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Simvastatin causes endothelial cell apoptosis and attenuates severe pulmonary hypertension.

Severe pulmonary hypertension (SPH) is characterized by precapillary arteriolar lumen obliteration, dramatic right ventricular hypertrophy, and pericardial effusion. Our recently published rat model of SPH recapitulates major components of the human disease. We used this model to develop new treatment strategies for SPH. SPH in rats was induced using VEGF receptor blockade in combination with chronic hypoxia. A large variety of drugs used in this study, including anticancer drugs (cyclophosphamide and paclitaxel), the angiotensin-converting enzyme inhibitor lisinopril, the antiangiogenic agent thalidomide, and the peroxisome proliferator-actived receptor-gamma agonist PGJ2, failed to decrease mean pulmonary artery pressure (PAP) or right ventricular hypertrophy. In contrast, treatment of rats with established SPH with simvastatin markedly reduced mean PAP and right ventricular hypertrophy, and this reduction was associated with caspase-3 activation and pulmonary microvascular endothelial cell apoptosis. Simvastatin partially restored caveolin-1, caveolin-2, and phospho-caveolin expression in vessel walls. In rat primary pulmonary microvascular endothelial cells, simvastatin induced caspase 3 activation and Rac 1 expression while suppressing Rho A and attenuated levels of Akt and ERK phosphorylation. We conclude that simvastatin is effective in inducing apoptosis in hyperproliferative pulmonary vascular lesions and could be considered as a potential drug for treatment of human SPH.

Animals↗

Effect of simvastatin on high glucose- and angiotensin II-induced activation of the JAK/STAT pathway in mesangial cells.

In the current study, we investigated the effect of simvastatin on the ability of high glucose (HG) and ANG II to activate the JAK2-STAT signaling cascade and induce glomerular mesangial cell (GMC) growth. We found that pretreatment with simvastatin significantly inhibited HG- and ANG II-induced collagen IV production, JAK2 activation, and phosphorylation of STAT1 and STAT3 in GMC. We also found that the activation of JAK2 by HG and ANG II was dependent on the Rho family of GTPases. Consistent with these in vitro results, both albumin protein excretion and phosphorylation of JAK2, STAT1, and STAT3 were attenuated in renal glomeruli by administration of simvastatin in a streptozotocin-induced rat model of HG diabetes. This study demonstrates that simvastatin blocks ANG II-induced activation of the JAK/STAT pathway in the diabetic environment, in vitro and in vivo, and, thereby, provides new insights into the molecular mechanisms underlying early diabetic nephropathy.

Angiotensin II↗

Simvastatin inhibits malignant transformation following expression of the Ha-ras oncogene in NIH 3T3 fibroblasts.

In previous studies we have shown that the expression of the transforming Ha-ras oncogene in NIH 3T3 fibroblasts stimulates cellular calcium entry, which triggers oscillatory calcium induced calcium release from internal stores. The intracellular calcium oscillations lead to cytoskeletal remodeling by actin stress fiber depolymerization and activation of the Na(+)/H(+) exchanger thus mediating cell swelling and intracellular alkalosis, both important mitogenic signals. This is evidenced by abrogation of Ha-ras induced growth factor independent cell proliferation by interference with any of these events, i.e. by inhibition of cellular calcium entry or inhibition of the Na(+)/H(+) exchanger. As shown in this study, simvastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the key enzyme for cholesterol biosynthesis, is able to prevent these events following the expression of the transforming Ha-ras oncogene. We show, that simvastatin inhibits farnesylation dependent membrane translocation of a CAAX motive bearing yellow fluorescent protein and suppresses Ha-ras stimulated cellular calcium influx, which can be identified as capacitative calcium entry. In addition simvastatin is able to block regulatory volume decrease channels and to suppress the cytoskeletal remodeling, intracellular alkalinization, increase in cell volume and growth factor independent cell proliferation induced by the oncogene. Thus simvastatin is able to prevent crucial cellular events following expression of the transforming Ha-ras oncogene.

3T3 Cells↗

Plasma concentration profiles of simvastatin 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitory activity in kidney transplant recipients with and without ciclosporin.

A few cases of severe rhabdomyolysis have been reported in heart transplant recipients treated simultaneously with ciclosporin (CS) and the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor lovastatin. When measured, plasma lovastatin HMG-CoA reductase inhibitor concentrations in these patients were higher than expected. This prompted us to study the plasma concentration profiles of simvastatin HMG-CoA reductase inhibitory activity after a single dose of simvastatin in kidney transplant recipients. Five patients treated with CS, azathioprine and prednisolone (CS patients) were compared to 5 patients treated with azathioprine and prednisolone (non-CS patients). The concentration curves had similar shapes but the mean area under the curve/24 h was almost 3 times higher (p = 0.047) and the mean peak concentration was twice as high in CS patients (p = 0.028). These results suggest a difference in the disposition of simvastatin in CS patients as compared to non-CS patients. Simvastatin should be administered in a reduced dosage to CS patients.

Adult↗

Reduced expression of endothelial connexin37 and connexin40 in hyperlipidemic mice: recovery of connexin37 after 7-day simvastatin treatment.

OBJECTIVE: We sought to clarify the response of endothelial connexins to hyperlipidemia and lipid-lowering therapy. METHODS AND RESULTS: Aortic endothelial gap junctions were analyzed by en face immunoconfocal microscopy and electron microscopy in C57BL/6 mice subjected to the following regimens: (1) normal chow (NC) for 3 months (3 mo), (2) NC for 9 mo, (3) NC for 3 mo, followed by a cholesterol-enriched diet (CED) for 6 mo, (4) NC for 3 mo and CED for 6 mo, with simvastatin in the final week, and (5) (in apoprotein E [apoE]-deficient mice) NC and examined at 3 mo and 7 to 9 mo. In wild-type mice, connexin37 (Cx37) and Cx40 were markedly downregulated in the CED-fed animals compared with those fed NC (CED vs 9-mo NC, 77% reduction in Cx37 and 65% reduction in Cx40; both P<0.01). After simvastatin treatment, Cx40 remained depressed, but Cx37 recovered to 94% of the level found in non-cholesterol-fed animals (P<0.01). Electron microscopy demonstrated that gap junctions were smaller in animals fed the CED compared with those given simvastatin and with controls fed NC (P<0.01). Endothelial connexins were rare in the atherosclerotic plaques of apoE-deficient mice. CONCLUSIONS: Mouse aortic endothelial gap junctions and connexins are downregulated during long-term hyperlipidemia. Short-term treatment with simvastatin leads to recovery of Cx37 expression but not Cx40 expression.

Animals↗

IDL composition and angiographically determined progression of atherosclerotic lesions during simvastatin therapy.

Some patients with coronary artery disease experience continued progression of one or more coronary lesions despite treatment with drugs that inhibit 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and markedly lower plasma cholesterol levels. We examined relationships between the progression of coronary artery lesions and plasma lipoproteins, in particular intermediate density lipoprotein (IDL) and its composition, in 38 patients with coronary artery disease who had been treated with simvastatin for 2 years. Patients were given lipid-lowering dietary advice; 3 months later they were started on simvastatin therapy (10 mg/d) for 1 month, and after review of their plasma cholesterol levels, the dose was increased to 20 mg/d and later to 40 mg/d if the target level of plasma cholesterol had not been attained. Progression of lesions was determined by serial quantitative coronary angiography (variability of 5.5%) and was defined as an increase in percent diameter stenosis (%S)> or =10%; regression was defined as a decrease in %S > or =10%. The proportions of cholesteryl esters (CEs) and free cholesterol decreased significantly (P<.001), and proportions of protein and triglycerides increased significantly (P<.001) in IDL during simvastatin therapy. The CE content of IDL decreased significantly (-7.2 weight [wt]%, n=20, P<.001) in nonprogressors (patients who did not show progression of any lesions) and did not change significantly (-1.8 wt%, n=14, P=.36) in progressors (patients who showed progression of one or more lesions without regression of any lesion). This decrease in IDL CE content in nonprogressors was significantly (P=.01) different compared with the corresponding change in patients classified as progressors. Mean plasma cholesterol concentration tended to increase in progressors (0.47 mmol/L) and tended to decrease in nonprogressors (-0.39 mmol/L) during the initial 3-month diet period, and these changes were significantly different (P=.02). Furthermore, this change in plasma cholesterol level during the initial diet period was correlated significantly with the change in IDL CE content during the entire study (r=.348, n=38, P=.03). These data suggest that IDL CE content may be a determinant of progression of coronary lesions and may be influenced by compliance with or metabolic response to lipid-lowering dietary advice in patients with coronary artery disease during simvastatin treatment.

Adult↗

Evidence for an independent and cumulative effect of postprandial hypertriglyceridemia and hyperglycemia on endothelial dysfunction and oxidative stress generation: effects of short- and long-term simvastatin treatment.

BACKGROUND: Postprandial hypertriglyceridemia and hyperglycemia are considered risk factors for cardiovascular disease. Evidence suggests that postprandial hypertriglyceridemia and hyperglycemia induce endothelial dysfunction through oxidative stress; however, the distinct role of these two factors is a matter of debate. METHODS AND RESULTS: Thirty type 2 diabetic patients and 20 normal subjects ate 3 different meals: a high-fat meal; 75 g glucose alone; and high-fat meal plus glucose. Glycemia, triglyceridemia, nitrotyrosine, and endothelial function were assayed during the tests. Subsequently, diabetics took 40 mg/d simvastatin or placebo for 12 weeks. The 3 tests were performed again at baseline, between 3 to 6 days after the start, and at the end of each study. High-fat load and glucose alone produced a decrease of endothelial function and an increase of nitrotyrosine in normal and diabetic subjects. These effects were more pronounced when high fat and glucose were combined. Short-term simvastatin treatment had no effect on lipid parameters but reduced the effect on endothelial function and nitrotyrosine observed during each different test. Long-term simvastatin treatment was accompanied by a lower increase in postprandial triglycerides, which was followed by smaller variations of endothelial function and nitrotyrosine during the tests. CONCLUSIONS: This study shows an independent and cumulative effect of postprandial hypertriglyceridemia and hyperglycemia on endothelial function, suggesting oxidative stress as common mediator of such effect. Simvastatin shows a beneficial effect on oxidative stress and endothelial dysfunction, which may be ascribed to a direct effect as well as the lipid-lowering action of the drug.

Blood Glucose↗

Simvastatin normalizes autonomic neural control in experimental heart failure.

BACKGROUND: HMG-CoA reductase inhibitors (statins) have been shown to beneficially affect outcomes in chronic heart failure (CHF). We hypothesized that statins exert effects on autonomic function, as assessed by plasma norepinephrine levels, direct recordings of renal sympathetic nerve activity (RSNA), and baroreflex function. METHODS AND RESULTS: Normolipidemic CHF rabbits were treated with simvastatin or vehicle. CHF was induced by continuous ventricular pacing at 320 to 340 bpm for 3 weeks. Two to 3 days after instrumentation of the rabbits with renal nerve electrodes and arterial and venous catheters, blood samples and RSNA recordings were obtained in the conscious state. Baroreflex function was assessed after administration of sodium nitroprusside and phenylephrine. Mean baseline RSNA (+/-SEM) in normal rabbits was 19.3+/-3.8%; in CHF rabbits, 39.4+/-2.9% (P<0.05); in CHF rabbits on low-dose (0.3 mg x kg(-1) x d(-1)) simvastatin, 39.8+/-8.3% (P<0.05); and in CHF rabbits on high-dose simvastatin (3 mg x kg(-1) x d(-1)), 21.1+/-4.5% (P=NS). Similar data were observed for plasma norepinephrine. In CHF rabbits treated with 3 mg x kg(-1) x d(-1) simvastatin, baroreflex regulation of heart rate to transient hypotension with sodium nitroprusside was normalized by 66% compared with CHF controls. CONCLUSIONS: These are the first data showing that non-lipid-lowering statin effects include a normalization of sympathetic outflow and reflex regulation in CHF. The precise neural and cellular pathways involved in these responses need further clarification. This finding may have important implications for the treatment of CHF and progression of the disease process.

Action Potentials↗

Inflammatory/antiinflammatory properties of high-density lipoprotein distinguish patients from control subjects better than high-density lipoprotein cholesterol levels and are favorably affected by simvastatin treatment.

BACKGROUND: The inflammatory/antiinflammatory properties of HDL were compared with HDL cholesterol in 2 groups of patients and in age- and sex-matched control subjects. METHODS AND RESULTS: Group 1 consisted of 26 patients not yet taking a statin who presented with coronary heart disease (CHD) or CHD equivalents by National Cholesterol Education Program Adult Treatment Panel III criteria studied before and 6 weeks after 40 mg/d of simvastatin. Group 2 consisted of 20 patients with documented CHD and HDL cholesterol > or =84 mg/dL. The inflammatory/antiinflammatory properties of HDL were determined by the ability of the subject's HDL to alter LDL-induced monocyte chemotactic activity (MCA) in a human artery wall coculture. Induction of MCA by a control LDL was determined in the absence or presence of the subject's HDL. Values in the absence of HDL were normalized to 1.0. Values >1.0 after the addition of HDL indicated proinflammatory HDL; values <1.0 indicated antiinflammatory HDL. Group 1 values before simvastatin were LDL cholesterol, 118+/-24 mg/dL; HDL cholesterol, 57+/-13 mg/dL; triglycerides, 125+/-64 mg/dL; and high-sensitivity C-reactive protein (hs-CRP), 1.7+/-1.9 mg/L; and MCA values were 1.38+/-0.91, compared with 0.38+/-0.14 for control subjects (P=1.5x10(-5)). After simvastatin, values were LDL cholesterol, 73+/-24 mg/dL; HDL cholesterol, 61+/-14 mg/dL; triglycerides, 99+/-52 mg/dL; and hs-CRP, 1.3+/-1.3 mg/L; and MCA values were 1.08+/-0.71. In group 2, values were LDL cholesterol, 108+/-34 mg/dL; HDL cholesterol, 95+/-14 mg/dL; triglycerides, 89+/-44 mg/dL; and hs-CRP, 0.8+/-0.7 mg/L; and MCA values were 1.28+/-0.29, compared with 0.35+/-0.11 for control subjects (P=1.7x10(-14)). Similar results were obtained with the cell-free assay. CONCLUSIONS: The inflammatory/antiinflammatory properties of HDL distinguished patients from control subjects better than HDL cholesterol and were improved with simvastatin.

Adult↗

Regression of coronary atherosclerosis by simvastatin: a serial intravascular ultrasound study.

BACKGROUND: Angiography of the coronary arteries reflects only changes in luminal dimensions. With intravascular ultrasound, cross-sectional images can be obtained and area measurements can be added to calculate volumes of the external elastic membrane (EEM), plaque plus media (P+M), and lumen. The aim of this study was to investigate the effect of lipid lowering by simvastatin on coronary atherosclerotic P+M as changes in volumes of EEM, P+M, and lumen. METHODS AND RESULTS: In 40 male patients with hypercholesterolemia, ischemic heart disease, and a nonsignificant coronary artery lesion in a not previously revascularized coronary artery, serial intravascular ultrasound studies with an ECG-triggered pullback were performed at baseline, after 3 months on a lipid-lowering diet, and after another 12 months on simvastatin 40 mg/d. Mean length of the analyzed atherosclerotic segments was 5.9+/-3.3 mm. After 12 months on simvastatin, a significant reduction in P+M volume of 6.3% (P=0.002) was observed, whereas only a nonsignificant reduction in EEM volume of 1.8% was seen without any concomitant change in lumen volume. A significant reduction in total cholesterol of 31.0% (6.1+/-0.8 versus 4.2+/-0.7 mmol/L, P<0.001) and LDL cholesterol of 42.6% (4.0+/-0.8 versus 2.2+/-0.6 mmol/L, P<0.001) was obtained. CONCLUSIONS: Lipid-lowering therapy with simvastatin for 12 months is associated with a significant P+M regression in coronary arteries measured as reduction in P+M and EEM volumes without any concomitant change in lumen volume.

Coronary Angiography↗

Effects of lipid-lowering by simvastatin on human atherosclerotic lesions: a longitudinal study by high-resolution, noninvasive magnetic resonance imaging.

BACKGROUND: This study was designed to investigate the effects of lipid-lowering by simvastatin on human atherosclerotic lesions. METHODS AND RESULTS: Eighteen asymptomatic hypercholesterolemic patients with documented aortic and/or carotid atherosclerotic plaques were selected for the study. A total of 35 aortic and 25 carotid artery plaques were detected. Serial black-blood MRI of the aorta and carotid artery of the patients was performed at baseline and 6 and 12 months after lipid-lowering therapy with simvastatin. The effects of the treatment on atherosclerotic lesions were measured as changes in lumen area, vessel wall thickness, and vessel wall area, a surrogate of atherosclerotic burden. Simvastatin induced a significant (P<0.01) reduction in total and LDL cholesterol levels at 6 weeks that was maintained thereafter. At 6 months, no changes in lumen area, vessel wall thickness, or vessel wall area were observed. However, at 12 months, significant reductions in vessel wall thickness and vessel wall area, without changes in lumen area, were observed in both aortic and carotid arteries (P<0.001). CONCLUSIONS: This in vivo human study demonstrates that effective and maintained lipid-lowering therapy by simvastatin is associated with a significant regression of atherosclerotic lesions. Our observation suggests that statins induce vascular remodeling, as manifested by reduced atherosclerotic burden without changes in the lumen.

Aorta↗

Simvastatin, an HMG-coenzyme A reductase inhibitor, improves endothelial function within 1 month.

BACKGROUND: Cholesterol-lowering therapy can improve cardiovascular morbidity and mortality in patients with atherosclerosis. Although the mechanisms responsible are unclear, these benefits precede macroscopic changes in the vasculature. Emerging evidence that improvement in endothelial function may occur requires substantiation; in particular, it is unclear how early any such improvement would be detectable after initiation of therapy. METHODS AND RESULTS: This randomized, double-blind, placebo-controlled crossover study evaluated the effect of simvastatin (20 mg daily for 4 weeks) on endothelium-dependent and endothelium-independent vasodilation and on the response to the inhibitor of nitric oxide synthesis, NG-monomethyl-L-arginine (L-NMMA), in the forearm vasculature of subjects with moderate elevation of total serum cholesterol (6.0 to 10.0 mmol/L) by use of strain-gauge plethysmography. Studies were repeated after 3 more months of open therapy. When the results are expressed as percentage changes in flow in the infused arm relative to the noninfused arm, the vasodilator response to acetylcholine was significantly increased after 4 weeks of treatment with simvastatin (P < .0005), and this improvement was further enhanced after 3 months (P < .005). Concurrently, simvastatin augmented the vasoconstrictor response to L-NMMA, an effect that was maintained at 3 months (P < .0005). The response to the endothelium-independent vasodilator sodium nitroprusside was unaltered. CONCLUSIONS: These observations indicate that within 1 month of treatment with simvastatin, both the stimulated and basal nitric oxide dilator functions of the endothelium are augmented, and the benefits of this HMG-coenzyme A reductase inhibitor persist with continued therapy.

Acetylcholine↗

Simvastatin prevents load-induced protein tyrosine nitration in overloaded hearts.

Hydroxymethylglutaryl-coenzyme A reductase inhibitors prevent load-induced left ventricular hypertrophy (LVH). Whether this effect is related to antioxidant properties of this class of drugs is poorly understood. The aim of the present report was to evaluate the regulation of nitrotyrosine production during the development of load-induced LVH and the effect of simvastatin treatment in this process. Rats were subjected to aortic constriction up to 15 days. LVH was evaluated by left/right ventricle mass ratio. Myocardial content of nitrotyrosine, nitric oxide synthase (NOS) isoforms, and phagocyte-type NAD(P)H-oxidase subunits (p67-phox and p22-phox) were analyzed by immunoblotting and immunohistochemistry assays. Another group of rats received treatment with either simvastatin or placebo for 15 days after the onset of pressure overload, and their hearts were also studied. Myocardial nitrotyrosine content was increased from 3 to 15 days of pressure overload in regions of cardiac myocytes in close apposition to myocardial stroma during LVH. Neuronal NOS (nNOS), inducible NOS (iNOS), and endothelial NOS (eNOS) isoforms had their expression increased in coronary vessels (nNOS and iNOS) and in myocardial stroma (eNOS) from day 3 to day 7 of aortic constriction. However, p67-phox and p22-phox expression was increased in cells of myocardial stroma in parallel to augmented myocardial nitrotyrosine content. Simvastatin treatment inhibited the increases in myocardial nitrotyrosine content and in p67-phox and p22-phox expression, and significantly reduced LVH. In conclusion, antioxidant properties of simvastatin might play a role in myocardial remodeling induced by pressure overload.

Animals↗

Involvement of Rho GTPases in the transcriptional inhibition of preproendothelin-1 gene expression by simvastatin in vascular endothelial cells.

Endothelial dysfunction is characterized by an impaired vasodilatory response to endothelial agonists as well as by alterations in adhesion and coagulation processes. 3-Hydroxy-3-methylglutaryl-CoA reductase inhibitors (statins) have been shown to be useful in the reversal of endothelial dysfunction, an effect that may be independent of the reduction in cholesterol levels. Both the L-arginine-nitric oxide-cGMP and endothelin pathways are involved in the regulation of vascular tone. Here, we show that the basal transcription rate of the preproendothelin-1 gene was decreased by simvastatin (10 micromol/L) in bovine aortic endothelial cells. Transfection studies with the preproendothelin-1 gene promoter showed that mevalonate (100 micromol/L) was able to prevent the inhibitory effect mediated by simvastatin. Protein geranylgeranylation, but not farnesylation, proved to be crucial for a correct expression of the preproendothelin-1 gene. The C3 exotoxin from Clostridium botulinum that selectively inactivates Rho GTPases, the processing of which involves geranylgeranylation, reproduced the inhibitory effect of simvastatin on the expression of preproendothelin-1. Overexpression of dominant-negative mutants of RhoA and RhoB led to a significant reduction in the preproendothelin-1 promoter activity, whereas the expression of wild-type and constitutively active forms of these proteins resulted in an increase, in support that Rho proteins are required for the basal expression of the preproendothelin-1 gene. Finally, we show that the Rho-dependent activation of the preproendothelin-1 gene transcription was inhibited by simvastatin. Thus, the control of vascular tone and proliferative response mediated by endothelin-1 is regulated at multiple levels, among which the Rho proteins play an essential role.

Alkyl and Aryl Transferases↗

Simvastatin attenuates smooth muscle neointimal proliferation and pulmonary hypertension in rats.

Hypertensive pulmonary vascular disease is characterized by abnormal proliferation of vascular endothelial and smooth muscle cells, leading to occlusion of pulmonary arterioles, pulmonary hypertension, right ventricular failure, and death. Compounds with antiproliferative effects on vascular endothelial and smooth muscle cells, such as 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, may prevent the development of experimental hypertensive pulmonary vascular disease. Pneumonectomized rats injected with monocrotaline at 7 days develop severe hypertensive pulmonary vascular disease with neointimal formation. Rats were randomized to receive either vehicle or treatment with the HMG-CoA reductase inhibitor simvastatin (2 mg/kg per day). By Day 35, rats that received vehicle had higher mean pulmonary arterial pressures (53 +/- 2 mm Hg) and right ventricular hypertrophy (right ventricle/[left ventricle plus septum] [RV/LV+S] = 0.78 +/- 0.09) than rats in Group PMS5-35 that received simvastatin from Day 5 to 35 (mean pulmonary arterial pressure = 27 +/- 3 mm Hg, RV/LV+S = 0.34 +/- 0.08; p < or = 0.001). Pulmonary vascular remodeling with neointimal formation consisting of vascular smooth muscle cells was more severe in vehicle-treated rats (vascular occlusion score, 1.98 +/- 0.02) than in Group PMS5-35 (vascular occlusion score, 0.59 +/- 0.46; p < 0.001). In addition, lung endothelial nitric oxide synthase gene expression was decreased in vehicle-treated animals but was restored toward normal levels in simvastatin-treated animals. Simvastatin attenuates monocrotaline-induced pulmonary vascular remodeling with neointimal formation, pulmonary arterial hypertension, and right ventricular hypertrophy in rats.

Animals↗

Effects of orlistat, a lipase inhibitor, on the pharmacokinetics of three highly lipophilic drugs (amiodarone, fluoxetine, and simvastatin) in healthy volunteers.

To investigate the effect of orlistat on the pharmacokinetics of three highly lipophilic drugs (amiodarone, fluoxetine, and simvastatin), the authors performed double-blind, placebo-controlled, randomized two-period crossover (for fluoxetine and simvastatin) or parallel (for amiodarone) studies in healthy volunteers ages 18 to 65 years of a body mass index between 18 and 30 kg/m2. During treatment with orlistat or matching placebo for 5 to 13 1/3 days, a single oral dose of highly lipophilic drug was administered, followed by obtaining serial blood samples for measuring plasma (for fluoxetine and simvastatin) or serum (for amiodarone) concentrations of the lipophilic drug and its active metabolite. Treatments were compared for the pharmacokinetic parameters AUC0-infinity, Cmax, tmax, and t 1/2 of highly lipophilic drugs and active metabolites. Analysis of variance was performed to assess the significance of the sequence effect and provide the variance estimate for the 90% confidence intervals. Subjects were also evaluated for adverse events, vital signs, and clinical and laboratory safety. The absorption of amiodarone (and active metabolite) was significantly reduced by approximately one-quarter using parameters of Cmax and AUC, while no inhibition of absorption was observed for fluoxetine and simvastatin as well as their active metabolites. There were no clinically significant differences in t 1/2 and tmax for all three drugs tested. Due to expected gastrointestinal adverse events known to occur with orlistat, there was a higher incidence of adverse events under regimen B (highly lipophilic drugs and orlistat) than under regimen A (highly lipophilic drugs and placebo). Other adverse events were sporadic and unremarkable. There were no clinically relevant changes in vital signs or laboratory values. In conclusion, except for amiodarone, there was no effect of orlistat on the pharmacokinetics of highly lipophilic drugs when these drugs were taken concomitantly with orlistat.

Adolescent↗

Simvastatin decreases IL-6 and IL-8 production in epithelial cells.

Many cardiovascular studies have suggested that 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors (statins) have anti-inflammatory effects independent of cholesterol lowering. As a chronic inflammatory disease, periodontitis shares some mechanisms with atherosclerosis. Since oral epithelial cells participate importantly in periodontal inflammation, we measured simvastatin effects on interleukin-6 and interleukin-8 production by cultured human epithelial cell line (KB cells) in response to interleukin-1alpha. Simvastatin decreased production, an effect reversed by adding mevalonate or geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate. Simvastatin was found to reduce NF-kappaB and AP-1 promoter activity in KB cells. Dominant-negative Rac1 severely inhibited interleukin-1alpha-induced NF-kappaB and AP-1 promoter activity. Our results may indicate an anti-inflammatory effect of simvastatin on human oral epithelial cells, apparently involving Rac1 GTPase inhibition.

Anti-Inflammatory Agents↗

Discordant expression of the sterol pathway in lens underlies simvastatin-induced cataracts in Chbb: Thom rats.

Simvastatin rapidly induced cataracts in young Chbb:Thom (CT) but not Sprague Dawley (SD) or Hilltop Wistar (HW) rats. Oral treatment for 14 but not 7 days committed CT rat lenses to cataract formation. The cholesterol to phospholipid molar ratio in lenses of treated CT rats was unchanged. Differences between strains in serum and ocular humor levels of simvastatin acid poorly correlated with susceptibility to cataracts. No significant differences were found between rat strains in the capacity of simvastatin acid to inhibit lens-basal sterol synthesis. Prolonged treatment with simvastatin comparably elevated HMG-CoA reductase protein and enzyme activity in lenses of both cataract resistant and sensitive strains. However, in contrast to SD and HW rats, where sterol synthesis was markedly increased, sterol synthesis in CT rat lenses remained at baseline. Discordant expression of sterol synthesis in CT rats may be due to inadequate upregulation of lens HMG-CoA synthase. HMG-CoA synthase protein levels, and to a much lesser extent mRNA levels, increased in lens cortex of SD but not CT rats. Because upregulation of the sterol pathway may result in increased formation of isoprene-derived anti-inflammatory substances, failure to upregulate the pathway in CT rat lenses may reflect an attenuated compensatory response to injury that resulted in cataracts.

Animals↗