Exploring the anti-osteoporotic potential of simvastatin and metformin: a comprehensive Mendelian randomization and animal experiment investigation

Background:Both simvastatin and metformin have demonstrated potential efficacy in osteoporosis(OP)treatment.However,there is a lack of systematic studies comparing their anti-osteoporotic effects.This study aims to compare the effects of simvastatin and metformin on OP through Mendelian randomization(MR)studies and animal experiments.Methods:Initially,we will analyze the causal impact of simvastatin or metformin treatment on OP prevalence and three common clinical OP diagnostic markers(bone mineral density(BMD),serum osteocalcin(OCN),and tartrate-resistant acid phosphatase(TRAP)levels)using genome-wide association study(GWAS)summary statistics.Additionally,we established animal models to further analyze and compare the anti-osteoporosis effects of simvastatin and metformin.8 male C57BL/6J mice(3-month-old)and 24 male C57BL/6J mice(18-month-old)were treated with simvastatin or metformin for 12 weeks.OP pathology was assessed using histology,immunohistochemistry,biomechanical tests,micro-computed tomography,and osteogenic differentiation assays.Results:In the MR analysis,metformin treatment was significantly associated with lower OP prevalence(OR(95%CI)=0.933(0.902–0.965),β=-0.0694,P<0.001)and higher BMD(OR(95%CI)=3.719(1.750–7.908),β=1.3136,P<0.001).In the animal experiment,both drugs increased bone mass,improved bone microstructure,and promoted osteoblast differentiation.However,metformin appeared more effective in several aspects.It significantly inhibited bone marrow adipocyte and osteoclast differentiation in aged mice compared to simvastatin.Additionally,metformin better promoted the expression of osteoprotegerin(OPG)and collagen type I(Col-I)in bone tissue and maintained the structure and biomechanical properties of cancellous bone.Conclusion:Both drugs significantly preserved bone homeostasis.Particularly,compared with simvastatin,metformin exhibited superior effects in inhibiting adipogenesis,enhancing the OPG/RANKL pathway,and promoting cancellous bone reconstruction.Metformin may serve as a valuable adjunct in preventing and treating OP in the elderly.

Simvastatin对大鼠坐骨神经crush损伤修复作用研究

目的探讨他汀类(statins)药物Simvastatin在大鼠坐骨神经损伤修复中的作用及可能的作用机制。方法制作SD大鼠标准坐骨神经钳夹损伤(crush)模型后,分别予Simvastatin和溶媒对照干预2周。手术前后不同时间点进行趾展功能指数测定、神经电生理学、血脂水平、血清IL-6检测和组织学评价。结果Simvastatin干预组与对照组比较,趾展功能指数在术后5d和8d显著增大(P<0.05),足趾展开速度快;2周肌肉复合动作电位幅度高,4周神经传导速度快;组织学显示有髓神经纤维数量多,髓鞘厚,排列相对整齐。各组手术前血脂水平无差异,手术后2周均有不同程度的降低,但Simvastatin干预组总胆固醇降低程度最轻,与对照组比较有显著差异(P<0.05);Simvastatin干预组手术后5d,血清IL-6水平明显低于对照组(P<0.05)。结论本研究发现,Simvastatin可能通过抑制免疫炎症反应,维持神经损伤后胆固醇的平衡,促进大鼠坐骨神经损伤的修复和再生。

Simvastatin抑制白介素-6的产生促进大鼠坐骨神经再生

[目的]探讨他汀类(statins)药物S imvastatin促进大鼠坐骨神经修复及其免疫调节机制。[方法]制作SD大鼠坐骨神经钳夹损伤(crush)模型,分别予S imvastatin和溶媒(0.3%羧甲基纤维素钠)对照干预2周,并设立假手术组。手术后作行为学、神经电生理学、组织学计价和血清TNFα-和IL-6检测。[结果]S imvastatin干预组趾展功能指数在术后5、8 d较对照组大,2周肌肉复合动作电位(CMAP)幅度高,4周神经传导速度(NCV)快;手术后5 d,血清IL-6和TNFα-水平均低于对照组,尤以IL-6为明显;S imvastatin干预组神经再生形态优于对照组。[结论]S imvastain可能通过减少血清IL-6和TNFα-的生成,抑制免疫反应,对大鼠坐骨神经crush损伤修复产生促进作用。

Preventive and therapeutic effect of simvastatin on secondary inflammatory damage of rats with cerebral hemorrhage

Objective:To investigate the preventive and therapeutic effect and mechanism of simvastatin on secondary inflammatory damage of rats with cerebral hemorrhage.Methods:Sixty SD rat aged 9-12 weeks were chosen and divided into the control group,model group and simvastatintreated group randomly with 20 rats in each group.Rats in the model group and simvastatintreated group were infused with autologous fresh uncoagulated blood to the right brain tissue of the basal ganglia to build the cerebral hemorrhage model,while rats in the control group were treated with the same amount of normal saline.Then,rats in the simvastatin-treated group were given a gavage of 3 mg/kg of simvastatin once a day after modeling.Rats in the three groups were given nerve dysfunction score(NDS) and wet-dry weighting method was used to detect the brain water content(BWC) of brain tissues around the lesion of the rats.Then Nissl staining was conducted and the undamaged neurons were counted.Immunohistochemical SP method was applied to count the number of NF-d the immuno fluorκB,TLR4 and IL-1escence method wasβ positive cells in brain tissues around the lesions,an employed to determine the expression levels of NF-κB,TLR4 and IL-1me points were aβ proteins.Results:The NDS results of the simvastatin-treated group at all till significantly higher than those of the model group(P < 0.05);the BWC values of the simvastatin-treated group at all time points were all significantly lower than those of the model group at the same periods(P < 0.05);the number of the undamaged neurons around the lesions of the simvastatin-treated group at all time points were all significantly higher than those of the model group(P < 0.05);seven days after treatment,the number of the NF-κB,TLR4 and IL-1β positive cells in brain tissues around the lesions of the simvastatin-treated group were all significantly lower than those of the model group(P < 0.05),and its expression levels of NF-ower than those of the model group(κB,TLR4 and IL-1P < 0.05).Conclusioβ protein were also significantly lns:Simvastatin can inhibit the expressions of NF-κB,TLR4 and IL-1β proteins in rats with cerebral hemorrhage,and protect neurons and reduce secondary inflammatory damages by down-regulating the above protein-mediated inflammatory responses.

The Effect of Simvastatin on mRNA Expression of Transforming Growth Factor-β1,Bone Morphogenetic Protein-2 and Vascular Endothelial Growth Factor in Tooth Extraction Socket

Aim To determine the effect of local simvastatin application on the mRNA expression level of transforming growth factor-β1 （TGF-β1）, bone morphogenetic protein-2 （BMP-2） and vascular endothelial growth factor （VEGF） in the tooth sockets of rat. Methodology Forty-eight male Wistar rats were randomly divided into experimental and control groups （n=24）. Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The expression of TGF-β1, BMP-2 and VEGF mRNA was determined by in situ hybridization in the tooth extraction socket at five days, one week, two weeks and four weeks after implantation. Results The fusiform stroma cells in the tooth extraction socket began to express TGF-β1, BMP-2 and VEGF mRNA in both experimental and control groups from one week after tooth extraction until the end of experiment. The expression of TGF-131 and BMP-2 mRNA in the experimental group was significantly up-regulated after one, two and four weeks, and expression of VEGF mRNA was significantly increased after one and two weeks compared with that in the control group. Conclusion The findings indicate that local administration of simvastatin can influence alveolar bone remodeling by regulating the expression of a school of growth factors which are crucial to osteogenesis in the tooth extraction socket.

Simvastatin Increases the Activity of Endothelial Nitric Oxide Synthase via Enhancing Phosphorylation

3-hydroxy-3-methylgulutaryl-coenzyme A （HMG-CoA） reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies suggested that statins, besides lowering cholesterol, may protect vessels by enhancing the activity of endothelial nitric oxide synthase （eNOS）. In the present study, we investigated if simvastatin increases eNOS activity through its phosphorylation in 293 cells （293-eNOS） with stable expression of eNOS. The results showed that incubation of 293-eNOS cells with simvastatin （10 μm/L） for 2 h significantly increased in the activity of eNOS as shown by the conversion of L-arginine to L-citrulline （2889.70±201.51 versus 5630.18＋218.75 pmol/min . mg proteins） （P〈0.01）. Western blotting revealed that simvastatin increased phosphorylation of eNOS at 1177 （ser） and also 495 （thr） but did not affect the overall expression of eNOS or inducible NOS. Further study found that simvastatin raised phosphorylation levels of Akt and AMPK, and such effect could be antagonized by Akt inhibitor or AMPK inhibitor. These results suggest that simvastatin could stimulate,the activity of eNOS via its phosphorylation by Akt and AMPK, which provides a new mechanism, other than lipid-lowering effect, for the cardiovascular protection of statins.

Simvastatin inhibits apoptosis of endothelial cells induced by sepsis through upregulating the expression of Bcl-2 and downregulating Bax

BACKGROUND: Many studies have showed that apoptosis of endothelial cells plays a curial role in the progress of sepsis. But the role of simvastatin in apoptosis of endothelial cells induced by sepsis is not clear. The present study aimed to investigate the role of simvastatin in apoptosis of endothelial cells induced by sepsis and its mechanism.METHODS: Human umbilical vein endothelial cells(HUVECs) were randomly divided into three groups: control group, sepsis serum intervention group(sepsis group) and simvastatin+sepsis serum intervention group(simvastatin group). After 24-hour incubation with corresponding culture medium, the relative growth rate of HUVECS in different groups was detected by MTT assay; the apoptosis of HUVECs was detected by Hoechst33258 assay and fl ow cytometry; and the expression of the Bcl-2 and Bax genes of HUVECs was detected by PCR.RESULTS: Compared with the sepsis group, HUVECs in the simvastatin group had a higher relative growth rate. Apoptotic HUVECs decreased significantly in the simvastatin group in comparison with the sepsis group. Expression of the Bcl-2 gene in HUVECs decreased obviously, but the expression of the Bax gene increased obviously after 24-hour incubation with sepsis serum; however, the expression of the Bcl-2 and Bax genes was just the opposite in the simvastatin group.CONCLUSIONS: Our study suggests that simvastatin can inhibit apoptosis of endothelial cells induced by sepsis through upregulating the expression of Bcl-2 and downregulating Bax. It may be one of the mechanisms for simvastatin to treat sepsis.

Addition of simvastatin to carvedilol non responders: A new pharmacological therapy for treatment of portal hypertension

AIMTo determine whether addition of simvastatin could be an important pharmacological rescue therapy for carvedilol non-responders. METHODSOne hundred and two consecutive patients of cirrhosis of liver with significant portal hypertension were included. Hepatic venous pressure gradient (HVPG) was measured at the base line and after proper optimization of dose; chronic response was assessed at 3 mo. Carvedilol non-responders were given simvastatin 20 mg per day (increased to 40 mg per day at day 15). Carvedilol plus simvastatin was continued for 1 mo and hemodynamic response was again measured at 1 mo. RESULTSA total of 102 patients with mean age of 58.3 ± 6.6 years were included. Mean baseline HVPG was 16.75 ± 2.12 mmHg and after optimization of dose and reassessment of HVPG at 3 mo, mean reduction of HVPG from baseline was 5.5 ± 1.7 mmHg and 2.8 ± 1.6 mmHg among responders and non-responders respectively (P CONCLUSIONAddition of simvastatin to carvedilol non-responders may prove to be an excellent rescue therapy in patients with portal hypertension.

Simultaneous determination of ezetimibe and simvastatin in rat plasma by stable-isotope dilution LC-ESI-MS/MS and its application to a pharmacokinetic study

A simple, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed for simultaneous quantification of ezetimibe and simvastatin in rat plasma. The deuterium isotopes： ezetimibe d4 and simvastatin d6 were used as internal standards for ezetimibe and simvastatin, respectively. MS/MS detection involved a switch of electron spray ionization mode from negative to positive at retention time 3.01 rain. Samples were extracted from plasma by liquid-liquid extraction using tertiary butyl methyl ether. Chromatographic separation was achieved with Agilent Eclipse XBD-CIs column using mobile phase that consisted of a mixture of ammonium acetate （pH4.5; 10 mM）-acetonitrile （25：75 v/v）. The method was linear and validated over the concentration range of 0.2--40.0 ng/rnL for simvastatin and 0.05-15.0 ng/mL for ezetimibe. The transitions selected were m/z 408.3→271.1 and m/z 412.0→275.10 for ezetimibe and ezetimibe d4, and m/z 419.30 → 285.20 and rrdz 425.40 →199.20 for simvastatin and simvastatin d6. Intra- and inter-batch precisions for ezetimibe were 1.6-14.8% and 2.1-13.4%; and for simvastatin 0.94-9.56% and 0.79-12%, respectively. The proposed method was sensitive, selective, precise and accurate for the quantification of ezetimibe and simvastatin simultaneously in rat plasma. The method was successfully applied to a pharmacokinetic study by oral co-administration of ezetimibe and simvastatin in SD rats.

Effects of Simvastatin on NF-κB-DNA Binding Activity and Monocyte Chemoattractant Protein-1 Expression in a Rabbit Model of Atherosclerosis

To observe the effects of simvastatin on nuclear factor kappaB （NF-kB）-DNA binding activity and on the expression of monocyte chemoattractant protein-1 （MCP-1） in atherosclerotic plaque in rabbits and to explore the anti-atherosclerotic properties beyond its lipid-lowering effects. Thirty-six New Zealand male rabbits were randomly divided into low-cholesterol group （LC）, high- cholesterol group （HC）, high-cholesterol＋ simvastatin group （HC＋S） and then were fed for 12 weeks. At the end of the experiment, standard enzymatic assays, electrophoretic mobility shift as- say （EMSA）, immunohistochemical staining, and morphometry were performed to observe serum lipids, NF-kB-DNA binding activity, MCP-1 protein expression, intirna thickness and plaque area of aorta respectively in all three groups. Our results showed that the serum lipids, NF-kB-DNA binding activity, expression of MCP-1 protein, intima thickness, and plaque area of aorta in the LC and HC＋S groups were significantly lower than those in the HC group （P〈0.05）. There was no significant difference in the serum lipids between the LC and HC＋S groups （P〉0.05）, but the NF-kB-DNA binding activity, the expression of MCP-1 protein and the intirna thickness and plaque area of aorta in the HC＋S group were significantly decreased as compared to the LC group （P〈0. 05）. This study demonstrated that simvastatin could decrease atherosclerosis by inhibiting the NF-kB-DNA binding activity and by reducing the expression of MCP-1 protein.

Influence of simvastatin on dopaminergic neurons of lipopolysaccharide—induced rat model of Parkinson's disease

Objective::To investigate the neuroprotective effects of simvastatin on lipopolysaccharide(LPS)-indueed rat model of Parkinson's disease(PD) and the mechanisms involved.Methods:Hemiparkinsonian rat models were induced by stereotaxieal injection of LPS in the right substantia nigra compacts.After 2 weeks of simvastatin treatment,rotational behavior test was performed after the intraperitoneal injection of apomorphine.Expression of tyroxine hydroxylase(TH) and glial fibrillan acidic protein were analyzed through immunohistochemical staining of substantia nigra and striatum,and the level of TNF-α was evaluated using enzyme-linked immunosorbent assay.Results:Comparing with untreated group,behavioral symptoms of the rats were significantly less in the rats that received simvastatin treatment.The TH positive cell count in substantia nigra and striatum were significantly increased(P<0.05) and TNF- α expression was significantly decreased(P<0.05) in simvastatin group compared to untreated group.Conclusions:Simvastatin could effectively inhibit the activation of astrocytes,reduce TNF-α expression,and exert anti-inflammatory effects,and thus protect the dopaminergic neurons in substantia nigra and striatum of the rat model of PD.

Effect of simvastatin on paraoxonase 1(PON1) activity and oxidative stress

Objective:To investigate the effect of simvastatin treatment on lipid pr of ile and oxidative stress in hypercholesterolaemic Indian population and determine the effect of simvastatin treatment on the activity of paraoxonase（PON）.Methods:Analyzed initially before medication administration and four months later after medication.Lipid and lipoprotein measurement were done by enzymatic kits,high density lipoprotein（HDL） was determined by phosphotungstic acid precipitation method and low density lipoprotein（LDL） was calculated by Friedewald’s formula.Lipid peroxidation was measured by three markers namely,conjugated diene,total peroxide,and malondialdehyde.Conjugated diene was assayed by Buege and Aust method.Total peroxide was determined by FOX2 method.Malondialdehyde determination was carried out by Flemming method and total antioxidant status was determined by Ozacan.Paraoxonase activity was determined by measuring the absorbance inrease of p-nitrophenol at 405 nm.Arylesterase activity was calculated from the molar coefficient of 1 310 M-1 cm-1.Results:Simvastatin significantly reduced total cholesterol,triglycerides,LDL,conjugated diene,total peroxide and MDA levels,where as antioxidant status was significantly increased.Besides,simvastatin significantly increased PON1 activity towards paraoxon.Conclusions:The results from the current study indicate simvastatin may have important antioxidant properties via increasing PON activity.

Effect of Taizhi'an Capsule (泰脂安胶囊) Combined with Simvastatin on Hyperlipidemia in Diabetic Patients

To evaluate the effectiveness and safety of Taizhi＇an （泰脂安, TZA） capsule combined with Simvastatin （Sim） in treating hyperlipidemia in diabetes mellitus （DM） patients. Methods： Eighty cases of type 2 DM patients with hyperlipidemia were randomized into two groups, 40 in each group. The patients in the treated group took orally TZA capsules at the dose of 0.9 g 3 times a day and Sim 10 mg at bedtime. And the patients in the control group were treated with Sim 20 mg alone at bedtime. Both regimens lasted for 12 weeks. Before and after the study the changes of blood lipid levels and adverse reaction were investigated. Results. The serum levels of total cholesterol （TO）, triglycerides （TG） and low density lipoprotein-cholesterol （LDL-C） were decreased respectively by 28.8%, 18.2% and 26.3% in the treated group; and by 29.4%, 19.4% and 24.6% in the control group. On the contrary, high density lipoprotein-cholesterol （HDL-C） was increased by 23.5% in the treated group and by 29.4% in the control group. All these changes were statistically significant before and after treatment （all P〈0.05）, but they did not differ statistically between the two groups （P〉0.05）. There was no significant changes in hemoglobin A1 c （HbA1c）. Patients in the treated group did not develop any adverse reactions. However, ALT was found to be higher above the normal range in 5% of the patients in the control group. Conclusion： In treating hyperlipidemia in DM patients, combination of TZA with Sim 10 mg taken daily achieved satisfactory efficacy which was similar to Sim 20 mg daily alone. But the combination therapy conducted in the treated group proved to be better in safety, and could overcome adverse reactions resulting from Sim that was seen in the control group.

Pretreatment with simvastatin upregulates expression of BK-2R and CD11b in the ischemic penumbra of rats

Inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A reductases, collectively known as statins, have been shown to minimize cerebral ischemic events in patients. We assessed the mechanisms of simvastatin pretreatment in preventing cerebral ischemia/reperfusion injury in rats using a model of middle cerebral artery occlusion（MCAO）.Rats were pretreated with simvastatin 14 days prior to MCAO induction. At 3, 24, and 48 hours after reperfusion,bradykinin levels in the ischemic penumbra were assayed by ELISA, mRNA levels of bradykinin B2 receptors（BK-2Rs） and CD11b were measured by fluorescent quantitative real-time PCR（RT-PCR）, and co-expression of microglia and BK-2Rs was determined by immunofluorescence. Simvastatin had no effect on bradykinin expression in the ischemic penumbra at any time point. However, the levels of BK-2R and CD11b mRNA in the ischemic penumbra,which were significantly decreased 3 hours after ischemia-reperfusion, were increased in simvastatin-pretreated rats.Moreover, the co-expression of BK-2Rs and microglia was confirmed by immunofluorescence analysis. These results suggest that the beneficial effects of simvastatin pretreatment before cerebral ischemia/reperfusion injury in rats may be partially due to increased expression of BK-2R and CD11b in the ischemic penumbra.

Rhabdomyolysis induced by simvastatin-diltiazem interaction in unrecognized hypothyriodism

Simvastatin,a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor,is widely prescribed to patients with hypercholesteremia and its muscular toxicity has been widely reported.The metabolism of simvastatin depends on the enzymic activity of cytochrome P450 3A4 （CYP3A4） and inhibitors of CYP3A4 can result in clinical events by interacting with simvastatin.Diltiazem is a moderate inhibitor of CYP3A4,which is known to increase the serum concentration of simvastatin.Here we report a patient with unrecognized hypothyroidism who had been stable for more than one year on low-dose simvastatin therapy of hypercholesteremia and rhabdomyolysis occurred with the addition of diltiazem.This is one of scanty reports of rhabdomyolysis induced by simvastatindiltiazem drug interaction,especially in hypothyroid patient.This case reminds the clinicians that although diltiazem as a moderate CYP3A4 inhibitor can be used cautiously with small doses of CYP3A4-dependent statius （eg,simvastatin）,these two commonly used drugs should be avoided in hypothyroid patient.

Effects of simvastatin on lipid levels and platelet activation in elderly patients with hypercholesterolemia

Background and Objective To investigate the effects of simvastatin on lipid lowering therapy and platelet activation in elderly patients with hypercholesterolemia. Methods Fasting serum lipids, CD63, CD41a, serum glucose, hepatic and renal function, routine urine analysis (UA) were measured in 50 healthy subjects, and in 50 elderly patients with hypercholesterolemia before and after 4 weeks treatment with simvastatin (20mg daily for 4 weeks). Results 1. After simvastatin treatment for 4 weeks, the fasting serum level of lipids in elderly patients with hypercholesterolemia was significantly lower than before treatment (P<0.01). 2. CD63 and CD41a were decreased after treatment compared with before, respectively (1.36 0.34) vs (4.26 1.06), (P<0.01) and (123.54 19.73) vs (253.78 16.75), (P<0.01). 3. Changes in serum lipid level tended to be positively correlated with the declines in CD63 and CD41a, but there was no statistical significance (P>0.05). Conclusions The results suggested that lipid lowering therapy with simvastatin inhibit platelet activity.(J Geriatr Cardiol 2007;4:215-217.)

Effect of Simvastatin on IL-6 and Adiponectin Secretion and mRNA Ex- pression in 3T3-L1 Adipocytes

In order to investigate the effects of simvastatin on secretion and mRNA expression of interleukin-6 (IL-6) and adiponectin in 3T3-L1 adipocytes, mouse 3T3-L1 adipocytes were stimu- lated with lipopolysaccharide (LPS). Production and mRNA expression of IL-6 and adiponectin in 3T3-L1 adipocytes were measured using enzyme-linked immunosorbent assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. The results showed that simvastatin could significantly suppress LPS-induced IL-6 production and mRNA expression in adipocytes (P<0.05), but increase the LPS-induced adiponectin secretion and mRNA expression in a dose-dependent manner (P<0.05). It was suggested that simvastatin could exert beneficial effects on prevention of obesity-induced metabolic changes in adipocytes.

Comparison of conventional and supported liquid extraction methods for the determination of sitagliptin and simvastatin in rat plasma by LC-ESI-MS/MS

Three extraction methods were compared for their efficiency to analyze sitagliptin and simvastatin in rat plasma by LC-MS/MS, including （1） liquid-liquid extraction （LLE）, （2） solid phase extraction （SPE） and （3） supported liquid extraction （SLE）. Comparison of recoveries of analytes with different extraction methods revealed that SLE was the best extraction method. The detection was facilitated with ion trap-mass spectrometer by multiple reactions monitoring （MRM） in a positive ion mode with ESI. The transitions monitored were m./z 441.1→325.2 for simvastatin, 408.2→235.1 for sitagliptin and 278.1→260.1 for the IS. The lower limit of quantification （LLOQ） was 0.2 ng/mL for sitagliptin and 0.1 ng/mL for simvastatin. The effective SLE offers enhanced chromatographic selectivity, thus facilitating the potential utility of the method for routine analysis of biological samples along with pharmacokinetic studies.

Effects of simvastatin on early oxidative stress and endothelial function in apolipoprotein E-deficient mice

Objective： To investigate the mechanisms that Simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A（HMG-CoA） reductase inhibitor, plays an important role in primary prevention of atherosclerosis independently of its lipid-lowering effect in Apolipoprotein E-deficient mice in the early stage of atherosclerosis. Methods： Twenty-four 6-week old male apoE-deficient mice were randomly divided into two groups：control group（normal saline） and treatment group[simvastatin（5 mg/（kg · d））]. Simvastatin was administered to treatment group mice by gavage and the same volume of normal saline was administered to control group mice by the same method for 2 or 4 weeks. Total cholesterol（TC）, super-oxide dismutase（SOD）, malondialdehyde（MDA） and serum nitric oxide（NO） were measured by biochemical analysis. Results： There was no significant difference in serum TC between control and treatment groups. Compared with the control＇ s, the effects of simvastatin were more significant in decreasing serum MDA level（P 〈 0.01 vs control＇ s at 2-week; P 〈 0.006 vs control＇ s at 4-week）, increasing serum SOD level（P 〈 0.03 vs control＇ s at 2-week; P 〈 0.003 vs control＇ s at 4-week） and NO level （P 〈 0.01 control＇ s at 2-week; P 〈 0.001 vs control＇ s at 4-week） either at 2 or 4 weeks. Conclusion： Simvastatin attenuates oxidative stress and protects endothelial function by the mechanisms of decreasing serum MDA level, increasing serum SOD level and NO level, which were inconsistent with its cholesterol-lowering effect. It may play an important role in primary（if not all） prevention of atherosclerosis and might be independent of lipid-regulation mechanism.