Assessment of the Potential Health Risk of Gold Nanoparticles Used in Nanomedicine.

Due to unique properties, nanoparticles (NPs) have become a preferred material in biomedicine. The benefits of their use are indisputable, but their safety and potential toxicity are becoming more and more important. Especially, excessive production of reactive oxygen species (ROS) induced by the strong oxidation potential of metal NPs could evoke adverse effects associated with damage to nucleic acids, proteins and lipids. Our study gives a view on the potential cytotoxicity of gold NPs (Au NPs) of different size from the perspective of the redox state of healthy (HEK 293 T) and cancer (A375 and A594) cell lines. These cells were incubated in the presence of two concentrations of Au NPs for 24 h or 72 h and total antioxidant capacity, 8-isoprostane, and protein carbonyl levels were determined. Furthermore, the activity of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and catalase was detected in cell lysates. Our results compared to the results of other laboratories are very contradictory. The outcomes also differ between healthy and cancer cell lines. However, there are certainly changes in the activities of antioxidant enzymes, as well as the damage to biological molecules due to increased NP-induced oxidative stress. But the final decision of the effect of Au NPs on the oxidative state of selected cell lines requires further research.

Preliminary Findings on the Effect of Ultrasmall Superparamagnetic Iron Oxide Nanoparticles and Acute Stress on Selected Markers of Oxidative Stress in Normotensive and Hypertensive Rats.

Several studies have reported that the administration of various nanoparticles in vivo can cause oxidative stress. The combination of ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) and acute stress was selected because, during intravenous application of a contrast agent, patients are exposed to psycho-emotional stress. This study was designed to investigate the effect of acute stress and USPIONs on selected markers of oxidative stress (antioxidant capacity, superoxide dismutase, glutathione peroxidase and catalase activities, levels of advanced oxidation protein products, protein carbonyls, lipoperoxides and 8-isoprostanes) in plasma and erythrocytes in normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). In the WKY and SHR groups, there was a significant main effect of genotype between groups on studied markers except protein carbonyls and lipoperoxides. In SHR, the combination of acute stress and USPIONs increased the antioxidant capacity of plasma and the selected enzyme activities of erythrocytes. In WKY, the combination of acute stress and USPIONs decreased the antioxidant capacity of erythrocytes and reduced levels of advanced oxidation protein products in plasma. Our study points to the fact that, when hypertensive subjects are treated with iron oxide nanoparticles, caution should be taken, especially in stress conditions, since they seem to be more vulnerable to oxidative stress produced by USPIONs.

The Effect of Omega-3 Fatty Acids on Thromboxane, Brain-Derived Neurotrophic Factor, Homocysteine, and Vitamin D in Depressive Children and Adolescents: Randomized Controlled Trial.

In the DEPOXIN project, we have found that a high ratio of omega-6/omega-3 fatty acids (FA) is associated with worsening of depressive symptoms in children and adolescents with depressive disorder (DD) and that the 12-week omega-3 FA supplementation modulates DD symptoms. Here we present our results of the secondary outcomes: the levels of thromboxane (TXB), brain-derived neurotrophic factor (BDNF), homocysteine (HCy) and vitamin D. Fifty-eight patients were randomized into two arms. One group received a fish oil emulsion enriched with omega-3 FA, and the other received a sunflower oil emulsion containing omega-6 FA, for 12 weeks. Depressive symptoms were evaluated, using the Child's Depressive Inventory (CDI). The patients with DD had elevated TXB levels and decreased vitamin D levels, as compared to healthy controls. Both CDI and omega-6/omega-3 ratio correlated positively with TXB and negatively with BDNF at baseline. Compared to the omega-6 FA group, the supplementation with omega-3 FA for 12 weeks significantly reduced plasma TXB (p = 0.024) and increased BDNF (p = 0.011) levels. No changes in HCy and vitamin D were observed. Our results demonstrate the possible role of TXB and BDNF in the pathophysiology of DD and the benefits of omega-3 FA supplementation. The study was registered with the ISRCTN registry (ISRCTN81655012).

Gender differences in LDL and HDL subfractions in atherogenic and nonatherogenic phenotypes.

OBJECTIVES: The aim of our study was to examine the role of low density lipoprotein (LDL)-subfractions in individuals with the atherogenic and non-atherogenic phenotype and the gender differences in lipoprotein subfractions including small dense LDL (sdLDL) and small high density lipoprotein (sHDL) subfractions representing the most atherogenic lipoprotein subfractions. DESIGN & METHODS: 35 persons in the atherogenic group (AG) (with sdLDL3-7 subfractions ≥6 mg/dl) and 104 individuals in the non-atherogenic group (NAG) (sdLDL3-7 subfractions <6 mg/dl) were included in our study. To analyze plasma lipoprotein subfractions, a polyacrylamide gel electrophoresis-the Lipoprint system was used. RESULTS: Males compared to females in the AG had significantly higher levels of atherogenic lipoprotein subfractions such as HDL8, HDL9 and HDL10. All participants in AG had significantly lower levels of intermediate density lipoprotein IDL-A than those in NAG but significantly higher levels of IDL-B and IDL-C. Males in the AG compared to NAG had significantly lower levels of LDL1 and higher levels of LDL2 and LDL3-7 subfractions. In the NAG LDL2 positively correlated with sHDL subfractions while in the AG with the large HDL subfraction. CONCLUSION: Results of our study demonstrate more atherogenic profile in males compared to females and a double role of LDL2 subfraction in the atherogenic process depending on the phenotype (atherogenic/non-atherogenic) of individuals.

The interleukin-33-mediated inhibition of expression of two key genes implicated in atherosclerosis in human macrophages requires MAP kinase, phosphoinositide 3-kinase and nuclear factor-κB signaling pathways.

Atherosclerosis, a chronic inflammatory disorder of the walls of arteries, causes more deaths worldwide than any other disease. Cytokines, which are present at high levels in atherosclerotic plaques, play important roles in regulating the initiation and the progression of the disease. Previous studies using animal and cell culture model systems revealed protective, anti-atherogenic effects of the cytokine interleukin-33 (IL-33). The action of this cytokine involves both the induction and suppression of expression of many genes. Unfortunately, the signaling pathways that are responsible for the inhibition of gene expression by this cytokine are poorly understood. Further studies are required given the important roles of genes whose expression is inhibited by IL-33 in key cellular processes associated with atherosclerosis such as monocyte recruitment, foam cell formation and lipoprotein metabolism. We have investigated here the roles of various known IL-33 activated signaling pathways in such inhibitory actions using RNA interference-mediated knockdown assays and monocyte chemotactic protein-1 and intercellular adhesion molecule-1 as model genes. Key roles were identified for extracellular signal-regulated kinase-1/2, p38α kinase, c-Jun N-terminal kinase-1/2, phosphoinositide 3-kinase-γ, and p50 and p65 nuclear factor-κB in such inhibitory action of IL-33. These studies provide new insights on the signaling pathways through which IL-33 inhibits the macrophage expression of key atherosclerosis-associated genes.

Self-Reported Exposure to ETS (Environmental Tobacco Smoke), Urinary Cotinine, and Oxidative Stress Parameters in Pregnant Women-The Pilot Study.

BACKGROUND: Exposure to ETS (environmental tobacco smoke) is one of the most toxic environmental exposures. OBJECTIVE: To investigate the association of ETS with physiological, biochemical, and psychological indicators, as well as with urine antioxidant capacity (AC) and oxidative damage to lipids in a pilot sample of healthy pregnant women. METHODS: Exposure to ETS was investigated via a validated questionnaire, and urine cotinine and the marker of oxidative damage to lipids via 8-isoprostane concentrations using an ELISA kit. Urine AC was determined by the spectrophotometric Trolox-equivalent antioxidant capacity (TEAC) method. From a sample of pregnant women (n = 319, average age 30.84 ± 5.09 years) in 80, the levels of cotinine and oxidative stress markers were analyzed. RESULTS: Among the 80 pregnant women, 5% (7.4% confirmed by cotinine) reported being current smokers and 25% reported passive smoking in the household (18.8% confirmed by cotinine). The Kappa was 0.78 for smokers and 0.22 for ETS-exposed nonsmokers. Pregnant women in the ETS-exposed group had significantly reduced AC compared to both the nonsmoker (ETS-) and the smoker groups (p < 0.05). Nonsmokers had significantly lower levels of 8-isoprostane than smokers (p < 0.01) and ETS-exposed nonsmokers (p < 0.05). Correlations between urine levels of cotinine and AC were positive in ETS-exposed nonsmokers. CONCLUSION: A harmful association of active and passive smoking and oxidative stress parameters among pregnant women has been indicated.

Effect of Neonatal Exposure to Poly(Ethylene Glycol)-block-Poly(Lactic Acid) Nanoparticles on Oxidative State in Infantile and Adult Female Rats.

Our goal was to evaluate the potential health risk of the polymeric NP, poly(ethylene glycol)-block-poly(lactic acid) (PEG-b-PLA), from the view of redox imbalance of the organism in two different life stages. Female Wistar rats were neonatally administered intraperitoneally with PEG-b-PLA NPs [20 mg/kg of b.w. (PEG20) or 40 (PEG40) mg/kg of b.w.] from postnatal day 4 (PND4) to PND7. We measured antioxidant capacity (TEAC), level of protein carbonyls and lipoperoxides in plasma, activities of catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD) in hemolysates of infantile (sacrificed on PND17) and adult (sacrificed after PND176) rats. Compared to controls, neonatal PEG40 exposure induced a significant TEAC reduction in the infantile rats. Protein carbonyls and lipoperoxide levels were not affected after any dose of PEG-b-PLA NP administration. In adult rats, PEG20 administration caused a significant decrease of protein carbonyl levels compared to controls. In infantile rats, both doses of PEG-b-PLA NP administration increased catalase, Gpx, and SOD activities compared to controls. Surprisingly, in adult rats, the activities of Gpx and SOD decreased significantly after administration of both doses of PEG-b-PLA NPs. Obtained data indicate a possible age-related association between the oxidative status and neonatal PEG-b-PLA NP administration in female rats.

Fish oil emulsion supplementation might improve quality of life of diabetic patients due to its antioxidant and anti-inflammatory properties.

Diabetes-related complications, including cardiovascular disease, retinopathy, nephropathy, and neuropathy, are a significant cause of increased morbidity and mortality among people with diabetes. Previous studies have confirmed that hyperglycemia has pro-oxidative and proinflammatory properties which cause diabetic complications. We hypothesized that supplementation of fish oil emulsion (FOE), rich in omega-3 polyunsaturated fatty acids, to diabetic patients might reduce hyperglycemia-induced pathological changes due to specific properties of FOE. Omega-3 polyunsaturated fatty acids have a wide range of biological effects. In this project, we have examined the potential protective effect of the FOE on hyperglycemia-induced oxidative stress and cytokine generation in monocytes/macrophages U937 system in vitro. The monocytes/macrophages U937 were cultivated under normal or hyperglycemic (35 mmol/L glucose) conditions with/without FOE for 72 hours. We have focused on specific markers of oxidative stress (antioxidant capacity; superoxide dismutase activity; oxidative damage to DNA, proteins, and lipids) and inflammation (tumor necrosis factor, interleukin-6, interleukin-8, monocytic chemotactic protein-1). Hyperglycemia caused reduction of antioxidant capacity, induction of DNA damage, and proinflammatory cytokine secretion. FOE significantly increased antioxidant capacity of cells as well as superoxide dismutase activity and significantly reduced tumor necrosis factor, interleukin-6, interleukin-8, and monocytic chemotactic protein-1 release. No effect was observed on oxidative damage to DNA, proteins, and lipids. Our results indicate that FOE can reduce hyperglycemia-induced pathological mechanisms by its antioxidant and anti-inflammatory properties.

Methionine metabolism and multiple sclerosis.

CONTEXT: Methylation reactions are particularly important in the brain and their inhibition can lead to a number of serious pathologies. Multiple sclerosis is one of the most common neurological disorders caused by interaction of genetic and environmental factors, but little is known about its cause or factors that contribute to the disorder. Although multiple sclerosis is primarily regarded as demyelinating disorder, there are no many articles focusing on methionine determination. OBJECTIVE: The aim of this work was to investigate whether serum methionine and its related compounds like homocysteine, cysteine, glutathione and asymmetric dimethylarginine were changed in multiple sclerosis patients. MATERIALS AND METHODS: Sulphur-containing compounds were determined by using high-performance liquid chromatography with electrochemical detection in a single run for providing more complex view on methionine metabolism and asymmetric dimetylarginine was measured by a commercial enzyme-linked immunosorbent assay kit. RESULTS: Methionine and glutathione were decreased, but homocysteine, asymmetric dimethylarginine and cysteine were unchanged in patients with multiple sclerosis compared with controls. CONCLUSIONS: Methionine and glutathione seem to be potential biomarkers for prognosis of the disease.

Oxidative Stress Markers and Their Dynamic Changes in Patients after Acute Ischemic Stroke.

We have focused on determining the range of oxidative stress biomarkers and their dynamic changes in patients at different time points after the acute ischemic stroke (AIS). 82 patients with AIS were involved in our study and were tested: within 24 h from the onset of the attack (group A); at 7-day follow-up (group B); and at 3-month follow-up (group C). 81 gender and age matched volunteers were used as controls. Stroke patients in group A had significantly higher concentrations of plasma lipid peroxides and urine 8-isoprostanes when compared with controls. Protein carbonyls were not significantly different in any experimental group compared to controls. Antioxidant capacity of plasma was increased only in experimental group C. Activities of superoxide dismutase and catalase were elevated in all three experimental AIS groups compared to controls. Paraoxonase activity was reduced in groups A and B and unchanged in group C when compared to controls. Glutathione peroxide activity was elevated only in group A. Our results suggest that free radical damage is the highest within 24 h after the attack. During the next 3 months oxidative damage to lipids caused by free radicals is reduced due to activated antioxidant system.

Effect of Schiff base Cu(II) complexes on signaling pathways in HT-29 cells.

Schiff base copper (II) complexes are known for their anticancer, antifungal, antiviral and anti­inflammatory activities. The aim of the current study was to investigate biological effects of Schiff base Cu (II) complexes (0.001­100 µmol/l)­[Cu2(sal­D, L­glu)2(isoquinoline)2]·2C2H5OH (1), [Cu(sal­5­met­L­glu)(H2O)].H2O (2), [Cu(ethanol)2(imidazole)4][Cu2(sal­D, L-glu)2(imidazole)2] (3), [Cu(sal­D,L­glu)(2­methylimidazole)] (4) on the human colon carcinoma cells HT­29, the mouse noncancerous cell line NIH­3T3 and the human noncancerous fibroblast cell line VH10. The results suggested that Cu (II) complexes exhibit cytotoxic effects against the HT­29 cell line, while complexes 3 and 4 were the most effective. Subsequent to 72 h of incubation, apoptosis was observed in the HT­29 cells induced by Cu (II) complexes 1 (0.1, 1, 10 and 50 µmol/l), 2 (1, 10, 50 and 100 µmol/l), 3 (0.01, 1, 10 and 50 µmol/l) and 4 (0.01, 0.1, 1 and 10 µmol/l). The apoptotic pathways activated by the Cu (II) complexes were identified. The results indicated that complexes 2, 3 and 4 were able to induce the mitochondria­dependent pathway of apoptosis in HT­29 cells, while complex 1 was obsered to activate the extrinsic pathway of apoptosis. The levels of the anti­apoptotic protein Bcl­2 were reduced and those of the pro­apoptotic protein Bax increased following treatment with complexes 2, 3 and 4. Complex 1 had no effect on Bax protein expression. Complexes 2 and 3 induced elevation of cytochrome c (cyt c), while complex 4 induced a time­dependent elevation of cyt c levels. No cyt c was detected in HT­29 cells exposed to complex 1, suggesting that Cu (II) complexes activated the extrinsic pathway of apoptosis. The results from the current study in addition to previous studies suggest that Schiff base Cu (II) complexes have potential as novel anticancer drugs.

Autophagy in MCF-7 cancer cells induced by copper complexes.

BACKGROUND: Autophagy plays an important role in cancer cells. Targeting autophagy in cancer can provide new opportunities for drug development. METHODS: In this study we tested four Schiff base Cu(II) complexes against human breast cancer cells (MCF-7) and human non-cancerous cells (HEK-293T). We have tested their cytotoxic effect by evaluating IC50 using MTT test. To detect morphological changes of the actin fibers we have used fluorescent microscopy. To determine the type of cell death we used electrophoretic analysis and western blot analysis (protein LC3). RESULTS: IC50 values of the complexes increased with time of their influence, indicating acquired resistance of MCF-7 to the complexes. Healthy cells HEK-293T were not sensitive to the Cu(II) complexes. Compared with the control cells (cells without Cu(II) complexes) which were without morphological changes of actin fibers, Cu(II) complexes induced condensation and asymmetric conformational changes in actin filaments. To examine the type of cell death induced by the Cu(II) complexes we treated MCF-7 cells with Cu(II) complexes (1, 10, 50 and 100µmol/L) during a 72h incubation period. By electrophoresis we have not detected any DNA fragmentation. To determine whether Cu(II) complexes induced autophagy or necrotic cell death we used the western blot analysis. MCF-7 cells influenced with tested Cu(II) complexes produced LC3 protein after their 72h incubation indicating autophagy in MCF-7 cancer cells. CONCLUSIONS: Tested Schiff base copper (II) complexes have antiproliferative activity against cancer cells but not against healthy cells. They have induced autophagy in the cancer cell line MCF-7.

The phosphoinositide 3-kinase signaling pathway is involved in the control of modified low-density lipoprotein uptake by human macrophages.

The transformation of macrophages into lipid-loaded foam cells is a critical early event in the pathogenesis of atherosclerosis. Both receptor-mediated uptake of modified LDL, mediated primarily by scavenger receptors-A (SR-A) and CD36 along with other proteins such as lipoprotein lipase (LPL), and macropinocytosis contribute to macrophage foam cell formation. The signaling pathways that are involved in the control of foam cell formation are not fully understood. In this study, we have investigated the role of phosphoinositide 3-kinase (PI3K) in relation to foam cell formation in human macrophages. The pan PI3K inhibitor LY294002 attenuated the uptake of modified LDL and macropinocytosis, as measured by Lucifer Yellow uptake, by human macrophages. In addition, the expression of SR-A, CD36 and LPL was attenuated by LY294002. The use of isoform-selective PI3K inhibitors showed that PI3K-ß, -γ and -δ were all required for the expression of SR-A and CD36 whereas only PI3K-γ was necessary in the case of LPL. These studies reveal a pivotal role of PI3K in the control of macrophage foam cell formation and provide further evidence for their potential as therapeutic target against atherosclerosis.

Effect of walnut oil on hyperglycemia-induced oxidative stress and pro-inflammatory cytokines production.

PURPOSE: In this study, we focused on the effect of hyperglycemia on the generation of reactive oxygen species and on the release of pro-inflammatory cytokines in the human monocytic cell line (U937). We also monitored potential anti-inflammatory effects of walnut oil as well as its protective effect against oxidative damage to biopolymers (DNA and proteins). METHODS: We cultured U937 cells under normoglycemic or hyperglycemic conditions for 72 h, in the absence or presence of walnut oil. We detected cell proliferation by the MTT test. To determine the antioxidant status of cells, we used the trolox equivalent antioxidant capacity method. We determined the activity of superoxide dismutase (SOD) spectrophotometrically, the oxidative damage to DNA by an enzyme-modified comet assay, and the oxidative damage to proteins by the marker-protein carbonyls and the levels of pro-inflammatory cytokines by the ELISA method. RESULTS: Hyperglycemia reduced the antioxidant capacity of cells, induced oxidative damage to DNA, and increased the release of pro-inflammatory cytokines. It had no effect on cell proliferation, SOD activity, nor oxidative damage to proteins. Walnut oil significantly increased the antioxidant capacity of cells as well as SOD activity on the second and third day of incubation, but had no effect on cell proliferation and showed no protective effect against oxidative damage to DNA and proteins. The walnut oil showed both anti-inflammatory and pro-inflammatory properties depending on its concentration and time of its incubation with the monocytic cell line. CONCLUSION: Our in vitro results indicate that walnut oil can diminish oxidative stress with its antioxidant properties. However, we could not confirm its protective effect against oxidative damage to DNA and proteins.

Effect of the French oak wood extract Robuvit on markers of oxidative stress and activity of antioxidant enzymes in healthy volunteers: a pilot study.

We examined in vitro antioxidant capacity of polyphenolic extract obtained from the wood of oak Quercus robur (QR), Robuvit, using TEAC (Trolox equivalent antioxidant capacity) method and the effect of its intake on markers of oxidative stress, activity of antioxidant enzymes, and total antioxidant capacity in plasma of 20 healthy volunteers. Markers of oxidative damage to proteins, DNA, and lipids and activities of Cu/Zn-superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined in the erythrocytes. We have found an in vitro antioxidant capacity of Robuvit of 6.37 micromole Trolox equivalent/mg of Robuvit. One month intake of Robuvit in daily dose of 300 mg has significantly decreased the serum level of advanced oxidation protein products (AOPP) and lipid peroxides (LP). Significantly increased activities of SOD and CAT as well as total antioxidant capacity of plasma after one month intake of Robuvit have been shown. In conclusion, we have demonstrated for the first time that the intake of Robuvit is associated with decrease of markers of oxidative stress and increase of activity of antioxidant enzymes and total antioxidant capacity of plasma in vivo.

Effect of the Schiff base complex diaqua-(N-salicylidene-l-glutamato)copper(II) monohydrate on human tumor cells.

The aim of our study was to estimate cytostatic/cytotoxic activity of the copper(II) Schiff base complex of the composition [Cu(N-salicylidene-l-glutamato)(H2O)2]·H2O, further Cu(SG-L)H2O, against human colon carcinoma cell line HT-29, as well as to determine type of cell death and to find out the molecular mechanism of apoptosis induced by this complex. Two highest concentrations (50, 100 µmol/l) of the complex showed a strong cytotoxic activity against human colon carcinoma cells HT-29 after 72 h of influence. Other concentrations had a cytostatic activity. Unchelated copper(II) ions and free ligands had no effect on the cell growth. Cu(SG-L)H2O preferentially reduced cancer cell viability compared to healthy cells (NIH-3T3). Cu(SG-L)H2O induced apoptosis of cells HT-29 at all concentrations used (1-100 µmol/l) after 48 h of influence. Apoptosis was carried out by the mitochondrial pathway with active caspases 3 and 9. By the spin-trapping technique combined with electron paramagnetic resonance we found that our complex is photochemically stable in aqueous systems and does not exhibit radical-scavenging activity when 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) cation radical was used as an oxidant. The complex exhibits a strong prooxidant property in the initial stages of thermal decomposition of K2S2O8 in water solutions leading to the massive production of (·)OH radicals. Therefore, this complex could strongly participate in anticancer action via a free radical mechanism.

The effect of simvastatin on lipid droplets accumulation in human embryonic kidney cells and pancreatic cancer cells.

BACKGROUND: Statins (HMG-CoA reductase inhibitors) represent a major class of compounds for the treatment of hypercholesterolemia due to their ability to inhibit de novo cholesterol synthesis. In addition to their hypolipidemic effects, chemoprotective properties have been attributed to statins as well. These effects involve multiple mechanisms, which, however, are not known in detail. The aim of our study was to assess in non-malignant as well as cancer cells the impact of simvastatin on the amount of cytosolic lipid droplets (LDs) implicated in many biological processes including proliferation, inflammation, carcinogenesis, apoptosis, necrosis or growth arrest. METHODS: Human embryonic kidney cells HEK-293T and human pancreatic cancer cells MiaPaCa-2 were treated with simvastatin (6 and 12 µM) for 24 and 48 hours respectively. Neutral lipid probe Nile Red was used for detection of LDs by fluorescence microscopy. Cellular cholesterol content was determined by HPLC. Changes in expression of genes related to lipid metabolism in simvastatin-treated MiaPaCa-2 cells were examined by DNA microarray analysis. Validation of gene expression changes was performed using quantitative RT-PCR. RESULTS: The treatment of the cells with simvastatin increased their intracellular content of LDs in both non-malignant as well as cancer cells, partially due to the uptake of cholesterol and triacylglyceroles from medium; but in particular, due to enhanced synthesis of triacylglyceroles as proved by significant overexpression of genes related to de novo synthesis of triacylglyceroles and phospholipids. In addition, simvastatin also markedly influenced expression of genes directly affecting cell proliferation and signaling. CONCLUSIONS: Simvastatin treatment led to accumulation of cytosolic LDs within the examined cells, a phenomenon which might contribute to the antiproliferative effects of statins.