Coadministration Of Simvastatin Research Articles

Simvastatin and adenosine-co-loaded nanostructured lipid carriers for wound healing: Development, characterization and cell-based investigation

Chronic wounds represent a significant global health burden, characterized by delayed skin healing and associated comorbidities. The present study aimed to develop nanostructured lipid carriers (NLCs) as a topical delivery system for the co-administration of simvastatin and adenosine to address chronic wound management. The rationale behind the co-delivery approach was to mitigate the cytotoxicity associated with high-dose simvastatin, while preserving its therapeutic benefits through a potential synergistic or additive effect. A significant challenge in the development of these NLCs was the encapsulation of the highly hydrophilic adenosine within the hydrophobic lipid matrix. The NLCs were prepared using a hot homogenization-sonication method with a double emulsion technique and optimized through a series of formulation trials, employing various surfactants, solid and liquid lipids, to achieve efficient drug encapsulation, particularly for the hydrophilic adenosine. Optimized formulations F5- and F10-S/A 0.6 %/2 % (containing 0.6 % simvastatin and 2 % adenosine), exhibited promising physicochemical properties. The main difference was the liquid lipid used: F5 contained Miglyol 810 N, while F10 contained Capmul MCM C-8. Both formulations displayed a mean particle size below 230 nm, a polydispersity index (PDI) of approximately 0.2, and a zeta potential around –22 mV. While simvastatin association efficiency (AE) was nearly 100 %, adenosine AE was higher for F10 (24 %), compared to F5 (13.5 %). F5 demonstrated superior stability compared to F10, maintaining consistent particle size and PDI over a 60-day period. Formulation F5 also demonstrated superior cell-based in vitro performance compared to F10, with higher cell viability (MTT assay), greater cell proliferation induction (SRB assay), and enhanced cell proliferation and migration in the wound-scratch assay. While F10 displayed higher adenosine AE, F5 excelled in terms of stability and biological activity. The slight increase in intracellular reactive oxygen species levels observed with F5 may contribute to its enhanced proliferative effects. In-depth characterization revealed that F5 comprised spherical nanoparticles, and thermal analysis indicated no significant changes in the nanocarrier structure upon drug encapsulation. Additionally, ex vivo permeability study demonstrated superior skin retention of both simvastatin and adenosine for F5 compared to an emulsion control. Overall, the F5 nanocarrier demonstrated suitable physicochemical properties, cellular biocompatibility, induction of cell proliferation and migration events, and drug retention capacity in the skin layers, indicating its potential as a promising topical treatment for difficult-to-heal wounds.

Effects of Simvastatin on Pharmacokinetics and Anticoagulant Effects of Dabigatran in Healthy Subjects.

Higher risk of major hemorrhage associated with concomitant use of dabigatran and simvastatin compared to other statins was previously reported with a suggestion of P-glycoprotein-mediated interaction. The aim of this study was to evaluate the effects of simvastatin on pharmacokinetics and anticoagulant effects of dabigatran, a direct oral anticoagulant. A total of 12 healthy subjects were enrolled in an open-label, two-period, single sequence study. Subjects were given 150 mg of dabigatran etexilate followed by 40 mg of once-daily simvastatin for seven days. Dabigatran etexilate was administered with simvastatin on the seventh day of simvastatin administration. Blood samples for pharmacokinetic and pharmacodynamic analyses were obtained until 24 h post-dose of dabigatran etexilate with or without co-administration of simvastatin. Pharmacokinetic parameters were derived from noncompartmental analysis for dabigatran etexilate, dabigatran, and dabigatran acylglucuronide. When simvastatin was co-administered, geometric mean ratios of area under time-concentration curves for dabigatran etexilate, dabigatran, and dabigatran acylglucuronide were 1.47, 1.21, and 1.57, respectively, compared to when dabigatran etexilate was administered alone. Thrombin generation assay and coagulation assay showed similar profiles between before and after co-administration of simvastatin. This study provides evidence that simvastatin treatment plays a minor role in modulating pharmacokinetics and anticoagulant effects of dabigatran etexilate.

Simvastatin Coadministration Modulates the Electrostatically Driven Incorporation of Doxorubicin into Model Lipid and Cell Membranes.

Understanding the interactions between drugs and lipid membranes is a prerequisite for finding the optimal way to deliver drugs into cells. Coadministration of statins and anticancer agents has been reported to have a positive effect on anticancer therapy. In this study, we elucidate the mechanism by which simvastatin (SIM) improves the efficiency of biological membrane penetration by the chemotherapeutic agent doxorubicin (DOX) in neutral and slightly acidic solutions. The incorporation of DOX, SIM, or a combination of them (DOX:SIM) into selected single-component lipid membranes, zwitterionic unsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), neutral cholesterol, and negatively charged 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) was assessed using the Langmuir method. The penetration of neutral lipid monolayers by the codelivery of SIM and DOX was clearly facilitated at pH 5.5, which resembles the pH conditions of the environment of cancer cells. This effect was ascribed to partial neutralization of the DOX positive charge as the result of intermolecular interactions between DOX and SIM. On the other hand, the penetration of the negatively charged DMPS monolayer was most efficient in the case of the positively charged DOX. The efficiency of the drug delivery to the cell membranes was evaluated under in vitro conditions using a panel of cancer-derived cell lines (A172, T98G, and HeLa). MTS and trypan blue exclusion assays were performed, followed by confocal microscopy and spheroid culture tests. Cells were exposed to either free drugs or drugs encapsulated in lipid carriers termed cubosomes. We demonstrated that the viability of cancer cells exposed to DOX was significantly impaired in the presence of SIM, and this phenomenon was greatly magnified when DOX and SIM were coencapsulated in cubosomes. Overall, our results confirmed the utility of the DOX:SIM combination delivery, which enhances the interactions between neutral components of cell membranes and positively charged chemotherapeutic agents.

The Effect of Simvastatin and Vitamin D Co-Administration on Rats Brain Function and Behavior: A Behavioral and Biochemical Study

Background & Objective: The simvastatin (Sim) is a lipophilic statin and can cross the blood-brain barrier. The role of vitamin D (Vit D) in brain development and function has been supported over the past decade. This study aimed to evaluate the effect of simvastatin on memory and anxiety levels in healthy male rats.
 Materials & Methods: In this experimental study, 36 male Wistar rats weighing 250-300 g were randomly divided into six groups (n=6) including control, Vit D (5 µg/kg/day; IP), Simvastatin (1 mg/kg/day; orally) (SimL), Simvastatin (10 mg/kg/day; orally) (SimH), SimL + Vit D and SimH + Vit D. After 28 days, at the end of the treatment, the behavioral anxiety test and memory behavioral test were performed. Then, the rats were euthanized, and oxidative stress markers of the brain, serum low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and cholesterol levels were investigated. Data were analyzed by SPSS 24 software and Tukey’s test.
 Results: Co-administration of simvastatin and vitamin D significantly increased working memory, catalase activity, total antioxidant capacity, HDL-C, and decreased anxiety levels, malondialdehyde (MDA) concentration, cholesterol, and LDL-C compared to the control group (p<0.05). However, the administration of simvastatin and vitamin D alone did not significantly change the mentioned parameters compared to the control group (p>0.05).
 Conclusion: Co-administration of simvastatin and vitamin D can improve brain function by reducing oxidative stress and cholesterol levels.

Co-Administration of Simvastatin Does Not Potentiate the Benefit of Gene Therapy in the mdx Mouse Model for Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is the most common and cureless muscle pediatric genetic disease, which is caused by the lack or the drastically reduced expression of dystrophin. Experimental therapeutic approaches for DMD have been mainly focused in recent years on attempts to restore the expression of dystrophin. While significant progress was achieved, the therapeutic benefit of treated patients is still unsatisfactory. Efficiency in gene therapy for DMD is hampered not only by incompletely resolved technical issues, but likely also due to the progressive nature of DMD. It is indeed suspected that some of the secondary pathologies, which are evolving over time in DMD patients, are not fully corrected by the restoration of dystrophin expression. We recently identified perturbations of the mevalonate pathway and of cholesterol metabolism in DMD patients. Taking advantage of the mdx model for DMD, we then demonstrated that some of these perturbations are improved by treatment with the cholesterol-lowering drug, simvastatin. In the present investigation, we tested whether the combination of the restoration of dystrophin expression with simvastatin treatment could have an additive beneficial effect in the mdx model. We confirmed the positive effects of microdystrophin, and of simvastatin, when administrated separately, but detected no additive effect by their combination. Thus, the present study does not support an additive beneficial effect by combining dystrophin restoration with a metabolic normalization by simvastatin.

Modulation of the Nitric Oxide/BH4 Pathway Protects Against Irradiation-Induced Neuronal Damage.

The kynurenine pathway (KP, IDO/Kyn pathway) is an important metabolic pathway related to many diseases. Although cranial radiotherapy is the mainstay in metastatic tumors management, its efficacy is limited owing to the associated neuropsychiatric disorders. Sildenafil (SD) and simvastatin (SV) were reported to have antioxidant/anti-inflammatory effects and to serve as NO donor/BH4 regulator, respectively. Fluoxetine (Fx) is an FDA-approved anti-depressant agent and one of the selective serotonin reuptake inhibitor drugs (SSRI), used in neurological disorder treatment. The study objective was to investigate the role of cranial irradiation (C-IR) on KP signaling impairment and the possible intervention by SD and/or SV (as nitric oxide (NO) donor/Tetrahydrobiopterin (BH4) regulatory) on KP following C-IR-induced disruption compared with Fx (as standard drug).Herein, rats were exposed to C-IR at a single dose level of 25Gy, then treated with sildenafil (SD) and/or simvastatin (SV), and fluoxetine (Fx) at doses of 75, 20, 10mg/kg/day, respectively. The body weight gain and forced swimming test (FST) were used for evaluation along with the biochemical quantifications of KP intermediates and histopathological examination of cortex and hippocampus. The results indicated a significant activation of KP following C-IR as manifested by decreased Trp content and increased activities of indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) with a rise in kynurenine (KYN) and quinolinic acid (QA) hippocampal contents. In addition, a state of C-IR-induced oxidative stress, inflammation, NO-pathway dysregulation and neuronal apoptosis were observed as compared to the control group. However, significant modulations were recorded after the combined administration of SD and SV than those offered by each of them alone and by Fx. The biochemical assessment results were supported by the histopathological tissue examination. It could be concluded that the co-administration of SV and SD offers a neuroprotective effect against irradiation-induced brain injury due to its NO donor/BH4 regulatory activities, anti-inflammatory and antioxidant properties that modulate IDO/KYN pathway.

Piceatannol reduces resistance to statins in hypercholesterolemia by reducing PCSK9 expression through p300 acetyltransferase inhibition

The purpose of this study was to investigate the role of piceatannol (PT) in statin (rosuvastatin and simvastatin) resistance and tolerance and its association with PCSK9 expression via its p300 inhibitory (p300i) activity. An in vitro study was performed using HepG2 cells that were exposed to statins (rosuvastatin or simvastatin) with or without PT in delipidated serum (DLPS) medium. In the statin exposed conditions, PCSK9 expression was reduced following PT treatment when compared to HepG2 cells w/o PT treatment. Furthermore, no significant difference was observed in the expression of the transcription factors SREBP2 and HNF1α, which regulate PCSK9 expression. This resulted in low density lipoprotein receptor (LDLR) stabilization and reduced cellular cholesterol levels. This indicates that PT epigenetically controls statin-induced PCSK9 expression. Interestingly, PT attenuated p300 histone acetyltransferase (HAT) activity. Moreover, simulation of PT-p300 binding suggested that PT inhibits p300 as PT could be docked in the p300 HAT domain. Furthermore, inhibition of p300 HAT activity using C-646, a selective p300 inhibitor, or through an siRNA system effectively reduced PCSK9 induction upon statin exposure in HepG2 cells. The chromatin immunoprecipitation (ChIP) assays revealed that PT blocked the recruitment of p300 to the PCSK9 promoter region. In summary, PT attenuated statin-induced PCSK9 expression by inhibiting p300 HAT activity. Finally, co-administration of simvastatin and PT for 10 weeks further reduced plasma low-density lipoprotein-cholesterol (LDL-C) levels and stabilized the hepatic LDLR protein level compared with those resulting from single treatment of simvastatin in a high-fat diet-induced hypercholesterolemia mouse model. Our findings indicate that PT is a new nutraceutical candidate to reduce the statin resistance and tolerance that occurs in patients with hypercholesterolemia.

Effects of multidose simvastatin co-administration on pharmacokinetic profile of apatinib in rats by UPLC-MS/MS

Apatinib, a small molecule anti-angiogenic tyrosine kinase inhibitor is used extensively to treat advanced gastric cancer and simvastatin (SV) is often co-prescribed to treat cardiovascular disease in cancer patients. As both apatinib and SV are metabolized primarily by cytochrome P450 variant CYP3A4, they are likely to interact. Therefore, the potential effect of SV co-administration on pharmacokinetics of apatinib in Sprague-Dawley male rats is demonstrated for the first time.Sixteen rats were randomly divided into two groups (n = 8), 2 mg/kg SV orally co-administrated for seven days (group B) and the corresponding control group (group A). Apatinib concentrations of rat plasma samples were detected by ultra-performance liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were calculated using non compartmental methods.Co-administration of SV for seven days significantly increased area under curve (AUC(0-t)), AUC(0-∞) and maximum plasma concentration of apatinib by 2.4-, 2.4-, and 2.7-fold, respectively while decreasing apparent volume of distribution and clearance by 81.7 and 73.9%, respectively.These findings suggest that concomitant administration of SV with 7 days may have inhibited the metabolism of apatinib in rats.

Abstract P4-16-09: Effect of simvastatin on cardiac strain in breast cancer patients receiving anthracycline therapy

Abstract Background: Cardiac toxicity (CT) is a rare late effect of anthracycline therapy for breast cancer (BC). Statins may attenuate the CT of anthracyclines. Myocardial strain can detect subclinical CT before ejection fraction (EF) declines. Global longitudinal strain (GLS) ≥-19% and relative change (RelΔ) in GLS≥11% predict future decline in EF. We conducted a pilot study to evaluate the effect of simvastatin on GLS in BC patients receiving anthracyclines. Methods: We enrolled women with stage I-III BC planning doxorubicin/cyclophosphamide (AC) x 4. Women with heart disease or taking a statin were excluded. Participants were randomized 1:1 to simvastatin 40 mg daily x 24 weeks (wk) + AC or to AC alone. We performed echo with strain 5 times: baseline (BL), pre-AC#2, 1-3 wk after AC#4, 24 wk after AC #1 and 52 wk after AC#1. The primary endpoint was the mean absolute change (|Δ|) in GLS from BL to 1-3 wk after AC#4. Secondary endpoints included RelΔ in GLS, feasibility and safety. We used two-sample t-tests to compare mean changes in GLS and Fisher's exact test to compare dichotomized GLS values. The study closed early due to loss of staff. Results: Of 31 patients, 15 (48%) received simvastatin+AC. Mean age was 46 years; 71% pre-menopausal, 61% white and 32% black. There were no significant differences in BL cardiovascular risk factors between the arms. After AC, 3 HER2+ patients received trastuzumab. There were no grade 3-4 AEs with simvastatin. Common grade 1-2 AEs included myalgia (20%), elevated AST (27%) and elevated ALT (53%). One patient in the AC arm died from heart failure with low EF 2 months after having a normal echo 1-3 wk after AC#4. The rate of missing echos was 14%. Of 133 completed echos, 124 (93%) were evaluable for GLS. Mean GLS was <-19% at all times in the simvastatin+AC arm. Mean GLS was <-19% at BL and pre-AC#2 in the AC arm, but ≥-19% at post-AC times in the AC arm. Mean EF was >60% at all times in both arms. Among 27 patients evaluable for the primary endpoint, there was no significant difference in mean |Δ| in GLS from BL to 1-3 wk after AC#4 between the arms (Simvastatin+AC: 0.42%; AC: 1.11%, p=0.57). In addition, there were no differences in the mean|Δ| in GLS from BL to any other time between the arms (all p>0.1). The proportion of patients with GLS<-19% was higher in the simvastatin+AC arm than in the AC arm pre-AC#2 (73% vs 44%), 1-3 wk after AC#4 (67% vs 38%), 24 wk after AC #1 (53% vs 25%) and 52 wk after AC#1 (53% vs 25%) (all p>0.05). The proportion of patients with RelΔ in GLS≥11% from BL was lower in the simvastatin+AC arm than in the AC arm pre-AC#2 (13% vs 19%), 1-3 wk after AC#4 (20% vs 44%) and 24 wk after AC#1(27% vs 31%) (all p>0.05). Conclusion: Simvastatin did not result in a statistically significant difference in the mean |Δ| in GLS from BL to 1-3 wk after AC#4. However, the study was underpowered due to small sample size and there was a suggestion of reduced CT with simvastatin. Co-administration of simvastatin and AC was safe and serial echocardiographic strain monitoring was feasible. Further studies are needed to evaluate the cardioprotective effect of statins on strain in BC patients receiving anthracyclines. Citation Format: Smith KL, Griffin JM, Tsai H-L, Leathers M, Hays A, Lu D-Y, Zhang Z, Rosner GL, Russell SD, Connolly RM, Jelovac D, Visvanathan K, Wolff AC, Stearns V, Abraham T. Effect of simvastatin on cardiac strain in breast cancer patients receiving anthracycline therapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-16-09.

Combination therapy of simvastatin and 5, 6-dimethylxanthenone-4-acetic acid synergistically suppresses the aggressiveness of B16.F10 melanoma cells

The major drawback of current anti-angiogenic therapies is drug resistance, mainly caused by overexpression of the transcription factor, hypoxia-inducible factor 1α (HIF-1α) as a result of treatment-induced hypoxia, which stimulates cancer cells to develop aggressive and immunosuppressive phenotypes. Moreover, the cancer cell resistance to anti-angiogenic therapies is deeply mediated by the communication between tumor cells and tumor-associated macrophages (TAMs)—the most important microenvironmental cells for the coordination of all supportive processes in tumor development. Thus, simultaneous targeting of TAMs and cancer cells could improve the outcome of the anti-angiogenic therapies. Since our previous studies proved that simvastatin (SIM) exerts strong antiproliferative actions on B16.F10 murine melanoma cells via reduction of TAMs-mediated oxidative stress and inhibition of intratumor production of HIF-1α, we investigated whether the antitumor efficacy of the anti-angiogenic agent—5,6-dimethylxanthenone-4-acetic acid (DMXAA) could be improved by its co-administration with the lipophilic statin. Our results provide confirmatory evidence for the ability of the combined treatment to suppress the aggressive phenotype of the B16.F10 melanoma cells co-cultured with TAMs under hypoxia-mimicking conditions in vitro. Thus, proliferation and migration capacity of the melanoma cells were strongly decelerated after the co-administration of SIM and DMXAA. Moreover, our data suggested that the anti-oxidant action of the combined treatment, as a result of melanogenesis stimulation, might be the principal cause for the simultaneous suppression of key molecules involved in melanoma cell aggressiveness, present in melanoma cells (HIF-1α) as well as in TAMs (arginase-1). Finally, the concomitant suppression of these proteins might have contributed to a very strong inhibition of the angiogenic capacity of the cell co-culture microenvironment.

Simvastatin reduces adrenal catecholamine secretion evoked by stimulation of cholinergic nicotinic and angiotensinergic AT1 receptors.

We investigated the influence of simvastatin, a statin, on the secretion of catecholamines (CA) in rat adrenal glands, and clarified its action mechanism. Simvastatin suppressed acetylcholine (ACh)-evoked CA release in a dose- and time-dependent fashion. In the presence of simvastatin, CA secretion evoked by 1.1-dimethyl-4-phenyl piperazinium iodide (DMPP), angiotensin II, high K+, veratridine, and Bay-K-8644 was time-dependently inhibited. However, in the simultaneous presence of simvastatin and Nω-nitro-L-arginine methyl ester hydrochloride, CA secretion evoked by angiotensin II and DMPP recovered to control levels. Adrenal NO release was increased by simvastatin-treatment. Simvastatin-inhibited CA secretion was not affected by treatment with mevalonate. Pravastatin did not influence ACh-evoked CA secretion, while atorvastatin reduced it. In the simultaneous presence of simvastatin and fimasartan, ACh-induced CA release was markedly reduced compared to that of fimasartan-treatment alone. We present the first evidence that simvastatin reduces adrenal CA secretion induced by stimulation of nicotinic and AT1-receptors. Simvastatin-induced inhibition seems to involve reducing the influx of both Ca2+ and Na+ into adrenochromaffin cells, partly via the elevation of NO production by NO synthase activation, without inhibition of 3-hydroxy-methylglutaryl coenzyme A reductase. Co-administration of simvastatin and fimasartan may be clinically helpful for the treatment of cardiovascular diseases.

Inhibition of the mevalonate pathway by simvastatin interferes with mast cell degranulation by disrupting the interaction between Rab27a and double C2 alpha proteins

Statins are well-known inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which block the mevalonate pathway. The activity of statins not only decreases cholesterol levels but also ameliorates inflammation and modulates the immune system. In this study, we investigated the effects of simvastatin on histamine release using rat basophilic leukaemia (RBL-2H3) cells, and examined its interaction with proteins involved in the exocytosis process. Treatment with simvastatin for 24h inhibited histamine release in RBL-2H3 cells in a concentration-dependent manner after stimulation with dinitrophenylated bovine serum albumin (DNP-BSA, as an antigen), ionomycin (a calcium ion [Ca2+] ionophore), and thapsigargin (an inhibitor of Ca2+-ATPase in the endoplasmic reticulum). Simvastatin-induced inhibition was counteracted by co-administration of mevalonolactone or geranylgeraniol, but not farnesol. Indeed, several exocytotic proteins were post-translationally modified by isoprenylation, which is required for proper localization in the lipid membrane. RBL-2H3 cells express proteins involved in the fusion of granules and the plasma membrane, such as Ras-like protein in the brain 27a (Rab27a), synaptosome-associated protein 23 (SNAP23), and vesicle-associated membrane protein 7 (VAMP7), as well as Ca2+ binding proteins, such as double C2 alpha (Doc2a), synaptotagmin2, and mammalian uncoordinated13-4 (munc13-4). The interaction of Rab27a and Doc2a proteins was detected using proximity ligation assays. Antigen stimulation caused these proteins to interact, and this interaction could be disrupted by co-administration of simvastatin. In conclusion, simvastatin inhibited the mevalonate pathway, which suppressed the geranylgeranylation of Rab27a by depleting geranylgeranyl pyrophosphate and interfering with the Rab27a-Doc2a interaction. This activity resulted in the inhibition of exocytosis in RBL-2H3 cells.

Protective Effects of Simvastatin against Doxorubicin-Induced Changes in Mice Testicular Tissue

Introduction: Doxorubicin (DOX), a widely used antineoplastic compound, is associated with testicular damage and infertility. This study was carried out to disclose the possible preventive effects of simvastatin (SIM), a lipid lowering agent with antioxidant and anti-inflammatory activities, against testicular morphometric-stereological changes due to DOX treatment in mice. Materials & methods: Male mice, five weeks old, were randomly divided into four groups of six mice each. The DOX was administered to two groups of mice in 5 equal intraperitoneal injections over a period of 4 weeks (4 mg/kg). One of these groups received 5 equal oral doses of SIM (12 mg/kg) along with DOX. A vehicle-treated control group and a SIM control group were also included. Morphometric measurement was determined using calibrated ocular micrometer. Findings: Histomorphometrical examinations revealed significant reductions in the seminiferous tubules diameters and their epithelial heights along with an increase in testicular capsule thickness and interstitial space widening in DOX-treated mice. All above-mentioned parameters recovered significantly by SIM co-administration. Discussion & conclusions: These results indicated that SIM may have a preventive role against morphometric-stereological changes caused by DOX in mouse testis.

Osteogenic/Odontogenic Bioengineering with co-Administration of Simvastatin and Hydroxyapatite on Poly Caprolactone Based Nanofibrous Scaffold.

Purpose: Statin is an effective factor for promoting osteogenesis. The aim of the present study was to evaluate the effect of simvastatin (SIM) and/or HA addition on changes in osteogenesis levels by human DPSCs transferred onto three-dimensional (3D) nanofibrous Poly (ε-caprolactone) (PCL)/Poly lactic acide (PLLA) polymeric scaffolds. Methods: For this purpose, a 3D nanofibrous composite scaffold of PCL/PLLA/HA was prepared by electrospinning method. SIM was added to scaffolds during DPSCs culturing step. Cell proliferation and osteogenic activity levels were assessed by using MTT assay and Alizarin Red assay methods. In addition, the expression of genes responsible for osteogenesis, including BMP2, Osteocalcin, DSPP and RUNX2, were determined before and 2 weeks after incorporation of SIM. Results: The MTT assay showed that PCL/PLLA/HA scaffolds seeded with DPSCs has significant (p<0.05) more proliferative effect than PCL/PLLA or DMEM cultured cells, additionally SIM administration improved this result over the PCL/PLLA/HA scaffolds without SIM treatment. SEM imaging revealed improved adhesion and probably osteogenic differentiation of DPSCs on PCL/PLLA/HA nanofibers treated with SIM, moreover the alizarin red assay ensured significant (p<0.05) higher mineralization of this group. Finally, real time PCR confirmed the positive regulation (P<0.05) of the expression of osteo/odontogenesis markers BMP2, Osteocalcin, DSPP and RUNX2 genes in PLLA-PCL-HA (0.1)-SIM group. Conclusion: As a result, addition of simvastatin with incorporation of hydroxyapatite in PCL-PLLA scaffolds might increase the expression of osteogenesis markers in the DPSCs, with a possible increase in cell differentiation and bone formation.

Lack of Potential Pharmacokinetic and Pharmacodynamic Interactions Between Piragliatin, a Glucokinase Activator, and Simvastatin in Patients With Type 2 Diabetes Mellitus.

To evaluate the potential pharmacokinetic (PK) and pharmacodynamic (PD, glucose-lowering effect) interaction between simvastatin and piragliatin, both CYP3A substrates, 30 patients with type 2 diabetes mellitus participated in this open-label, randomized, 6-sequence, 3-way crossover (William's design) study. During 3 periods, patients were randomized to receive a single dose of 80 mg simvastatin alone, a single dose of 100 mg piragliatin alone, as well as single doses of 80 mg simvastatin and 100 mg piragliatin together. Primary PK and PD parameters were AUCs on dosing days. The ratio of geometric means (90% confidence intervals) of the AUCinf of piragliatin coadministered with simvastatin compared with piragliatin alone was 0.98 (0.92-1.05), whereas that of the AUCinf of simvastatin acid (active metabolite) coadministered with piragliatin compared with simvastatin alone, was 1.02 (0.90-1.16), suggesting lack of pharmacokinetic interaction between piragliatin and simvastatin. Piragliatin's glucose-lowering effect was not affected by coadministration of simvastatin. Overall, administration of piragliatin with simvastatin was without additional clinically relevant adverse effects as well as abnormality in laboratory tests, vital signs, and electrocardiogram parameters. Concomitant administration of simvastatin and piragliatin, both CYP3A substrates, has no clinically relevant effect on the pharmacokinetics of either piragliatin or simvastatin or on the pharmacodynamics for piragliatin.

Modulation of morphine antinociceptive tolerance and physical dependence by co-administration of simvastatin

Statins, 3-hydroxy-3-methylglutaryl co-enzyme A (HMG-CoA) reductase inhibitors, are widely used in the management of different diseases beyond their primary indication for lowering cholesterol. Previous studies have demonstrated the neuroprotective effects of simvastatin in different animal models. In the present study, we examined the effects of simvastatin (30, 60, 100 and 300mg/kg, p.o.) on the development and expression of morphine-induced tolerance and dependence in mice. For the induction of morphine tolerance and dependence, mice were twice daily treated with morphine (10mg/kg, s.c.) for 5 consecutive days. Tolerance was evaluated by the hot-plate test and physical dependence by naloxone challenge, on the sixth day. The results showed that oral administration of simvastatin produced antinociceptive activity in a dose-dependent way. Co-administration of simvastatin with morphine did not affect the acute morphine-induced analgesia (10mg/kg, s.c.). However, repeated co-administration of simvastatin with morphine significantly attenuated the development of tolerance to the analgesic effect of morphine and inhibited the naloxone (5mg/kg, s.c.)-precipitated withdrawal signs (jumping and body weight loss). Also, simvastatin at doses of 100 and 300mg/kg attenuated the expression of morphine-induced tolerance and dependence. These data indicated that, while simvastatin can alleviate both development and expression of morphine-induced tolerance, it cannot enhance morphine-induced antinociception. Taken together, simvastatin may be used as an adjutant therapeutic agent in combination with morphine and or other opioids in patients with severe chronic pain.

Interaction of clopidogrel and statins in secondary prevention after cerebral ischaemia - a randomized, double-blind, double-dummy crossover study.

Variability in responsiveness to clopidogrel is a clinical problem in secondary prevention after cerebral ischaemia which has been suggested to be linked to competitive metabolization of clopidogrel and cytochrome P450 (CYP) 3A4-oxidated statins such as simvastatin. We assessed the hypothesis that simvastatin, in contrast to CYP 2C9-metabolized fluvastatin, reduces clopidogrel-mediated platelet inhibition. We performed a randomized, double-blind, double-dummy, two period crossover study in 13 patients with cerebral ischaemia (8F, 5 M), aged 64.1 ± 8.0 years (mean ± SD). After a 14 day period in which all patients received 75 mg clopidogrel day(-1) , patients additionally received either 20 mg simvastatin day(-1) or 80 mg fluvastatin day(-1) for 14 days. Regimens were crossed over after a 14 day wash-out period and switched regimens were continued for another 14 days. Platelet aggregation, clopidogrel active metabolite (CAM) plasma concentrations and routine laboratory parameters including prothrombin time (PT) Quick percent value were assessed at baseline and following each treatment phase. Clopidogrel reduced platelet aggregation in all patients as expected. Platelet aggregation and CAM plasma concentrations were unaltered when simvastatin or fluvastatin was added to clopidogrel. Simvastatin decreased PT Quick percent value (decrease from 109 ± 10.5% to 103 ± 11%, P < 0.05) when combined with clopidogrel but there was no such change following treatment with fluvastatin and clopidogrel. Our data indicate that treatment with CYP 3A4-metabolized simvastatin does not jeopardize clopidogrel-mediated inhibition of platelet aggregation. After co-administration of simvastatin and clopidogrel we observed a decrease in the PT Quick percent value which could be due to simvastatin-induced reduction of activity of prothrombin fragment 1 + 2.

Pharmacokinetic modeling of simvastatin, nelfinavir and their interaction in humans.

Simvastatin, a commonly used HMG-CoA reductase inhibitor, is extensively metabolized by CYP3A4. Therefore, co-administration of simvastatin and CYP3A4 inhibitor can affect simvastatin pharmacokinetics. Nelfinavir, a protease inhibitor, and its major metabolite (M8) are known to be potent CYP3A4 inhibitors. When simvastatin and nelfinavir are co-administered, simvastatin pharmacokinetics is significantly altered and may result in an increased risk of rhabdomyolysis. To develop a mathematical model describing a drug-drug interaction between simvastatin and nelfinavir in humans. Eligible pharmacokinetic studies were selected from Pubmed database and concentration time course data were digitally extracted and used for model development. Compartmental pharmacokinetic models for simvastatin and nelfinavir were developed separately. A drug-drug interaction model of simvastatin and nelfinavir was subsequently developed using the prior information. Finally, the final drug-drug interaction modeled was validated against observed simvastatin concentrations. Three compartmental pharmacokinetic models were successfully developed. Simvastatin pharmacokinetics was best described by a one compartment model for simvastatin linked to its active form, simvastatin hydroxy acid. Nelfinavir pharmacokinetics could be adequately described by a one compartment parent-metabolite model. Our final drug-drug interaction model predicted an increase in simvastatin exposure which is in line with clinical observations linking the simvastatin-nelfinavir combination to an increased risk of rhabdomyolysis. Simvastatin-nelfinavir pharmacokinetic interaction can be explained by our final model. This model framework will be useful in further advanced developing other mechanism based drug-drug interaction model used to predict the risk of rhabdomyolysis occurrence in patients prescribed simvastatin and nelfinavir concurrently.

Synergistic effect of simvastatin plus NS398 on inhibition of proliferation and survival in hepatocellular carcinoma cell line

NS398, a selective cyclooxygenase-2 inhibitor, and simvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, both exert an anticancer effect on hepatocellular carcinoma cells, but the effect of co-administration of the two drugs remains unknown. We aimed to investigate the synergistic in vitro anticancer effect of co-administration of NS398 and simvastatin and its mechanism. The Hep3B and Huh-7 cell lines were cultured. Cells were treated with simvastatin, NS398, or a combination. 5-bromo-2'-deoxyuridine ELISA assay, flow cytometry, Western blot analyses, and immunofluorescence assay were performed. In both cell lines, co-administration of simvastatin and NS398 resulted in a greater effect on proliferation and apoptosis. In Hep3B cells, co-administration of the two drugs resulted in a greater decrease in procaspase 3 and Bcl-2 and an increase in cleaved caspase 9 than that noted with monotherapy. In Huh-7 cells, co-administration of the two drugs resulted in a greater decrease in procaspase 3 and cyclin D1 and an increase in cleaved caspase 9. Expression of NF-κB and Akt were also decreased to a greater extent when the two drugs were co-administered in both cell lines. Immunofluorescence assay showed suppression of the nuclear localization of NF-κB by simvastatin or NS398. The effect was greater by co-administration. The co-administration of NS398 and simvastatin produced greater antiproliferative and proapoptotic effects against Hep3B cells and Huh-7 cells. Inhibition of the NF-κB and Akt pathway and activation of caspase cascade, which are considered as the major mechanism of synergistic anticancer properties, were observed in both cell lines.

Abstract 240: Effect of Co-Administration of Simvastatin and Pioglitazone on Lipid Profile and Insulin Resistance in Insulin-Resistant Rats

Objective: Insulin resistance is characterized by hyperglycemia, dyslipidemia, hyperinsulinemia and hypertension. Also, in obesity, decreased plasma adiponectin and increased free fatty acids, are the main factors that correlate with insulin resistance. Thiazolidinediones, like pioglitazone are used to improve insulin sensitivity and ATPIII guidelines suggest statin therapy for correction of dyslipidemia in metabolic syndrome. In this study we evaluated co-administration of simvastatin and pioglitazone on insulin resistance in rats. Materials and Methods: Rats were randomly divided into five groups. After 6 weeks on a high-fructose diet, one group received simvastatin, one group received pioglitazone, and one received pioglitazone and simvastatin. After 2 weeks of treatment, animals were anesthetized with ether. Blood was collected from their heart. Liver, visceral adipose, and muscle tissues were collected and were immediately frozen. Serum glucose, TGs, cholesterol, insulin, adiponectin, and free fatty acids were measured. Expression of PPAR.γ and GLUT4 genes was checked by real-time PCR and Western blotting. Results: Only the results that showed a significant difference are shown. Blood glucose: pioglitazone group (129.1±5.8mg/dl), simvastatin-pioglitazone treated group (137.1±9.9 mg/dl); TG: simvastatin group (123.6±16.6 mg/dl), simvastatin-pioglitazone group (101.5±7.5 mg/dl); Insulin: pioglitazone group (40.27±2.75 p mol/l), simvastatin group (70.07±10.35 pmol/l), simvastatin-pioglitazone (47.62±2.8 pmol/l); Adiponectin: pioglitazone (5.90±0.29 μg/ml), simvastatin-pioglitazone (5.89±0.41μg/ml); HOMA-IR: pioglitazone (2.11±0.13), simvastatin (4.76±0.37), simvastatin-pioglitazone (2.70±0.29). In pioglitazone group, PPAR.γ expression at both mRNA and protein levels was significantly different from insulin resistant group. Conclusion: As the results show, simvastatin has beneficial effects on insulin resistance in rats. Pioglitazone did not show any synergistic effect with simvastatin, however, when used in combination with simvastatin, pioglitazone shows a synergistic effects in lowering TG and HOMAIR that potentially can lower diabetes complications.