The Emerging Role of Nutraceuticals in Cardiovascular Calcification: Evidence from Preclinical and Clinical Studies.

Cardiovascular calcification is the ectopic deposition of calcium-phosphate crystals within the arterial wall and the aortic valve leaflets. This pathological process leads to increased vascular stiffness, reduced arterial elasticity, and aortic valve stenosis, increasing the risk of cardiovascular diseases. Although cardiovascular calcification is an increasing health care burden, to date no medical therapies have been approved for treating or preventing it. Considering the current lack of therapeutic strategies and the increasing prevalence of cardiovascular calcification, the investigation of some nutraceuticals to prevent this pathological condition has become prevalent in recent years. Recent preclinical and clinical studies evaluated the potential anti-calcific role of nutraceuticals (including magnesium, zinc, iron, vitamin K, and phytate) in the progression of vascular calcification, providing evidence for their dietary supplementation, especially in high-risk populations. The present review summarizes the current knowledge and latest advances for nutraceuticals with the most relevant preclinical and clinical data, including magnesium, zinc, iron, vitamin K, and phytate. Their supplementation might be recommended as a cost-effective strategy to avoid nutritional deficiency and to prevent or treat cardiovascular calcification. However, the optimal dose of nutraceuticals has not been identified and large interventional trials are warranted to support their protective effects on cardiovascular disease.

Lipid Profile and Vascular Remodelling in Young Dyslipidemic Subjects Treated with Nutraceuticals Derived from Red Yeast Rice.

BACKGROUND AND AIMS: A relevant role is emerging for functional foods in cardiovascular prevention. The aim of this study was to assess the effect of a nutraceutical multitargeted approach on lipid profile and inflammatory markers along with vascular remodelling in a cohort of dyslipidemic subjects without history of cardiovascular (CV) disease. METHODS AND RESULTS: We enrolled 25 subjects (mean age 48.2 years) with low to moderate CV risk profile and total cholesterol (TC) levels between 150 and 250 mg/dl. The patients were assigned to receive for one year a tablet/die of a nutraceutical combination containing red yeast rice (RYR) extract (Monacolin 3 mg/tablet) and coenzyme Q10 (30 mg/tablet). Treatment with the nutraceutical compounds led to a significant reduction of TC (from 227 to 201 mg/dl, p < 0.001), LDL-c (from 150 to 130 mg/dl, p = 0.001), triglycerides (from 121 to 109 mg/dl, p = 0.013), non-HDL-cholesterol (from 168 to 141 mg/dl, p < 0.001), hs-CRP (from 1.74 to 1.20 mg/l, p = 0.015), and osteoprotegerin (from 1488 to 1328 pg/ml, p = 0.045). Levels of HDL-c, Lp(a), glucose, liver enzyme, CPK, or creatinine did not change over time. An ultrasound study was performed to assess changes in mean carotid intima-media thickness (IMT) and maximum IMT (M-MAX) as well as modification in local carotid stiffness by means of determining the carotid compliance coefficient (CC) and distensibility coefficient (DC). At the end of the treatment, we observed small but significant reductions in both mean-IMT (from 0.62 to 0.57 mm, p = 0.022) and M-MAX (from 0.79 to 0.73 mm, p = 0.002), and an improvement in carotid elasticity (DC from 22.4 to 24.3 × 10-3/kPa, p = 0.006 and CC from 0.77 to 0.85 mm2/kPa, p = 0.019). CONCLUSIONS: A long-term treatment with a combination of RYR and coenzyme Q10 showed lipid-lowering activity along with a reduction of inflammatory mediators and an improvement of vascular properties in young subjects with a low-to-moderate CV risk profile.

Cholesterol-Lowering Action of a Novel Nutraceutical Combination in Uremic Rats: Insights into the Molecular Mechanism in a Hepatoma Cell Line.

Appropriate nutraceutical combinations may represent a valid approach to prevent vascular calcification associated with chronic kidney disease (CKD). In the present study, we tested the effect of a new nutraceutical combination named RenaTris®, containing MK-7, magnesium carbonate, and Sucrosomial® Iron, on vascular calcification in uremic rats. Rats were randomly divided into three groups, i.e. control (high-phosphate diet), uremic (high-phosphate diet containing 0.5% adenine), and supplemented uremic diet (0.5% adenine, MK-7, magnesium carbonate, and Sucrosomial® Iron). After six weeks, sera and vascular calcification were examined. The uremic diet increased creatinine and phosphate levels and induced extensive vascular calcification. The uremic condition also induced a mild hypercholesterolemic condition (+52% of total cholesterol; p < 0.05). The supplemented uremic diet did not reduce creatinine, phosphate levels, or vascular calcification, however, we observed a significant hypocholesterolemic effect (-18.9% in supplemental uremic vs. uremic diet; p < 0.05). Similar to simvastatin, incubation of cultured human hepatoma cells (Huh7) with MK-7 significantly reduced cholesterol biosynthesis (-38%) and induced 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and low-density lipoprotein receptor (LDLR) at both mRNA and protein levels. The effect of MK-7 on LDLR was counteracted by the co-incubation with squalene. Unlike simvastatin, MK-7 reduced PCSK9 in Huh7. These results indicated that the new nutraceutical combination significantly impacts cholesterol metabolism and its supplementation may help to control mild hypercholesterolemic conditions in CKD patients.

Warfarin, but not rivaroxaban, promotes the calcification of the aortic valve in ApoE-/- mice.

INTRODUCTION: Vitamin K antagonists, such as warfarin, are known to promote arterial calcification through blockade of gamma-carboxylation of Matrix-Gla-Protein. It is currently unknown whether other oral anticoagulants such as direct inhibitors of Factor Xa can have protective effects on the progression of aortic valve calcification. AIMS: To compare the effect of warfarin and rivaroxaban on the progression of aortic valve calcification in atherosclerotic mice. RESULTS: 42 ApoE-/- mice fed with Western-type Diet (WTD) were randomized to treatment with warfarin (n = 14), rivaroxaban (n = 14) or control (n = 14) for 8 weeks. Histological analyses were performed to quantify the calcification of aortic valve leaflets and the development of atherosclerosis. The analyses showed a significant increase in valve calcification in mice treated with warfarin as compared to WTD alone (P = .025) or rivaroxaban (P = .005), whereas no significant differences were found between rivaroxaban and WTD (P = .35). Quantification of atherosclerosis and intimal calcification was performed on the innominate artery of the mice and no differences were found between the 3 treatments as far as atherogenesis and calcium deposition is concerned. In vitro experiments performed using bovine interstitial valve cells (VIC) showed that treatment with rivaroxaban did not prevent the osteogenic conversion of the cells but reduce the over-expression of COX-2 induced by inflammatory mediators. CONCLUSION: We showed that warfarin, but not rivaroxaban, could induce calcific valve degeneration in a mouse model of atherosclerosis. Both the treatments did not significantly affect the progression of atherosclerosis. Overall, these data suggest a safer profile of rivaroxaban on the risk of cardiovascular disease progression.

Extracellular pyrophosphate is reduced in aortic interstitial valve cells acquiring a calcifying profile: implications for aortic valve calcification.

OBJECTIVES: Pyrophosphate (PPi) is a potent inhibitor of ectopic mineralization but its role during aortic valve calcification is not known. METHODS: Anti-calcific effect of PPi was investigated by using an in vitro model of serum-driven calcification of collagen sponges and decellularized porcine aortic valve leaflets. Bovine interstitial valve cells (VIC), seeded either within the collagen matrices or in transwell chambers, were used to test cellular ability to inhibit serum-induced calcification. PPi metabolism was investigated in clonal VIC harboring different calcifying potential. RESULTS: In a cell-free system, high serum levels induced a dose-dependent calcification of type I collagen matrices which was prevented by PPi and ATP supplementation. Blockade of serum-driven calcification by PPi and ATP was also observed when using decellularized porcine aortic valve leaflets. A similar anti-calcific effect was also seen for bovine VIC, either statically seeded into the collagen matrices or co-cultured by using a transwell system. However, when we performed co-culture experiments by using clonal VIC harboring different calcifying potential, we observed that the subset of cells acquiring a pro-calcific profile lost the ability to protect the collagen from serum-driven calcification. Pro-calcific differentiation of the clonal VIC was accompanied by increase in ALP along with significant reduction in NPP activity and ATP/PPi extracellular accumulation. These changes were not observed in the clonal subtype with lower propensity towards calcification. CONCLUSIONS: We showed that PPi and ATP are potent inhibitors of serum-driven calcification of collagen matrix and that their extracellular accumulation is reduced in calcifying VIC.

Ectopic calcification in diabetic vascular disease.

INTRODUCTION: Cardiovascular diseases represent over one-half of all deaths in both type 1 and type 2 diabetes mellitus. In diabetic patients, vascular calcifications are more frequently observed than in people without diabetes. In particular, elevated degrees of coronary artery and valvular calcifications are reported in populations with diabetes. AREAS COVERED: We will present and discuss findings from clinical and basic science studies that investigate the pathophysiological processes leading to exaggerated arterial/valve calcification in diabetic patients. We will also illustrate the likely effects of the current therapies on vascular calcification progression in diabetic patients. A special focus will be dedicated to the contribution of resident/circulating calcifying cells to the calcific processes observed under diabetic conditions. EXPERT OPINION: Interest in the topic of ectopic calcification in diabetic vascular disease is expanding and more knowledge is adding on its mechanisms and consequences. Importantly, new therapeutic targets are emerging, implying possible future chances to modulate vascular calcification for cardiovascular protection.

Atorvastatin reduces macrophage accumulation in atherosclerotic plaques: a comparison of a nonstatin-based regimen in patients undergoing carotid endarterectomy.

BACKGROUND AND PURPOSE: The object of our study was to compare the effect of high-dose vs low-dose atorvastatin vs nonstatin-based treatment (cholestyramine plus sitosterol) on cell composition of carotid plaque. METHODS: We recruited 60 hypercholesterolemic patients (total cholesterol, 5.83-7.64 mmol/L) eligible for carotid endarterectomy. Three months before surgery, patients were randomized into 3 groups (n=20) receiving atorvastatin 10 mg/day (AT-10) or atorvastatin 80 mg/day (AT-80) or cholestyramine 8 g/day plus sitosterol 2.5 g/day. Analysis of cell composition was performed on endarterectomy specimens. RESULTS: The 3 treatments resulted in a significant reduction of total cholesterol and low-density lipoprotein cholesterol (LDL-C), although the decrease in total cholesterol and LDL-C was of smaller magnitude in the cholestyramine plus sitosterol group. The 3 regimens did not influence the levels of inflammatory markers (including high-sensitivity C-reactive protein). Macrophage content was significantly lower in the AT-10 group plaques compared to the cholestyramine plus sitosterol group. It was further reduced in the AT-80 group plaques. These differences were no longer significant after adjustment for changes in LDL-C. No difference in lymphocyte number was observed among treatments, whereas the content of smooth muscle cells was higher in the AT- 80 group. An inverse association was observed between LDL-C changes in the 3 groups and macrophage content in the plaques. CONCLUSIONS: Short-term treatment with high-dose statin is superior to a nonstatin lipid-lowering regimen in reducing the macrophage cell content within atherosclerotic lesions, but this effect was determined by the degree of LDL-C-lowering.

Leptin is associated with the size of the apolipoprotein(a) particle in African tribal populations living on fish or vegetarian diet.

OBJECTIVE: Apolipoprotein(a) [or apo(a)] isoform size, which is strongly genetically determined, showed significant association with the cardiovascular risk. Subjects on a fish diet have lower lipoprotein(a) levels, larger apo(a) isoform sizes and lower leptin levels than their vegetarian diet counterparts. We hypothesized that leptin may contribute to a potential association between the type of diet and the size of apo(a) isoforms. METHODS: Anthropometric data, dietary nutrients, lipoprotein profile, plasma leptin levels, and apo(a) isoforms were evaluated in two related homogenous African tribal populations of Tanzania, one on a primarily freshwater fish diet (n=278), and the other on a vegetarian diet (n=326). RESULTS: We observed a strong negative association between leptin levels and size of each of the apo(a) isoforms in both fish and vegetable diet groups, and in both genders. However, leptin was not associated with levels of lipoprotein(a). In multivariate analysis, a strong and independent association between leptin and size of apo(a) isoforms was observed. The size of apo(a) isoforms was strongly associated with high and low leptin states. Subjects with low leptins had 30% larger sizes of apo(a) isoforms than their high leptin counterparts. CONCLUSIONS: High leptin subjects have smaller, potentially more atherogenic, apo(a) isoform sizes than low leptin ones. We suggest that omega-3 rich diet can influence the levels of apo(a) and/or Lp(a) even though they are mainly genetically determined. These findings may have implications for understanding the interaction between leptin and cardiovascular risk.

Neither antioxidants nor genistein inhibit the progression of established atherosclerotic lesions in older apoE deficient mice.

Supplements and diets enriched in antioxidants and soy isoflavones are purported to reduce cardiovascular disease risk. Many experimental studies have demonstrated inhibitory effects of antioxidants and soy isoflavones on the development of fatty streaks in animal models. However, it is still unknown whether antioxidants and isoflavones have comparable inhibitory effects on the progression of advanced stages of atherosclerosis. This is an important question because clinical trials in humans have not supported a cardio-protective role for antioxidants or isoflavones. Thus, we examined the effects of antioxidants and genistein on the progression and composition of established, advanced atherosclerotic lesions in the innominate arteries (IA) of older apolipoprotein E-deficient (apoE(-/-)) mice. Thirty-week-old male apoE(-/-) mice were fed chow with or without genistein (0.27%, w/w) for 6, 12 and 24 weeks. Twenty-week-old male apoE(-/-) mice were fed chow with or without a cocktail of antioxidants (vitamin E 0.2%, w/w; vitamin C 0.05%, w/w; and beta carotene 0.5%, w/w) for 10, 16, and 22 weeks. There were no significant differences in total plasma cholesterol, body weight, average lesion or medial area, or changes in lesion composition with either treatment in comparison to control mice.