Antioxidants and heart disease: epidemiology and clinical evidence

Could Right Coronary Artery-Aorta Angle be Used to Predict Atherosclerotic Lesion Localization in Critical Site of the Right Coronary Artery in Patients With Right Dominancy?

BACKGROUND

This study aimed to evaluate the impact of the aorta-right coronary artery angle (ARA) on lesion localization and its protective effect in the critical osteal region in patients with dominant right coronary artery (RCA).

METHODS

This cross-sectional study included 294 patients who underwent elective coronary angiography for stable angina pectoris and had a single significant lumen stenosis (50%-95%) before the RCA crux. Patients with tortuous vessels, previous interventions, left-dominant circulation, or insufficient image quality were excluded. ARA, lesion criticality, length, and distance from the aorto-osteal junction were calculated using quantitative coronary analysis. Patients were categorized based on lesion location: osteal, proximal, mid, and distal regions.

RESULTS

ARA increased significantly as the lesion localization moved distally (osteal: 53.26° ± 5.65°, proximal: 60.79° ± 9.53°, mid: 82.33° ± 9.85°, distal: 93.53° ± 7.46°; p < 0.0001). A strong positive correlation was found between ARA and the distance of the lesion from the aorto-osteal junction (r = 0.759, p < 0.0001). In binary regression, ARA was the only independent risk factor for critical lesion localization in the osteal region (OR = 0.915; 95% CI 0.868-0.965, p < 0.001). ROC analysis showed that an ARA > 73.50° had 83.2% sensitivity and 81.3% specificity for excluding critical lesions in the osteal region (AUC = 0.861; 95% CI 0.815-0.907).

CONCLUSION

A narrow ARA increases the likelihood of critical lesions in the osteal RCA, while an ARA > 73.50° is protective. These findings suggest ARA could guide risk assessment and treatment planning in coronary interventions.

Hydroxytyrosol, a Promising Supplement in the Management of Human Stroke: An Exploratory Study

Hydroxytyrosol (HT) is a bioactive olive oil phenol with beneficial effects in a number of pathological situations. We have previously demonstrated that an HT-enriched diet could serve as a beneficial therapeutic approach to attenuate ischemic-stroke-associated damage in mice. Our exploratory pilot study examined this effect in humans. Particularly, a nutritional supplement containing 15 mg of HT/day was administered to patients 24 h after the onset of stroke, for 45 days. Biochemical and oxidative-stress-related parameters, blood pressure levels, serum proteome, and neurological and functional outcomes were evaluated at 45 and 90 days and compared to a control group. The main findings were that the daily administration of HT after stroke could: (i) favor the decrease in the percentage of glycated hemoglobin and diastolic blood pressure, (ii) control the increase in nitric oxide and exert a plausible protective effect in oxidative stress, (iii) modulate the evolution of the serum proteome and, particularly, the expression of apolipoproteins, and (iv) be beneficial for certain neurological and functional outcomes. Although a larger trial is necessary, this study suggests that HT could be a beneficial nutritional complement in the management of human stroke.

Role of Circular RNAs in Atherosclerosis through Regulation of Inflammation, Cell Proliferation, Migration, and Apoptosis: Focus on Atherosclerotic Cerebrovascular Disease

Atherosclerosis (AS) is a disease dangerous to human health and the main pathological cause of ischemic cardiovascular diseases. Although its pathogenesis is not fully understood, numerous basic and clinical studies have shown that AS is a chronic inflammatory disease existing in all stages of atherogenesis. It may be a common link or pathway in the pathogenesis of multiple atherogenic factors. Inflammation is associated with AS complications, such as plaque rupture and ischemic cerebral infarction. In addition to inflammation, apoptosis plays an important role in AS. Apoptosis is a type of programmed cell death, and different apoptotic cells have different or even opposite roles in the process of AS. Unlike linear RNA, circular RNA (circRNA) a covalently closed circular non-coding RNA, is stable and can sponge miRNA, which can affect the stages of AS by regulating downstream pathways. Ultimately, circRNAs play very important roles in AS by regulating inflammation, apoptosis, and some other mechanisms. The study of circular RNAs can provide new ideas for the prediction, prevention, and treatment of AS.

DiDang decoction improves mitochondrial function and lipid metabolism via the HIF-1 signaling pathway to treat atherosclerosis and hyperlipidemia

ETHNOPHARMACOLOGICAL RELEVANCE

DiDang Decoction (DDD) is a traditional classical prescription that has been used to treat atherosclerosis (AS) and hyperlipidemia (HLP) in China. Nevertheless, the underlying mechanism of DDD remains unclear.

AIM OF THE STUDY

To validate the mechanism of DDD in AS and HLP based on network pharmacology and in vitro experiments.

MATERIALS AND METHODS

The chemical components of DDD were obtained from the Traditional Chinese Medicine System Pharmacology Database and Analysis Platform (TCMSP) database and literature mining, and the disease targets of AS and HLP were obtained from the Gencards, OMIM, and DisGeNET databases. The intersection genes were imported into the STRING database to construct protein-protein interaction (PPI) network, and the DAVID database was used for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Combined with the results of KEGG pathway analysis, the HIF-1 signaling pathway was selected for further in vitro experiments.

RESULTS

The results showed that network pharmacology predicted 112 targets related to DDD treatment of AS and HLP, and the top 10 related pathways are: Lipid and atherosclerosis, AGE-RAGE signaling pathway in diabetic complications, Chemical carcinogenesis - receptor activation, Pathways in cancer, Proteoglycans in cancer, Fluid shear stress and atherosclerosis, HIF-1 signaling pathway, Alcoholic liver disease, PPAR signaling pathway, and Coronavirus disease-COVID-19. In vitro experiments showed that DDD effectively reduced lipid accumulation in FFA-treated L02 cells; DDD attenuated mitochondrial damage and reduced ROS content; DDD inhibited ferroptosis and apoptosis; DDD up-regulated the expression of HIF-1α, Glutathione Peroxidase 4(GPX4), and Bcl2 proteins, and down-regulated expression of Bax protein.

CONCLUSION

DDD exerts therapeutic effects on AS and HLP through multiple targets and pathways, and improves mitochondrial function, reduces ROS content, inhibits ferroptosis and apoptosis by activating the HIF-1 signaling pathway, which provides reliable theoretical and experimental support for DDD treatment of AS and HLP.

Integrated investigation of DNA methylation, gene expression and immune cell population revealed immune cell infiltration associated with atherosclerotic plaque formation

BACKGROUND

The clinical consequences of atherosclerosis are significant source of morbidity and mortality throughout the world, while the molecular mechanisms of the pathogenesis of atherosclerosis are largely unknown.

METHODS

In this study, we integrated the DNA methylation and gene expression data in atherosclerotic plaque samples to decipher the underlying association between epigenetic and transcriptional regulation. Immune cell classification was performed on the basis of the expression pattern of detected genes. Finally, we selected ten genes with dysregulated methylation and expression levels for RT-qPCR validation.

RESULTS

Global DNA methylation profile showed obvious changes between normal aortic and atherosclerotic lesion tissues. We found that differentially methylated genes (DMGs) and differentially expressed genes (DEGs) were highly associated with atherosclerosis by being enriched in atherosclerotic plaque formation-related pathways, including cell adhesion and extracellular matrix organization. Immune cell fraction analysis revealed that a large number of immune cells, especially macrophages, activated mast cells, NK cells, and Tfh cells, were specifically enriched in the plaque. DEGs associated with immune cell fraction change showed that they were mainly related to the level of macrophages, monocytes, resting NK cells, activated CD4 memory T cells, and gamma delta T cells. These genes were highly enriched in multiple pathways of atherosclerotic plaque formation, including blood vessel remodeling, collagen fiber organization, cell adhesion, collagen catalogic process, extractable matrix assembly, and platelet activation. We also validated the expression alteration of ten genes associated with infiltrating immune cells in atherosclerosis.

CONCLUSIONS

In conclusion, these findings provide new evidence for understanding the mechanisms of atherosclerotic plaque formation, and provide a new and valuable research direction based on immune cell infiltration.

Nanoconfined anti-oxidizing RAFT nitroxide radical polymer for reduction of low-density lipoprotein oxidation and foam cell formation

Atherosclerosis is a leading cause of death worldwide. Antioxidant therapy has been considered a promising treatment modality for atherosclerosis, since reactive oxygen species (ROS) play a major role in the pathogenesis of atherosclerosis. We developed ROS-scavenging antioxidant nanoparticles (NPs) that can serve as an effective therapy for atherosclerosis. The newly developed novel antioxidant ROS-eliminating NPs were synthesized via reversible addition-fragmentation chain-transfer (RAFT) polymerization and act as a superoxide dismutase (SOD) mimetic agent. SOD is an anti-ROS enzyme which is difficult to use for passive delivery due to its low half-life and stability. Copolymers were synthesized using different feed ratios of 2,2,6,6-tetramethyl-4-piperidyl methacrylate (PMA) and glycidyl methacrylate (GMA) monomers and an anti-ROS nitroxyl radical polymer was prepared via oxidation. The copolymer was further conjugated with a 6-aminofluorescein via a oxirane ring opening reaction for intracellular delivery in RAW 264.7 cells. The synthesized copolymers were blended to create NPs (∼150 nm size) in aqueous medium and highly stable up to three weeks. The NPs were shown to be taken up by macrophages and to be cytocompatible even at high dose levels (500 μg mL-1). Finally, the nitroxide NPs has been shown to inhibit foam cell formation in macrophages by decreasing internalization of oxidized low-density lipoproteins.

Multifaceted Protective Effects of Hesperidin by Aromatic Hydrocarbon Receptor in Endothelial Cell Injury Induced by Benzo[a]Pyrene

Benzo[a]pyrene (BaP) causes atherosclerosis by activating the aromatic hydrocarbon receptor (AHR) signaling pathway to trigger lipid peroxidation and inflammation, thereby promoting the development of atherosclerosis. Hesperidin (Hsd), one of the 60 flavonoids of citrus, exhibits therapeutic effects on atherosclerosis. However, its antagonistic function for BaP remains unclear. In this study, the EA.hy926 cell model was used to systematically examine the antagonistic effect of Hsd with BaP, especially in low-density lipoprotein (LDL) oxidation and transport. Results showed that Hsd could reduce BaP-induced AHR activation in mRNA and protein expression level, and reduce LDL accumulation by decreasing the BaP-induced expression of advanced glycation end products and enhancing the BaP-inhibited Adenosine Triphosphate-binding cassette transporter A1 (ABCA1) protein and mRNA expression in EA.hy926 cells. In addition, Hsd could antagonize BaP-induced interaction of reactive oxygen species and the subsequent generation of oxidized LDL and malondialdehyde. Finally, Hsd could alleviate BaP-induced inflammatory response by decreasing IL-1β and TNF-α expression. All these results suggest that Hsd suppresses LDL accumulation, oxidation, and inflammatory response, and thus strongly impedes the AHR pathway activated by BaP.

Prostaglandin E2 (PGE2) synthesis pathway is involved in coronary artery stenosis and restenosis

The inflammatory events related to prostaglandins may play an important role in the progression of vessel stenosis. The aim of this study was to investigate the monocyte PTGES and 15-PGDH gene expression levels and the serum 13,14-dihyro-15-keto-PGF2α value involved in PGE2 metabolism in patients with coronary artery stenosis and restenosis. Moreover, the effects of miR-520, miR-1297 and miR-34 were studied on the gene expression levels. A total of sixty subjects referred for coronary angiography including healthy controls (stenosis <5%), subjects with stent no restenosis) SNR, stenosis <5%) and subjects in stent restenosis (ISR, restenosis >70%) were participated in the study. The gene expression levels and the serum 13,14-dihyro-15-keto- PGF2α value were measured by RT-qPCR and ELISA techniques, respectively. Moreover, the effects of miRNAs on the gene expression levels were investigated by the monocyte transfection of miR/PEI complexes. The PTGES and 15-PGDH gene expression levels and serum 13,14-dihyro-15-keto- PGF2α value increased significantly (P <0.05). Based on the miR-520 and miR-34 expression levels, the miR/PEI transfection studies were confirmed significantly the gene expression changes. The monocyte PGE2 synthesis pathway is actively considered in the SNR and ISR patients and might be related to miR-34 and miR-520 functions.

Effect of Coronary Artery Bifurcation Angle on Atherosclerotic Lesion Localization Distance to the Bifurcation Site

Objectives

Although percutaneous coronary interventions become a common treatment modality for coronary artery diseases, lesion localization make these procedures more complex. As the lesion localizes near to the bifurcation site, more complex PCI procedures, overqualified equipments are needed and complication risk increases. Previous studies have demonstrated the strong correlation between wide angulation and significant coronary stenosis. However, a paucity of data exists about the association between bifurcation angle and lesion localization distance. In this study we analysed the effect of coronary bifurcation angle and left main coronary artery length on the atherosclerotic lesion localization.

Methods

Patients, who underwent coronary angiography between 01.01.2017- 31.12.2019 were scanned. Patients having atherosclerotic lesions causing more than 50% luminal narrowing and Medina classification score (0,0,0) were evaluated. After exclusion, 467 patients were included. 5 bifurcation subgroups (LAD-CX, LAD-Dx, CX-OM, RCA-RV, RPD-RPL) were formed. Distance of lesion to the bifurcation site, bifurcation angle and left main coronary artery length were analysed by 2 experienced cardiologists with invasive quantitaive coronary angiography (QCA) by using “extreme angio and cardiac pacs” software system.

Results

There was a strong inverse correlation between bifurcation angle and lesion localization distance to the bifurcation site (r = −0.706; p < 0.0001). There was a nonsignificant negative correlation between Left-main coronary artery length and lesion localization. Regression analysis revealed that bifurcation angle is an independent risk factor for predicting the localization of an atheroslerotic lesion in 5 mm length from the point of bifurcation site (β = −0.074, p < 0.0001). A cut-off value of 80.5° coronary bifurcation angle was found to have 84.1% sensitivity and 81.3% specificity in prediction of atherosclerotic lesion localization in 5 mm length from the point of bifurcation site.

Conclusion

In this study we showed that as the bifurcation angle increases, atherosclerotic lesions tend to approach to the bifurcation site. Since invertentions encompassing bifurcation sites are more complex, lesions with increased angulation may need extra care as they are more likely to present with further complications. Furthermore, bifurcation angle is an independent risk factor for lesion localization.

The contribution of syndemic conditions to cardiovascular disease risk

The syndemic conditions of low education, childhood maltreatment, depression, HIV, alcohol and cocaine use, and obesity have been established as independent risk factors for cardiovascular risk, but research examining the association between syndemic conditions and cardiovascular risk in high-risk populations is lacking. A total of N = 503 participants underwent an ultrasound of the carotid artery to assess for atherosclerotic plaque. Participants, HIV-infected (n = 202) and HIV-uninfected (n = 301) with and without a history of cocaine use, were a mean age of 36.13 years (SD = 9.51); 50% were male, and 62% were African-American. Each syndemic condition was associated with 8% greater odds of atherosclerotic plaque (OR = 1.08), 9% greater odds of systolic blood pressure (OR = 1.09), and 10% greater odds of diastolic blood pressure (OR = 1.10). Multilevel research, interventions, and public policy initiatives are needed to activate stakeholders at each level to maximize their impact at a community level among populations with high rates of syndemic conditions.

Antioxidants and Atherosclerosis: Mechanistic Aspects

Atherosclerosis is a chronic inflammatory disease which is a major cause of coronary heart disease and stroke in humans. It is characterized by intimal plaques and cholesterol accumulation in arterial walls. The side effects of currently prescribed synthetic drugs and their high cost in the treatment of atherosclerosis has prompted the use of alternative herbal medicines, dietary supplements, and antioxidants associated with fewer adverse effects for the treatment of atherosclerosis. This article aims to present the activity mechanisms of antioxidants on atherosclerosis along with a review of the most prevalent medicinal plants employed against this multifactorial disease. The wide-ranging information in this review article was obtained from scientific databases including PubMed, Web of Science, Scopus, Science Direct and Google Scholar. Natural and synthetic antioxidants have a crucial role in the prevention and treatment of atherosclerosis through different mechanisms. These include: The inhibition of low density lipoprotein (LDL) oxidation, the reduction of reactive oxygen species (ROS) generation, the inhibition of cytokine secretion, the prevention of atherosclerotic plaque formation and platelet aggregation, the preclusion of mononuclear cell infiltration, the improvement of endothelial dysfunction and vasodilation, the augmentation of nitric oxide (NO) bioavailability, the modulation of the expression of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, and the suppression of foam cell formation.

Effects of Cornelian Cherry on Atherosclerosis and Its Risk Factors

Functional food represents an important alternative management of atherosclerosis, its risk factors, and clinical complications. Atherosclerosis is characterized by microinflammation, formation of atheromatous lipoprotein-rich plaques, and protrombogenic status. Cornelian cherry (Cornus mas L., CC) contains polyphenols influencing all three components of atherosclerosis. Its high antioxidant potential, verified in experimental studies, exhibited a pronounced decrease of inflammatory markers. CC treatment demonstrated a favourable effect on lipid spectrum (comparable with statins), decrease of glycemia, and increase of insulin (comparable with glibenclamide). Polyphenols identified in CC exhibited both direct antiplatelet effects and reduction of platelet hyper-reactivity mediated via attenuation of oxidative stress. The first clinical trials confirmed a clinically relevant decrease of total and low-density lipoprotein cholesterol, triacylglycerols, lipoproteins, amelioration of inflammatory activity, and insulin secretion improvement after the treatment with CC polyphenolic compounds. However, the limitation of published studies is the use of undefined cultivars of CC, their experimental nature, small scale, and missing longitudinal trials. Nevertheless, biochemical properties of CC, hitherto described, predispose its products for the adjuvant management of atherosclerosis.

Maximizing your "nutrition minute": Bridging nutritional gaps across the life span

BACKGROUND AND PURPOSE

Poor diet quality has been associated with increased mortality and an increased risk of chronic disease. Given the shortfalls in the typical American diet and the prevalence of nutrition-related chronic disease among US adults, the need for nutrition education is paramount. Nurse practitioners (NPs) are well placed to provide basic nutrition counseling but often face challenges to making this a reality. In a typical office visit, the time available to discuss diet and nutrition can be as little as one minute or less.

METHODS

Nutritional issues of concern facing specific age and risk groups are reviewed. The "Nutrition Minute," a tool comprising 5 questions that enable NPs to identify patients at higher risk of nutritional shortfalls, has been developed.

CONCLUSIONS

Nutrition counseling includes discussion of not only fat, carbohydrate, and protein intake, but also micronutrient intake. Although a food-first approach to nutrition is preferred, nutritional shortfalls exist even in the best diets. Supplementation with a multivitamin is an effective approach to bridge many nutritional gaps and can be recommended for many patients with poor diet quality. In addition to shortfalls apparent from a patient's diet, nutritional needs change across the life span (e.g., women of childbearing age and older persons) and in those with certain medical conditions such as diabetes and obesity.

IMPLICATIONS FOR PRACTICE

Although NPs clearly have an important role to play in the nutrition management of many patients, they should work in collaboration with registered dietitians wherever possible, especially for medical nutrition therapy in those patients needing specialist counseling, such as those with diabetes, obesity, cardiovascular disease, and renal disease.

Simvastatin Does Not Affect Nitric Oxide Generation Increased by Sesame Oil in Obese Zucker Rats

Current treatments for cardiovascular and obesity-associated diseases, such as statin therapy, may be associated with several side effects. Products from food sources with polyphenolic compounds may represent promising agents in the treatment of cardiovascular and metabolic diseases with minimal side effects. Thus, we aimed to study the effect of sesame oil and simvastatin treatment on plasma lipid profile, nitric oxide generation, and oxidative load in obese Zucker rats. 12-week-old male Zucker rats were divided into the control and sesame oil- (1.25 ml/kg/day) treated Zucker lean groups, the control and sesame oil (1.25 ml/kg/day), or simvastatin (15 mg/kg/day) together with sesame oil-treated Zucker fa/fa groups, n = 6 in each group. The treatment lasted for 6 weeks. Sesame oil composition and plasma lipid profile were analyzed. Nitric oxide synthase (NOS) activity, endothelial NOS (eNOS), phosphorylated eNOS, and inducible NOS (iNOS) protein expressions were determined in the left ventricle and aorta. Oxidative load, measured as conjugated diene (CD) and thiobarbituric acid reactive substance (TBARS) concentrations, was detected in the liver. Neither sesame oil nor cotreatment with simvastatin affected plasma lipid profile in Zucker fa/fa rats. Sesame oil and similarly cotreatment with simvastatin markedly increased NOS activity and phosphorylated eNOS protein expressions in the left ventricle and aorta of Zucker fa/fa rats. There were no changes in eNOS and iNOS protein expressions within the groups and tissues investigated. Hepatic CD concentration was higher in Zucker fa/fa comparing Zucker lean rats, and sesame oil treatment decreased it significantly. Interestingly, this decrease was not seen after cotreatment with simvastatin. In conclusion, phosphorylation of eNOS and decreased oxidative load may significantly contribute to increase in total NOS activity with potential beneficial properties. Interestingly, simvastatin did not affect NO generation already increased by sesame oil in obese Zucker rats.

Efficacy of lycopene on modulation of renal antioxidant enzymes, ACE and ACE gene expression in hyperlipidaemic rats

INTRODUCTION

We aimed to evaluate the efficacy of lycopene on renal tissue antioxidant enzymes and angiotensin converting enzyme (ACE) gene expression and serum activity in diet-induced hyperlipidaemia.

METHODS

Thirty-two female Wistar albino rats (200-250 g weight), 5-6 months of age, were randomly selected and divided into four groups. Group I received normal diet; group II received 24 g high fat diet/100 g of daily diet; group III received 24 g high fat diet/100 g daily diet and 200 ml of lycopene extract (twice a week) for 8 weeks; and group IV received 200 ml oral lycopene extract twice a week for 8 weeks.

RESULTS

A marked increase was observed in plasma urea and creatinine levels, serum C-reactive protein, kidney weight, tissue renal malonyldialdehyde level, ACE gene expression and serum level, while a decrease catalase level among hyperlipidaemic rats was observed. Histologically, interstitial inflammation and proliferation was seen. Lycopene supplementation significantly decreased plasma urea and creatinine, serum ACE, renal tissue malonyldialdehyde level and C-reactive protein level, while it increased tissue antioxidant enzymes level and total protein. Tissue inflammation and proliferation was improved.

CONCLUSIONS

This finding suggests that supplementation of lycopene is effective for renal antioxidant enzymes, ACE gene expression and ACE serum level in hyperlipidaemic rats.

The effect of a 12-week moderate intensity interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah: a cohort study

Aim. To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. Methods. Thirty-five participants performed an interval training (2 : 1 work : rest ratio) 3 times a week for 12 weeks at an intensity of 70% of VO₂max. All subjects were subjected to a biochemical test session before and after the training program. Results. The increase of total antioxidant status (TAS), glutathione peroxidase (GPx), and α-tocopherol, is significant only for cigarette smokers (CS) and hookah smokers (HS) groups. The decrease of malondialdehyde (MDA) and the increase of glutathione reductase (GR) are more pronounced in smokers groups compared to those of nonsmokers (NS). Superoxide dismutase (SOD) increases in NS, CS, and HS groups by 10.1%, 19.5%, and 13.3%, respectively (P < 0.001). Likewise, a significant improvement of high-density lipoprotein cholesterol (HDL-C) and TC/HDL-C ratio was observed in CS and HS groups (P < 0.05). Conclusion. Although the interval training program does not have a significant effect on blood lipid levels, it seems to be very beneficial in the defense and prevention programs of oxidative stress.

Atherosclerosis: process, indicators, risk factors and new hopes

Background:

Atherosclerosis is the major cause of morbidities and mortalities worldwide. In this study we aimed to review the mechanism of atherosclerosis and its risk factors, focusing on new findings in atherosclerosis markers and its risk factors. Furthermore, the role of antioxidants and medicinal herbs in atherosclerosis and endothelial damage has been discussed and a list of important medicinal plants effective in the treatment and prevention of hyperlipidemia and atherosclerosis is presented.

Methods:

The recently published papers about atherosclerosis pathogenesis and herbal medicines effective in the treatment and prevention of hyperlipidemia and atherosclerosis were searched.

Results:

Inflammation has a crucial role in pathogenesis of atherosclerosis. The disease is accompanied by excessive fibrosis of the intima, fatty plaques formation, proliferation of smooth muscle cells, and migration of a group of cells such as monocytes, T cells, and platelets which are formed in response to inflammation. The oxidation of low density lipoprotein (LDL) to Ox-LDL indicates the first step of atherosclerosis in cardiovascular diseases. Malondialdehyde factor shows the level of lipoperoxidation and is a sign of increased oxidative pressure and cardiovascular diseases. In special pathological conditions such as severe hypercholesterolemia, peroxynitrite concentration increases and atherosclerosis and vascular damage are intensified. Medicinal plants have shown to be capable of interacting these or other pathogenesis factors to prevent atherosclerosis.

Conclusions:

The pathogenesis factors involved in atherosclerosis have recently been cleared and the discovery of these factors has brought about new hopes for better prevention and treatment of atherosclerosis.

Effect of supplemental vitamin E for the prevention and treatment of cardiovascular disease

OBJECTIVE

To evaluate and synthesize the evidence on the effect of supplements of vitamin E on the prevention and treatment of cardiovascular disease.

DESIGN

Systematic review of placebo-controlled randomized controlled trials; meta-analysis where justified.

MEASUREMENTS AND MAIN RESULTS

Eighty-four eligible trials were identified. For the outcomes of all-cause mortality, cardiovascular mortality, fatal or nonfatal myocardial infarction, and blood lipids, neither supplements of vitamin E alone nor vitamin E given with other agents yielded a statistically significant beneficial or adverse pooled relative risk (for example, pooled relative risk of vitamin E alone = 0.96 [95% confidence interval (CI), 0.84 to 1.10]; 0.97 [95% CI, 0.80 to 1.90]; and 0.72 [95% CI, 0.51 to 1.02] for all-cause mortality, cardiovascular mortality, and nonfatal myocardial infarction, respectively.

CONCLUSIONS

There is good evidence that vitamin E supplementation does not beneficially or adversely affect cardiovascular outcomes.

Antioxidant vitamins in the prevention of cardiovascular disease: a systematic review

Do antioxidant vitamins, in regular food or as food supplements, protect against myocardial infarction and stroke? In this systematic literature review on the effects of antioxidant vitamins in the primary prevention of cardiovascular disorders, studies with ischaemic heart disease, stroke or combined cardiovascular events as end-points have been included. Studies on the effects of antioxidant vitamins on intermediary end-points (such as blood lipids and blood pressure) and as secondary prevention in patients with manifest cardiovascular disease are reviewed in a conventional manner. In observational studies (case-control or cohort design), people with high intake of antioxidant vitamins by regular diet or as food supplements generally have a lower risk of myocardial infarction and stroke than people who are low-consumers of antioxidant vitamins. The associations in observation studies have been shown for carotene, ascorbic acid as well as tocopherol. In randomized controlled trials, however, antioxidant vitamins as food supplements have no beneficial effects in the primary prevention of myocardial infarction and stroke. Serious adverse events have been reported. After an initial enthusiasm for antioxidants in the secondary prevention of cardiovascular disease, recent reports from of several large randomized trials have failed to show any beneficial effects. Thus, the apparent beneficial results of high intake of antioxidant vitamins reported in observational studies have not been confirmed in large randomized trials. The discrepancy between different types of studies is probably explained by the fact that supplement use is a component in a cluster of healthy behaviour. Antioxidant vitamins as food supplements cannot be recommended in the primary or secondary prevention against cardiovascular disease.

Dietary intake, body mass index, exercise, and alcohol: are college women following the dietary guidelines for Americans?

Study findings suggest that college women practice diet and health behaviors that contradict the 1995 Dietary Guidelines for Americans. To confirm this hypothesis, the authors surveyed the diet, exercise, and health habits of 60 female students enrolled in three university aerobics courses. They measured height and weight to calculate body mass index (BMI) and assessed physical activity, using the Self-Reported Physical Activity scale. To estimate food and nutrient intake, they used 3-day food records. Participants reported diets that were nutritionally adequate but exceeded national recommendations for fat, sugar, and sodium, and their reports of exercise habits suggested that the lifestyles of 66% of the respondents were sedentary. Although the students' mean BMIs suggested healthy weights, 25% of the women were classified as overweight. A majority of the participants were following at least 1 of the 7 dietary guidelines; however, no participant was adhering to all proposed behaviors.

Effects of lisinopril and amlodipine on antioxidant status in experimental hypertension

The objective of this investigation was to compare changes in antioxidant status (together with other metabolites relevant to hypertension) in plasma and cardiac tissue from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto rats (WKY), following 8 weeks of treatment with lisinopril (angiotensin converting enzyme inhibitor) or amlodipine (Ca(2+) channel antagonist) respectively. There was no significant difference in the levels of total antioxidant capacity, retinol, urea, albumin or triglyceride in plasma from SHR or WKY rats, with or without lisinopril or amlodipine treatment. However in SHR rats, levels of alpha-tocopherol were substantially reduced in both plasma (-54% WKY, P<0.01) and cardiac tissue (-43% WKY, P<0.05). Treatment with lisinopril ameliorated reduced levels of plasma alpha-tocopherol in SHR rats, but not in cardiac tissue. Amlodipine treatment had no effect on alpha-tocopherol levels in plasma or cardiac tissue in SHR rats. In SHR rats total cholesterol levels were significantly lower thanWKY controls (-36%, P<0.001). This effect was reversed in lisinopril treated SHR rats (+27%, P<0.01). Plasma high density lipoprotein (HDL) and low density lipoprotein (LDL) cholesterol were reduced in untreated SHR rats (P<0.025) when compared to WKY controls; neither lisinopril nor amlodipine treatment significantly altered these parameters. These findings suggest possible alternative mechanisms of action for lisinopril, and reinforce its use in hypertensive patients or patients with left ventricular hypertrophy.

Comparative content of total polyphenols and dietary fiber in tropical fruits and persimmon

Recent studies have shown that dietary fiber and polyphenols of vegetables and fruits improve lipid metabolism and prevent the oxidation of low density lipoprotein cholesterol (LDL-C), which hinder the development of atherosclerosis. The goal of this study was to measure the total polyphenol and dietary fiber contents of some tropical fruits (i.e., pineapple, wax apple, rambutan, lichi, guava, and mango) and compare the results to the content of these substances in the better characterized persimmon. It was found that lichi, guava, and ripe mango (cv. Keaw) have 3.35, 4.95, and 6.25 mg of total polyphenols in 100 g fresh fruit, respectively. This is significantly higher than in persimmon, pineapple, wax apple, mature green mango, and rambutan [P < 0.0005 for pineapple (Smooth Cayene variant), wax apple, persimmon, rambutan, mature green mango (cv. Keaw); the value of P < 0.001 is found only for pineapple (Phuket, Queen variant)]. The same relationship was observed for the contents of gallic acid and of dietary fiber. It can be supposed that among the studied fruit, lichi, guava, and ripe mango may be preferable for dietary prevention of atherosclerosis.

Antioxidant potentials of vitamin A and carotenoids and their relevance to heart disease

Despite being one of the first vitamins to be discovered, the full range of biological activities for vitamin A remains to be defined. Structurally similar to vitamin A, carotenoids are a group of nearly 600 compounds. Only about 50 of these have provitamin A activity. Recent evidence has shown vitamin A, carotenoids and provitamin A carotenoids can be effective antioxidants for inhibiting the development of heart disease. Vitamin A must be obtained from the diet: green and yellow vegetables, dairy products, fruits and organ meats are some of the richest sources. Within the body, vitamin A can be found as retinol, retinal and retinoic acid. Because all of these forms are toxic at high concentrations, they are bound to proteins in the extracellular fluids and inside cells. Vitamin A is stored primarily as long chain fatty esters and as provitamin carotenoids in the liver, kidney and adipose tissue. The antioxidant activity of vitamin A and carotenoids is conferred by the hydrophobic chain of polyene units that can quench singlet oxygen , neutralize thiyl radicals and combine with and stabilize peroxyl radicals. In general, the longer the polyene chain, the greater the peroxyl radical stabilizing ability. Because of their structures, vitamin A and carotenoids can autoxidize when O2 tension increases, and thus are most effective antioxidants at low oxygen tensions that are typical of physiological levels found in tissues. Overall, the epidemiological evidence suggests that vitamin A and carotenoids are important dietary factors for reducing the incidence of heart disease. Although there is considerable discrepancy in the results from studies in humans regarding this relationship, carefully controlled experimental studies continue to indicate that these compounds are effective for mitigating and defending against many forms of cardiovascular disease. More work, especially concerning the relevance of how tissue concentrations, rather than plasma levels, relate to the progression of tissue damage in heart disease is required. This review assembles information regarding the basic structure and metabolism of vitamin A and carotenoids as related to their antioxidant activities. Epidemiological, intervention trials and experimental evidence about the effectiveness of vitamin A and carotenoids for reducing cardiovascular disease is also reviewed.

Determination of retinol, alpha-tocopherol, alpha- and beta-carotene by direct extraction of human serum using high performance liquid chromatography

In this report we describe a modified reverse phase HPLC method that avoids the solvent evaporation step and allows simple and rapid determination of retinol, alpha-tocopherol, alpha-carotene and beta-carotene and achieves complete separation of alpha- and beta-carotene. Retinyl acetate, alpha-tocopheryl acetate and retinyl palmitate in ethanol were added to serum as internal standards. Serum was then deproteinized with an equal volume of ethanol, and the lipid was extracted with ethyl acetate-butanol (1:1 v/v). A portion of this solution was injected into a C18 reverse phase chromatographic column and absorbencies of the vitamins and internal standards were measured at 292 nm for tocopherols, 325 nm for retinoids and 450 nm for carotenoids; peak-height ratios were used to quantify each vitamin. The analytical recoveries for retinol, alpha-tocopherol alpha- and beta-carotene at various concentrations tested were 95-103, 90-98, 92-99 and 94-96%, respectively. The intra- and interassay variations for low and high concentrations of retinol, alpha-tocopherol, alpha- and beta-carotene ranged from 2.4 to 6.7 for intraassay and from 4.3 to 8.5 for interassay replication. The detection limits were 1.25 (0.04), 19 (0.44), 0.35 (0.006) and 0.94 (0.017) micrograms/dL (delta mol/L) for retinol, alpha-tocopherol, alpha- and beta-carotene, respectively.

Effect of vitamin E and probucol on dietary cholesterol-induced atherosclerosis in rabbits

The preventive effect of vitamin E and Probucol against atherosclerosis in rabbits were compared. Atherosclerosis was induced by a 2% cholesterol-containing vitamin E-poor diet (5-10 ppm). Six groups of five rabbits each were studied. Group I (control) was fed on a vitamin E-poor diet. The other groups had the following supplements: group II, 50 mg/kg vitamin E i.m.; group III, 2% cholesterol; group IV, 2% cholesterol plus 50 mg/kg vitamin E i.m., group V, 2% cholesterol plus 1% Probucol; group VI, 2% cholesterol + 1% Probucol plus 50 mg/kg vitamin E i.m. After 4 weeks, aortas were removed and analyzed by light and scanning electron microscopy for atherosclerotic lesions. Samples of the media were analyzed for protein kinase C activity. The aortas of cholesterol-fed rabbits showed typical atherosclerotic lesions, detected by microscopic examination, their media smooth muscle cells exhibited an increase in protein kinase C activity. Vitamin E fully prevented cholesterol-induced atherosclerotic lesions and the induction of protein kinase C activity. Probucol was not effective in preventing either cholesterol-induced atherosclerotic lesions or the induction of protein kinase C activity. These results show that the protective effect of vitamin E against hypercholesterolemic atherosclerosis is not produced by an other antioxidant such as Probucol, and therefore, may not be linked to the antioxidant properties of this vitamin. The effects observed at the level of smooth muscle cells ex vivo suggest an involvement of signal transduction events in the protective effect of vitamin E against atherosclerosis.

Microcirculation, vitamin E and omega 3 fatty acids: an overview

We have observed significant increases in LDF and similar trends for CBV after FO supplementation in younger subjects (both normolipidemic and hyperlipidemic). In elderly subjects, this trend appears to be reversed unless subjects are supplemented with higher doses of vit. E (100 IU/10 KG/day). Our mouse data suggest that dietary vit. E at 100 IU/Kg does not adequately protect against lipid oxidation in vivo or in vitro following an oxidative insult when mice are fed an 8% FO & 2% linoleic acid containing diet. It has been reported that FO significantly lowers triglycerides and VLDL-cholesterol (especially where subjects have higher initial triglyceride values) and tends to increase LDL-cholesterol and Apo-B100. These findings are all the more important because the oxidation of LDL from FO-supplemented subjects caused a time-dependent increase in the ability to facilitate albumin transfer which was not diminished following a 2 month washout (WO). Addition of vit. E to the FO supplement prevented this change. These data suggest that FO supplementation without sufficient vit. E may be deleterious to the vascular endothelium. The western fat blend supplement appeared to be protective with increased length of supplementation most likely due to increased MONO fatty acids which are resistant to oxidation; vit. E supplementation appeared to have little additional effect. Our combined studies, and those reported by others, suggest that in humans, increased peripheral microcirculatory flow is most likely due to changes in precapillary vascular tone i.e., vasodilation. It is also possible that subtle changes in each of the three variables i.e. blood pressure, blood viscosity and vascular tone when combined may contribute to the significant changes which we have noted as increased LDF or CBV after intervention with dietary n-3 fatty acids. We hypothesize that interactions between dietary fatty acids and vit. E alters the ratios of vasoconstrictive-platelet aggegatory/vasodilatory-antiplatelet aggregatory agents (TXA2 and endothelin/PGI2 and nitric oxide), the expression of adhesion molecules (P-selectin and E-selectin) and thereby directly influences the modulation of free radical mediated events between blood elements and the vascular endothelium. Fatty acids of the n3 series may alter these events by favoring the production of vasodilatory compounds and decreased expression of P and/or E-selectins, provided that these highly oxidizable lipids are protected by adequate antioxidants.

PSK protects macrophages from lipoperoxide accumulation and foam cell formation caused by oxidatively modified low-density lipoprotein

In previous works, it has been evidenced that lipoperoxidative injury to macrophages caused by oxidatively modified low-density lipoprotein (O-LDL) plays an important role in foam cell formation, and that PSK, a protein bound polysaccharide extracted from the class Basidiomycetes Coriolus Versicolor, can protect macrophages from lipoperoxidative injury induced by tert-butyl hydroperoxide (tbOOH). In this paper PSK protection of macrophages from lipoperoxide (LPO) accumulation and foam cell formation caused by O-LDL and its action mechanism were further studied. The LPO accumulation was determined by using ACAS 570. Dynamic assay of the LPO level in eight single cells after adding O-LDL or determination of the average LPO content in a lot of cells incubated in advance with O-LDL for 12 h, both indicated that O-LDL might induce LPO accumulation in macrophages and the effects of O-LDL could be prevented by PSK. O-LDL might cause the changes of morphological structure in macrophages and the transformation of macrophages into foam cells, and the effects could also be prevented by PSK. The determination of selenium-dependent glutathione peroxidase (SeGSHPx) activities and mRNA contents of macrophages and changes of SeGSHPx activity and mRNA content after incubation with tbOOH showed that PSK might increase the SeGSHPx activity of macrophage and the enhanced SeGSHPx activity may occur at the level of gene transcription.

Lipid peroxidation: a review of causes, consequences, measurement and dietary influences

In this review the process of lipid peroxidation and the atherogenicity of peroxidied lipids are discussed. Recent findings with regard to the effect of selected dietary factors on susceptibility of lipids to oxidative stress and on antioxidant defences are analysed with particular reference to their potential use in the prevention and treatment of atherogenesis and, by extension, coronary heart disease. Laboratory methods of assessing antioxidant defences, lipid peroxidation and the effects of lipid peroxidation are also reviewed and discussed with particular reference to their ability to assess in vivo oxidative stress and lipid peroxidation status. A range of oxidative stress indices are presented and their limitations discussed, but the main focus is on the most commonly used laboratory test for lipid peroxidation, the thiobarbituric acid reacting substances (TBARS) test. Finally, the influence of selected dietary factors on measured peroxidation status is discussed, with particular reference to the antioxidant vitamins C (ascorbic acid) and E (alpha tocopherol) and the type of fatty acids (mono- and poly-unsaturated) in the diet.

No effect of beta-carotene supplementation on the susceptibility of low density lipoprotein to in vitro oxidation among hypercholesterolaemic, postmenopausal women

The effect of beta-carotene on the susceptibility of low density lipoprotein (LDL) to oxidative modification was investigated in a double-blind, randomized placebo-controlled study. Hypercholesterolaemic, postmenopausal women were given 30 mg beta-carotene per day (n = 15 subjects) or placebo capsules (n = 15 subjects) for 10 weeks. They were instructed to follow the American Heart Association Step One diet. LDL, isolated before and after treatment was subjected to copper-catalysed lipid peroxidation. There were no significant differences between LDL from the beta-carotene and placebo groups, as assessed by measuring the lag time for formation of conjugated dienes; the rate of formation and the amount of conjugated dienes formed; the amount of lipid peroxides generated; and the relative electrophoretic mobility, at baseline and after treatment. Dietary records showed that the subjects were consuming similar amounts and types of fat. No significant differences were found in the lipid composition and fatty acid pattern of LDL from the two groups. In conclusion, the results indicated that supplementation with beta-carotene in non-smoking, hypercholesterolaemic, postmenopausal women had no protective effect on the susceptibility of LDL to copper-catalysed modification in vitro.

Oxygen free radicals and antioxidants: a review

In 1989, nearly 43% of deaths in the United States were due to some form of cardiovascular disease, and 23% were caused by cancer. Thus, two of every three people in this country die from either cardiovascular disease or cancer. Based on both experimental and epidemiological evidence, investigators believe that free radicals play a critical role in the development of both diseases. Low levels of antioxidants, which increases free radical activity, are clearly associated with an increased risk of these diseases. This link has led to the conclusion that use of antioxidant vitamin supplements to scavenge free radicals could potentially decrease the risks of cancer and cardiovascular disease. Results from numerous studies to date have been very promising, although a true protective or preventive causal relationship has not yet been established. Numerous primary and secondary intervention trials currently underway should more definitively assess the role of antioxidants in disease prevention. In the interim, many people feel the evidence is now strong enough to begin supplementation on their own. The pharmacist is in a position to advise patients on the safe and moderate use of antioxidants. The antioxidants discussed in this article are relatively non-toxic, with the exception of vitamin A. The possible benefits of vitamin A are better achieved with the use of beta-carotene. Megadose antioxidant supplementation does not appear to provide any additional benefit beyond what a more moderate supplement can provide and should therefore be discouraged. Taking a trace mineral with antioxidant potential is generally a waste of money, provided the patient is not initially deficient in the element.(ABSTRACT TRUNCATED AT 250 WORDS)