances (709.3 mg gallic acid equivalents/100 ml juice). Anthocyanins (106.8 mg cyanidin-3-glucoside equivalents/100 ml juice) were the main flavonoid group. The aim of this study was to assess the influence of AMFJ on plasma lipids and lipoprotein profile, and histopathology of liver and aorta in rats with dietary-induced hyperlipidemia. AMFJ was administered by gavage for 30 days at doses of 5, 10 and 20 ml/kg body weight to rats fed a standard diet (SD) or a 4% cholesterol-containing diet (4% ChD). The 4% ChD caused a significant elevation of plasma total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG). AMFJ did not significantly influence plasma lipids in rats fed the SD and significantly hindered the elevation of plasma TC, LDL-C and TG in rats fed the 4% ChD. High-density lipoprotein cholesterol (HDL-C) levels were not significantly influenced either by the 4% ChD or by AMFJ. Neither the cholesterol feeding, nor AMFJ treatment induced any histopathological changes in rat liver and aorta. In conclusion, AMFJ showed an antihyperlipidemic effect in rats with hyperlipidemia and could be valuable in reducing this factor of cardiovascular risk.