Chol Group Research Articles

Hypolipidemic Effect of Arborium Plus in Experimentally Induced Hypercholestermic Rabbits

Hypercholesteremia is one of the risk factors for coronary artery disease. The present study highlights the efficacy of the ayurvedic herbal formulation Arborium Plus [Hyppophae ramnoides L. fruit juice (S) and Rhododendron arboreum Sm. Linn flower juice (R) in a 1:4 ratio] on triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), atherogenic index (AI), high-density lipoprotein (HDL), and high-sensitivity c-reactive protein (hs CRP) in experimentally induced hypercholesterolemic rabbits. Four groups of rabbits were subjected to different treatments for 8 weeks: control group, CHOL group (1% w/w cholesterol for 8 weeks), S+R group (1% w/w cholesterol and Arborium Plus for 8 weeks), and A group (1% w/w cholesterol and atorvastatin for 8 weeks). The results showed significant increases in TG, TC, LDL, AI, and hs CRP in hypercholesterolemic rabbits which was significantly reduced in Arborium Plus-treated hypercholesterolemic rabbits. The data demonstrated that the Arborium Plus formulation was associated with hypolipidemic effects in experimentally induced hypercholesterolemic rabbits.

Simvastatin in contrast to postconditioning reduces infarct size in hyperlipidemic rabbits: possible role of oxidative/nitrosative stress attenuation

Postconditioning (POC) reduces lethal reperfusion injury under normal conditions, but its effectiveness under certain pathological states is in dispute. In the present study, we sought to determine the effect of chronic simvastatin treatment in hyperlipidemic animals with or without POC. Anesthetized rabbits were randomized into eight groups, as follows, and were subjected to 30-min myocardial ischemia followed by 3-h reperfusion. Normally fed animals: a Control group with no additional intervention, a Sim group treated with simvastatin for 3 weeks at a dose of 3 mg kg(-1), a POC group subjected to POC with eight cycles of 30-s ischemia/reperfusion, a Sim-POC group treated with simvastatin, and POC. Cholesterol fed (6 weeks) animals: a Chol group with no additional interventions, a Chol-Sim group treated with simvastatin for 3 weeks, a Chol-POC group subjected to POC, and a Chol-Sim-POC group treated with simvastatin and POC. Infarct size and plasma levels of malondialdehyde (MDA), nitrotyrosine (NT), NOx, total cholesterol, and LDL were evaluated. In a second series of experiments, heart tissue samples were taken for MDA, NT, and NOx assessment. Infarct size, circulating MDA, NT, NOx and cardiac MDA, NT, and NOx levels declined in POC and all Sim groups compared with Control, Chol, and Chol-POC (p < 0.05). Simvastatin also reduced total cholesterol and LDL plasma levels. In conclusion, a 3-week simvastatin treatment limits the infarct size and attenuates the oxidative and nitrosative stress both in normo- and in hyper-cholesterolemic rabbits subjected to ischemia-reperfusion irrespective of the presence of POC, while POC is effective only in normocholesterolemic animals.

Effects of caponization and testosterone implantation on immunity in male chickens

This study examined the effects of caponization using different doses of testosterone (TES) on sexuality, hematology, and immune responses in male chickens. Healthy male chickens were caponized at 12 wk of age and selected at 16 wk of age for a 10-wk experiment. Fifteen intact male and 15 caponized male chickens were assigned to trial 1. In trial 2, ten sham-operated male chickens (sham) and 40 capons (randomly divided into 4 treatments) were implanted with cholesterol (CHOL, 9.24 ± 0.36 mg), low TES (5.88 ± 0.23 mg), medium TES (9.81 ± 0.17 mg), or high TES (16.7 ± 0.24 mg) administered at 16, 20, and 24 wk of age. Results from trial 1 showed caponization decreased the comb length, height and weight, and hematocrit (P < 0.05) and increased the hemagglutination inhibition (HI; 1 wk postchallenge) and hemagglutination titer after Newcastle disease virus (NDV) and SRBC injections (P < 0.05). In trial 2, the medium TES increased the comb length and height as compared with the CHOL group. Only the high TES increased the comb weight (P < 0.05). The HI titer (1 wk postchallenge) in the CHOL group was higher than the sham (P < 0.05). The medium TES decreased the HI titer (P < 0.05) to the level of the sham (P > 0.05). The phytohemagglutinin response was higher in the high TES group 24 h postinjection (P < 0.05) and in the medium TES 48 h postinjection (P < 0.05) as compared with the CHOL group. High dose TES implantation decreased the white blood cell counts as compared with the CHOL and sham groups (P < 0.05). It appears that caponization decreased the blood androgen concentration and enhanced the humoral (anti-NDV and anti-SRBC) immune response. Testosterone implantation up to a threshold concentration could inhibit the humoral (anti-NDV) immune response and increase the cell-mediated (phytohemagglutinin) immune response.

적송잎 추출물의 혈행 및 지질개선 효과

Pine needles have long been used as a traditional health-promoting medicinal food in Korea. To investigate the effects of pine (pinus densiflora) needle extracts on blood flow and serum lipid improvement were assessed in vivo. 8 week-old Sprague Dawley strain rats were divided into four groups of seven rats each; CON, 0.5% CHOL, HOT water and Sub-supercritical group. Serum total cholesterol and triglyceride contents were lower in the CON group than the 0.5% CHOL group. Three weeks of feeding hot water and sub-supercritical extract resulted in a decrease in serum triglyceride and total cholesterol level. The level of HDL-cholesterol in the 0.5% CHOL group was significantly (p＜0.05) reduced compared to the CON group, but it had a tendency to increase with pine needle extract supplementation. Blood passage time of the pine needle extracts supplemented group was higher than the 0.5% CHOL group. Microscopic observation showed that whole blood passed smoothly through the micro channels in pine needle extracts supplemented groups. The platelet aggregation ability of the groups treated with pine needle extracts was less than that of the 0.5% CHOL group. All these results suggest that pine needle extracts might improve blood homeostasis mediated via antiplatelet activities.

고콜레스테롤 식이 섭취 흰쥐에 대한 적송잎 추출물의 항산화 효과

This study was conducted to investigate the effects of pine (Pinus densiflora) needle extracts on hepatic antioxidative system in rats fed high-cholesterol diet. Eight-week old Sprague Dawley rats were divided into four groups; normal diet group (CON), 0.5% cholesterol diet group (0.5% CHOL), 0.5% cholesterol diet and pine needle extracts prepared by using hot water group (HOT water), and 0.5% cholesterol diet and pine needle extracts prepared by using sub-supercritical CO₂ group (Sub-supercritical). The serum ALP, AST, and ALT activities were increased by 0.5% cholesterol diet supplementation, but treatment with pine needle extracts showed decrease compared with 0.5% CHOL group. The SOD activity in liver at 0.5% cholesterol diet group was more decreased than control group while Sub-supercritical group had significantly higher SOD activity than 0.5% CHOL group. Moreover, groups with pine needle extracts supplementation had higher level of GPx in liver than 0.5% cholesterol diet group. These results suggest that pine needle extracts increased antioxidative activities.

Complex porcine model of atherosclerosis: Induction of early coronary lesions after long-term hyperlipidemia without sustained hyperglycemia

The incidence of coronary artery disease (CAD) is still increasing in industrialized countries and it is even higher in diabetic patients. For experimental studies investigating the pathophysiology of CAD, the use of an animal model comparable with the pathological situation in patients is crucial. To develop a model of advanced coronary atherosclerosis with induction of hyperlipidemia and hyperglycemia in domestic pigs. Six pigs were fed a standard pig chow (controls), two were fed a 2% cholesterol and 17% coconut fat diet (Chol group), and two pigs received a 4% cholesterol and 17% coconut fat diet combined with streptozotocin (STZ) injections to induce diabetes (High Chol+STZ group). Serum lipid and plasma glucose values were analyzed, and histochemical staining for morphometric analysis and immunohistochemistry were performed. Pigs on the hyperlipidemic diet had elevated mean (+/- SD) serum lipid levels (total cholesterol 5.05+/-1.45 mmol/L [Chol] and 5.03+/-2.41 mmol/L [High Chol+STZ] versus 2.09+/-0.23 mmol/L [controls]). Histopathological evaluation revealed an initial stage of coronary atherosclerosis. None of the STZ-treated pigs showed a sustained elevation of plasma glucose (mean glucose before STZ injection was 5.11+/-0.94 mmol/L and thereafter was 6.03+/-2.39 mmol/L) or a decline in pancreatic beta cells. The current data suggest that the domestic porcine model is not suitable to create severe CAD using an atherogenic diet in combination with STZ injections for experimental interventional vascular research. This may be due to different STZ sensitivities among species. However, hyperlipidemia induced early pathological lesions in coronary arteries resembling initial stages of atherosclerosis without severe luminal narrowing.

Pitavastatin prevents intestinal ischemia/reperfusion–induced bacterial translocation and lung injury in atherosclerotic rats with hypoadiponectinemia

Atherosclerosis with hypoadiponectinemia can be further aggravated by intestinal ischemia/reperfusion (II/R)-induced injuries, such as bacterial translocation and lung injury. We investigated the effect of statin administration on the risk of II/R-induced injury in atherosclerotic rats with hypoadiponectinemia. Wistar rats were divided into 4 groups: (1) the Normal group (normal diet), (2) the Chol group (2% high cholesterol diet), (3) the St-1w group, and (4) the St-2w group (Chol group plus pitavastatin administration for 1 or 2 weeks, respectively). The serum concentrations of lipids and adiponectin were measured preoperatively. After midline laparotomy (time, T0), the superior mesenteric artery was occluded with a microvascular clamp for 30 min, followed by 360 min of reperfusion (T1). Intestinal and lung nitric oxide (NO) concentrations were measured. Intestinal injury was assessed by microcirculatory flow, histology, and permeability. Bacterial translocation was assessed by analysis of serum peptidoglycan concentration. Lung injury was assessed by histologic examination, pulmonary permeability index, and wet/dry lung weight ratio. The 2-week administration of statins with high-cholesterol feeding (St-2w group) improved hypoadiponectinemia to levels similar to those of the Normal group. Intestinal and lung NO concentrations were significantly lower at T1 in the Normal and St-2w groups than in the Chol group. Statin administration improved poor recovery of intestinal microcirculatory flow in the Chol group. At T1, intestinal and lung injuries were significantly aggravated and serum peptidoglycan concentration was significantly elevated in the Chol group compared with the Normal and St-2w groups. The 1-week administration of statins had no significant influence on serum adiponectin levels, tissue NO concentration, or tissue injury. Administration of pitavastatin reduces the risk of II/R-induced injury in atherosclerotic rats with hypoadiponectinemia by improving hypoadiponectinemia and inhibiting inducible NO synthase-produced NO. Furthermore, preoperative improvement of hypoadiponectinemia may be important as an index of the protective effect of pitavastatin for II/R-induced injury in atherosclerotic rats with hypoadiponectinemia.

Intestinal ischemia/reperfusion-induced bacterial translocation and lung injury in atherosclerotic rats with hypoadiponectinemia

Intestinal ischemia/reperfusion causes intestinal mucosal injury, which may result in bacterial translocation (BT) and multiple organ failure. Lung injury is a common complication after intestinal ischemia/reperfusion. Adiponectin is an antiinflammatory adipokine, and it plays an important role in the development of metabolic syndrome in hypoadiponectinemia. In atherosclerosis with hypoadiponectinemia, BT also may aggravate injuries induced by intestinal ischemia/reperfusion. Wistar rats were divided into 3 groups: Normal group (normal diet), Chol group (2% high cholesterol diet), and Chol+1400W group (Chol group plus 1400W, an inducible nitric oxide [iNOS] inhibitor, at 1 mg/kg intraperitoneally 30 minutes preoperatively). The serum concentrations of lipids and adiponectin and vascular responses were measured. After midline laparotomy (time, T0), the superior mesenteric artery was occluded with a microvascular clamp for 30 minutes, followed by 360 minutes of reperfusion (T1). Intestinal injury was assessed from microcirculatory flow, histology, serum diamine oxidase activity, and permeability. Lung injury was assessed by histology, pulmonary permeability index (PPI), and wet-to-dry lung weight (W/D) ratio. Intestinal and lung nitric oxide (NO) concentrations were also measured. BT was assessed by serum peptidoglycan (PG) concentration. The Chol and Chol+1400W groups developed hyperlipidemia and hypoadiponectinemia; the 2 groups also had vascular endothelial dysfunction without histological changes, indicating early atherosclerosis. These groups also showed poor recovery of intestinal microcirculatory flow at T1. The serum diamine oxidase activity, histological intestinal damage, and permeability were elevated at T1 in the Chol group; however, these findings were not significant in the Normal and Chol+1400W groups. Histological lung damage and lung PPI and W/D ratio were increased only in the Chol group. Intestinal and lung NO concentrations were significantly elevated at T1 in the Chol group. The serum PG concentration was elevated significantly in the Chol group. In atherosclerotic rats with hypoadiponectinemia, intestinal microcirculatory flow does not recover adequately after intestinal ischemia/reperfusion because of endothelial dysfunction. Atherosclerosis with hypoadiponectinemia increased the incidence of BT further by aggravating intestinal mucosal injury and, moreover, it aggravated lung injury. Although inhibition of iNOS does not lead to adequate recovery of intestinal microcirculatory flow, it reduces injury by decreasing the amount of NO derived from high enzymatic iNOS activity in the intestine.

The nutritional and metabolic indices in rats fed cholesterol‐containing diets supplemented with durian at different stages of ripening

The aim of this investigation was to assess the nutritional and health properties of Mon Thong durian cultivar at different stages of ripening. The assessment was carried out in vitro and in vivo. The contents of dietary fibers, minerals and trace metals at different stages of ripening were comparable. Total polyphenols (mgGAE/100 g FW) and flavonoids (mg CE/100 gFW) in ripe durian (358.8 +/- 31.4 and 95.4 +/- 9.3) were significantly higher (p < 0.05) than in mature (216.1 +/- 1 and 39.9 +/- 3.8) and overripe (283.3 +/- 26.2 and 53.5 +/- 4.9). Antioxidant capacity (muMTE/100 g FW) in total polyphenol extracts of ripe durian measured by 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and [2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)] (ABTS) assays (259.4 +/- 23.6 and 2341.8 +/- 93.2) were significantly higher (p < 0.05) than that of mature (151.6 +/- 15.2 and 1394.6 +/- 41.5) and overripe (201.7 +/- 19.4 and 1812.2 +/- 61.4) samples. The correlation coefficients between the bioactive compounds in different stages of ripening and their antioxidant capacities were high (R;{2} = 0.99). Then 35 male Wistar rats were divided into 5 dietary groups each of 7 and named Control, Chol, Chol/Mature, Chol/Ripe and Chol/Overripe. During 30 days of the experiment the rats of all 5 groups were fed basal diet (BD), which included wheat starch, casein, soybean oil, vitamin and mineral mixtures. The rats of the Control group were fed a BD only. To the BD of the Chol group was added 1% of cholesterol. The BD of the Chol/Mature, Chol/Ripe and Chol/Overripe groups was supplemented with 1% of cholesterol and 5% of the mature, ripe and overripe durian as freeze-dried powder, respectively. Diets containing ripe and to a lesser degree mature and overripe durian significantly hindered the rise in plasma lipids and also hindered a decrease in plasma antioxidant activity. The nitrogen retention in rats of the Chol/Ripe group was significantly higher (63.6%, P < 0.05) than in other diet groups and the level of the plasma glucose remained normal. A decrease in fibrinogen fraction with ripe durian included in rat's diets was shown by electrophoretic separation. These changes were detected mostly in the low molecular weight proteins of rat's serum. Histological examination of aorta showed only slight differences in the tissue. In conclusion, ripe durian contains higher quantity of bioactive compounds, has higher antioxidant capacity and nutritional value. It positively affects the plasma lipid profile, the plasma glucose and the antioxidant activity in rats fed cholesterol enriched diets. Therefore, the ripe durian supplemented diet could be beneficial for patient suffering from hypercholesterolemia and diabetes mellitus. <

High-Dose Atorvastatin Improves Hypercholesterolemic Coronary Endothelial Dysfunction Without Improving the Angiogenic Response

Although 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) can restore endothelial function in coronary disease, in vitro and murine studies have shown their effects on myocardial angiogenesis to be biphasic and dose dependent. We investigated the functional and molecular effects of high-dose atorvastatin on the endogenous angiogenic response to chronic myocardial ischemia in hypercholesterolemic swine. Yucatan pigs were fed either a normal (NORM group; n=7) or high-cholesterol diet, with (CHOL-ATR group; n=7) or without (CHOL group; n=6) atorvastatin (3 mg/kg per day) for 13 weeks. Chronic ischemia was induced by ameroid constrictor placement around the circumflex artery. Seven weeks later, microvessel relaxation responses, myocardial perfusion, and myocardial protein expression were assessed. The CHOL group demonstrated impaired microvessel relaxation to adenosine diphosphate (29+/-3% versus 61+/-6%, CHOL versus NORM; P<0.05), which was normalized in the CHOL-ATR group (67+/-2%; P=NS versus NORM). Collateral-dependent myocardial perfusion, adjusted for baseline, was significantly reduced in the CHOL group (-0.27+/-0.07 mL/min per gram versus NORM; P<0.001) as well as the CHOL-ATR group (-0.35+/-0.07 mL/min per gram versus NORM; P<0.001). Atorvastatin treatment was associated with increased phosphorylation of Akt (5.7-fold increase versus NORM; P=0.001), decreased vascular endothelial growth factor expression (-68+/-8%; P<0.001 versus NORM), and increased expression of the antiangiogenic protein endostatin (210+/-48%; P=0.004 versus NORM). Atorvastatin improves hypercholesterolemia-induced endothelial dysfunction without appreciable changes in collateral-dependent perfusion. Increased myocardial expression of endostatin, decreased expression of vascular endothelial growth factor, and chronic Akt activation associated with atorvastatin treatment may account for the diminished angiogenic response.

Dose-Dependent Influence of Commercial Garlic (Allium sativum) on Rats Fed Cholesterol-Containing Diet

The aim of this investigation was to evaluate the dose-dependent influence of commercial garlic on rats fed cholesterol-containing diets. It was found that commercial garlic contains high concentrations of dietary fibers, microelements, and total polyphenols, and its total antioxidant capacity as determined by two independent assays [1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS)] was similar to that of the original garlic samples. Wistar rats (35) were randomly divided into five diet groups, named control, Chol, Garlic500, Garlic750, and Garlic1000. Control rats were fed basal diet (BD), which included wheat starch, casein, soybean oil, and vitamin and mineral mixtures. To the BD of the Chol group was added 1% of cholesterol. To the BD of the other three groups (Garlic500, Garlic750, and Garlic1000) were added 1% of cholesterol and commercial garlic equal to 500, 750, and 1000 mg of raw garlic per kilogram of animal weight. After 4 weeks of the experiment only in rats from the Garlic500 group were a significant hindering in the rise in plasma lipids and also a significant hindering in a decrease of plasma antioxidant activity registered. A significant decrease in plasma circulating fibrinogen and an increase in the clotting time were found in the same group of rats (P < 0.05 in both cases). The fibrinogenolytic effect of garlic diets was visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In the fibrinogen fraction of Garlic500 the 66, 24, and 14 kDa protein bands were detected with weaker protein intensity than in the corresponding ones in the Garlic750 and Garlic1000 diet groups. In conclusion, the positive influences of commercial garlic on plasma lipids, proteins, antioxidant activity, and some indices of blood coagulation are dose-dependent. Therefore, commercial garlic (Elena, Zelazków, Poland) could be a valuable component of atherosclerosis-preventing diets only in optimal doses.

Pathophysiologic pressure induces the expression of matrix metalloproteinase-2 in thoracic aortic aneurysms

fusion, adjusted for baseline, was significantly reduced in the CHOL group (-0.27 0.07 ml/min/g vs. NORM, p 0.001) as well as the CHOL-ATR group (-0.35 0.07 ml/min/g vs. NORM, p 0.001). Myocardial expression of anti-angiogenic protein, endostatin, was increased in both the CHOL (94 29%, p 0.08 vs. NORM) and CHOL-ATR pigs (210 22%, p 0.004 vs. NORM). VEGF expression was mildly decreased in the CHOL animals (-19 10%, p 0.32 vs. NORM) but significantly reduced in the CHOL-ATR group (-68 22%, p 0.001 vs. NORM).

Effects of L-arginine on the endogenous angiogenic response in a model of hypercholesterolemia

The angiogenic properties of vascular endothelial growth factor and fibroblast growth factor-2 are mediated in part through nitric oxide release, whose availability is decreased in endothelial dysfunction associated with advanced coronary artery disease. We examined the influence of L-arginine supplementation on the endogenous angiogenic response to ischemia in a porcine model of hypercholesterolemia. Eighteen Yucatan pigs were fed either a normal (NORM, n=6) or a high-cholesterol diet, with (CHOL-ARG, n=6) or without (CHOL, n=6) L-arginine (100 mg/kg/day), throughout the experiment. All pigs underwent ameroid constrictor placement on the circumflex artery (LCx). Seven weeks later, endothelium-dependent coronary microvascular responses to fibroblast growth factor-2 and vascular endothelial growth factor were assessed by videomicroscopy. Perfusion was assessed with radioactive microspheres; angiogenesis was evaluated by platelet-endothelial cell adhesion molecule-1 (CD-31) staining. Regional myocardial function was assessed by sonomicrometry. Expression of endothelial nitric oxide synthase and inducible nitric oxide synthase was measured by Western blot analyses. Pigs from the CHOL group showed significant endothelial dysfunction in the LCx territory. The dysfunction was normalized partially by L-arginine supplementation, which restored the response in the LCx territory to the level of the nonischemic anterior wall. L-arginine supplementation resulted in increases of perfusion, density of capillary endothelial, and level of endothelial nitric oxide synthase in the ischemic region. Despite these findings, no improvement in myocardial regional function was found. L-arginine supplementation can partially restore endothelium-dependent vasorelaxation and improve myocardial perfusion in a swine model of chronic myocardial ischemia with hypercholesterolemia-induced endothelial dysfunction. These findings suggest a putative role for L-arginine in combination with growth factor therapy for end-stage coronary artery disease.

Initial validation of a novel rat model of vasculogenic erectile dysfunction with generalized atherosclerosis

Although rats have been widely used in evaluating various causes of vasculogenic erectile dysfunction (VED), the atherosclerotic rat model has seldom been tried probably due to its inherent tolerance to a cholesterol diet. To enhance endothelial sensitivity to cholesterol diet, we tested the effects of transient interruption of nitric oxide synthase on atherogenesis induced by cholesterol diet in a rat model. Rats with atherosclerosis (AS group) received 1% cholesterol diet for 6 weeks. During the initial 2 weeks, they drank water that contained N(G)-nitro-L-arginine methyl ester (L-NAME) (3 mg/ml). After 6 weeks, we carried out histologic and hemodynamic evaluation to confirm pelvic atherosclerosis and erectile dysfunction, respectively, and the results were compared with those of cholesterol only (Chol) group and normal control (C) group. Compared to the C or Chol group, the mean intima/media (I/M) of the internal pudendal artery, which contributes approximately 70% of the total resistance of the penile vasculature, was markedly increased by the treatment (1.82+/-0.25 vs 0.77+/-0.13, P<0.05). Correspondingly, significantly diminished erectile function was observed. Combined treatment for 2 weeks elicited early atherosclerotic changes in proximal arteries and erectile impairment and further 4 weeks of cholesterol diet spread overt atherosclerosis to the periphery. The Chol group showed no arterial pathology, although they showed mild VED. A correlation study showed that atherosclerosis of the distal artery was better correlated with erectile dysfunction than the proximal artery. Based on these results, our study demonstrates that combination treatment of cholesterol diet with L-NAME would be used as a rapid, effective protocol of developing atherosclerotic rat model of VED.

Normalization of coronary microvascular reactivity and improvement in myocardial perfusion by surgical vascular endothelial growth factor therapy combined with oral supplementation of l-arginine in a porcine model of endothelial dysfunction

Vascular endothelial growth factor acts in part through nitric oxide release, the availability of which is decreased in endothelial dysfunction associated with advanced coronary artery disease. This could explain the relatively disappointing results of vascular endothelial growth factor therapy in clinical studies compared with animal studies. We examined the influence of L-arginine supplementation to vascular endothelial growth factor therapy on myocardial microvascular reactivity and perfusion in a porcine model of endothelial dysfunction. Twenty-four pigs were fed either a normal (NORM, n = 8) or high-cholesterol diet with (CHOL-ARG, n = 8) or without (CHOL, n = 8) L-arginine. All pigs underwent ameroid placement on the circumflex artery and then 3 weeks later received surgical vascular endothelial growth factor treatment. Four weeks after treatment, endothelial-dependent coronary microvascular responses and lateral myocardial perfusion were assessed. Endothelial cell density was determined by means of immunohistochemistry. Vascular endothelial growth factor, endothelial nitric oxide synthase, and Akt levels were determined by means of immunoblotting. Pigs from the CHOL group showed endothelial dysfunction in the circumflex territory, which was normalized by L-arginine supplementation. Vascular endothelial growth factor treatment was ineffective in the CHOL group (circumflex/left anterior descending coronary artery blood flow ratios: 0.95 [rest] and 0.74 [pace] before-after treatment; P < .05 compared with the NORM group). Addition of L-arginine restored the angiogenic effect of vascular endothelial growth factor (ratios: 1.13 [rest] and 1.20 [pace]; P < .05) and was associated with increased endothelial cell density, as well as vascular endothelial growth factor, endothelial nitric oxide synthase, and Akt protein levels in the ischemic territory. L-Arginine supplementation can restore normal endothelium-dependent vasorelaxation and angiogenic response to vascular endothelial growth factor in a swine model of chronic myocardial ischemia with hypercholesterolemia-induced endothelial dysfunction. These findings suggest a putative role for L-arginine in combination with vascular endothelial growth factor therapy for end-stage coronary artery disease.

High dietary methionine plus cholesterol exacerbates atherosclerosis formation in the left main coronary artery of rabbits

Although mild hyperhomocysteinemia is a risk factor for cardiovascular events and mortality, there is no evidence to suggest that mild hyperhomocysteinemia stimulates coronary artery atherosclerosis formation. Objective: To compare the development of coronary artery atherosclerosis in rabbits following the induction of hyperhomocysteinemia and hypercholesterolemia through diet, and whether the combination of these risk factors exacerbated atherosclerosis formation. Methods: New Zealand White rabbits were fed for 12 weeks either a control diet, a 1% methionine diet (Meth), a 0.5% cholesterol diet (Chol) or the combination of the two diets (MethChol). Using volumetric stereological techniques, we quantitated the volume of intima, media and lumen of the left main coronary artery (LMCA). Results: Atherosclerosis was present in the Chol group, and increased in the MethChol group. There was no atherosclerosis in the control or Meth groups. Conclusions: These results underscore the difference in the atherogenicity of hypercholesterolemia alone and mild hyperhomocysteinemia alone. Thus, we suggest that isolated mild hyperhomocysteinemia is not a risk factor for the initiation of coronary artery atherosclerosis formation over a short period of time, but may act in conjunction with other risk factors to further increase plaque formation.

Effect of different olive oils on bile excretion in rats fed cholesterol-containing and cholesterol-free diets.

The mechanism of the hypocholesterolemic effect of olive oils was investigated in 60 Wistar rats adapted to cholesterol-containing and cholesterol-free diets. The rats were divided in six diet groups of 10. The control group was fed only basal diet (BD), which contained wheat starch, casein, cellulose, and mineral and vitamin mixtures. For the five other groups, 10 g/100 g virgin (virgin group) or lampante (lampante group) olive oils, 1 g/100 g cholesterol (chol group), or both cholesterol and oil (chol/virgin and chol/lampante groups) were added to the BD. The experiment lasted 4 weeks. Before and after the experiment the bile was collected, and its flow and biliary bile acids and cholesterol concentrations were registered. Plasma lipids, liver cholesterol, plasma antioxidative potential (TRAP), fecal output, fecal bile acids, and fecal cholesterol excretion were measured. Groups did not differ before the experiment. After the experiment significant hypocholesterolemic and antioxidant effects were registered mainly in groups of rats fed cholesterol-containing diets supplemented with both olive oils (chol/virgin and chol/lampante). Significant increases in the bile flow and in the bile cholesterol and bile acids concentrations were observed (19.2% and 16.9%, 30.5% and 18.2%, and 79.6% and 45.6% for the chol/virgin and chol/lampante groups, respectively). Also, significant increases of the fecal output and fecal excretion of bile acids and cholesterol in rats of these groups were found. In conclusion, olive oils positively affect plasma lipid metabolism. The hypocholesterolemic effect of olive oils is genuine and is most likely mediated through increases in bile flow and biliary cholesterol and bile acids concentrations and subsequent increases in their fecal excretion.

Seed oils improve lipid metabolism and increase antioxidant potential in rats fed diets containing cholesterol

The goal of this investigation was to find the most valuable among four often-used seed oils for atherosclerosis preventing diets. Fatty acids, sterols, antioxidant compounds, stability and total radical-trapping antoxidative potential (TRAP) in sunflower, sunflower high oleic, rapeseed and grapeseed oils were determined. The highest stability and the highest TRAP (3.8 Rancimat 120°C, hours and 324 nmol/ml) and the lowest stability and the lowest TRAP (2.4 Rancimat 120°C, hours and 201 nmol/ml) were in rapeseed and sunflower oils, respectively. The effect of these two seed oils on lipid metabolism and antioxidant activity was investigated on 60 (divided in six diet groups of 10) male Wistar rats adapted to cholesterol-free or 1% cholesterol diets. The control group (Control) consumed basal diet (BD) only. To the BD were added 10g/100g rapeseed (Rapeseed group) or sunflower (Sunflower group) oils, 1 g/100 g cholesterol (Chol group) or both (Chol/Rapeseed group) and (Chol/Sunflower group). The experiment lasted 4 weeks. In the Chol/Rapeseed and Chol/Sunflower vs. Chol group, the oil supplemented diets significantly ( P < 0.05) hindered the rise in plasma lipids due to dietary cholesterol. Rapeseed and to less degree sunflower oils have increased the plasma antioxidant activity in rats fed BD without cholesterol (an increase in TRAP: 20.8% and 16.0% and a decrease in MDA: 22.0% and 14.9%, respectively). In the rats of Chol/Rapeseed and Chol/Sunflower vs. Chol diet group the added oils significantly hindered the decrease in the plasma antioxidant activity (TRAP: 21.7% and 16.3% and MDA: 26.2% and 21.5%, respectively). Therefore, rapeseed and to less degree sunflower oils possess hypolipidemic and antioxidant properties. It is more evident when these oils are added to the diets of rats fed cholesterol. In conclusion, rapeseed oil has high organoleptic properties and the highest antioxidant capacity. Its influence on plasma lipid levels and antioxidant potential is significantly higher than of oils with relatively low antioxidant capacity. The above-mentioned properties make rapeseed oil preferable choice for atherosclerosis preventing diets.

Olive oils improve lipid metabolism and increase antioxidant potential in rats fed diets containing cholesterol.

The effect of olive oils on lipid metabolism and antioxidant activity was investigated on 60 male Wistar rats adapted to cholesterol-free or 1% cholesterol diets. The rats were divided into six diet groups of 10. The control group (control) consumed the basal diet (BD) only, which contained wheat starch, casein, cellulose, and mineral and vitamin mixtures. To the BD were added 10 g/100 g virgin (virg group) or Lampante (Lamp group) oils, 1 g/100 g cholesterol (chol group), or both (chol/virg group) and (chol/Lamp group). The experiment lasted 4 weeks. Plasma total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), triglycerides (TG), total phospholipids (TPH), HDL-phospholipids (HDL-PH), total radical-trapping antioxidative potential (TRAP), malondialdehyde lipid peroxidation (MDA), and liver TC were measured. Groups did not differ before the experiment. In the chol/virg and chol/Lamp vs chol group, the oil-supplemented diets significantly (P < 0.05) lessened the increase in plasma lipids due to dietary cholesterol as follows: TC (25.1 and 23.6%), LDL-C (39.3 and 34.7%), TG (19.3 and 17.0%), and TC in liver (36.0 and 35.1%) for the chol/virg and chol/Lamp group, respectively. The chol/virg and chol/Lamp diets significantly decreased the levels of TPH (24.7 and 21.2%; p < 0.05 in both cases) and HDL-PH (22.9 and 18.0%; p < 0.05 in both cases) for the chol/virg and chol/Lamp group, respectively. Virgin and Lampante oils in rats fed basal diet without cholesterol did not affect the lipid variables measured. Virgin, and to a lesser degree Lampante, oils have increased the plasma antioxidant activity in rats fed BD without cholesterol (an increase in TRAP, 20.6 and 18.5%; and a decrease in MDA, 23.2 and 11.3%, respectively). In the rats of chol/virg and chol/Lamp vs Chol diet groups the added oils significantly hindered the decrease in the plasma antioxidant activity (TRAP, 21.2 and 16.7%; and MDA, 27.0 and 22.3%, respectively). These results demonstrate that virgin, and to less degree Lampante, oils possess hypolipidemic and antioxidant properties. It is more evident when these oils are added to the diets of rats fed cholesterol. These positive properties are attributed mostly to the phenolic compounds of the studied oils.

Mycophenolate mofetil treatment reduces cholesterol-induced atherosclerosis in the rabbit

Immunosuppressive therapy has been shown to either improve or, more frequently, enhance the development of atherosclerosis. We tested the effect of mycophenolate mofetil (MMF), an inhibitor of nucleotide synthesis widely used in transplant therapy, in diet-induced atherosclerosis in the rabbit. Two groups ( n=10 each) of New Zealand White (NZW) rabbits were fed a 1% cholesterol diet for 12 weeks. One group received MMF (CHOL+MMF group) by gastric gavage (30 mg/kg daily) and the other group (CHOL) received the same volume of saline by the same route. There were no differences in the serum cholesterol (mean values ≥30 mmol/l in both groups after 2 weeks) or in the triglyceride, blood sugar, total protein, and albumin serum levels and weight gain in both groups of animals. The cholesterol-fed untreated rabbits had atherosclerotic plaques covering 43.9.1±SD 16.40% of their thoracic aorta and 41.9±22.59% of their abdominal aorta, while the MMF treated group had 18.5±7.17% and 17.7±9.71%, respectively ( P<0.01). The cholesterol content of the aorta (mg/g) in the cholesterol-fed untreated group was 4.61±SD 1.21 in the thoracic aorta and 4.54±2.07 in the abdominal aorta, whereas the MMF treated group had and 2.83±0.84 and 2.77±1.44, respectively ( P<0.01). Infiltrating macrophages (RAM 11 positive cells/100 nuclei) in the intimal layer of the aorta were 58.4±SD26.16 in the CHOL group and 8.5±5.51 in the CHOL+MMF group: ( P<0.001). CD18 positive cells/100 nuclei were 27.4±17.6 in the CHOL group and 5.3±3.82 in the CHOL+MMF group ( P<0.01), and the intima/media ratio was 0.66±0.11 in the CHOL group and 0.30±0.09 in the MMF treated rabbits ( P<0.001). MMF also reduced proliferating smooth muscle cells (HHF35 positive) infiltrating between the macrophages. These results indicate that MMF ameliorates importantly the atherogenic potential of a high cholesterol diet and this effect is associated with a reduction in macrophage and foam cell infiltration and smooth muscle cell proliferation and infiltration. Since chronic treatment with this drug is given routinely in various clinical conditions with relatively minor side effects, consideration may be given to its use as adjuvant therapy in artheriosclerotic cardiovascular disease.