Fluvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase, scavenges free radicals and inhibits lipid peroxidation in rat liver microsomes

Use of Statins in Heart Failure with Preserved Ejection Fraction: Current Evidence and Perspectives

Systemic inflammation and coronary microvascular endothelial dysfunction are essential pathophysiological factors in heart failure (HF) with preserved ejection fraction (HFpEF) that support the use of statins. The pleiotropic properties of statins, such as anti-inflammatory, antihypertrophic, antifibrotic, and antioxidant effects, are generally accepted and may be beneficial in HF, especially in HFpEF. Numerous observational clinical trials have consistently shown a beneficial prognostic effect of statins in patients with HFpEF, while the results of two larger trials in patients with HFrEF have been controversial. Such differences may be related to a more pronounced impact of the pleiotropic properties of statins on the pathophysiology of HFpEF and pro-inflammatory comorbidities (arterial hypertension, diabetes mellitus, obesity, chronic kidney disease) that are more common in HFpEF. This review discusses the potential mechanisms of statin action that may be beneficial for patients with HFpEF, as well as clinical trials that have evaluated the statin effects on left ventricular diastolic function and clinical outcomes in patients with HFpEF.

Anti-Inflammatory Effects of Lipid-Lowering Drugs and Supplements-A Narrative Review

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Since the establishment of the "lipid hypothesis", according to which, cholesterol level is directly correlated to the risk of CVD, many different lipid-lowering agents have been introduced in clinical practice. A majority of these drugs, in addition to their lipid-lowering properties, may also exhibit some anti-inflammatory and immunomodulatory activities. This hypothesis was based on the observation that a decrease in lipid levels occurs along with a decrease in inflammation. Insufficient reduction in the inflammation during treatment with lipid-lowering drugs could be one of the explanations for treatment failure and recurrent CVD events. Thus, the aim of this narrative review was to evaluate the anti-inflammatory properties of currently available lipid-lowering medications including statins, ezetimibe, bile acid sequestrants (BAS), proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, fibrates, omega-3 fatty acids, and niacin, as well as dietary supplements and novel drugs used in modern times.

Anti-inflammatory Action of Statins in Cardiovascular Disease: the Role of Inflammasome and Toll-Like Receptor Pathways

Atherosclerosis is one type of cardiovascular disease (CVD) in which activation of the NLRP3 inflammasome and toll-like receptor (TLR) pathways is implicated. One of the most effective treatments for atherosclerosis is the use of statin medications. Recent studies have indicated that statins, in addition to their lipid-lowering effects, exert inhibitory and/or stimulatory effects on the NLRP3 inflammasome and TLRs. Some of the statins lead to activation of the inflammasome and subsequently cause secretion of IL-1β and IL-18. Thus, these actions may further aggravate the disease. On the other hand, some statins cause inhibition of the inflammasome or TLRs and along with lipid-lowering, help to improve the disease by reducing inflammation. In this article, we discuss these contradictory studies and the mechanisms of action of statins on the NLRP3 inflammasome and TLR pathways. The dose-dependent effects of statins on the NLRP3 complex are related to their chemistry, pharmacokinetic properties, and danger signals. Lipophilic statins have more pleiotropic effects on the NLRP3 complex in comparison to hydrophilic statins. Statins can suppress TLR4/MyD88/NF-ĸB signaling and cause an immune response shift to an anti-inflammatory response. Furthermore, statins inhibit the NF-ĸB pathway by decreasing the expression of TLRs 2 and 4. Statins are cost-effective drugs, which should have a continued future in the treatment of atherosclerosis due to both their immune-modulating and lipid-lowering effects.

Effect of statin treatment on circulating malondialdehyde concentrations: a systematic review and meta-analysis

Background

The effect of statins on oxidative stress markers, such as malondialdehyde (MDA), is still a matter of debate. We sought to address this issue by conducting a systematic review and meta-analysis of published data on the effect of statin treatment on systemic MDA concentrations.

Methods

A literature search was conducted on MEDLINE/PubMed, ISI Web of Sciences and Scopus. Data were pooled using a random-effects model.

Results

A total of 35 studies assessing MDA concentrations before and after statin treatment in 1512 participants (mean age 53.6 years, 48.7% males) were identified. Extreme between-study heterogeneity was observed (I² = 96.0%, p < 0.001). Pooled standardized mean difference (SMD) showed a significant reduction in plasma MDA concentrations after treatment (SMD = -1.47 µmol/l, 95% confidence interval = -1.89 to -1.05 μmol/l; p < 0.001). Similarly, a subgroup analysis of 10 studies that also included a placebo group showed a significant reduction in plasma MDA concentrations with statins (-1.03 μmol/l, 95% confidence interval = -1.52 to -0.29 μmol/l; p = 0.036).

Conclusions

This systematic review and meta-analysis showed that statin treatment significantly reduces systemic MDA concentrations. However, the results should be interpreted with caution because of extreme between-study heterogeneity, which warrants further intervention studies.

Translating the effects of statins: from redox regulation to suppression of vascular wall inflammation

Vascular oxidative stress is a key feature of atherogenesis, and targeting vascular redox signalling is a rational therapeutic goal in vascular disease pathogenesis. 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors or statins are potent lipid-lowering drugs that improve cardiovascular outcomes. It is now widely accepted that cardiovascular disease prevention by statins is dependent not only on their lipid lowering effects, but also on their beneficial effects on vascular redox signalling. Cell culture and animal models have provided important findings on the effects of statins on vascular redox and nitric oxide bioavailability. Recent evidence from studies on human vessels has further enhanced our understanding of the "pleiotropic" effects of statins on vascular wall. Reversal of endothelial dysfunction in human vessels by statins is dependent on the mevalonate pathway and Rac1 inhibition. These critical steps are responsible for reducing NADPH-oxidase activity and improving tetrahydrobiopterin bioavailability and nitric oxide synthase (NOS) coupling in human vessels. However, mevalonate pathway inhibition has been also held responsible for some of the side effects observed after statin treatment. In this review we summarise the existing knowledge on the effects of statins on vascular biology by discussing key findings from basic science as well as recent evidence from translational studies in humans. Finally, we discuss emerging aspects of statin pleiotropy, such as their effects on adipose tissue biology and adipokine synthesis that may light additional mechanistic links between statin treatment and improvement of clinical outcome in primary and secondary prevention.

Early Effects of Simvastatin versus Atorvastatin on Oxidative Stress and Proinflammatory Cytokines in Hyperlipidemic Subjects

The authors investigated the time-dependent action of atorvastatin and simvastatin on oxidative stress and cytokine levels immediately after the start of treatment. These factors play a role in endothelial dysfunction. Hyperlipidemic patients (n=132) were assigned to treatment with 40 mg atorvastatin, 40 mg simvastatin, or placebo. Blood samples were taken before, 2 hours, 24 hours, 7 days, and 3 weeks after the administration of the statin or placebo to evaluate serum concentrations of total peroxides (TP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-a) and soluble intercellular vascular adhesion molecule 1 (sICAM 1). In the atorvastatin group the TP changes were significantly different at 2 hours and 24 hours (p=0.005), whereas in the simvastatin group there was a gradual, more or less linear decline in TP until 7 days (p=0.006) and then a plateau. Simvastatin exhibited a faster statistically significant decrease over time in IL-6 and sICAM 1 levels (at 7 days, p=0.014 and p=0.001, respectively). TNF-a demonstrated a faster linear trend in the simvastatin group, but the significant effect appeared late (p=0.006). Both simvastatin and atorvastatin exerted early beneficial effects on oxidative stress, proinflammatory cytokines, and endothelial activation in hyperlipidemic subjects. These effects became significant 2 hours following the initiation of therapy.

Pharmacological actions of statins: a critical appraisal in the management of cancer

Statins, among the most commonly prescribed drugs worldwide, are cholesterol-lowering agents used to manage and prevent cardiovascular and coronary heart diseases. Recently, a multifaceted action in different physiological and pathological conditions has been also proposed for statins, beyond anti-inflammation and neuroprotection. Statins have been shown to act through cholesterol-dependent and -independent mechanisms and are able to affect several tissue functions and modulate specific signal transduction pathways that could account for statin pleiotropic effects. Typically, statins are prescribed in middle-aged or elderly patients in a therapeutic regimen covering a long life span during which metabolic processes, aging, and concomitant novel diseases, including cancer, could occur. In this context, safety, toxicity, interaction with other drugs, and the state of health have to be taken into account in subjects treated with statins. Some evidence has shown a dichotomous effect of statins with either cancer-inhibiting or -promoting effects. To date, clinical trials failed to demonstrate a reduced cancer occurrence in statin users and no sufficient data are available to define the long-term effects of statin use over a period of 10 years. Moreover, results from clinical trials performed to evaluate the therapeutic efficacy of statins in cancer did not suggest statin use as chemotherapeutic or adjuvant agents. Here, we reviewed the pharmacology of the statins, providing a comprehensive update of the current knowledge of their effects on tissues, biological processes, and pathological conditions, and we dissected the disappointing evidence on the possible future use of statin-based drugs in cancer therapy.

Potential benefit of statin therapy for dyslipidemia with chronic kidney disease: Fluvastatin Renal Evaluation Trial (FRET)

BACKGROUND

Dyslipidemia is a common complication of chronic kidney disease (CKD) and contributes to cardiovascular morbidity and mortality of CKD patients.

AIM

The aim of the present study was to determine whether fluvastatin, which is mostly characterized by its pleiotropic anti-oxidant effects, has renoprotective effects in dyslipidemic patients with CKD.

METHODS

In 43 dyslipidemic patients with CKD taking fluvastatin 10 mg/day, 20 mg/day or 30 mg/day, renal functions as well as lipid profiles were assessed.

RESULTS

After 3 months of treatment with fluvastatin, LDL-cholesterol level significantly decreased. Serum creatinine level, estimated glomerular filtration rate (eGFR), urinary albumin excretion (UAE), urinary liver-type fatty acid binding protein (L-FABP) level and urinary 8-hydroxydeoxyguanosine (8-OHdG) level did not change in overall patients. However, in patients with microalbuminuria (baseline UAE ≥ 30 mg/g·creatinine; n = 23), the UAE significantly decreased [2.43 ± 0.67 to 1.98 ± 0.80 log(mg/g·creatinine), p = 0.01]. In patients with high L-FABP group (baseline L-FABP ≥ 11 µg/g·creatinine; n = 18), the urinary L-FABP level was significantly decreased (1.52 ± 0.45 to 1.26 ± 0.43 µg/g·creatinine, p < 0.01). In the limited 23 patients with microalbuminuria, the L-FABP level was significantly decreased [1.20 ± 0.62 to 1.03 ± 0.49 log(µg/g·creatinine), p = 0.042], although the LDL-cholesterol level (139 ± 28 to 129 ± 23 mg/dL, p = 0.08) only showed a tendency to decrease. The 8-OHdG level also was significantly decreased (13.6 ± 9.6 to 9.8 ± 3.8 ng/g·creatinine, p = 0.043). In the overall patients, changes in the values for UAE and urinary L-FABP were not correlated with the changes in LDL-levels.

CONCLUSION

Fluvastatin reduces both UAE and the urinary L-FABP level, and thus, has renoprotective effects, independent of its lipid lowering effects in dyslipidemic patients with CKD.

The effect of lovastatin on oxidative stress and antioxidant enzymes in hydrogen peroxide intoxicated rat

Oxidative stress has been linked to the development of many diseases and hastens the progression of cardiovascular diseases. Since lovastatin is used worldwide as a cholesterol lowering drug, the present study was undertaken to evaluate the antioxidant property of lovastatin against H(2)O(2) induced oxidative stress in rats. Four study groups of rats of four animals each were treated with DMSO (control), H(2)O(2) (OS), lovastatin (L) and H(2)O(2) + lovastatin (OSL). On the 15th day the animals were sacrificed, and the liver and heart tissues were analyzed for oxidative stress biomarkers and anti-oxidant enzymes. Results of the OSL-group showed a reduction in thiobarbituric acid reactive substances in liver (42.7%) and heart tissue (8%) compared with the control group. An increase was observed in the activity of the antioxidant enzymes, catalase (34.6% in liver and 33.3% in heart) and glutathione peroxidase (50.5% in liver and 34.7% in heart). A commensurate increase in the activity of G6PDH was observed indicating an enhanced requirement of NADPH. The ratio GSH:GSSG in liver (1.05) and heart (0.84) was satisfactorily regulated compared to the control group (1.01 in liver and 0.93 in heart). These results suggest that lovastatin possesses antioxidant activity and reduces oxidative stress.

Effect of long term, non cholesterol lowering dose of fluvastatin treatment on oxidative stress in brain and peripheral tissues of streptozotocin-diabetic rats

One of the main goals of treatment of diabetes mellitus is to prevent its complications. Oxidative stress is universal in diabetes, being ultimately involved with the development complications. As a result of hyperglycemia, reactive oxygen/nitrogen species are produced in various tissues that leads to tissue damage with lipid peroxidation and protein oxidation, along with disruption in cellular homeostasis and accumulation of damaged molecules. Hence, supplementation with antioxidant compounds may offer some protection against diabetic complications. The pleiotropic effects of statins, including antioxidant and anti-inflammatory properties, represent an area of great interest in prevention and therapy of cardiovascular and neurological disorders. Using biomarkers of oxidative stress, in this study we examined the effect of non cholesterol lowering dose, long term fluvastatin treatment on oxidative stress in streptozotocin-diabetic rats. Experiments were conducted in 24 Wistar adult male rats. Diabetic and non-diabetic rats were treated orally for 6 months with fluvastatin (2mg/kg/day, p.o) starting one week after streptozotocin injection (55 mg/kg, i.p.), (preventive study). In brain, heart, liver, pancreas and kidney homogenates malondialdehyde, lipid hydroperoxide, protein carbonyl content, advanced oxidation protein products, 3-nitrotyrosine levels and superoxide dismutase, catalase activities were measured. Hyperglycemia and dyslipidemia in diabetic groups remained unchanged after fluvastatin treatment. The drug act as antioxidant in the tissues. Hence, antioxidant property of fluvastatin, independent of cholesterol lowering effect, may play a role in prevention of diabetic complications. Clinical relevance of this effect of fluvastatin seems worthy of further studies.

Preparation of a highly specific polyclonal antibody against and its use in development of ELISA for determination of in plasma

For therapeutic monitoring and pharmacokinetic studies of the potent hypocholesterolaemic agent fluvastatin (FLV), a specific antibody was required for the development of a sensitive enzyme-linked immunosorbent assay (ELISA) for the accurate determination of FLV in plasma. In this study, a highly specific polyclonal antibody against FLV has been prepared. FLV was coupled to keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) using carbodiimide reagent. FLV-KLH conjugate was used as an immunogen. Female 8-weeks old New Zealand white rabbits were immunized with an emulsion of FLV-KLH with Freund's adjuvant. The immune response of the rabbits was monitored by direct ELISA using FLV-BSA immobilized onto microwell plates as a solid phase. The rabbit that showed the highest antibody titer and affinity to FLV was scarified and its sera were collected. The IgG fraction was isolated and purified by affinity chromatography on a protein A column. The specificity of the purified antibody for FLV was evaluated by indirect competitive ELISA using various competitors from the FLV-structural analogues and therapeutic agents used with FLV in a combination therapy. The high affinity of the antibody (IC50 = 150 pg ml-1) enabled the determination of FLV in plasma at concentrations as low as 20 pg ml-1.

Chronic treatment with pravastatin prevents early cardiovascular changes in spontaneously hypertensive rats

BACKGROUND AND PURPOSE

This study investigates the effect of pravastatin on blood pressure, cardiovascular remodelling and impaired endothelial function induced as early signs of cardiovascular disease in young spontaneously hypertensive rats (SHR).

EXPERIMENTAL APPROACH

Eight-week-old SHR were treated for 4 weeks with pravastatin (20 mg kg(-1) day(-1)). Systolic blood pressure was measured periodically during the study using the tail-cuff method. At the end of the study, the left ventricular weight /body weight ratio was used as an index of left ventricular hypertrophy (LVH). Vascular function, superoxide (O(2)(-*)) production and structure were studied in aortic rings. Lipid peroxidation was measured in plasma (thiobarbituric acid reactive substances assay).

KEY RESULTS

Systolic blood pressure was lower in treated SHR than in control SHR, at the end of the study (171 +/- 1 vs. 159 +/- 2 mmHg, P < 0.05), and LVH was significantly reduced by pravastatin (2.7 +/- 0.02 vs. 2.5 +/- 0.01 mg g(-1), P < 0.05). Vascular responses to sodium nitroprusside and phenylephrine were similar in both groups; nevertheless, the relaxation response to acetylcholine was higher in the treated rats (45.6 +/- 2.6 vs. 58.1 +/- 3.2 %, P < 0.05). Vascular O(2)(-*) and plasma thiobarbituric acid reactive substances were reduced by pravastatin treatment, and urinary nitrites was elevated. Finally aortic wall became thinner after pravastatin treatment.

CONCLUSIONS AND IMPLICATIONS

Chronic treatment with pravastatin attenuated the increase of systolic blood pressure in SHR, prevented early LVH and improved vascular structure and function. These effects were accompanied by decreased measures of oxidative stress and improvements in NO production.

Treatment options for nonalcoholic Fatty liver disease

Nonalcoholic fatty liver disease comprises a range of disorders from steatosis and steatohepatitis through to cirrhosis. Nonalcoholic steatohepatitis can progress to cirrhosis and liver-related death. Therefore, managing this common disorder is becoming an important public health issue. Lifestyle measures are commonly suggested but robust data are lacking. Trials with antioxidants (vitamin E, betaine) as well as cytoprotectants (ursodeoxycholic acid) have been disappointing. While data for insulin sensitizers such as metformin are less conclusive, thiazolidinediones appear promising. However, not all patients respond to thiazolidinediones. Moreover, issues related to weight gain, cardiovascular risk need to be addressed. The use of endocannabinoid antagonists and insulin secretagogues are novel strategies to combat this disorder.

Mitochondrial electron transport inhibition in full genomic hepatitis C virus replicon cells is restored by reducing viral replication

BACKGROUND/AIM

Hepatitis C virus (HCV) core protein has been shown to inhibit mitochondrial electron transport and to increase reactive oxygen species (ROS) in vitro and in vivo. The aim of this study was to investigate whether inhibiting HCV replication could restore the mitochondrial redox state and electron transport activity.

METHODS

We measured ROS, mitochondrial reduced glutathione content, and mitochondrial complex I, II, III and IV activities and protein expression in full genomic HCV replicon cells and cured cells that had been prepared by eliminating HCV RNA from replicon cells by interferon (IFN)-alpha treatment.

RESULTS

Cured cells had significantly lower ROS production and greater mitochondrial glutathione content than replicon cells. Complete inhibition of HCV replication by IFN-alpha restored complex I and IV activities by 20-30% (P<0.01) and complex I expression (P<0.05). Treatment with fluvastatin, one of the 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors, which is known to have anti-HCV activity, partially inhibited core protein expression and restored complex I activity in full genomic HCV replicon cells to a lesser degree (P<0.05).

CONCLUSIONS

Our results show that the mitochondrial redox state and electron transport activity can be restored by reducing HCV replication.

Statins and cancer: a meta-analysis of case-control studies

3-HMG-CoA reductase inhibitors (statins) block the growth of malignant cells in vitro. A meta-analysis of randomized controlled trials failed to show reduced risk of cancers in statin users. Case-control studies, however, have the advantage of examining remote exposures. This study determined the association between statins and breast cancer, colon cancer, lung cancer, prostate cancer, or any cancer in case-control studies. A comprehensive search for studies published through November 2006 was performed. Twenty case-control studies (100 129 incident cancer cases) were combined to obtain a pooled odds ratio using an inverse variance method. A funnel plot did not suggest a significant absence of unpublished data. The studies were significantly heterogeneous (P<0.01), thus a random effects model was used. The pooled OR and 95% confidence intervals for statin users and cancer were as follows: any cancer 0.71 (0.56-0.89), breast cancer 0.86 (0.60-1.23), colon cancer 0.89 (0.82-0.97), lung cancer 0.75 (0.50-1.11), and prostate cancer 0.74 (0.45-1.20). In this meta-analysis of case-control studies, we found a significant association between statin usage and any cancer, but when stratified by cancer type, only the association with colon cancer remained. On the basis of these results, randomized control trials with longer follow-up times than previously used are warranted.

Weight loss, dietary advice and statin therapy in non-alcoholic fatty liver disease: a retrospective study

BACKGROUND

Studies have shown that weight loss can have a favourable effect upon non-alcoholic fatty liver disease (NAFLD). However, the most effective means of achieving weight loss and safety profile of lipid-lowering drugs in the presence of NAFLD is unknown.

AIM

To investigate the effect of dietary advice and lipid-lowering drugs, particularly statins, on patients with NAFLD and dyslipidaemia.

DESIGN

Observational records based study.

METHODS

We studied 71 patients with NAFLD and dyslipidaemia diagnosed and treated between 1996 and 2002 at University Hospital Lewisham. Some were referred to a dietician for weight loss advice as part of their management. After treatment all patients were assessed for changes in weight, serum alanine transaminase (ALT) and serum lipids including serum cholesterol, serum high density lipoprotein (HDL) and serum triglycerides.

RESULTS

Thirty-seven male and 34 female patients with NAFLD and dyslipidaemia were followed up for a mean period of 440 +/- 374 days (median 335). Regression analysis revealed a significant association between changes in weight and changes in serum ALT (p < 0.039). Dietary advice failed to reduce body weight but significantly lowered the serum cholesterol to HDL ratio (p = 0.05). Only 15.4% of patients taking statins experienced a rise in serum ALT > or = 40 U/l, and in each case the rise was transient, returning near baseline or below without discontinuation of statin treatment.

CONCLUSIONS

Weight loss appears to improve NAFLD, and dietary advice and lipid-lowering drugs may be beneficial for patients with NAFLD and dyslipidaemia even if weight loss is not achieved. Statins appear to be safe and efficacious in this group.

Statin Therapy for Vascular Failure

There is increasing evidence that statins reduce cardiovascular events such as coronary artery disease or stroke in hypercholesterolemic patients in both primary and secondary prevention. The striking benefit achieved with statin treatments in patients with a wide range of cholesterol levels cannot be attributed to their cholesterol lowering effect alone. Substantial data has recently accumulated showing that statins exert various effects on multiple targets, namely pleiotropic effects, especially targeting the concept of 'vascular failure', including the improvement of vascular endothelial function, inhibition of vascular smooth muscle cell proliferation and migration, anti-inflammatory actions, anti-oxidative effects or stabilization of vulnerable plaques. These effects have potential in the treatments of coronary artery disease in various settings, such as prevention of its onset as well as its progression, or plaque rupture. Statin therapy should be more extensively applied even in normolipidemic patients if there are additional risk factors such as hypertension, diabetes mellitus, or others. Furthermore, statins may be used to intervene in earlier stage risk conditions such as postprandial hyperlipidemia or hyperglycemia, insulin resistant state, masked hypertension, or metabolic syndrome to further reduce mortality or morbidity of coronary artery disease and heart failure.

Statin Therapy for Secondary Stroke Prevention: Evidence Catches Up to Practice

Current approaches for the secondary prevention of ischemic stroke include the aggressive use of antithrombotic therapy, particularly antiplatelet agents, and carotid endarterectomy for eligible patients. Blood pressure lowering with angiotensin converting enzyme inhibitors and diuretics in hypertensives, glucose control to a hemoglobin A1C of less than 7% in diabetics, and statin therapy in patients with hyperlipidemia and/or cardiovascular disease are also important measures forsecondary prevention of stroke. Support for the routine use of statin therapy in all patients with ischemic stroke, regardless of lipid profile or a history of cardiovascular disease, has been, until recently, of debate. Clinical evidence found in studies such as the SPARCL trial and the Heart Protection Study now support the routine use of statin therapy in all ischemic stroke patients. This article focuses on the potential and proven benefits of statins in ischemic stroke.

Molecular basis of differences among statins and a comparison with antioxidant vitamins

Although all statin drugs lower levels of circulating low-density lipoprotein cholesterol by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A, molecular differences among statins affect their metabolism, solubility, and intramembrane localization, which in turn is likely to influence their efficacy and safety. In addition, these properties may have a differential impact on the pleiotropic effects of statins, including their ability to improve endothelial function and to affect proliferation and apoptosis in vascular tissues. Many pleiotropic effects of statins appear to be due to inhibition of small guanosine triphosphate-binding proteins and/or restoration of nitric oxide bioavailability, and atorvastatin metabolites may also directly protect vascular tissues from oxidative damage. The possibility of cardiovascular benefits from antioxidant effects of atorvastatin metabolites contrasts with the lack of benefits seen in most studies of antioxidant vitamins. This article reviews some of the differences in pleiotropic effects of statins and assesses the contribution of their solubility and membrane localization as the possible basis for these differences. In addition, the possibility that statin benefits on stroke reflect pleiotropic effects is reviewed. Finally, possible reasons for differences between the effects of atorvastatin metabolites and antioxidant vitamins are considered.

Effects of simvastatin on plasma antioxidant status and vitamins in hypercholesterolemic patients

BACKGROUND

Statins are known to possess antioxidant properties in addition to their cholesterol-lowering effects. However, recent studies have suggested that statins reduce the levels of antioxidant vitamins such as vitamin E and coenzyme Q(10), possibly resulting in impaired left ventricular function. We investigated the effects of simvastatin on the blood lipids, LDL oxidation and plasma antioxidant status, and whether these effects were associated with changes in plasma antioxidant vitamin levels.

METHODS

Simvastatin (20-40 mg/day) was administered for 8 weeks in seventy-six hypercholesterolemic patients. We measured plasma lipids, oxidized LDL, total radical trapping antioxidant potential (TRAP) and plasma antioxidant vitamin levels at baseline and after 8 weeks of simvastatin administration.

RESULTS

Simvastatin significantly lowered serum levels of total cholesterol and LDL-cholesterol by 30.1% and 41.9%, respectively. A significant reduction in oxidized LDL levels (p<0.0001) and improvement in plasma antioxidant status as measured by TRAP (p<0.05) after the 8-week simvastatin treatment were observed. Regarding the effects of simvastatin on plasma antioxidant vitamin levels, there were significant increases in the levels of lipid-corrected retinol (p<0.001), alpha-tocopherol (p<0.001) and gamma-tocopherol (p<0.005) after the 8-week simvastatin treatment. Lipid-corrected levels of coenzyme Q10 and carotenoids remained unchanged after simvastatin treatment.

CONCLUSIONS

Our results show that simvastatin reduced blood lipids and circulating oxidized LDL, and improved plasma antioxidant status without altering the antioxidant vitamin system. These data indicate that simvastatin not only decreases blood lipids and circulating oxidized LDL but also increases lipid corrected levels of antioxidant vitamins and may improve plasma antioxidant status synergizing with the biological effects of antioxidants.

Potential therapeutic role for statins in respiratory disease

Statins reduce cholesterol levels by inhibiting 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and have an established role in the treatment of atherosclerotic disease. Recent research has identified anti-inflammatory properties of statins. Statins appear to reduce the stability of lipid raft formation with subsequent effects on immune activation and regulation, and also prevent the prenylation of signalling molecules with subsequent downregulation of gene expression. Both these effects result in reduced cytokine, chemokine, and adhesion molecule expression, with effects on cell apoptosis or proliferation. This review considers the evidence for the anti-inflammatory properties of statins in the lung, and how these effects are being applied to research into the role of statins as a novel treatment of respiratory diseases.

A beneficial effect of simvastatin on DNA damage in 242T allele of the NADPH oxidase p22phox in hypercholesterolemic patients

BACKGROUND

The effect of simvastatin on DNA damage in hypercholesterolemic patients was investigated, and the relationship between the C242T polymorphism of the NADPH oxidase p22phox gene and the antioxidant effects of simvastatin was examined.

METHODS

Simvastatin (20-40 mg /day) was administered for 8 weeks in 72 hypercholesterolemic patients. DNA damage in lymphocytes was quantified using single-cell gel electrophoresis (COMET assay) by measuring tail DNA (%), tail length (microm) and tail moment (tail length x % tail DNA/100).

RESULTS

Simvastatin significantly reduced DNA damage as expressed by tail DNA (%, p< 0.001), tail length (mum, p<0.001) and tail moment on the DNA in lymphocytes (p<0.001) after 8 weeks. The frequencies of the C242T genotypes for CC, TC, and TT were 75.0%, 23.6% and 1.4% in the subjects. In the presence of the 242T allele, there were higher levels of baseline DNA damage and also a greater improvement in the DNA damage after 8 week simvastatin treatment compared with the CC homozygotes.

CONCLUSION

Simvastatin significantly reduced DNA damage of hypercholesterolemic patients. This study showed that simvastatin has a beneficial effect on the improvement of DNA damage in patients with the 242T allele of NADPH oxidase p22phox gene.

Intermolecular differences of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors contribute to distinct pharmacologic and pleiotropic actions

Statin drugs inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase and share the common mechanism of lowering circulating levels of low-density lipoprotein (LDL) cholesterol, a powerful indicator of risk for cardiovascular disease. Large clinical trials have documented the benefit of hypolipidemic therapy for both primary and secondary prevention of coronary artery disease and stroke. Recent clinical findings, including direct comparator studies, now indicate that certain statins may slow progression of disease at a rate and to an extent that cannot be solely attributed to LDL reduction. The proposed mechanisms for such pleiotropic actions include enhancement of endothelial-dependent nitric oxide bioavailability, anti-inflammatory activity, and inhibition of oxidative stress. To understand the biochemical basis for such differences among statins, this article reviews their physicochemical properties and pharmacology at the molecular level.

Induction of micronuclei in CHO cells by bleomycin but not by X-irradiation is decreased by treatment with HMG-CoA reductase inhibitors

We investigated the effect of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, pravastatin and fluvastatin, on the induction of micronuclei by ionizing radiation or bleomycin in Chinese hamster ovary cells in order to assess the radical-scavenging ability of these inhibitors. The results indicated that both pravastatin and fluvastatin had no effect on the induction of micronuclei by X-irradiation when they were applied for either pre-treatment or post-treatment. In contrast, both drugs effectively reduced the frequency of bleomycin-induced micronuclei when they were applied for simultaneous treatment or post-treatment, but not for pre-treatment. This indicates that the radical-scavenging ability of these two HMG-CoA reductase inhibitors differs according to the origins of the radicals--e.g., X-rays or bleomycin--even when the two drugs are compared at an equivalent cytotoxic dose. Our results suggest that both pravastatin and fluvastatin have the ability to scavenge certain types of radicals and to protect cells against oxidative stress.

Effects of Simvastatin on Oxidative Stress in Streptozotocin-Induced Diabetic Rats: A Role for Glomeruli Protection

AIMS

To study the effects of simvastatin on oxidative stress in rats with early stage diabetic nephropathy.

METHODS

60 male Sprague-Dawley rats were divided into three groups: control group (CN), streptozotocin (STZ)-induced diabetic rats group (DM) and STZ-induced diabetic rats group treated with simvastatin (DM+S). The following parameters were measured at weeks 6 and 12 in similar rats chosen randomly from each group: body and kidney weight, 24-hour urinary albumin excretion (UAE), biochemical indexes including blood glucose (GLU), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), serum creatinine (SCr), antioxidant enzymes including superoxide dismutase (SOD), glutathione S-transferase (GST), catalase (CAT) in plasma, lipid peroxidation production as malondialdehyde in plasma (MDAp) and erythrocytes (MDAe), morphology parameters such as glomerular volume (GV) and mesangial area/total glomerular area (M/T).

RESULTS

At weeks 6 and 12, GLU and kidney weight to body weight ratio were notably increased in both of the diabetic groups compared with those in the CN group without significant differences between the two diabetic groups. There were no significant differences of SCr, LDL, HDL and TG among all groups within all the experimental time. MDAp and MDAe were significantly increased in both of the diabetic groups, especially at week 12, while SOD, GST and CAT were significantly decreased compared with those in the CN group. At week 12, GV, M/T and UAE were also increased in the two diabetic groups. However, in the DM+S group, changes of lipid peroxidation production, antioxidant enzymes, UAE and GV were less pronounced than those in the DM group. Pearson's correlation analysis and regression analysis shown that MDAp was increased while SOD, GST and CAT in plasma were decreased with elevation of UAE, GV and M/T.

CONCLUSION

Increased lipid peroxidation and decreased antioxidant enzymes in plasma may play a role in the progression of diabetic nephropathy. Simvastatin may ameliorate these changes to protect kidney from oxidative lesion in diabetes even in the absence of lipid abnormalities.

Inhibitory effect of fluvastatin on ileal ulcer formation in rats induced by nonsteroidal antiinflammatory drug

AIM: Nonsteroidal anti-inflammatory drugs (NSAIDs) cause gastrointestinal damage as one of their side effects in humans and experimental animals. Lipid peroxidation plays an important role in NSAID-induced ulceration. The aim of this study was to investigate the inhibitory effect of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on the ulceration in small intestines of rats.

METHODS: The effects of three HMG-CoA reductase inhibitors, fluvastatin, pravastatin and atorvastatin on ileal ulcer formation in 5-bromo-2-(4-fluorophenyl)-3-(4- methylsulfonylphenyl) thiophene (BFMeT)-treated rats were examined. Antioxidative activity of the inhibitors was measured by a redox-linked colorimetric method.

RESULTS: Fluvastatin, which was reported to have antioxidative activity, repressed the ileal ulcer formation in rats treated with BFMeT an NSAIDs. However, the other HMG-CoA reductase inhibitors (pravastatin and atorvastatin) did not repress the ileal ulcer formation. Among these HMG-CoA reductase inhibitors, fluvastatin showed a significantly stronger reducing power than the others (pravastatin, atorvastatin).

CONCLUSION: Fluvastatin having the antioxidaitive activity suppresses ulcer formation in rats induced by NSAIDs.

Role of oxidative stress in age-associated chronic kidney pathologies

The kidneys exhibit age-associated deterioration in function via a loss of 20% to 25% kidney mass, particularly from the renal cortex and increased fibrosis. Oxidative stress has been found to mediate age-associated renal cell injury and cell death, particularly apoptosis. Oxidative stress results from an imbalance between the levels of free radicals generated during aerobic metabolism, inflammation, and infection and the safe breakdown of these species by endogenous and exogenous scavengers. Other factors may influence these pathologies. For example, growth hormone and caloric restriction have been shown to influence life span, although neither method of prolonging life is likely to find general acceptance in humans. Some genetic knockout models offer promise; for example, knockout of the p66 isoform of the Shc gene in mice increases life span by 30%, but appetite, size, and fertility are retained. Whether the increase in life span is via increased kidney health is not yet clear, but decreasing the age-related renal pathologies will no doubt aid in increasing life span and health in general. This review looks at the role and modulation of factors that influence life span, in particular modulation of oxidative stress, with particular relevance to age-related renal pathologies.

Long-term effects of statins on arterial pressure and stiffness of hypertensives

Although lowering blood pressure (BP) reduces aortic stiffness, achieving the recommended BP goal can be difficult. Recent studies have shown that short-term use of statins can reduce BP significantly. To determine the long-term effects of statins on BP and aortic stiffness, a single-blind randomized prospective study was performed on 85 hyperlipidaemic hypertensive patients whose BP was insufficiently controlled by antihypertensive therapy. Every 3 months, aortic stiffness was assessed by measuring pulse wave velocity (PWV). Patients were randomly allocated to groups treated with pravastatin, simvastatin, fluvastatin, or a nonstatin antihyperlipidaemic drug. No significant differences in patient characteristics, kinds of antihypertensive drugs, BP, ankle brachial index, PWV, or serum lipid, creatinine, or C-reactive protein levels were found between the four groups at the start of the study. During the 12-month treatment period, PWV did not change in the pravastatin group or nonstatin group, but it was transiently reduced in the simvastatin group and significantly decreased in the fluvastatin group, even though the doses of the statins used in this study were lower than the usually prescribed dose. All four antihyperlipidaemic drugs significantly decreased serum cholesterol levels without affecting BP, ankle brachial index, or serum triglyceride levels. The C-reactive protein serum levels decreased significantly in the three statin groups but not in the nonstatin group. These results suggest that long-term use of fluvastatin by hyperlipidaemic hypertensive patients is associated with a significant reduction in aortic stiffness without any effect on BP.

The antioxidant effects of statins

Oxidative stress contributes to the initiation and the development of atherosclerotic plaques and adversely influences myocardial integrity. Statins interfere with oxidation in several ways that may contribute to reducing the atherogenic process. In addition to direct antioxidant effects, statins reduce circulating oxidized low-density lipoproteins (oxLDL) and inhibit their uptake by macrophages. They also reduce circulating markers of oxidation such as F2-isoprostane and nitrotyrosine. Statins inhibit oxidant enzymes activity such as that of reduced nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase and myeloperoxidase and up-regulate the activity of antioxidant enzymes such as catalase and paraoxonase. They reduce endothelial dysfunction mainly by their ability to enhance endothelial nitric oxide bioavailability, which is achieved by several mechanisms. The antioxidant properties of statins extend to organ protection especially the myocardium and the lungs.

Amlodipine and atorvastatin in atherosclerosis: a review of the potential of combination therapy

Hypertension and hyperlipidaemia are major risk factors for the development of atherosclerosis. Calcium channel blockers (CCBs) have been used for decades and have established antihypertensive effects. Statins have been extensively used because of their potent lipid lowering properties. Amongst other factors, inflammation and oxidation are involved in enhanced progression of atherosclerosis and new lesion development. Therefore, research has been initiated focusing on the antioxidant and anti-inflammatory properties of CCBs and statins, beyond their primary effect, in order to evaluate the possible additive effects of combined treatment of CCBs with statins as antiatherosclerotic therapy. Clinical studies (e.g., the International Nifedipine Trial on Antiatherosclerotic Therapy [INTACT]) have demonstrated that the antiatherosclerotic action of CCBs is limited to the attenuation of the first stage of atherosclerogenesis (fatty streak formation or new lesion growth). The lesions that pre-existed at the start of CCB therapy did not demonstrate progression or regression on angiography. However, because the mechanisms of action of lipid-lowering drugs and CCBs, and their role in preventing the progression of atherosclerosis differ, it is conceivable to conclude that these two classes may have an additive or synergic effect, not only on new lesion formation but also on inhibiting the progression of established coronary atherosclerosis. Indeed, this combined effect of lipid-lowering therapy and CCBs on human coronary atherosclerosis has been reported in the Regression Growth Evaluation Statin Study (REGRESS) trial. This beneficial effect of combining CCBs with statins has now been replicated in transgenic atherosclerotic mice, where the combination of amlodipine and atorvastatin produced an additional 60% reduction of atherosclerosis compared with that observed with the statin alone. Serum markers of atherosclerosis and vascular integrity also improved most in the combination group. Synergistic effects of the combination of atorvastatin and amlodipine on acute nitric oxide release/endothelial function, and additive effects of the combination of amlodipine and atorvastatin in the improvement of arterial compliance in hypertensive hyperlipidaemic patients has been demonstrated. Collectively, these studies support the clinical antiatherosclerotic advantages of combination of CCBs and statins and in particular, of atorvastatin with amlodipine beyond their established antihyperlipidaemic and antihypertensive modes of action.

Effects of HMG-CoA reductase inhibitors on endothelial function: role of microdomains and oxidative stress

Certain pleiotropic activities reported for 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are related to reductions in cellular cholesterol biosynthesis and isoprenoid levels. In endothelial cells, these metabolic changes contribute to favorable effects on nitric oxide (NO) bioavailability. Given the essential role of NO in preserving vascular structure and function, this effect of statins is of considerable therapeutic importance. Statins have been demonstrated to restore endothelial NO production by several mechanisms, including upregulating endothelial NO synthase (eNOS) protein expression and blocking formation of reactive oxygen species. In this article, we will discuss additional ways in which statins restore endothelial NO production and improve endothelial function. (1) Statins modulate membrane microdomain formation, resulting in reduced expression of proteins that specifically inhibit eNOS activation. (2) Statins reduce sterol biosynthesis, thus interfering with the formation of pathologic microdomains, including cholesterol crystalline structures. This observation has important implications for plaque stabilization, as these microdomains contribute to cholesterol crystal formation and endothelial apoptosis. Finally, (3) statins improve endothelial function by interfering with oxidative stress pathways through both enzymatic and nonenzymatic mechanisms. The relationships between membrane microdomains, cholesterol biosynthesis, and endothelial function will be discussed.

Fluvastatin reduces atherogenic lipids without any effect on native endothelial function early after kidney transplantation

BACKGROUND

Cardiovascular risk is greatly increased in renal transplant recipients. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor (statin) therapy may reduce cardiovascular risk by improving both dyslipidemia and endothelial function. We therefore performed this study to assess the effect of fluvastatin on endothelial function in renal transplant recipients.

METHODS

This randomized, placebo-controlled, double-blind designed study investigated the effect of fluvastatin on endothelial function. Thirty-seven recipients received fluvastatin 40 mg/d and 35 received placebo during the first 12 wk following transplantation. All patients initially received cyclosporin A, prednisolone and azathioprine. At the end of treatment, endothelial function was assessed in the forearm skin microvasculature by laser Doppler flowmetry following acetylcholine stimulation. Samples were taken for measurements of serum lipids and vasoactive markers.

RESULTS

There were no differences in endothelial function between fluvastatin recipients and controls, AUCACh was 656 +/- 479 and 627 +/- 518 AU min, respectively (fluv vs. control, p > 0.65). In the placebo limb, total cholesterol and LDL cholesterol increased 22 +/- 12% and 22 +/- 18%, respectively in the first 12 wk following transplantation. The respective values were 18 +/- 13% (p = 0.010) and 34 +/- 19% (p = 0.0013) lower at 12 wk in the fluvastatin treated patients. Plasma ET-1, BigET-1 and urinary excretion of cGMP were not significantly different between treatment groups (p > 0.55).

CONCLUSION

Although fluvastatin 40 mg/d significantly lowers cholesterol it does not affect endothelial function the first 3 months after renal transplantation. The lack of effect on endothelial function is consistent with a lack of effect on vasoactive substances.

Simvastatin ameliorates injury in an experimental model of lung ischemia-reperfusion

OBJECTIVES

Statins are lipid-lowering drugs with anti-inflammatory and antioxidant properties. This study explores the potential of these commonly prescribed agents to ameliorate lung ischemia-reperfusion injury.

METHODS

Left lungs of Long-Evans rats were rendered ischemic for 90 minutes and reperfused for up to 4 hours. Treated animals received simvastatin orally (0.5 mg/kg) for 5 days before the experiment. Injury was quantitated in terms of tissue myeloperoxidase content, vascular permeability ((125)I bovine serum albumin extravasation), and bronchoalveolar lavage leukocyte and cytokine content. Changes in nuclear translocation of transcription factors were evaluated by electromobility shift assay. Additional animals received N(G)-nitro-L-arginine methyl ester before ischemia-reperfusion to assess whether inhibition of nitric oxide synthase could reverse simvastatin's protective effects. The presence of nicotinamide adenine dinucleotide phosphate oxidase was also evaluated using enzyme staining both histologically and in native electrophoresis.

RESULTS

Lung vascular permeability was reduced in treated animals by 71% compared with positive controls (P <.001). Administration of N(G)-nitro-L-arginine methyl ester reversed this protection. The protective effects of statin pretreatment correlated with a 68% reduction in tissue myeloperoxidase content (P <.01), marked reductions in bronchoalveolar lavage leukocyte accumulation, and decreased expression of proinflammatory cytokines. Nicotinamide adenine dinucleotide phosphate oxidase expression also decreased with statin treatment.

CONCLUSION

In addition to its antioxidant properties, the protective effects of simvastatin are likely mediated by modulation of endothelial nitric oxide synthase. The potential to pretreat recipients of lung transplantation with statins to ameliorate reperfusion injury is promising.

Antioxidative potential of fluvastatin via the inhibition of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity

We previously reported that fluvastatin, a potent 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, a strong lipid lowering drug, exerted an anti-atherosclerotic effect at doses insufficient to lower serum lipids in cholesterol fed rabbits. The evidence demonstrated that the superoxide anions from nicotinamide adenine dinucleotide phosphate (NADPH) oxidase plays a critical role in several steps in the development of atherosclerosis. This study was designed to determine the effects of HMG-CoA reductase inhibitors on the production of the superoxide anions of NADPH oxidase in isolated rat peritoneal neutrophils. Fluvastatin (1-10 microM) decreased phorbol 12-myristate 13-acetate (PMA, 10 nM)-dependent reactive oxygen species (ROS) generation in a concentration-dependent manner. It also (10 microM) decreased PMA-dependent O(2) consumption of the rat neutrophils. These effects were reversed by the addition of mevalonate, a metabolite in the HMG-CoA reductase pathway. Treatment with pravastatin did not show any significant changes. Fluvastatin (10 microM) decreased ROS, such as hydroxyl radicals and superoxide anions generated by the Fenton reaction, and by the xanthine-xanthine oxidase system. Rats were treated with either fluvastatin (5 mg/kg per day, p.o.) or pravastatin (5 mg/kg per day, p.o.) for 1 week. Treatment with fluvastatin decreased the PMA-dependent ROS generation. The fluvastatin induced effect on the PMA-dependent ROS generation was reversed by the combined administration with 40 mg/kg mevalonate per day. The antioxidative effect of fluvastatin was thought to have caused not only the scavenging action of the radicals but also to have inhibited ROS generation by inhibiting the NADPH oxidase activity. This antioxidative potential of fluvastatin via the inhibition of NADPH oxidase activity may be profitable in preventing atherosclerosis.

Antioxidants, statins, and atherosclerosis

Research into the oxidation of lipoproteins has yielded many new insights into the pathogenesis of atherosclerosis. However, despite lipoprotein oxidation's biologically plausible role in atherogenesis, several studies have reported inconsistent effects of antioxidants on clinical coronary end points, in sharp contrast with the studies of lipid modification with the 3-hydroxy-3-methylglutaryl coenzyme A inhibitors, or statins. There appears to be little support for the use of antioxidants in coronary prevention. However, the picture remains incomplete. What are the limitations of available antioxidant studies and the agents used? Until the picture can be clarified, lipid modification with strategies proved to reduce the risk for coronary events, such as statins or dietary changes in the style of the Mediterranean diet, should be better implemented in clinical practice.

Pathophysiological implications of insulin resistance on vascular endothelial function

BACKGROUND

Insulin resistance is a key component of the insulin resistance syndrome and is a crucially important metabolic abnormality in Type 2 diabetes. Insulin-resistant individuals are at significantly increased risk of cardiovascular disease, although the underlying mechanisms remain incompletely understood. The endothelium is thought to play a critical role in maintaining vascular homeostasis, a process dependent on the balance between the production of nitric oxide, superoxide and other vasoactive substances. Endothelial dysfunction has been demonstrated in insulin-resistant states in animals and humans and may represent an important early event in the development of atherosclerosis. Insulin resistance may be linked to endothelial dysfunction by a number of mechanisms, including disturbances of subcellular signalling pathways common to both insulin action and nitric oxide production. Other potential unifying links include the roles of oxidant stress, endothelin, the renin angiotensin system and the secretion of hormones and cytokines by adipose tissue. Lifestyle measures and drug therapies which improve insulin sensitivity and ameliorate endothelial dysfunction may be important in delaying the progression to overt cardiovascular disease in at risk individuals.

METHODS

We conducted a literature search using Medline, restricted to articles published in the English language between 1966 and the present, and reviewed bibliographies of relevant articles. An initial search strategy employing combinations of the MeSH terms: insulin resistance; endothelium, vascular; insulin; nitric oxide or hyperinsulinaemia produced over 300 references. Focused searches using keywords relevant to the molecular aspects of endothelial function and insulin signalling, and lifestyle or pharmacological interventions relevant to insulin resistance or endothelial function, produced over 300 further references. Abstracts of all references were screened before selecting those relevant to this review.

HMG-CoA reductase inhibitors regulate inflammatory transcription factors in human endothelial and vascular smooth muscle cells

OBJECTIVE

Pleiotropic atheroprotective effects of HMG-CoA reductase inhibitors may be mediated on the level of vascular gene transcription. The aim of this study was to characterize the effects of statins on the activation of transcription factors known to regulate inflammation and cell proliferation/differentiation.

METHODS AND RESULTS

Simvastatin, atorvastatin, and lovastatin (0.1 to 10 micro mol/L) inhibited the binding of nuclear proteins to both the nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1) DNA consensus oligonucleotides in human endothelial and vascular smooth muscle cells as assessed by electrophoretic mobility shift assay (EMSA). The inhibitory effects of statins on NF-kappaB or AP-1-dependent transcriptional activity were examined by transient transfection studies. HMG-CoA reductase inhibitors upregulated IkappaB-alpha protein levels in endothelial cells and decreased c-Jun mRNA expression in smooth muscle cells as analyzed by Western and Northern blotting, respectively. Furthermore, statins inhibited DNA binding of hypoxia-inducible factor-1alpha. Downstream effects of statins included inhibition of plasminogen activator inhibitor-1 and vascular endothelial growth factor-A mRNA levels in endothelial cells.

CONCLUSIONS

HMG-CoA reductase inhibitors downregulate the activation of transcription factors NF-kappaB, AP-1, and hypoxia-inducible factor-1alpha. These findings support the concept that statins have antiinflammatory and antiproliferative effects that are relevant in the treatment of atherosclerotic diseases.

Antioxidative effects of fluvastatin and its metabolites against DNA damage in streptozotocin-treated mice

Fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, and its metabolites have been reported to protect against oxidative DNA damage in vitro. Streptozotocin (STZ) has drawn attention as a potential source of oxidative stress that induces genotoxicity. In order to elucidate the antioxidative effects of fluvastatin in vivo, we investigated the effects of 7-day treatment with fluvastatin on DNA damage in STZ-treated mice, as well as the effects of the main fluvastatin metabolites (M2, M3 and M4) and other inhibitors of the same enzyme, pravastatin and simvastatin. Protective effects against DNA damage in the liver and kidney from STZ-treated mice were assessed by the single-cell gel electrophoresis assay, and by detecting 8-hydroxy-2'-deoxyguanosine. A single intraperitoneal injection of STZ (150 mg/kg) increased serum levels of glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and blood urea nitrogen (BUN), and also caused DNA damage in the liver and kidney. Fluvastatin and its metabolites prevented the STZ-induced elevation of DNA damage and inhibited the increase in serum levels of AST, ALT and BUN. Fluvastatin and its metabolites showed protective effects against DNA damage as potent as that of the reference antioxidants (ascorbic acid, trolox and probucol) though pravastatin and simvastatin still lacked protective activity. Fluvastatin protected the mice against STZ-induced DNA damage, and may reduce the risk of oxidative stress in vivo.

Valsartan therapy has additive anti-oxidative effect to that of fluvastatin therapy against low-density lipoprotein oxidation: studies in hypercholesterolemic and hypertensive patients

In hypercholesterolemic and hypertensive patients, an increased propensity of their low-density lipoprotein (LDL) to oxidative modification has been observed. Because oxidized LDL (ox-LDL) plays a major role in atherosclerosis, the current study analyzed the anti-oxidative effect of valsartan (an angiotensin II receptor antagonist) therapy in combination with fluvastatin therapy in these patients. Administration of 40 mg/d of fluvastatin for 2 months to seven patients resulted in significant reduction in plasma total and LDL cholesterol (by 24-28%). Valsartan administration (80 mg/d for an additional 2-month period) in combination with fluvastatin did not further affect plasma cholesterol levels. Fluvastatin therapy inhibited the susceptibility of LDL to copper ion-induced oxidation, as shown by prolongation of the lag time by 22% and by a reduction of thiobarbituric acid-reactive substances (TBARS) levels by 14%, as compared with the patient's LDL baseline oxidation. The addition of valsartan to fluvastatin resulted in a further 17% prolongation of the lag time and in an additional reduction of 21% in TBARS levels. In a parallel study, the LDL from eight patients who were first treated with 80 mg/d of valsartan for 2 months demonstrated reduced susceptibility to copper ion-induced oxidation, as observed by prolongation of lag time by 23% and reduction in TBARS levels by 19%, compared with the baseline values. The administration of 40 mg/d of fluvastatin for an additional 2 months in combination with valsartan, however, demonstrated no further inhibitory effect on LDL oxidation. The anti-oxidative properties of fluvastatin and valsartan against LDL oxidation were also demonstrated in vitro and the combination of both drugs was shown to have an additive effect. Valsartan therapy in hypercholesterolemic and hypertensive patients has an additive anti-oxidative effect to that of fluvastatin therapy. This may be related both to the anti-oxidative properties of valsartan and to the blocking of angiotensin II-induced oxidative stress.