Pycnogenol® and Centella asiatica in the management of asymptomatic atherosclerosis progression.

AIM: The aim of the study was to evaluate the effect of the nutritional supplements Pycnogenol® and total triterpenic fraction of Centella asiatica (TTFCA) on atherosclerosis progression in low-risk asymptomatic subjects with carotid or femoral stenosing plaques. METHODS: This was an observational pilot, substudy of the San Valentino epidemiological cardiovascular study. The study included 824 subjects aged 45-60 without any conventional risk factors who had a stenosing atherosclerotic plaque (>50-60%) in at least one carotid or common femoral bifurcation, allocated into 6 groups: Group 1 (Controls): management was based on education, exercise, diet and lifestyle changes. This same management plan was used in all other groups; group 2: Pycnogenol® 50 mg/day; group 3: Pycnogenol® 100 mg/day; group 4: Aspirin® 100 mg/day or ticlopidine 250 mg/day if intolerant to aspirin; group 5: Aspirin® 100 mg/day and Pycnogenol® 100 mg/day; group 6: Pycnogenol® 100 mg/day plus TTFCA 100 mg/day. The follow-up lasted 42 months. Plaque progression was assessed using the ultrasonic arterial score based on the arterial wall morphology and the number of plaques that progressed and on the number of subjects that had cardiovascular events. A secondary endpoint was to evaluate the changes in oxidative stress at baseline and at 42 months. RESULTS: The ultrasonic score increased significantly in groups 1, 2, and 4 (>1%) but not in groups 3, 5 and 6 (<1%) suggesting a beneficial effect of Pycnogenol® 100 mg. Considering the percent of patients that progressed from class V (asymptomatic) to VI (symptomatic) there was a progression of plaques in 48.09% of controls. In the Pycnogenol® 100 (group 3, 10.4%) and in the Aspirin®+ Pycnogenol® (group 5, 10.68%) progression was half of what observed with antiplatelet agent (group 4, 20.93%); in the TTFCA+ Pycnogenol®group (group 6) progression was 7.4 times lower than in controls; 3.22 times lower than in the antiplatelet agents group (4). Events (hospital admission, specialized care) were observed in 16.03% of controls; there were 8.83% of subjects with events with Pycnogenol® 50 mg and 8% in group 3 (Pycnogenol® 100 mg). In group 4 (antiplatelets), 8.52% of subjects had events; in group 5, 6.87% of subjects had events and in group 6 (TTFCA+ Pycnogenol®) only 4.41% had events (this was the lowest event rate; P<0.05). All treatment groups had a significantly lower event rate (P<0.05) in comparison with controls. Considering treatments groups 2, 3, 5, 6 had a lower number (P<0.05) of subjects in need of cardiovascular management in comparison with controls. The need for risk factor management was higher in controls and lower in group 6 (P<0.05). In groups 2 to 6 the need for risk factor management was lower than in controls (P<0.05). Including all events (hospital admission, need for treatment or for risk management) 51.9% of controls were involved. In the other groups there was a reduction (from a -9.28% reduction in group 2 to a -26% in group 6) (P<0.002). The most important reduction (higher that in all groups; P<0.05) was in group 6. At 42 months, oxidative stress in all the Pycnogenol® groups was less than in the control group. In the combined group of Pycnogenol® and TTFCA the oxidative stress was less than with Pycnogenol® alone (P<0.001). CONCLUSION: Pycnogenol® and the combination of Pycnogenol® +TTFCA appear to reduce the progression of subclinical arterial plaques and the progression to clinical stages. The reduction in plaque and clinical progression was associated with a reduction in oxidative stress. The results justify a large, randomized, controlled study to demonstrate the efficacy of the combined Pycnogenol® and TTFCA prophylactic therapy in preclinical atherosclerosis.

Cardiotonic pill attenuates white matter and hippocampal damage via inhibiting microglial activation and downregulating ERK and p38 MAPK signaling in chronic cerebral hypoperfused rat.

BACKGROUND: The cardiotonic pill (CP) is a herbal medicine composed of Salvia miltiorrhiza (SM), Panax notoginseng (PN), and Dryobalanops aromatica Gaertner (DAG) that is widely used to treat cardiovascular diseases. The present experiment was conducted to examine the effects of CP on white matter and hippocampal damage induced by chronic cerebral hypoperfusion. METHODS: Chronic cerebral hypoperfusion was induced in male Wistar rats by permanent bilateral common carotid artery occlusion (BCCAo). Daily oral administration of CP (200 mg/kg) began 21 days after BCCAo and continued for 42 days. The levels of microglial activation and myelin basic protein (MBP) were measured in the white matter and hippocampus of rats with chronic BCCAo, and the expression levels of mitogen-activated protein kinases (MAPKs) and inflammatory markers such as cyclooxygenase-2, interleukin-1ß, and interleukin-6 were examined. RESULTS: MBP expression was reduced in the white matter and hippocampal regions of rats that received BCCAo. In contrast, reduced levels of MBP were not observed in BCCAo rats given CP treatments. The administration of CP alleviated microglial activation, the alteration of ERK and p38 MAPK signaling, and inflammatory mediator expression in rats with chronic BCCAo. CONCLUSION: These results suggest that CP may have protective effects against chronic BCCAo-induced white matter and hippocampal damage by inhibiting inflammatory processes including microglial activation and proinflammatory mediator expression, and downreguating the hyperphosphorylation of ERK and p38 MAPK signaling.

[Oxygen provision of the brain during carotid endarterectomy in the settings of general and local anaesthesia].

Based on the indices of cerebral oximetry, analysed herein is efficiency of oxygen support of the brain in various types of anaesthesiological provision (total and general anaesthesia) in patients presenting with atherosclerosis of the brachiocephalic arteries during carotid endarterectomy. It was shown that at the expense of preserving the mechanism of autoregulation, the use of local anaesthesia provides higher efficiency of cerebral perfusion than general anaesthesia which is evidenced by the values of cerebral oximetry exceeding 60% at all stages of the operation. Dynamics of cerebral oxygenation during occlusion of the carotid arteries in the setting of local anaesthesia suggests high reactivity of the cerebral vessels in this cohort of patients and hence preservation of the cerebrovascular reserve in them.

Evaluation of antioxidant and neuroprotective effect of date palm (Phoenix dactylifera L.) against bilateral common carotid artery occlusion in rats.

The cerebral ischemia in rats was induced by occluding bilateral common carotid arteries (BCCAO) for 30 min., followed by 45 min reperfusion. BCCAO caused significant depletion in superoxide dismutase, catalase, glutathione, glutathione peroxidase, glutathione-S-transferase, glutathione reductase and significant increase in lipid peroxidation along with severe neuronal damage in the brain. All the alterations except depletion in glutathione peroxidase and glutathione-S-transferase levels induced by cerebral ischemia were significantly attenuated by 15 days pretreatment with methanolic extract of P. dactylifera fruits (100, 300 mg/kg), whereas 30 mg/kg dose was insignificant in this regard. These results suggest the possible use P. dactylifera against bilateral common carotid artery occlusion induced oxidative stress and neuronal damage.

The role of cerebral oximetry in combination with awake testing in patients undergoing carotid endarterectomy under local anaesthesia.

INTRODUCTION: The aim of this study is to analyse the role of cerebral oximetry in combination with awake testing in detecting cerebral ischaemia in patients undergoing carotid endarterectomy (CEA) under local anaesthesia (LA). METHODS: One hundred consecutive patients scheduled for CEA under LA were investigated. Regional oxygen saturation (rSO(2)) was measured with a cerebral oximeter. Cerebral ischaemia was assessed by awake testing in conjunction with rSO(2). Shunting was based solely on deterioration in conscious state assessed by awake testing. The correlation between awake testing and percentage fall in rSO(2) levels was statistically analysed. RESULTS: Patients requiring general anaesthesia were excluded from analysis (n = 17). Seven patients developed deterioration in conscious state and an immediate drop in rSO(2) ≥20% following carotid cross-clamping. Two patients requiring shunting for non-neurological reasons were excluded from analysis. Two patients had a drop in rSO(2) ≥20%, but remained conscious and were not shunted. There were no permanent neurological deficits postoperatively. Statistical analysis showed a sensitivity of 100% with a specificity of 96% yielding a positive predictive value of 81% and negative predictive value of 100% for a ≥19% drop in rSO(2). CONCLUSION: Cerebral oximetry using a cut off ≥19% drop in rSO(2) has a high sensitivity and specificity when compared with awake testing.

Quantitative trait locus analysis of neointimal formation in an intercross between C57BL/6 and C3H/HeJ apolipoprotein E-deficient mice.

BACKGROUND: Inbred mouse strains C57BL/6J (B6) and C3H/HeJ (C3H) exhibit marked differences in neointimal formation after arterial injury when deficient in apolipoprotein E (apoE(-/-)) and fed a Western diet. Quantitative trait locus (QTL) analysis was performed on an intercross between B6.apoE(-/-) and C3H.apoE(-/-) mice to determine genetic factors contributing to the phenotype. METHODS AND RESULTS: Female B6.apoE(-/-) mice were crossed with male C3H.apoE(-/-) mice to generate F(1)s, which were intercrossed to generate 204 male F(2) progeny. At 10 weeks of age, F(2)s underwent endothelium denudation injury to the left common carotid artery. Mice were fed a Western diet for 1 week before and 4 weeks after injury and analyzed for neointimal lesion size, plasma lipid and MCP-1 levels. One significant QTL, named Nih1 (61cM, LOD score: 5.02), on chromosome 12 and a suggestive locus on chromosome 13 (35cM, LOD: 2.67) were identified to influence lesion size. One significant QTL on distal chromosome 1 accounted for major variations in plasma non-HDL cholesterol and triglyceride levels. Four suggestive QTLs on chromosomes 1, 2, and 3 were detected for circulating MCP-1 levels. No correlations were observed between neointimal lesion size and plasma lipid levels or between lesion size and plasma MCP-1 levels. CONCLUSIONS: Neointimal formation is controlled by genetic factors independent of those affecting plasma lipid levels and circulating MCP-1 levels in the B6 and C3H mouse model.

[Experimental study of effect of tanshinone on artery restenosis in rat carotid injury model].

OBJECTIVE: To observe the preventive and therapeutic effect of tanshinone (TA) on artery restenosis in the rat carotid injury model and explor the mechanism. METHOD: Male SD rats were randomly divided into model control group, and low dose, moderate dose and high dose TA groups. Each group had 10 rats. The rats in the high, moderate and low dose groups were respectively fed with TA 120, 40,13.3 mg x kg(-1) x d(-1) by gast rogavage; the rats in the model control group were fed with the same volume solvent. Two days later, the rat's right carotid artery was injuried by balloon dilatation to induce intimal thickening for establishing the restenosis model. After 2 weeks of treatment, the artery was harvested and stained by hematoxylin-elsin (HE) and immunohistochemistry of PCNA, NF-kappaB and iNOS. The morphological changes were checked under microscope. The area of the intimal and medial layer of the vessels, and their ratios were analyzed with image analysis software. The expression level of PCNA, NF-kappaB and iNOS were used as the positive index. RESULT: The intimal area and intima-to-media ratio of the injuried artery increased obviously, suggesting the model was successful. Compared with the model group, TA significantly decreased the intimal area and intima-to-media ratio (P < 0.05), and also decreased the positive index of PCNA and the positive ratio of NF-kappaB and iNOS (P < 0.05). CONCLUSION: TA can effectively inhibit intimal thickening and inflammation. This result suggestes that TA may play a positive role in the prevention of restenosis after PTCA.

Supplementary taurine may stabilize atheromatous plaque by antagonizing the activation of metalloproteinases by hypochlorous acid.

The rupture of atherosclerotic plaque, responsible for triggering the majority of myocardial infarctions, presumably requires proteolysis of collagen fibers and other protein components of the intercellular matrix. This is achieved by activated matrix metalloproteases (MMPs) secreted by intimal macrophages and foam cells. MMPs are synthesized as inactive pro-enzymes in which coordinate binding of the thiol group of a key cysteine residue to the active-site zinc atom blocks proteolytic activity. Physiological activation of MMPs is mediated, in large measure, by phagocyte-derived hypochlorous acid (HOCL), which can oxidize the zinc-bound thiol to sulfinic acid, thus freeing the active-site zinc. HOCL also encourages proteolysis of ground substance by inactivating proteins such as TIMP-1 that are physiological inhibitors of MMPs. In vivo, the unrestrained oxidant activity of HOCL is opposed by taurine, which reacts spontaneously with HOCL to generate taurine chloramine, much more stable than HOCL. Taurine chloramine has less impact than HOCL on MMP activation, and does not impair the activity of TIMP-1. Since tissue levels of taurine can be boosted via supplementation, taurine may thus have potential for stabilizing plaque and thereby warding off infarction--an effect that should be reinforced by taurine's platelet-stabilizing activity. In light of recent epidemiological evidence that increased expression of myeloperoxidase - the enzyme which generates HOCL--is an important risk factor for coronary disease, supplemental taurine may indeed have broader utility for suppressing both the genesis and the rupture of atherosclerotic plaque.

Vitamin E supplementation in patients with carotid atherosclerosis: reversal of altered oxidative stress status in plasma but not in plaque.

OBJECTIVE: Oxidative stress is believed to play a pivotal role in the initiation and progression of atherosclerosis. We analyzed whether vitamin E supplementation influences oxidative stress in plasma and atherosclerotic plaques of patients with severe atherosclerosis. METHODS AND RESULTS: In 16 patients who were candidates for carotid endarterectomy and in 32 age- and sex-matched controls, plasma levels of 7beta-hydroxycholesterol, 7-ketocholesterol, cholesterol, and vitamin E were measured. Patients were randomly allocated to standard treatment with or without 900 mg/d vitamin E. After 6 weeks of treatment, the reported variables were measured in plasma and plaques. The plasma vitamin E/cholesterol ratio was significantly lower in patients than in controls (3.05+/-0.6 versus 6.3+/-1.7 micromol/mmol cholesterol, P<0.001). Plasma 7beta-hydroxycholesterol was significantly higher in patients than in controls (5.0+/-1.04 versus 4.4+/-0.6 ng/mL, P<0.05). Patients who were given vitamin E supplementation showed a significant increase of plasma vitamin E with concomitant decrease of 7beta-hydroxycholesterol. Conversely, no treatment dependence was observed in oxysterol or vitamin E content of plaques. CONCLUSIONS: An imbalance between oxidative stress and antioxidant status is present in patients with advanced atherosclerosis. Vitamin E supplementation improves this imbalance in plasma but not in plaques.

[The experimental study of the effect of tanshinone on artery restenosis in mouse].

OBJECTIVE: To observe the preventive and therapeutic effect of tanshinone (TA) on artery restenosis in mice and primarily explore the mechanism. METHOD: Female KM mice were randomly divided into model control, low dose and high dose TA groups. Each group had 12 mice. The low and high dose drug groups were respectively given TA 3 and 6 g x kg(-1) x d(-1) by ig; the model control group was given the same volume solvent. The controlateral carotid of ligated artery of model control group was regarded as normal control. 2 days later, the mice' s left common carotid artery was dissected and ligated near the carotid bifurcation, leading to intima hyperplasia and then establishing restenosis model. 4 weeks later, the artery was harvested and stained by hematoxylin-elsin (HE) and immunohistochemistry of PCNA. The morphological changes were checked under microscope; the area of the intimal and medial layer of the vessels, and their ratios were analyzed with image analysis software. The expression level of PCNA was expressed as the positive index. RESULT: Compared with those of normal artery, the intimal area, media area and intima-to-media ratio of ligated artery increased obviously (P < 0.01). But TA could significantly decrease all of these parameters (P < 0.01), and also decrease the positive index of PCNA (P < 0.01). CONCLUSION: TA effectively inhibits intima hyperplasia, which is mainly characterized with the proliferation and migration of smooth muscle cell induced by abnormal hemodynamic changes. This result suggestes that TA may play a positive role in the prevention of restenosis after PTCA.

Radiolabeled native low-density lipoprotein injected into patients with carotid stenosis accumulates in macrophages of atherosclerotic plaque : effect of vitamin E supplementation.

BACKGROUND: Accumulation of LDL within the arterial wall appears to play a crucial role in the initiation and progression of atherosclerotic plaque. The dynamic sequence of this event has not been fully elucidated in humans. METHODS AND RESULTS: In 7 patients with previous transient ischemic attack or stroke and critical (>70%) carotid stenosis, autologous native [(125)I]-labeled LDL or [(125)I]-labeled human serum albumin were injected 24 to 72 hours before endarterectomy. Carotid specimens obtained at endarterectomy were analyzed by autoradiography and immunohistochemistry. Autoradiographic study showed that LDL was localized prevalently in the foam cells of atherosclerotic plaques, whereas the accumulation in the lipid core was negligible. Immunohistochemistry revealed that foam cells that had accumulated radiolabeled LDL were mostly CD68 positive, whereas a small number were alpha-actin positive. No accumulation of the radiotracer was detected in atherosclerotic plaques after injection of radiolabeled human serum albumin. In 3 patients treated for 4 weeks with vitamin E (900 mg/d), an almost complete suppression of radiolabeled LDL uptake by macrophages was observed. CONCLUSIONS: This study shows that circulating LDL rapidly accumulates in human atherosclerotic plaque. The prevalent accumulation of LDL by macrophages provides strong support to the hypothesis that these cells play a crucial role in the pathogenesis of atherosclerosis.

Reduction in atherosclerotic lesion size in pigs by alphaVbeta3 inhibitors is associated with inhibition of insulin-like growth factor-I-mediated signaling.

Insulin-like growth factor-I (IGF-I) is a potent stimulant of smooth muscle cell (SMC) migration and proliferation and has been implicated in the development of experimental atherosclerotic lesions. Because optimal stimulation of SMC in vitro by IGF-I requires ligand occupancy of alphaVbeta3, these studies were conducted to determine whether alphaVbeta3 antagonists would result in a change in lesion size and whether they could alter IGF-I-mediated actions. Clamps were placed on the carotid and femoral arteries of normal pigs that had been fed a high-cholesterol diet for 4 weeks. alphaVbeta3 inhibitors (SC-69000, SC-65811) (10(-6) mol/L) or saline were infused for 2 weeks into the peristenotic area. Lesion area, the number of SMC layers, and proliferating cell nuclear antigen positive cells were determined in a 1.2-mm segment of each artery. Lesion areas were 304 788+/-113 453 micron(2) (saline), compared with 149 799+/-35 456 micron(2) (SC-69000) (P<0.01). Lesion areas in arteries treated with SC-64258, a compound that does not bind to alphaVbeta3, were 310 284+/-160 467 micron(2), P=not significant. In a second experiment, lesion areas were 110 391+/-17 347 micron(2) (saline) and 59 533+/-17 568 micron(2) (SC-65811, P<0.001). Neointimal SMC layers were reduced by SC-65811 from 7.4+/-4.5 to 3.0+/-0.4 (P<0.001). To determine whether IGF-I action was altered, IGF binding protein-5, which is synthesized in response to IGF-I, was analyzed. IGF-I binding protein-5 mRNA abundance was reduced by 67+/-8% in the 6 lesions treated with SRL-69000 compared with saline controls (P<0.001). We conclude that alphaVbeta3 antagonists block the development of lesions in pigs that have been induced by a high-cholesterol diet and stenosis, and the effect of these compounds is associated with their ability to inhibit IGF-I-mediated signaling.