New insights into the pharmacodynamic and pharmacokinetic properties of statins

Statins in the last six months of life: a recognizable, life-limiting condition does not decrease their use

BACKGROUND

Some have advocated discontinuing statins in patients with life-limiting conditions. However, the extent of statin use at the end of life has yet to be described and whether statin prescribing may already be influenced by the presence of a recognizable, life-limiting condition is unknown.

OBJECTIVE

To measure the prevalence of statin use during the last 6 months of life and determine if statin prescribing varies according to the presence of a recognizable, life-limiting condition.

DESIGN

Matched, case-control trial nested within a retrospective, cohort study.

SETTING/SUBJECTS

From 3031 VISN 11 patients who died in FY2004, we identified 1584 (52%) receiving statins at least 6 months before death. Of those, we identified 337 cases with a recognizable, life-limiting condition and 1247 controls matched on number of comorbidities, age, and socioeconomic status.

ANALYSES

We used survival analysis to test the relationship between days without statins and the presence of a life limiting condition, while controlling for pills supplied and comorbidity score.

RESULTS

There was no significant difference in the time off statins between cases and controls even though the study was sufficiently powered to detect one.

CONCLUSIONS

These findings underscore a missed opportunity to reduce the therapeutic burden upon dying patients and limit health care spending.

Pharmacologic management of isolated low high-density lipoprotein syndrome

High-density lipoprotein (HDL) cholesterol is a heterogeneous group of lipoproteins exhibiting a variety of properties like prostacyclin production stimulation, decrease in platelet aggregation, endothelial cell apoptosis inhibition, and low-density lipoprotein oxidation blockade. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and cardiovascular risk. Low HDL cholesterol is associated with increased risk for myocardial infarction, stroke, sudden death, peripheral artery disease, and postangioplasty restenosis. In contrast, high HDL levels are associated with longevity and protection against atherosclerotic disease development. Given the evolving epidemic of obesity, diabetes mellitus, and metabolic syndrome, the prevalence of low HDL will continue to rise. In the United States, low HDL is present in 35% of men, 15% of women, and approximately 63% of patients with coronary artery disease. Data extracted from the Framingham study highlight that 1-mg increase in HDL levels decreases by 2% to 3% the risk of cardiovascular disease. There is no doubt regarding clinical importance about isolated low HDL, but relatively few clinicians consider a direct therapeutic intervention of this dyslipidemia. In this sense, lifestyle measures should be the first-line strategy to manage low HDL levels. On the other hand, pharmacologic options include niacin, fibrates, and statins. Fibrates appear to reduce risk preferentially in patients with low HDL with metabolic syndrome, whereas statins reduce risk across all levels of HDL. Torcetrapib, a cholesteryl esters transfer protein inhibitor, represented a hope to raise this lipoprotein; however, all clinical trials on this drug had ceased after ILLUMINATE, RADIANCE and ERASE trials had recorded an increase in mortality, rates of myocardial infarction, angina, and heart failure. In the near future, drugs as beta-glucans, Apo-A1 mimetic peptides, and ACAT inhibitors, are the new promises to treat this condition.

Statins limit Rickettsia conorii infection in cells

Recent data suggest that statins may have a beneficial effect during sepsis. In this study, we tested the effect of lovastatin and pravastatin on the cellular culture of Rickettsia conorii using a quantitative plaque assay model associated with an original image analysis algorithm. Statins added at the time of infection did not modify plaque formation, whereas pre-incubation with statins for 48h resulted in a significant 30-68% plaque reduction, depending on the tested compounds and doses. These preliminary findings raise the hypothesis that statins may prevent or moderate rickettsial disease in exposed people.

Combination of simvastatin with berberine improves the lipid-lowering efficacy

We have identified berberine (BBR) as a novel cholesterol-lowering drug acting through stabilization of the low-density lipoprotein receptor (LDLR) messenger RNA. Because the mechanism differs from that of statins, it is of great interest to examine the lipid-lowering activity of BBR in combination with statins. Our results showed that combination of BBR with simvastatin (SIMVA) increased the LDLR gene expression to a level significantly higher than that in monotherapies. In the treatment of food-induced hyperlipidemic rats, combination of BBR (90 mg/[kg d], oral) with SIMVA (6 mg/[kg d], oral) reduced serum LDL cholesterol by 46.2%, which was more effective than that of the SIMVA (28.3%) or BBR (26.8%) monotherapy (P < .01 for both) and similar to that of SIMVA at 12 mg/(kg d) (43.4%). More effective reduction of serum triglyceride was also achieved with the combination as compared with either monotherapy. Combination of BBR with SIMVA up-regulated the LDLR messenger RNA in rat livers to a level about 1.6-fold higher than the monotherapies did. Significant reduction of liver fat storage and improved liver histology were found after the combination therapy. The therapeutic efficacy of the combination was then evaluated in 63 hypercholesterolemic patients. As compared with monotherapies, the combination showed an improved lipid-lowering effect with 31.8% reduction of serum LDL cholesterol (P < .05 vs BBR alone, P < .01 vs SIMVA alone). Similar efficacies were observed in the reduction of total cholesterol as well as triglyceride in the patients. Our results display the rationale, effectiveness, and safety of the combination therapy for hyperlipidemia using BBR and SIMVA. It could be a new regimen for hypercholesterolemia.

Improvement of endothelial dysfunction with simvastatin in patients with autosomal dominant polycystic kidney disease

Cardiovascular problems are a major cause of morbidity and mortality in patients with autosomal dominant polycystic kidney disease (ADPKD). Endothelial dysfunction (ED), which is an early manifestation of vascular injury, has been shown in patients with ADPKD. Statins have a beneficial effect in the reversal of ED. The aim of this study was to investigate the effects of a statin, simvastatin, on ED in patients with ADPKD. Sixteen patients with ADPKD having well-preserved renal function were included in the study. Endothelial function of the brachial artery was evaluated by using high-resolution vascular ultrasound. Endothelial-dependent dilatation (EDD) was expressed as the percentage change in the brachial artery diameter from baseline to reactive hyperemia. After the baseline evaluations of EDDs, patients were started treatment with simvastatin at a dose of 40 mg/day and were treated for six months. EDDs were recalculated after one and six months of therapy. Interleukin-6 (IL-6) and high-sensitivity C-reactive protein were also measured as markers of inflammation. Baseline EDD was 11.3 +/- 6.9% in patients with ADPKD. After one month of simvastatin treatment, EDD increased significantly to 14.6 +/- 4.6 % (P = 0.016 versus baseline). Endothelial-dependent dilatation further increased significantly to 18.9 +/- 7.5 % (P = 0.011 versus baseline, P = 0.048 versus first month) after six months of therapy. There was also a significant decrease in the level of IL-6 from 21.6 +/- 21.7 pg/mL to 9.1 +/- 3.5 pg/mL (P= 0.002). Six months of simvastatin therapy resulted in a significant improvement of ED in patients with ADPKD. This finding may be in part related to the pleiotropic effects of simvastatin.

Efficacy of alternate day dosing of atorvastatin

Atorvastatin is a synthetic inhibitor of 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor. It has a longer half life and longer duration of action than that of all other available HMG-CoA inhibitors. We evaluated the efficacy of alternate-day dosing of atorvastatin in comparison with the standard one-daily dose on total cholesterol, low and High-density lipoprotein (LDL and HDL) and triglycerides. This study is a randomized, blinded, and controlled clinical trial. Sixty-six patients with LDL cholesterol of more than 100 mg/dl were enrolled. Baseline fasting lipid profile (total cholesterol, LDL, HDL and triglyceride), liver function tests and creatine kinase were drawn. Patients were randomized to three atorvastatin dose groups. Group I received 10 mg of atorvastatin every day, group II received 20 mg of atorvastatin every day, and group III received 20 mg every other day. After 6 weeks of treatment with atorvastatin, fasting lipid profiles, liver function tests and creatine kinase concentrations were re-taken. Compliance to treatment was assessed at each visit. Of the sixty-six patients enrolled, sixty completed the study. All three regimens significantly reduced total cholesterol and LDL compared to baseline. No statistically significant difference existed between the three groups in regards to total or a percentage decrease in total cholesterol and LDL cholesterol at 6 weeks compared to baseline. All regimens were well tolerated and none of the patients showed significant elevation of liver enzyme or creatine kinase during the course of the study. In conclusions the alternate-day dosing of atorvastatin is an efficacious and safe alternate to daily dosing and yet inexpensive.

Physicochemical properties and oral bioavailability of amorphous atorvastatin hemi-calcium using spray-drying and SAS process

The objective of the study was to prepare amorphous atorvastatin hemi-calcium using spray-drying and supercritical antisolvent (SAS) process and evaluate its physicochemical properties and oral bioavailability. Atorvastatin hemi-calcium trihydrate was transformed to anhydrous amorphous form by spray-drying and SAS process. With the SAS process, the mean particle size and the specific surface area of amorphous atorvastatin were drastically changed to 68.7+/-15.8nm, 120.35+/-1.40m2/g and 95.7+/-12.2nm, 79.78+/-0.93m2/g from an acetone solution and a tetrahydrofuran solution, respectively and appeared to be associated with better performance in apparent solubility, dissolution and pharmacokinetic studies, compared with unprocessed crystalline atorvastatin. Oral AUC0-8h values in SD rats for crystalline and amorphous atorvastatin were as follow: 1121.4+/-212.0ngh/mL for crystalline atorvastatin, 3249.5+/-406.4ngh/mL and 3016.1+/-200.3ngh/mL for amorphous atorvastatin from an acetone solution and a tetrahydrofuran solution with SAS process, 2227.8+/-274.5 and 2099.9+/-339.2ngh/mL for amorphous atorvastatin from acetone and tetrahydrofuran with spray-drying. The AUCs of all amorphous atorvastatin significantly increased (P<0.05) compared with crystalline atorvastatin, suggesting that the enhanced bioavailability was attributed to amorphous nature and particle size reduction. In addition, the SAS process exhibits better bioavailability than spray-drying because of particle size reduction with narrow particle size distribution. It was concluded that physicochemical properties and bioavailability of crystalline atorvastatin could be improved by physical modification such as particle size reduction and generation of amorphous state using spray-drying and SAS process. Further, SAS process was a powerful methodology for improving the physicochemical properties and bioavailability of atorvastatin.

Cholesterol lowering and beyond: role of statins in Alzheimer’s disease

Alzheimer’s disease (AD), the most common form of dementia, is a major health problem with increasing prevalence associated with the increase in life span. Unfortunately, drugs currently used to treat this disorder have only modest therapeutic efficacy. Therefore, there is an urgent need to develop new pharmacological strategies to prevent or delay the onset of AD. As it has been suggested that there is a link between cholesterol and the development of AD, one such strategy could be the inhibition of cholesterol synthesis using HMG-CoA reductase inhibitors (statins). In addition to their cholesterol-lowering properties, statins exert multiple lipid-independent (pleiotropic) effects that may explain some of their beneficial actions. The aim of this article is to summarize the current knowledge on the effects of statins on AD and the mechanisms involved, based on data from in vitro, in vivo and clinical studies, and to provide an overview of the future perspectives in this field.

Biological consequences of statins in Candida species and possible implications for human health

The statins, simvastatin and atorvastatin are the most widely prescribed drugs. Statins lower cholesterol levels through their action on HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase, an essential enzyme for the biosynthesis of cholesterol. Fungal HMG-CoA reductases are also inhibited by statins, resulting in reduced levels of ergosterol (the fungal equivalent of cholesterol) and concomitant growth inhibition. This effect occurs in a range of fungal species and possibly affects fungal colonization of people on statin therapy. Furthermore, it may suggest that statins could have a role in new antifungal therapies. Possibly associated with the reduction in ergosterol levels, statins also inhibit respiratory growth. In the yeast, Candida glabrata, passage with statins dramatically increased the frequencies of petite mutants that were devoid of mitochondrial DNA, suggesting that statins caused a defect in the maintenance of mitochondrial DNA. These observations in C. glabrata may provide further insights into side effects of statins in humans undergoing treatment for hypercholesterolaemia. In addition, C. glabrata may be highly useful for the preliminary screening of agents to reduce statin side effects.

Does it matter whether or not a lipid-lowering agent inhibits Rho kinase?

Lipid-lowering agents, such as 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitors, also known as statins, have been shown to reduce cardiovascular events. However, evidence from recent clinical trials suggests that some of the beneficial effects of statins may be unrelated to changes in low-density lipoprotein cholesterol. In animal studies, many of the cholesterol-independent or "pleiotropic" effects of statins are mediated by inhibition of Rho kinase (ROCK). Indeed, ROCK has been implicated in the regulation of vascular tone, proliferation, inflammation, and oxidative stress. To what extent ROCK activity is inhibited in patients on lipid-lowering therapy, and in particular on statins, is not known, but it may have important clinical and therapeutic implications. This review attempts to make the case that, in addition to lipid lowering, inhibition of ROCK contributes to some of the benefits of statin therapy in patients with cardiovascular disease.

Systemic evaluation of gene expression changes in major target organs induced by atorvastatin

Statins have been reported to protect against end-organ damage in essential hypertension; however, detailed mechanisms underlying organ-protective actions of statins remain unclear. Statins can exert pleiotropic effects aside from lowering cholesterol and blood pressure levels through several different pathways, which may lead to distinct patterns of changes in gene expression in vital end-organs. The aim of the present study was to systemically evaluate gene expression changes in three major end-organs (the brain, heart and kidney) induced by atorvastatin at a dose that altered neither blood pressure nor plasma total cholesterol levels. The stroke-prone spontaneously hypertensive (SHRSP) rats, an established model of hypertension and end-organ damage, was treated with atorvastatin (15 mg/kg/day) for 4 weeks from 12 to 16 weeks of age. DNA microarray technology was used to identify gene expression changes in three end-organs. In the current experimental setting, 4 weeks of atorvastatin treatment lowered plasma levels of non-esterified fatty acid significantly (P=0.0012) and triglyceride modestly (P=0.07) without altering blood pressure and plasma total cholesterol levels in male SHRSP rats. The level of expression of a number of genes was changed in an organ-specific manner after 4 weeks of drug administration to SHRSP rats. Among the end-organs studied, the most prominent alteration in gene expression was observed in the heart. The identical treatment protocol was applied to age-matched normotensive control rats, Wistar Kyoto rats, and this also caused a number of genes to be differentially expressed in an organ-specific manner. These results provide new insights into the mechanisms underlying the potential efficacy of statins in protecting against end-organ damage in essential hypertension and thus lay the foundation for future studies.

Adverse balance of nitric oxide/peroxynitrite in the dysfunctional endothelium can be reversed by statins

Vascular endothelial dysfunction is a complex phenomenon that might be caused by a deficiency of nitric oxide (NO) and an overproduction of peroxynitrite (ONOO-). This study used a nanotechnological approach to monitor the in vitro effect of statins on the [NO]/[ONOO-] balance in normal and dysfunctional endothelial cells. NO and (ONOO-) were measured by electrochemical nanosensors in a single human umbilical vein endothelial cell (HUVEC) treated with atorvastatin or simvastatin for 24 hours in the presence or absence of 50 microg/mL oxidized-LDL. An imbalance between [NO]/[ONOO-] concentrations was used as an indicator of endothelial dysfunction and correlated with endothelial nitric oxide synthase (eNOS) expression. Ox-LDL induced dysfunction of the endothelium by uncoupling eNOS. NO concentration decreased from 300 +/- 12 to 146 +/- 8 nmol/L and (ONOO-) increased from 200 +/- 9 to 360 +/- 13 nmol/L. The [NO]/[ONOO-] balance decreased from 1.50 +/- 0.04 (control) to 0.40 +/- 0.03 for cells co-incubated with ox-LDL. Treatment with statins reversed eNOS uncoupling, induced by oxidized-LDL and significantly increased the [NO]/[ONOO-] balance to 1.2 +/- 0.1. These results demonstrate that statins can restore endothelial function by increasing eNOS expression, decreasing eNOS uncoupling, reducing the (ONOO-) level (nitroxidative stress), and shifting the [NO]/[ONOO-] balance towards NO.

Atorvastatin: pharmacological characteristics and lipid-lowering effects

By inhibiting 3-hydroxy-3-methylglutaryl coenzyme-A (HMG-CoA) reductase, the statins reduce hepatocyte cholesterol levels, which results in up-regulation of low-density lipoprotein (LDL) receptors and, consequently, increased clearance of LDL-cholesterol (LDL-C) from the plasma. Structural differences among the available statins partially account for differences in their capacity to inhibit HMG-CoA reductase and their lipid-lowering efficacy, and for variability in other biological properties, such as their pharmacokinetic characteristics and their tolerability and propensity to interact with other drugs. In terms of pharmacokinetic properties, the synthetic (type II) HMG-CoA analogue atorvastatin exhibits a number of characteristics that are different to those of other members of the class, including a longer plasma half-life and metabolites that have an ability to inhibit HMG-CoA reductase equivalent to that of the parent drug. These characteristics are postulated to be responsible for a more prolonged inhibition of HMG-CoA reductase, and, hence, for the greater efficacy of atorvastatin in decreasing total and LDL-C levels relative to other statins (with the exception of rosuvastatin) noted in clinical trials in patients with dyslipidaemias. From the available clinical trial data, atorvastatin can be considered one of the most effective statins, not only by taking into account its effects on LDL-C and ability to meet recommended treatment guidelines for this parameter, but also its effect on triglyceride levels and capacity to modify lipoprotein composition in a non-atherogenic manner. Clinical studies with atorvastatin have also shed some light on the question as to whether it is better to focus on obtaining maximal reduction of LDL-C in at-risk patients or on cardiovascular outcomes. Cardiovascular event rates have been shown to be substantially lower in patients attaining LDL-C levels between 1.0 and 1.6 mmol/L (40-60 mg/dL) or < or =1.0 mmol/L (< or =40 mg/dL) compared with higher levels (>2.1-2.6 mmol/L [>80-100 mg/dL]). This finding reinforces the update of the National Cholesterol Education Programme's clinical practice guidelines, which recommend LDL-C levels <2.6 mmol/L (100 mg/dL) to be the goal of antihyperlipidaemic drug therapy in high-risk patients with CHD, with an optional therapeutic target of <1.8 mmol/L (70 mg/dL) in patients at very high risk.

The effect of simvastatin on bone formation and ceramic resorption in a peri-implant defect model

Experimental use of statins as stimulators of bone formation suggests they may have widespread applicability in the field of orthopaedics. With their combined effects on osteoblasts and osteoclasts, statins have the potential to enhance resorption of synthetic materials and improve bone ingrowth. In this study, the effect of oral and local administration of simvastatin to a beta tricalcium phosphate (betaTCP)-filled defect around an implant was compared with recombinant human bone morphogenetic protein 2 (rhBMP2). On hundred and sixty-two Sprague-Dawley rats were assigned to treatment groups: local application of 0.1, 0.9 or 1.7 mg of simvastatin, oral simvastatin at 5, 10 or 50 mg kg(-1) day(-1) for 20 days, local delivery of 1 or 10 microg of rhBMP2, or control. At 6 weeks rhBMP2 increased serum tartrate-resistant acid phosphatase 5b levels and reduced betaTCP area fraction, particle size and number compared with control, suggesting increased osteoclast activity. There was reduced stiffness and increased mechanical strength with this treatment. Local simvastatin resulted in a decreased mineral apposition rate at 6 weeks and increased fibrous area fraction, betaTCP area fraction, particle size and number at 26 weeks. Oral simvastatin had no effect compared with control. Local application of rhBMP2 increased resorption and improved mechanical strength whereas simvastatin was detrimental to healing. Oral simvastatin was ineffective at promoting either ceramic resorption or bone formation. The effect of statins on the repair of bone defects with graft substitute materials is influenced by its bioavailability. Thus, further studies on the optimal delivery system are needed.

Statins decrease expression of the proinflammatory neuropeptides calcitonin gene-related peptide and substance P in sensory neurons

Clinical and experimental observations suggest that statins may be useful for treating diseases presenting with predominant neurogenic inflammation, but the mechanism(s) mediating this potential therapeutic effect are poorly understood. In this study, we tested the hypothesis that statins act directly on sensory neurons to decrease expression of proinflammatory neuropeptides that trigger neurogenic inflammation, specifically calcitonin gene-related peptide (CGRP) and substance P. Reverse transcriptase-polymerase chain reaction, radioimmunoassay, and immunocytochemistry were used to quantify CGRP and substance P expression in dorsal root ganglia (DRG) harvested from adult male rats and in primary cultures of sensory neurons derived from embryonic rat DRG. Systemic administration of statins at pharmacologically relevant doses significantly reduced CGRP and substance P levels in DRG in vivo. In cultured sensory neurons, statins blocked bone morphogenetic protein (BMP)-induced CGRP and substance P expression and decreased expression of these neuropeptides in sensory neurons pretreated with BMPs. These effects were concentration-dependent and occurred independent of effects on cell survival or axon growth. Statin inhibition of neuropeptide expression was reversed by supplementation with mevalonate and cholesterol, but not isoprenoid precursors. BMPs signal via Smad activation, and cholesterol depletion by statins inhibited Smad1 phosphorylation and nuclear translocation. These findings identify a novel action of statins involving down-regulation of proinflammatory neuropeptide expression in sensory ganglia via cholesterol depletion and decreased Smad1 activation and suggest that statins may be effective in attenuating neurogenic inflammation.

Effects of atorvastatin on bone in postmenopausal women with dyslipidemia: a double-blind, placebo-controlled, dose-ranging trial

CONTEXT

In preclinical models, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase have been shown to positively affect bone remodeling balance. Observational studies and secondary analyses from lipid-lowering trials have yielded inconsistent results regarding the effect of these agents on bone mineral density and fracture risk.

OBJECTIVE

Our objective was to determine whether clinically significant skeletal benefits result from hydroxymethylglutaryl-coenzyme A reductase inhibition in postmenopausal women.

DESIGN AND SETTING

We conducted a prospective, randomized, double-blind, placebo-controlled, dose-ranging comparative clinical trial at 62 sites in the United States.

PARTICIPANTS

Participants included 626 postmenopausal women with low-density lipoprotein cholesterol levels of at least 130 mg/dl (3.4 mmol/liter) and less than 190 mg/dl (4.9 mmol/liter), and lumbar (L1-L4) spine bone mineral density T-score between 0.0 and -2.5.

INTERVENTION

Once-daily placebo or 10, 20, 40, or 80 mg atorvastatin was administered.

MAIN OUTCOME MEASURES

We assessed percent change from baseline in lumbar (L1-L4) spine bone mineral density with each dose of atorvastatin compared with placebo.

RESULTS

At 52 wk, there was no significant difference between each atorvastatin and placebo group or change from baseline at any tested dose of atorvastatin or placebo in lumbar (L1-L4) spine bone mineral density. Nor did atorvastatin produce a significant change in bone mineral density at any other site. Changes in biochemical markers of bone turnover did not differ significantly between each atorvastatin and placebo group. All doses of atorvastatin were generally well tolerated, with similar incidences of adverse events across all dose groups and placebo.

CONCLUSIONS

Clinically relevant doses of atorvastatin that lower lipid levels had no effect on bone mineral density or biochemical indices of bone metabolism in this study, suggesting that such oral agents are not useful in the prevention or treatment of osteoporosis.

Statin treatment and 3' polyadenylation of eNOS mRNA

OBJECTIVE

Statins have been shown to increase endothelial nitric oxide synthase expression via enhanced mRNA stability. Because the poly(A) tail is an important determinant of transcript stability, we sought to characterize the effect of statins on eNOS mRNA 3' polyadenylation.

METHODS AND RESULTS

Endothelial cells treated with statins had a time- and dose-dependent increase in eNOS transcripts with long poly(A) tails (75 to 160 adenosines). This effect was dependent on 3-hydroxy-3-methylglutaryl (HMG)-coenxyme A (CoA) reductase inhibition and was observed with both lipophilic (simvastatin) and hydrophilic (rosuvastatin) statins. In mRNA stability assays, polyadenylated eNOS transcripts from statin-treated cells were 2- to 3-fold more stable than transcripts from untreated cells. The effect of statins on eNOS polyadenylation was related to cytoskeleton organization; there was increased eNOS mRNA polyadenylation after Rho inhibition and cytochalasin D treatment. Further, we found increased phosphorylation of RNA polymerase II in statin-treated cells, suggesting that statin-induced polyadenylation involved modulation of RNA polymerase II activity.

CONCLUSIONS

Our data provide insight into a mechanism by which statins enhance eNOS mRNA stability and increase eNOS protein: statins increase eNOS mRNA polyadenylation through Rho-mediated changes in the actin cytoskeleton.

Statin therapy, alone or with rapamycin, does not reverse monocrotaline pulmonary arterial hypertension: the rapamcyin-atorvastatin-simvastatin study

Pulmonary arterial hypertension (PAH) is characterized by excessive pulmonary artery smooth muscle cell proliferation and impaired apoptosis leading to obstruction of resistance pulmonary arteries. We hypothesized that antiproliferative (rapamycin) and proapoptotic (statins) agents, already used clinically for other indications, would decrease experimental PAH, facilitating translation to human therapies. Prior studies in the rat monocrotaline-PAH model have indicated that simvastatin regresses and rapamycin prevents, but cannot reverse, PAH. Two PAH regression strategies (rapamycin monotherapy vs. rapamycin + atorvastatin) and one prevention strategy (simvastatin) were tested in a rat monocrotaline-PAH model. Adult male Sprague-Dawley rats were randomized to saline ( n = 6) or monocrotaline (60 mg/kg ip, n = 36) treatment groups. Monocrotaline rats were randomized to gavage with vehicle, rapamycin (2.5 mg·kg−1·day−1), or rapamycin + atorvastatin (10 mg·kg−1·day−1) treatment groups, beginning 12 days post-monocrotaline. Echocardiographic and hemodynamic end points were assessed 2 wk later. Additional monocrotaline-PAH rats ( n = 20) were randomized to vehicle or simvastatin (2 mg·kg−1·day−1) treatment groups and followed echocardiographically for 4 wk. Monocrotaline-PAH increased lung p70 S6 kinase phosphorylation, and this was reversed by rapamycin, confirming the biological activity of rapamycin. Despite the use of high doses, neither rapamcyin nor rapamycin + atorvastatin improved survival nor reduced PAH, vascular remodeling, and right ventricular hypertrophy. Although prophylactic simvastatin slowed PAH progression, by 4 wk PAH severity and mortality were not different from placebo. Apart from the new finding of p70 S6 kinase phosphorylation in monocrotaline-PAH, this is a negative therapeutic trial (none of these promising therapies improved monocrotaline-PAH). These negative results should be considered as human trials with these agents are underway (simvastatin) or proposed (rapamycin).

Rational approach to the treatment for heterozygous familial hypercholesterolemia in childhood and adolescence: a review

Atherosclerosis represents a disease that begins in childhood and in which LDL cholesterol plays a pivotal role for the development of the pathology. Children and adolescents with high cholesterol levels are more likely than their peers to present cholesterol elevation as adults. The identification of genetic dyslipidemias associated with premature cardiovascular disease is crucial during childhood to delay or prevent the atherosclerotic process. Guidelines for the diagnosis and treatment of hypercholesterolemia during pediatric age are available from the National Cholesterol Education Program. A heart-healthy diet should begin at the age of 2 yr and a large number of studies have demonstrated no adverse effects on nutritional status, growth, pubertal development, and psychological aspects in children and adolescents limiting total and saturated fat intake. Pharmacotherapy should be considered in children over 10 yr of age when LDL cholesterol concentrations remain very high despite severe dietary therapy, especially when multiple risk factors are present. The only lipid-lowering drugs recommended up to now for childhood and adolescence are resins reported to be effective and well tolerated, although compliance is very poor because of unpalatability. The use of statins is increasing and seems to be effective and safe in children, even if studies enrolled a small number of patients and evaluated efficacy and safety for short-term periods. Recently, an interesting drug represented by ezetimibe has been found that may provide cholesterol-lowering additive to that reached with statin treatment. This review provides an update on recent advances in the diagnosis, therapy, and follow-up of familial hypercholesterolemia during pediatric age and adolescence.

First clinical experience with simvastatin to overcome drug resistance in refractory multiple myeloma

In vitro statins overcome cell adhesion-mediated drug resistance at non-toxic concentrations that are achievable in humans by standard dose simvastatin. A pilot phase-II trial was initiated to determine feasibility and antimyeloma efficacy. In six myeloma patients refractory to two cycles of bortezomib or bendamustine simvastatin was concomitantly administered during further two cycles. The therapy was well tolerated without grade 3/4 toxicity. Intrapatient (cycles I/II vs. III/IV) and interpatient comparison (vs. ten patients without simvastatin) showed reduction of drug resistance by inhibition of HMG-CoA-reductase. In summary, this is the first phase II experience to study antimyeloma activity of statins in humans.

Effect of HMG-CoA reductase inhibitors on beta-amyloid peptide levels: implications for Alzheimer's disease

To date, a number of hypotheses of the cause of Alzheimer's disease, the most common form of dementia, have been postulated. The beta-amyloid peptide (Abeta) is the major constituent of senile plaques, which together with atrophy and neurofibrillary tangles, is the main neuropathological finding in Alzheimer's disease. It is a widely accepted theory that aggregation of Abeta into plaques is an initial event in the pathogenesis of Alzheimer's disease, driving neurodegeneration. The cholesterol hypothesis, primarily based on in vitro and animal studies, states that increased levels of cholesterol promote the production of Abeta. Furthermore, treating animals with HMG-CoA reductase inhibitors ('statins'; cholesterol-lowering agents), or adding these agents to cell culture, results in decreased production of Abeta. This 'positive' effect of statin treatment has further been verified by some, but not all, longitudinal studies where a reduced prevalence of Alzheimer's disease is seen among patients taking statins. These findings have together been interpreted to indicate that statins act via a cholesterol-dependent mechanism, reducing the production of Abeta and, hence, the risk of developing Alzheimer's disease. This review focuses on the cholesterol hypothesis of Alzheimer's disease and investigations into its validity in the clinical setting, i.e. the outcome of clinical trials where the effect of statin treatment on Abeta production has been studied. To date, the cholesterol hypothesis has not been shown to be valid in clinical trials. We hypothesise that the vascular contributions in Alzheimer's disease may be one possible mechanism for statins to interfere with the disease process and reduce the prevalence of Alzheimer's disease. We also suggest that statins may act through the inflammatory pathway. Both of these mechanistic suggestions are good candidates, supported by the literature, for the underlying mechanistic link between statin treatment and a reduced prevalence for Alzheimer's disease.

Statins and fracture risk. A systematic review

PURPOSE

To summarize current evidence on statin use and fracture risk and to explore potential sources of heterogeneity among study results.

METHODS

A computerized search was conducted on MEDLINE, EMBASE, and the Cochrane databases using the keywords HMG-CoA reductase inhibitor, osteoporosis, and fractures. A meta-analysis was performed to summarize results of studies identified.

RESULTS

Statin use was associated with a 23% lower fracture risk (OR = 0.77, 95%CI: 0.66-0.90). An effect of statins was found in case-control (OR = 0.62, 0.45-0.85, n = 6) and cohort (OR = 0.77, 0.59-1.00, n = 8) studies, but not in post hoc analyses of randomized trials (OR = 1.03, 0.91-1.16, n = 4). A reduced risk with statin use was found for fractures of the hip (OR = 0.58, 0.46-0.74, n = 16), spine (OR = 0.65, 0.48-0.88, n = 8) and other sites (OR = 0.77, 0.60-1.00, n = 7), and both in women (OR = 0.80, 0.66-0.96, n = 11) and men (OR = 0.62, 0.36-1.08, n = 3). Among the observational studies that also evaluated the effect of other lipid-lowering drugs, no reduced fracture risk was found for these agents (OR = 0.96, 0.85-1.09, n = 10). The test for heterogeneity was significant for study results of statin use versus no-use (p < 0.01). Meta-regression analyses suggested that study design might partly account for the heterogeneity. There was an indication of publication bias by examining Begg's plot, although Egger's test was not significant (p = 0.13).

CONCLUSIONS

Current evidence does not support an effect of statins in preventing fractures given (i) the lack of association in randomized trials, (ii) the heterogeneity among observational studies, (iii) the potential residual confounding, and (iv) the potential publication bias.

Effect of statin withdrawal on frequency of cardiac events after vascular surgery

The discontinuation of statin therapy in patients with acute coronary syndromes has been associated with an increase of adverse coronary events. Patients who undergo major surgery frequently are not able to take oral medication shortly after surgery. Because there is no intravenous formula for statins, the interruption of statins in the postoperative period is a serious concern. The objective of this study was to assess the effect of perioperative statin withdrawal on postoperative cardiac outcome. Also, the association between outcome and type of statin was studied. In 298 consecutive statin users who underwent major vascular surgery, detailed cardiac histories were obtained, and medication use was noted. Postoperatively, troponin levels were measured on days 1, 3, 7, and 30 and whenever clinically indicated by electrocardiographic changes. End points were postoperative troponin release, myocardial infarction, and a combination of nonfatal myocardial infarction and cardiovascular death. Multivariate analyses and propensity score analyses were performed to assess the influence of type of statin and the discontinuation of statins for these end points. Statin discontinuation was associated with an increased risk for postoperative troponin release (hazard ratio 4.6, 95% confidence interval 2.2 to 9.6) and the combination of myocardial infarction and cardiovascular death (hazard ratio 7.5, 95% confidence interval 2.8 to 20.1). Extended-release fluvastatin was associated with fewer perioperative cardiac events compared with atorvastatin, simvastatin, and pravastatin. In conclusion, the present study showed that statin withdrawal in the perioperative period is associated with an increased risk for perioperative adverse cardiac events. Furthermore, there seemed to be better outcomes in patients who received statins with extended-release formulas.

Inhibition of HMGcoA reductase by atorvastatin prevents and reverses MYC-induced lymphomagenesis

Statins are a class of drugs that inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMGcoA) reductase, a critical enzyme in the mevalonate pathway. Several reports document that statins may prevent different human cancers. However, whether or not statins can prevent cancer is controversial due to discordant results. One possible explanation for these conflicting conclusions is that only some tumors or specific statins may be effective. Here, we demonstrate in an in vivo transgenic model in which atorvastatin reverses and prevents the onset of MYC-induced lymphomagenesis, but fails to reverse or prevent tumorigenesis in the presence of constitutively activated K-Ras (G12D). Using phosphoprotein fluorescence-activated cell sorter (FACS) analysis, atorvastatin treatment was found to result in the inactivation of the Ras and ERK1/2 signaling pathways associated with the dephosphorylation and inactivation of MYC. Correspondingly, tumors with a constitutively activated K-Ras (G12D) did not exhibit dephosphorylation of ERK1/2 and MYC. Atorvastatin's effects on MYC were specific to the inhibition of HMGcoA reductase, as treatment with mevalonate, the product of HMG-CoA reductase activity, abrogated these effects and inhibited the ability of atorvastatin to reverse or suppress tumorigenesis. Also, RNAi directed at HMGcoA reductase was sufficient to abrogate the neoplastic properties of MYC-induced tumors. Thus, atorvastatin, by inhibiting HMGcoA reductase, induces changes in phosphoprotein signaling that in turn prevent MYC-induced lymphomagenesis.

The unique character of cardiovascular disease in chronic kidney disease and its implications for treatment with lipid-lowering drugs

Although the risk for cardiovascular disease (CVD) is high in individuals with chronic kidney disease (CKD), there are very limited data to guide the use of lipid-lowering drugs (LLDs) in this population because the major trials of LLDs in the general population have included very few individuals with CKD. The pathophysiologic and epidemiologic differences of CVD in the CKD population suggest that the study findings derived in the general population may not be directly applicable to those with CKD, and the few trials that have been directed at patients with kidney disease have not shown clear clinical benefits of LLDs. The National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) Work Group has provided consensus-based guidelines for managing dyslipidemias in individuals with CKD and after renal transplantation. Since the publication of these statements, further data have emerged and multiple studies are ongoing to define better the role of LLDs in patients with CKD. In this article, the data that are pertinent to the CKD population are reviewed, and updated recommendations for use of LLD in the CKD population are provided.

Fluvastatin inhibits hypoxic proliferation and p38 MAPK activity in pulmonary artery fibroblasts

The earliest structural change in hypoxia-induced pulmonary hypertension is increased proliferation of adventitial fibroblasts. This fibroproliferative response occurs in acute and chronic hypoxic models, is dependent on p38 mitogen-activated protein (MAP) kinase activation, is selective for the pulmonary circulation, and would seem an important therapeutic target. Simvastatin attenuates pulmonary vascular remodeling in animal models, but additional information regarding mechanisms of action, differential antiproliferative effects and dose responses of available statins is required for appropriate clinical trial design. Our objectives were to determine the effects of statins on acute hypoxia-induced proliferation and p38 MAP kinase activation in pulmonary and systemic artery fibroblasts, to assess the effects of cholesterol intermediates, prenyltransferase and related inhibitors, and to determine the statin's mechanism of action. Atorvastatin, fluvastatin, and simvastatin inhibited adventitial fibroblast proliferation. At low doses (1 microM), this effect was selective for hypoxic (versus serum-induced) proliferation and was also selective for pulmonary (versus systemic) fibroblasts. Complete inhibition of hypoxia-induced p38 MAP kinase activity was achieved at this 1-microM dose. The lipophilic statins exhibited similar potency. The statin effect was reversed by geranylgeranyl pyrophosphate and mimicked by geranylgeranyl transferase and Rac1 inhibitors. Hypoxia-induced p38 MAP kinase activation and proliferation in pulmonary adventitial fibroblasts is dependent on a geranylgeranylated signaling protein, probably Rac1. One micromolar of fluvastatin exhibits a circulation- and stimulus-selective antiproliferative effect on pulmonary artery fibroblasts. The pharmacokinetics of fluvastatin would suggest that its antiproliferative effects may be useful in pulmonary hypertension associated with hypoxia.

Iatrogenic rheumatic syndromes in the elderly

Rheumatic complaints are common in the geriatric population. However, uncommonly autoimmune or musculoskeletal complaints and disorders may arise as a consequence of pharmacotherapy. These rare events include stain myopathy, drug-induced lupus, arthralgias, vasculitis, or tight skin syndromes. This article discusses the possible iatrogenic causes of rheumatic conditions, potential inciting agents, and the various types of rheumatic manifestations seen in the elderly.

Distribution of lovastatin to bone and its effect on bone turnover in rats

Statins, the widely used lipid-lowering drugs, are inhibitors of 3-hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase, which catalyses a rate-limiting step in the biosynthesis of cholesterol. Many previous reports show that statins can act both as bone anabolic and as anti-resorptive agents but their beneficial effects on bone turnover are still controversial. Considering their high liver specificity and low oral bioavailability, the distribution of statins to the bone microenvironment is questionable. In this study, the distribution of lovastatin and its active metabolites to bone, with respect to plasma and liver compartments, was examined after oral and intravenous administration in female rats. As compared with oral administration, the distribution of lovastatin to the bone compartment was significantly enhanced after intravenous administration. Further, the effect of lovastatin on bone turnover was studied in-vitro and in-vivo to assess its anti-osteoporotic potential. Lovastatin acid but not lovastatin was found to inhibit parathyroid-hormone-induced bone resorption in an in-vitro chick embryo bone assay. Oral, as well as intravenous, short-term lovastatin treatment significantly reduced the serum total cholesterol, serum total alkaline phosphatase and urinary crosslinks in ovariectomized rats. In accordance with its increased distribution to the bone compartment, intravenously administered lovastatin was more effective in reducing the ovariectomy-induced increase in markers of bone metabolism, especially urinary crosslinks. The findings of this study suggest that statins inhibit bone resorption and that their anti-resorptive efficacy can be increased by administering them by routes other than oral so as to achieve their enhanced concentration in bone.

Atorvastatin-induced early-onset rhabdomyolysis in a patient with nephrotic syndrome

PURPOSE

A case of early-onset rhabdomyolysis in a patient treated with atorvastatin is described.

SUMMARY

A 17-year-old Indian boy weighing 55 kg was admitted to the hospital after complaining of facial puffiness and pedal edema for four days. His medical history revealed a diagnosis of nephrotic syndrome when he was 2 years old. He had six relapses, the last of which occurred 10 years ago. He was not taking any medications on admission and had not for the past 9 years. His vital signs were normal on admission (day 1), but anasarca was noticed during general examination. Cardiovascular, respiratory, and abdominal examinations were normal. Relapse of nephrotic syndrome was considered, and his 24-hour urine protein value confirmed the diagnosis. Further laboratory tests revealed that the patient had high total and low-density-lipoprotein cholesterol values (597 and 465 mg/dL, respectively), and atorvastatin 10 mg p.o. once daily was initiated on day 2. Prednisolone 60 mg p.o. once daily was initiated on day 3. On day 6, the patient complained of pain in both thighs and had difficulty walking. His creatine kinase (CK) concentration was then measured and found to be elevated (11,821 IU/L). Prednisolone and atorvastatin were then stopped, as statin-induced myopathy was suspected. The patient received i.v. hydration and sodium bicarbonate, and he began to show improvement by day 9. Follow-up three weeks later revealed a normal CK level and no myopathy-related complaints.

CONCLUSION

Early-onset rhabdomyolysis was reported in a patient with nephrotic syndrome who was treated with atorvastatin. Concomitant use of prednisolone and the patient's underlying renal impairment may have predisposed the patient to this adverse reaction.

Myotoxicity associated with lipid-lowering drugs

PURPOSE OF REVIEW

Lipid-lowering drugs are associated with myotoxicity, which ranges in severity from myalgias to rhabdomyolysis resulting in renal failure and death. Although rhabdomyolysis is rare, muscle symptoms and serum creatine kinase elevations are sufficiently frequent during the course of lipid-lowering drug therapy to pose diagnostic challenges for the clinician. Progress in our understanding of this form of myotoxicity is reviewed.

RECENT FINDINGS

Muscle pain and weakness are the cardinal symptoms and often interfere with vigorous exercise. These symptoms may occur with or without serum creatine kinase elevations. The risk of myotoxicity is increased by combination statin-fibrate therapy as well as by factors that elevate tissue levels of the lipid-lowering drug, including the dose, drug-drug interactions, and host factors. Underlying neuromuscular diseases may become clinically apparent during statin therapy and may predispose to myotoxicity. The pathophysiology of myotoxicity most probably involves metabolic effects of the statins on the isoprenoid pool and on mitochondrial function.

SUMMARY

Management of myotoxicity requires an evaluation of risk factors prior to prescribing lipid-lowering drugs, attention to muscle symptoms, and withdrawal of drug in the event of significant abnormalities.

Synergistic antimyeloma effects of zoledronate and simvastatin

Despite advances in the treatment of multiple myeloma, it remains an incurable disease because of primary and secondary drug resistance. Mevalonate pathway inhibitors like bisphosphonates and statins have antimyeloma activity in vitro at very high concentrations, which may probably not be reached in vivo. NCI-H929, OPM-2, U266 and RPMI-8226 myeloma cell lines were treated in the presence or absence of bone marrow stromal cells with simvastatin or zoledronate in combination with classical antimyeloma drugs like melphalan or bortezomib. Zoledronate did not show substantial antimyeloma activity at low and intermediate concentrations, whereas simvastatin potently induced apoptosis in myeloma cells without signs of primary, cell-adhesion-mediated drug resistance. Furthermore, sequential blockage of the mevalonate pathway by zoledronate and simvastatin demonstrated synergistic induction of apoptosis and reversal of cell-adhesion-mediated drug resistance. Our data provide a rationale for combining zoledronate and simvastatin with classical antimyeloma drugs.

Role of P-glycoprotein in statin drug interactions

Understanding the mechanisms of drug interactions with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) has become increasingly important because of the potential for serious adverse effects, most notably myopathy. Most of the evidence supports the role of cytochrome P450 (CYP) isoenzymes in many of these drug interactions. However, P-glycoprotein (P-gp), an efflux protein located in the gastrointestinal tract, placenta, kidneys, brain, and liver, may also play a role. Results of several studies with in vitro models have shown that lovastatin, simvastatin, and atorvastatin are inhibitors for P-gp and may be substrates for this transporter as well. Pravastatin and fluvastatin consistently demonstrate no significant inhibition of P-gp. Drug interaction studies involving statins and digoxin support a role for P-gp. Many additional drugs such as diltiazem, verapamil, itraconazole, ketoconazole, and cyclosporine, as well as dietary supplements such as St. John's wort and grapefruit juice, interact with statins and are modulators of both CYP3A4 and P-gp. However, the role of P-gp in these specific drug interactions remains unclear.

Statins, bugs and prophylaxis: intriguing possibilities

Statin therapy may represent a potential prophylactic intervention in certain high-risk scenarios, for example in pandemic influenza and in those undergoing aggressive medical treatments. Emerging data indicate a potential prophylactic role in these high-risk groups.

The effect of simvastatin, ezetimibe and their combination on the lipid profile, arterial stiffness and inflammatory markers

OBJECTIVE

Arterial stiffness and highly sensitive C-reactive protein (hsCRP) serum level predict the risk for cardiovascular events. The most commonly used drugs for lowering cholesterol levels, the statins, also have anti-inflammatory effects and can decrease arterial stiffness. Ezetimibe is the first drug of a new class of cholesterol absorption inhibitors in common use and, to date, its effect on arterial stiffness has not yet been studied. The aim of this study was to compare the effect of simvastatin and ezetimibe, both singly and in combination, on arterial stiffness and hsCRP serum concentration in hypercholesterolemic patients.

METHODS

Forty hypercholesterolemic patients were studied. Group1 comprised previously untreated patients, who received simvastatin at doses of 40 mg/day during the study; group 2 comprised patients previously treated with simvastatin at 40 mg/day, who received simvastatin at 80 mg/day during the study; group 3 consisted of patients previously untreated, who received ezetimibe at doses of 10 mg/day during the study; group 4 comprised patients previously treated with simvastatin at 40 mg/day, who received simvastatin at 40 mg/day and ezetimibe at 10 mg/day during the study. Arterial stiffness expressed as the Augmentation Index (AIx) (assessed by pulse wave analysis), the lipid profile and the hsCRP level were measured at baseline and after 3 months of treatment.

RESULTS

The reduction in low-density lipoprotein (LDL) after treatment was significantly greater in groups 1 and 4 (39.9 and 35.7%) than in groups 2 and 3 (17.7 and 16.9%; p = 0.005). The AIx decreased significantly only in group 1 patients, from 30.2 +/- 8.3% before treatment to 21.6 +/- 6.5% after treatment (p < 0.001). Changes in hsCRP paralleled the changes in AIx, with a significant decrease in patients in group 1 only, from 2.8 +/- 2.5 mg/L before treatment to 1.6 +/- 1.5 mg/L after treatment (p = 0.016).

CONCLUSION

Ezetimibe as a monotherapy had no effect on arterial stiffness or hsCRP, while the administration of simvastatin at 40 mg per day improved arterial stiffness and CRP. However, increasing the dose of simvastatin or administering ezetimibe in combination with simvastatin had no beneficial effects on arterial stiffness.

Asymptomatic statin-induced rhabdomyolysis after long-term therapy with the hydrophilic drug pravastatin

CASE SUMMARY

A male patient aged 73 years, 165 cm in height, and weighing 78 kg presented to the emergency department with dsypnea. He had undergone heart transplantation 7 years earlier and been receiving daily pravastatin therapy for >3 years without complaining of any symptoms. A physical examination of the patient at admission was unremarkable, except for dyspnea. However, laboratory testing revealed that his serum creative kinase (CK) concentration was substantially above the reference range. Pravastatin was immediately discontinued, and the patient was admitted to the intensive care unit for treatment. CK values declined after 3 days, and they returned to within reference range after 3 weeks. The patient was diagnosed with acute rhabdomyolysis; a score of 6 on the Naranjo adverse drug reaction probability scale indicated that pravastatin was the probable cause.

DISCUSSION

The hydrophilic statin pravastatin is frequently recommended for patients who have undergone heart transplantation due to its favorable tolerability profile. Unlike lipophilic statins, hydrophilic statins such as pravastatin are not metabolized in the liver via the cytochrome P450 system and have little potential for adverse events through interaction with drugs metabolized via this pathway. Based on a search of relevant literature, this report appears to be the first to describe a case of asymptomatic rhabdomyolysis occurring in a patient receiving long-term daily therapy with pravastatin after undergoing heart transplantation and who had no muscular symptoms or history of intense physical exertion. The occurrence of acute statin-induced rhabdomyolysis in this case suggests that even hydrophilic statins may have the potential to damage myocytes.

CONCLUSIONS

The hydrophilic statin pravastatin appears to have caused asymptomatic rhabdomyolysis, in the absence of physical exertion, in a patient who had undergone heart transplantation and had been receiving the drug for >3 years. Statin therapy should be initiated at the lowest effective dose, especially in patients who have undergone heart transplantation, and should be followed by close monitoring.

The matrix metalloproteinases as pharmacological target in osteoarthritis: Statins may be of therapeutic benefit

Osteoarthritis (OA) is a common joint disease; however, current pharmacologic agents for OA are only symptomatic and they can not prevent the disease progression. Matrix metalloproteinases (MMPs) produced by chondrocytes play an important role in the development of cartilage destruction in OA, and agents that can target against MMPs activity may be of therapeutical value. There were reports that statins can inhibit the secretion of MMPs in vitro and in vivo, which were believed to account for the plaque stabilizing effects of statins in the treatment of atherosclerosis. We based our hypothesis on that atherosclerosis possesses some aspects that are similar to that of osteoarthritis, such as inflammation and matrix degradation. Since statins have displayed great benefits in modifying the progression of atherosclerosis via anti-inflammatory and matrix-stabilizing mechanisms, it is conceivable that statins may also prevent the disease progression of osteoarthritis. Further work are needed to verify if statins can protect cartilage from destruction through inhibition of MMP secretion by chondrocytes, and their potential to be used as therapeutic agents in OA should be investigated.

Simvastatin improves the healing of infected skin wounds of rats

PURPOSE: This study explores the potential of the simvastatin to ameliorate inflammation and infection in open infected skin wounds of rats. METHODS: Fourteen Wistar rats weighing 285±12g were used. The study was done in a group whose open infected skin wounds were treated with topical application of sinvastatina microemulsion (SIM, n=7) and a second group with wounds treated with saline 0.9 % (SAL, n=7). A bacteriological exam of the wounds fluid for gram positive and gram negative bacteria, the tecidual expression of TNFá and IL-1â by imunohistochemical technique, and histological analysis by HE stain were performed. RESULTS: The expression of TNFa could be clearly demonstrated in lower degree in skin wounds treated with simvastatin (668.6 ± 74.7 ìm²) than in saline (2120.0 ± 327.1 ìm²). In comparison, wound tissue from SIM group displayed leukocyte infiltration significantly lower than that observed in SAL group (p<0.05). Culture results of the samples taken from wound fluid on fourth post treatment day revealed wound infection in only one rat of group simvastatin (SIM), where Proteus mirabilis, Escherchia coli and Enterobacter sp were isolated. In the rats whose wounds were treated with saline (SAL), polymicrobial infection with more than 100,000 CFU/g was detected in all the wounds. CONCLUSION: In addition to its antiinflammatory properties, the protective effects of simvastatin in infected open skin wounds is able to reduce infection and probably has antibacterial action. The potential to treat these wounds with statins to ameliorate inflammation and infection is promising.