Investigating the potential neuroprotective effects of statins on DNA damage in mouse striatum

DNA-binding activities of compounds acting as enzyme inhibitors, ion channel blockers and receptor binders

The DNA-binding activities of compounds used as remedies can display DNA-protection, but also damaging effects in biological systems. The current review compiles literature data on DNA-binding activities of drugs widely used as remedies with different therapeutic indications. The compounds are classified according their mechanism of action: enzyme inhibitors, ion channel inhibitors, inhibitors of viral RNA replication and HIV protease and receptor agonists. DNA binding was reported for such widely used drugs as paracetamol, aspirin, metformin, statins and many others. The capability of the drug to bind DNA is sometimes coupled to genotoxic effects, but in some cases - to genome protection. Data on atoms and chemical groups involved in the drug-DNA interactions are also presented. In many cases the same atoms are involved in both interactions of the compounds with proteins and DNA.

Simvastatin Reduces Hepatic Oxidative Stress and Endoplasmic Reticulum Stress in Nonalcoholic Steatohepatitis Experimental Model

Objective

In this study, we evaluated the efficacy of simvastatin in the treatment of nonalcoholic steatohepatitis induced by methionine and choline-deficient diet in mice and its possible effect on factors involved in the pathogenesis of the disease including oxidative stress and endoplasmic reticulum stress.

Method

Male C57BL6 mice were fed either a normal diet (control) or a methionine and choline-deficient diet for four weeks and then treated orally with simvastatin (4 mg/kg once a day) for two final weeks. At the end of the experimental period, liver integrity, biochemical analysis, hepatic lipids, histology, DNA damage, biomarkers of oxidative stress, and endoplasmic reticulum stress were assessed.

Results

Simvastatin treatment was able to significantly reduce hepatic damage enzymes and hepatic lipids and lower the degree of hepatocellular ballooning, without showing genotoxic effects. Simvastatin caused significant decreases in lipid peroxidation, with some changes in antioxidant enzymes superoxide dismutase and glutathione peroxidase. Simvastatin activates antioxidant enzymes via Nrf2 and inhibits endoplasmic reticulum stress in the liver.

Conclusions

In summary, the results provide evidence that in mice with experimental nonalcoholic steatohepatitis induced by a methionine and choline-deficient diet, the reduction of liver damage by simvastatin is associated with attenuated oxidative and endoplasmic reticulum stress.

Vitamin C partially prevents reproductive damage in adult male rats exposed to rosuvastatin during prepuberty

Pediatric obesity is closely associated with dyslipidemias and environmental factors, such as diet and lack of physical exercises, which may alter lipid profile in children. Rosuvastatin decreases serum total cholesterol and triglycerides concentrations. Vitamin C (ascorbic acid) plays an important role on sperm integrity and fertility. Juvenile male rats were distributed into six experimental groups that received saline solution 0.9%, 3 or 10 mg/kg/day of rosuvastatin, 150 mg/day of ascorbic acid, or 3 or 10 mg/kg/day of rosuvastatin co-administered with 150 mg/day of ascorbic acid from PND23 until PND53 and then the rats were maintained until sexual maturity. Rosuvastatin-exposed groups showed lower sperm quality, androgen depletion and germ cell death. Ascorbic acid was capable to prevent partially the reproductive adverse effects provoked by rosuvastatin. In conclusion, prepubertal exposure to rosuvastatin provokes long-term reproductive damages at sexual maturity and ascorbic acid supplementation at prepuberty may be a preventive mode against these reproductive adverse effects.

Statins and the brain: New perspective for old drugs

Statins are one of the most popular lipid-lowering drugs (LLDs). Upon oral administration, these drugs are well absorbed by the intestine and effectively used for the treatment of dyslipidemias. Recently, statins are becoming also well-known for their cholesterol-independent effects and their potential use in brain diseases and different types of cancers. While still controversial, recent research has suggested that statin's cholesterol-independent activities work possibly through alterations on isoprenoid levels. This reduction of isoprenoids in the central nervous system might result in effective biochemical and behavioral improvements on certain neurological disorders. This manuscript aims to highlight current research describing the use of statin therapy in the brain and discuss whether statins might affect neuronal dynamics and function independently of their cholesterol regulatory role.

Detection of asymptomatic nigrostriatal dopaminergic lesion in rats by exhaled air analysis using carbon nanotube sensors

The ante-mortem diagnosis of Parkinson's disease (PD) still relies on clinical symptoms. Biomarkers could in principle be used for the early detection of PD-related neuronal damage, but no validated, inexpensive, and simple biomarkers are available yet. Here we report on the breath-print of presymptomatic PD in rats, using a model with 50% lesion of dopaminergic neurons in substantia nigra. Exhaled breath was collected from 19 rats (10 lesioned and 9 sham operated) and analyzed using organically functionalized carbon nanotube sensors. Discriminant factor analysis detected statistically significant differences between the study groups and a classification accuracy of 90% was achieved using leave-one-out cross-validation. The sensors' breath-print was supported by determining statistically significant differences of several volatile organic compounds in the breath of the lesioned rats and the sham operated rats, using gas chromatography combined with mass spectrometry. The observed breath-print shows potential for cost-effective, fast, and reliable early PD detection.

Differential effects of simvastatin and pravastatin on expression of Alzheimer's disease-related genes in human astrocytes and neuronal cells

Inhibitors of HMG-CoA reductase (statins) are widely used medications for reduction of cholesterol levels. Statin use significantly reduces risk of cardiovascular disease but has also been associated with lower risk of other diseases and conditions, including dementia. However, some reports suggest that statins also have detrimental effects on the brain. We provide evidence that simvastatin and pravastatin have significantly different effects on expression of genes related to neurodegeneration in astrocytes and neuroblastoma (SK-N-SH) cells in culture. Simvastatin significantly reduced expression of ABCA1 in astrocytes and neuroblastoma cells (by 79% and 97%, respectively; both P < 0.001). Pravastatin had a similar but attenuated effect on ABCA1 in astrocytes (-54%, P < 0.001) and neuroblastoma cells (-70%, P < 0.001). Simvastatin reduced expression of apolipoprotein E in astrocytes (P < 0.01). Furthermore, both statins reduced expression of microtubule-associated protein tau in astrocytes (P < 0.01), while both statins increased its expression in neuroblastoma cells (P < 0.01). In SK-N-SH cells, simvastatin significantly increased cyclin-dependent kinase 5 and glycogen synthase kinase 3beta expression, while pravastatin increased amyloid precursor protein expression. Our data suggest that simvastatin and pravastatin differentially affect expression of genes involved in neurodegeneration and that statin-dependent gene expression regulation is cell type specific.