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Introduction: Early life ethanol exposure is known to program hypothalamic proopiomelanocortin (POMC) neurons to express a reduced level of POMC and its control of stress axis functions throughout the life span. In this study we tested whether miRNAs contribute to the ethanol-induced suppression of Pomc gene expression during the developmental period. Methods: In in vivo studies, POMC-EGFP male mice were fed with 2.5 g/kg ethanol using milk formula (AF) or pair-fed isocaloric milk formula (PF) or left in the litter (AD) during postnatal day (PND)-2-6. In in vitro studies, mHypoA-POMC/GFP cells were treated with ethanol (50 mM) for a 24 h period. Hypothalamic tissues or cell extracts were used for measurement of miRNAs and POMC mRNA. Results: Determination of genome-wide microRNA expression profile identified 40 miRNAs significantly altered in hypothalamic tissues of AF mice. In-silico analysis further identified miRNA-383, 384 and 488 have putative binding sites at the POMC 3’UTR. However, only miR-383 and miR-384 are identified to be responsive to ethanol. Administration of miR-383 or 384 inhibitor oligos suppressed ethanol-stimulated miR-383 or 384 expression and restored Pomc mRNA and protein expression in AF mice. mHypoA-POMC/GFP cells when treated with ethanol showed elevated levels of miR-383 and miR-384 and reduced level of Pomc mRNA. Treatment with miR-383 or 384 mimic oligos reduced the level of Pomc mRNA, while treatment with miR-383 or 384 inhibitor oligos increased the level of Pomc mRNA. Reporter assay further confirms the binding specificity of miR-383 and miR-384 to Pomc 3’UTR. Conclusion: These data suggest that miR-383 and miR-384 suppress Pomc gene expression and may contribute to the ethanol-induced alteration of the stress axis functions.

Valproic acid (VPA) is short branched-chain fatty acid (BCFA) derived from valeric acids which are naturally produced by

In this systematic review with elements of meta-analytic approaches we employed publicly available Gene Expression Omnibus (GEO) datasets to determine the role of epigenetic mechanisms in prenatal alcohol exposure (PAE)-induced dysfunction of hypothalamic-pituitary-adrenal (HPA) axis functions in the offspring. Several studies have demonstrated that PAE has long-term consequences on HPA axis functions in the offspring. Reports of some of these studies determined that alcohol-induced epigenetic alterations during fetal development persist in adulthood. However, additional research is necessary to understand the major epigenetic events leading to alcohol-induced teratogenesis on the HPA axis. Our network analysis of GEO datasets identified key pathways in relevance to alcohol-mediated histone modifications, DNA methylation and miRNA involvement associated with PAE-induced alteration of the HPA axis. Our analysis indicated that PAE perturbated the epigenetic machinery to activate corticotrophin-releasing hormone, while it suppressed opioid, glucocorticoid receptors, and circadian clock genes. We hope that our results would be helpful to further understanding and investigating the epigenetic basis of alcohol effect on the HPA axis development.

Valproic acid (VPA)-a short branched chain fatty acid (BCFA), is widely recognized as an anticonvulsant and a mood-stabilizing drug, but various adverse effects of VPA have also been investigated. However, the impact of BCFAs aggregation on brain cells, in the pathogenesis of neurodegeneration remains elusive. The objective of this study is to understand the cellular mechanisms underlying VPA-induced neuronal cell death mediated by oxidative stress, and the neuroprotective role of exogenous melatonin treatment on VPA-induced cell death. Neurotoxicity of VPA and protective role exerted by melatonin were assessed in vitro in SH-SY5Y cells and in vivo in the cerebral cortex and cerebellum regions of Wistar rat brain. The results show that melatonin pre-treatment protects the cells from VPA-induced toxicity by exerting an anti-apoptotic and anti-inflammatory effect by regulating apoptotic proteins and pro-inflammatory cytokines. The findings of the present study emphasize novel insights of melatonin as a supplement for the prevention and treatment of neuronal dysfunction induced by VPA.

Background and Aims A short branched chain fatty acid, valproic acid (VPA), has been used worldwide for decades in the intervention of seizure disorders, neuropathic pain and migraine. However, several adverse effects of VPA have been reported over the years. The aim of our investigation was to evaluate the adverse effects of VPA on synaptic functions by using synaptosomal preparation of rat brain as an in vitro model and the possible protective role of melatonin against VPA induced neurotoxicity. Melatonin is an antioxidant and scavenger of free radicals secreted by the pineal gland. Methods In the present investigation, synaptosomes prepared from rat brain were co-treated with melatonin (10 μmol) and VPA (5 mmol) for 2 h under in vitro conditions. Results In this study, co-treatment of melatonin with VPA significantly restored the elevated levels of lipid peroxidation (LPO) and protein oxidation. In addition, melatonin prevented VPA induced alterations in non-enzymatic antioxidant defence reduced glutathione (GSH) and activities of synaptosomal integral enzymes such as AChE, Na+, K+ -ATPase and MAO. A significant increase in the generation of reactive oxygen species (ROS) induced by VPA was observed and melatonin ameliorated elevated level of ROS generation. Moreover, the enhanced level of NO and diminished activity of synaptosomal mitochondrial membrane potential was completely prevented by melatonin treatment. Conclusion Our results corroborate the use of melatonin as a nutraceutical and mitigatory agent against VPA induced neurotoxicity in brain synaptosomes.

Cadmium (Cd) is a soft, malleable bluish-white metal with low melting point, a ubiquitous heavy metal and an environmental pollutant, found in soil, water and air. The presence of Cd in the components of the environment such as air, soil and groundwater is to a large part due to human activity, and the general population is exposed mainly by contaminated drinking water or food. Manganese (Mn) is a component in many enzymes, which play an important role in counteracting oxidative stress. In vitro experiments have revealed the ability of Mn to scavenge oxygen free radicals generated in differently mediated lipid peroxidation (LPO) conditions. The aim of the present study was to investigate the in vivo preventive effect of Mn(2+) pre-treatment on acute Cd-intoxication with regard to oxidative stress biomarker and antioxidant defense system in liver of Swiss albino mice. On exposure to Cd a significant increase in LPO levels, decrease in thiol content and induction in glutathione metabolizing enzyme were observed. Mn pre-treatment attenuated the modulation caused in the above-mentioned parameters due to acute Cd exposure in mice. In conclusion, the results from this study demonstrate that the protective effect of Mn in Cd-induced systemic toxicity in mice. Further investigations are required on the relation between Mn accumulation and resistance to oxidative stress and on the factors influencing Mn/Cd transport in rodents are needed to elucidate the molecular basis of this protective effect.

Phytanic acid (3,7,11,15-tetramethylhexadecanoic acid) (Phyt) is a saturated branched chain fatty acid which originates after the breakdown of chlorophyll molecule, phytol. It plays an important role in a variety of metabolic disorders with peroxisomal impairments. The aim of our investigation was to evaluate the adverse effects of Phyt on synaptic functions by using synaptosomal preparation of rat brain as an in vitro model and the possible protective role of melatonin against Phyt-induced neurotoxicity. Melatonin is an antioxidant, secreted by the pineal gland. Melatonin and its metabolites have neuroprotective effects on cellular stress, by reducing reactive oxygen species (ROS) and reactive nitrogen species (RNS). In the present investigation, synaptosomes prepared from rat brain were co-treated with melatonin (10μM) and Phyt (50μM) for 2h. Co-treatment of Phyt with melatonin significantly restored the altered levels of protein carbonyl (PC) contents and lipid peroxidation (LPO). It also replenished the Phyt-induced alterations on the levels of non-enzymatic antioxidant defence reduced glutathione (GSH), enzymatic antioxidants such as catalase (CAT) and superoxide dismutase (SOD) and synaptosomal integral enzymes such as AChE, Na+, K+-ATPase and MAO. We observed that Phyt induced oxidative stress in synaptosomes as indicated by an elevation in the generation of ROS and melatonin was able to inhibit the elevated ROS generation. Moreover, the neurotoxic effects elicited by Phyt on NO level and membrane potential were totally prevented by the treatment of melatonin. The results of our investigation emphasize the potential use of melatonin as a nutraceutical and mitigatory agent against Phyt-induced oxidative stress.

Valproic acid (VPA) is ubiquitously used as a major drug in the intervention of epilepsy and in the control of several kinds of seizures. Cellular toxicities are the serious dose-limiting side effects of VPA when applied in the treatment of diseases. Oxidative stress has been proven to be involved in VPA-induced toxicity. Accumulating evidence intimates that oxidative stress caused by free radicals and in kidney cells contributes to the pathogenesis of VPA-induced nephrotoxicity. The pathogenesis of these forms of VPA nephrotoxicity is still not clear. The aim of our investigation was to evaluate the nephrotoxic potential of VPA and protective effects of quercetin (QR) against VPA-induced nephrotoxicity by using rat kidney tissue preparation as an in vitro model. Oxidative stress indexes such as lipid peroxidation (LPO) and protein carbonyl (PC) content were appraised. The levels of oxidative stress markers, LPO, and PC were significantly elevated. Nonenzymatic antioxidants effect was also demonstrated as a significant increase in reduced glutathione (GSH) and nonprotein thiol level (NP-SH). VPA exposure altered the activities of glutathione metabolizing enzymes such as glutathione-S-transferase, glutathione peroxidase, and glutathione reductase. Pre-treatment with QR could reverse the VPA-induced effects in kidney tissue preparation of rat. Based on reno-protective and antioxidant action of QR, we suggest that this flavonoid compound could be considered as a potential safe and effective approach in attenuating the adverse effect of VPA-induced nephrotoxicity.

Phytanic acid, a saturated branched chain fatty acid and a major constituent of human diet, is predominantly found in dairy products, meat, and fish. It is a degradation product from the phytol side chain of chlorophyll. Degradation of PA is known to occur mainly in peroxisomes via α-oxidation and in mitochondria via β-oxidation. Due to its β-methyl group present at the 3-position of the carbon atoms, PA cannot be β-oxidized. Although alteration in the metabolism of PA may play an important role in neurodegeneration, the exact mechanism behind it remains to be evaluated. In this study, we have described the potential of PA to induce neurotoxicity as an in vitro model (neuronal cell line, SH-SY5Y cells). Cells were pretreated with melatonin (10 μM) for 1 h followed by with and without PA (100 μM) for 24 h. In the present study, our data has confirmed that PA markedly increased both intracellular reactive oxygen species and reactive nitrogen species levels. Our results have shown that PA treatment did not induce cell death by cleavage of caspase-3/PARP-1 mediated by mitochondria through intrinsic pathways; however, PA induced nitric oxide-dependent apoptosis in SH-SY5Y cells. Additionally, melatonin pretreatment reduced the cell death in SH-SY5Y cells. Melatonin also effectively exerted an antiapoptotic and anti-inflammatory action by regulating Bax, Bcl-2, p-NFκB, and iNOS expressions in SH-SY5Y cells. These results suggested that melatonin acted as an antioxidative and antiapoptotic agent by modulating ROS, apoptotic proteins, and inflammatory responses under BCFA-induced neurotoxic conditions. The protective effects of melatonin depend on direct scavenging activity of free radicals and indirect antioxidant effects. Further deciphering of the cellular and molecular mechanism associated with neuroprotection by melatonin is warranted in BCFA-induced neurotoxicity.

Cadmium (Cd) is a toxic heavy metal commonly found in industrial workplaces, a food contaminant and a major constituent of cigarette smoke. Most of the organs are susceptible to Cd-induced toxicity, including brain. Postnuclear supernatant (PNS) has been accepted as an in vitro model for assessing xenobiotic induced toxicity. The goal of the present study was to validate PNS as an in vitro model for investigating the effect of Cd-induced neurotoxicity. Neurotoxic induction by Cd was established in a dose-dependent manner in PNS in vitro. Enzymatic and non-enzymatic antioxidants were used as biomarkers of exposure. Antioxidant enzymatic activity was measured as a significant increase in activities of catalase, superoxide dismutase, and glutathione S-transferase. On exposure to Cd, a significant increase in acetylcholinesterase and decrease in sodium-potassium ATPase activity was also observed. Non-enzymatic effect was also demonstrated as a significant elevation in reduced glutathione and non-protein thiol activity, but there was no significant increase or decrease in the concentrations of protein thiol. In accordance with the toxicity of Cd towards the studied brain structure, Cd-induced oxidative stress has been a focus of toxicological research as a possible mechanism of neurotoxicity. Our results suggest that PNS preparations can be used as a model for future investigation of xenobiotic-induced neurotoxicity under in vitro conditions.

Cadmium (Cd(2+) ) causes alteration of the cellular homeostasis and oxidative damage. The aim of the present study was to investigate the possible protective role of thymoquinone (TQ), a predominant bioactive component present in black seed oil (Nigella sativa) on the hepatotoxicity of Cd(2+) with special reference to its protection against perturbation of nonenzymatic and enzymatic antioxidants. The effect of TQ pretreatment was examined in postnuclear supernatant prepared from liver of Swiss albino mice under in vitro conditions. CdCl(2) treatment (5 mM) resulted in a significant increase in antioxidant enzymatic activities. It also caused a significant (p < 0.001) increase in protein carbonyl and reduced glutathione content. Pretreatment with TQ (10 μM) showed a significant protection as manifested by noticed attenuation of protein oxidation and rejuvenation of the depleted antioxidants of cellular fraction. These results strengthen the hypothesis that TQ exerts modulatory influence on the antioxidant defense system on being subjected to toxic insult.

Valproic acid (VPA) is ubiquitously used as a major drug in the intervention of epilepsy and in the control of several kinds of seizures. Cellular toxicities are the serious dose-limiting side effects of VPA when applied in the treatment of diseases. Oxidative stress has been proven to be involved in VPA-induced toxicity. Accumulating evidence intimates that oxidative stress caused by free radicals and in kidney cells contributes to the pathogenesis of VPA-induced nephrotoxicity. The pathogenesis of these forms of VPA nephrotoxicity is still not clear. The aim of our investigation was to evaluate the nephrotoxic potential of VPA and protective effects of quercetin (QR) against VPA-induced nephrotoxicity by using rat kidney tissue preparation as an in vitro model. Oxidative stress indexes such as lipid peroxidation (LPO) and protein carbonyl (PC) content were appraised. The levels of oxidative stress markers, LPO, and PC were significantly elevated. Nonenzymatic antioxidants effect was also demonstrated as a significant increase in reduced glutathione (GSH) and nonprotein thiol level (NP-SH). VPA exposure altered the activities of glutathione metabolizing enzymes such as glutathione-S-transferase, glutathione peroxidase, and glutathione reductase. Pre-treatment with QR could reverse the VPA-induced effects in kidney tissue preparation of rat. Based on reno-protective and antioxidant action of QR, we suggest that this flavonoid compound could be considered as a potential safe and effective approach in attenuating the adverse effect of VPA-induced nephrotoxicity.