An in vitro approach to assess the neurotoxicity of valproic acid-induced oxidative stress in cerebellum and cerebral cortex of young rats

Protective effects of curcumin against valproic acid induced brain kidney and liver damage in rats

Valproic acid (VPA) is a broad-spectrum drug that is now widely used as an antiepileptic. Although VPA has positive therapeutic effects, it also causes various toxic effects in tissues. Curcumin, a natural antioxidant found in ginger, has antibacterial and antiinflammatory activity. In this study, the toxic effects of VPA on brain, kidney, and liver tissues and the protective activity of curcumin against these effects were investigated. In this study, male Wistar-Albino rats were used. Rats were divided into 4 groups control, VPA, CUR, and CUR + VPA. Rats were administered intraperitoneal VPA and CUR intragastrically. In the study, MDA, SOD, IL-6, and IL-18 levels were measured by the ELISA method in rats. It was observed that VPA triggered oxidative stress and inflammation in tissues, while CUR administration positively regulated these parameters. Studies also showed that VPA increased the expressions of TNF-α and NF-kB in tissues, but CUR administration downregulated these expressions The findings revealed that CUR protects by preventing the oxidative stress and inflammation caused by VPA in the tissues and may be an important agent in reducing the side effects of this drug used as an antiepileptic.

Indole-3-acetic acid and chenodeoxycholic acid attenuate TLR4/NF-κB signaling and endoplasmic reticulum stress in valproic acid-induced neurotoxicity

Valproic acid (VA) is a commonly prescribed medication for epilepsy and other neurological conditions. Although effective, VA use can lead to neurotoxicity, especially with chronic use. This study aimed to investigate the potential neuroprotective properties of indole-3-acetic acid (IAA) and chenodeoxycholic acid (CDCA) in an animal model of VA-induced brain injury. Rats received intraperitoneal injections of VA at a dose of 500 mg/kg/day for 3 weeks. Concurrently, they were orally treated with IAA (40 mg/kg/day) and/or CDCA (90 mg/kg/day). The results showed significantly increased oxidative stress and inflammation markers in the VA-exposed group indicated by the reduced levels of glutathione (GSH, P < 0.0001) and superoxide dismutase (SOD, P < 0.01) and the elevated inflammatory cytokines Interleukin-6 (IL-6, P < 0.0001) and tumor necrosis factor-alpha (TNFα, P < 0.01). VA also induced nuclear factor kappa B (NF-κB, P < 0.01), toll-like receptor 4 (TLR4, P < 0.05), and endoplasmic reticulum (ER) stress markers, as evidenced by increased immunoreactivity of GRP78 (glucose-regulated protein 78, P < 0.0001), transcription factor 6 (ATF-6, P < 0.05) and CHOP (C/EBP homologous protein, P < 0.0001). Treatment with IAA or CDCA attenuated VA-induced neurotoxicity, to a variable extent, by improving oxidative, inflammatory, and ER stress markers. This study demonstrates that IAA and CDCA exert protective effects against VA-induced neurotoxicity by mitigating oxidative stress, inflammation, and ER stress. Further investigations are recommended to validate these findings in other neurotoxicity models.

Pharmacodynamic characterization and evaluation of oxidative stress effects of digitoxigenin derivatives on HeLa cells

Cancer is a leading cause of death worldwide and its treatment is hampered by the lack of specificity and side effects of current drugs. Cardiotonic steroids (CTS) interact with Na+/K+-ATPase (NKA) and induce antineoplastic effects, but their narrow therapeutic window is key limiting factor. The synthesis of digitoxigenin derivatives with glycosidic unit modifications is a promising approach to develop more selective and effective antitumor agents. This study aimed to compare the pharmacological properties as well as the cytotoxic effects of digitoxigenin-α-L-amiceto-pyranoside and digitoxigenin-α-L-rhamno-pyranoside and to evaluate the mechanism of these derivatives in oxidative conditions in HeLa cells. The rhamnose derivative increased the binding affinity and inhibitory effect of digitoxigenin by approximately 5-15 times, unlike the amicetose derivative. Despite this difference, both compounds similarly increased H2O2 levels, induced membrane lipid peroxidation, and reduced GSH levels and SOD activity at nanomolar concentrations. This study highlights the importance of the sugar moiety in CTS structure for NKA binding and demonstrates that a primary mechanism of cytotoxicity of digitoxigenin derivatives may involve cellular oxidative stress, underscoring their potential as therapeutic agents for cancer treatment.

Brivaracetam and rufinamide combination increased seizure threshold and improved neurobehavioral deficits in corneal kindling model of epilepsy

BACKGROUND

Besides seizures, a myriad of overlapping neuropsychiatric and cognitive comorbidities occur in patients with epilepsy, which further debilitates their quality of life. This study provides an in-depth characterization of the impact of brivaracetam and rufinamide individually and in combination at 10 and 20 mg/kg doses, respectively, on corneal kindling-induced generalized seizures and behavioral alterations. Furthermore, observed convulsive frequency and behavioral changes were correlated to post-kindling-induced changes in the activity of markers of oxidative stress.

METHODS

Adult C57BL/6 mice were kindled via twice-daily transcorneal 50-Hz electrical stimulations (3 mA) for 3 s for 12 days until animals reached a fully kindled state. After the kindling procedure, animals were tested using a set of behavioral tests, and neurochemical alterations were assessed.

RESULTS

Corneal-kindled animals exhibited intense generalized convulsions, altered behavioral phenotypes typified by positive symptoms (hyperlocomotion), negative symptoms (anxiety and anhedonia), and deficits in semantic and working memory. BRV 10 + RFM 20 dual regime increased convulsive threshold and propensity toward the start of stage 4-5 seizures and improved phenotypical deficits, that is, anxiety, depression, and memory impairments. Moreover, this combination therapy mitigated kindling-induced redox impairments as evidenced by reduced malondialdehyde and acetylcholinesterase levels and increased glutathione antioxidant activity in the brain of animals subjected to repetitive brain insult.

CONCLUSION

Based on our outcomes, this dual therapy provides supporting evidence in alleviating epilepsy-induced neurobehavioral comorbidities and changes in redox homeostasis.

Dopamine-D2-agonist targets mitochondrial dysfunction via diminishing Drp1 mediated fission and normalizing PGC1-α/SIRT3 pathways in a rodent model of Subarachnoid Haemorrhage

The adverse impact of disturbmitochondrialbiogenesis onearly brain injury (EBI) following subarachnoid haemorrhage (SAH) has been broadly recognized and is closely associated with oxidative stress and neuronal apoptosis. Previous studies have indicated the therapeutic potential of Ropinirole, a dopamine D2 agonist, in Ischemic Stroke. However, there is a lack of evidence regarding the ability of Ropinirole to enhance mitochondrial biogenesis and quality control after subarachnoid haemorrhage. The objective of this study is to investigate the effects of Ropinirole specific doses (10 & 20 mg/kg b. wt.) on mitochondria dysfunction in endovascular perforation SAH model in male Wistar rat. An endovascular perforation model was established using male Wistar rats that had sustained SAH injury. After the SAH injury, SAH grading on blood clot, Nissl staining, and neurobehavioral assessment were used to determine the severity. ROS and MMP, which are indicators of oxidative stress, were examined using flow cytometry. The findings demonstrated that the use of Ropinirole improved neurobehavioral outcomes, decreased brain edema, and reduced oxidative stress and mitochondrial based apoptosis. Further research showed that, Ropinirole therapy inhibit Drp1-mediated fission by accelerating the activity of fusion protein Mfn2/OPA1 along with regulating the translocation of PGC1-α and SIRT3 through restricting cytochrome C inside mitochondria to maintain mitochondrial metabolism. Ropinirole exerted neuroprotective effects by improving mitochondrial activity in a PGC1-α/SIRT3-dependent way via regulating Drp1 mediated fission. The effective treatment for SAH-induced EBI may involve increasing biogenesis and inhibiting excessive mitochondrial fission with Ropinirole.

The effects of hesperidin on valproic acid-induced reduction in hippocampal neurogenesis through the antioxidant and apoptotic pathways in adult rats

Treatment with valproic acid (VPA) can induce oxidative stress, leading to neuronal degeneration. Hesperidin (HSD) has an antioxidant function that can mitigate oxidative stress, thereby promoting hippocampal neurogenesis. Because brain function and memory are reliant on hippocampal neurogenesis, this work is planned to elucidate the effects of HSD on the VPA-induced alterations in hippocampal neurogenesis and apoptosis via oxidative damage. Twenty-four male Sprague-Dawley rats were grouped into the vehicle, VPA, HSD, and VPA + HSD groups. After administration, the hippocampi and prefrontal cortex were harvested for p21 staining, assessment of MDA, CAT, SOD, and GPx, and Western blotting analysis of Nrf2, Bax, caspase3, and Bcl-2 proteins. The results exhibited a significantly elevated level of p21-positive cells in VPA-treated rats, indicating cell cycle arrest in hippocampal neurogenesis. Additionally, our findings demonstrated a notable rise in oxidative stress, a decrease in antioxidant enzyme activity and the transcription factor Nrf2 in VPA-treated rats. Furthermore, VPA induced apoptotic activities, as substantiated by the upregulation of Bax and caspase3, and the downregulation of Bcl-2. These findings demonstrate that HSD can reduce oxidative stress levels, thereby mitigating the arrest of the cell cycle and apoptotic activity induced by VPA treatment in both the hippocampus and prefrontal cortex.

Probiotics by Modulating Gut-Brain Axis Together With Brivaracetam Mitigate Seizure Progression, Behavioral Incongruities, and Prevented Neurodegeneration in Pentylenetetrazole-Kindled Mice

BACKGROUND

The microbiota-gut-brain axis (MGBA) is a central nexus that integrates higher cognitive and emotional centers of the central nervous system (CNS) within the intricate functioning of the intestine. Accumulating evidence suggests that dysbiosis in the taxonomic diversity of gut flora plays a salient role in the progression of epilepsy and comorbid secondary complications.

METHODS

In the current study, we investigated the impact of long-term oral bacteriotherapy (probiotics; 10 mL/kg; 109 colony-forming unit/ml) as an adjunctive treatment intervention with brivaracetam (BRV; 10 mg/kg) over 21 days on pentylenetetrazole (PTZ) induced augmented epileptic response and associated electrographical and behavioral perturbations in mice. Moreover, we also unveiled antioxidant capacity and histopathologic changes in treated versus non-treated animals.

RESULTS

Results revealed combination increases seizure threshold and prevented high ictal spiking. Additionally, it alleviated PTZ-induced neuropsychiatric disturbances such as anxiety and depressive-like phenotype along with cognitive deficits. Furthermore, dual therapy prompted physiological oxidant/antioxidant balance as evidenced by increased activity of antioxidant enzymes (SOD and catalase) and reduced levels of oxidative stressor (MDA). This therapeutic intervention with commensal species suppressed network-driven neuroinflammation and preserved normal cytoarchitecture with intact morphology in the pyramidal layers of cornu ammonis (CA1 and CA3).

CONCLUSION

Our study provides supporting evidence for the use of probiotics as adjunctive therapy with anti-seizure medications to modulate epileptogenic processes and related multimorbidities, particularly in individuals with drug-resistant seizures.

Endocrine disrupting effects on morphological synaptic plasticity

Neural regulation of the homeostasis depends on healthy synaptic function. Adaptation of synaptic functions to physiological needs manifests in various forms of synaptic plasticity (SP), regulated by the normal hormonal regulatory circuits. During the past several decades, the hormonal regulation of animal and human organisms have become targets of thousands of chemicals that have the potential to act as agonists or antagonists of the endogenous hormones. As the action mechanism of these endocrine disrupting chemicals (EDCs) came into the focus of research, a growing number of studies suggest that one of the regulatory avenues of hormones, the morphological form of SP, may well be a neural mechanism affected by EDCs. The present review discusses known and potential effects of some of the best known EDCs on morphological synaptic plasticity (MSP). We highlight molecular mechanisms altered by EDCs and indicate the growing need for more research in this area of neuroendocrinology.

Neuroprotective potential of topiramate, pregabalin and lacosamide combination in a rat model of acute SE and intractable epilepsy: Perspectives from electroencephalographic, neurobehavioral and regional degenerative analysis

The lithium-pilocarpine model is commonly used to recapitulate characteristics of human intractable focal epilepsy. In the current study, we explored the impact of topiramate (TPM) alone and in combination with pregabalin and lacosamide administration for 6 weeks on the evolution of spontaneous recurrent seizures (SRS) and disease-modifying potential on associated neuropsychiatric comorbidities. In addition, redox impairments and neurodegeneration in hippocampus regions vulnerable to temporal lobe epilepsy (TLE) were assessed by cresyl violet staining. Results revealed that acute electrophysiological (EEG) profiling of the ASD cocktail markedly halted sharp ictogenic spikes as well as altered dynamics of brain wave oscillations thus validating the need for polytherapy vs. monotherapy. In TLE animals, pharmacological intervention for 6 weeks with topiramate 10 mg/kg in combination with PREG and LAC at the dose of 20 mg/kg exhibited marked protection from SRS incidence, improved body weight, offensive aggression, anxiety-like behavior, cognitive impairments, and depressive-like behavior (p < 0.05). Moreover, combination therapy impeded redox impairments as evidenced by decreased MDA and AchE levels and increased activity of antioxidant SOD, GSH enzymes. Furthermore, polytherapy rescued animals from SE-induced neurodegeneration with increased neuronal density in CA1, CA3c, CA3ab, hilus, and granular cell layer (GCL) of the dentate gyrus. In conclusion, early polytherapy with topiramate in combination with pregabalin and lacosamide prompted synergy and prevented epileptogenesis with associated psychological and neuropathologic alterations.

The Effect of Neuropsychiatric Drugs on the Oxidation-Reduction Balance in Therapy

The effectiveness of available neuropsychiatric drugs in the era of an increasing number of patients is not sufficient, and the complexity of neuropsychiatric disease entities that are difficult to diagnose and therapeutically is increasing. Also, discoveries about the pathophysiology of neuropsychiatric diseases are promising, including those initiating a new round of innovations in the role of oxidative stress in the etiology of neuropsychiatric diseases. Oxidative stress is highly related to mental disorders, in the treatment of which the most frequently used are first- and second-generation antipsychotics, mood stabilizers, and antidepressants. Literature reports on the effect of neuropsychiatric drugs on oxidative stress are divergent. They are starting with those proving their protective effect and ending with those confirming disturbances in the oxidation-reduction balance. The presented publication reviews the state of knowledge on the role of oxidative stress in the most frequently used therapies for neuropsychiatric diseases using first- and second-generation antipsychotic drugs, i.e., haloperidol, clozapine, risperidone, olanzapine, quetiapine, or aripiprazole, mood stabilizers: lithium, carbamazepine, valproic acid, oxcarbazepine, and antidepressants: citalopram, sertraline, and venlafaxine, along with a brief pharmacological characteristic, preclinical and clinical studies effects.

Reversal of Valproate-Induced Major Salivary Gland Changes By Moringa Oleifera Extract in Rats

This study aimed to explore the potential protective impacts of Moringa oleifera extract on major alteration in salivary glands of rats exposed to sodium valproate (VA). Groups were defined as control, control+moringa extract, sodium valproate, and sodium valproate+moringa extract. Antioxidant and oxidant status, activities of digestive and metabolic enzymes were examined. VA treatment led to various biochemical changes in the salivary glands, including decreased levels of antioxidants like glutathione, glutathione-S-transferase, and superoxide dismutase (except for sublingual superoxide dismutase). Conversely, a decrease in alpha-amylase, alkaline and acid phosphatase, lactate dehydrogenase, protease, and maltase activities were observed. The study also demonstrated that VA induces oxidative stress, increases lipid peroxidation, sialic acid, and nitric oxide levels in the salivary glands. Total oxidant capacity was raised in all glands except in the sublingual gland. The electrophoretic patterns of proteins were similar. Moringa oleifera extract exhibited protective properties, reversing these VA-induced biochemical changes due to its antioxidant and therapeutic attributes. This research suggests that moringa extract might serve as an alternative treatment approach for individuals using VA and experiencing salivary gland issues, although further research is necessary to confirm these findings in human subjects.

Fluvoxamine Ameliorates the Damage to the Neuro-Behavioral Status of Rats Caused by the Administration of Valproic Acid by Preventing Cognitive Memory Deficits and Decreased Hippocampal Cellular Proliferation

Fluvoxamine is a major antidepressant of the selective serotonin-reuptake inhibitor class, previously studied as a drug that improves cognitive memory by enhancing hippocampal cell division and proliferation. Valproic acid (VPA) is a commonly used antiepileptic drug and mood stabilizer that has negative effects on cognitive memory as it inhibits cellular division and proliferation in the hippocampus. This study assessed the protective effects of fluvoxamine treatment versus the memory impairment, decreased hippocampal cellular proliferation, and weight loss produced by VPA treatment. The cognitive memory of 40 male Sprague-Dawley rats was assessed by the novel object location (NOL) test. Immunostaining by Ki67 and glutathione peroxidase 1 (GPX-1) was performed to quantify the number of dividing cells in the subgranular zone (SGZ) of the dentate gyrus and to assess the antioxidant activity of different treatments, respectively. Results showed that the VPA group had fewer Ki67-positive cells than the control group (p < 0.001), indicating reduced hippocampal proliferation. In contrast, the VPA and fluvoxamine combination group showed increased proliferation (p < 0.001) compared to VPA alone. Notably, fluvoxamine treatment significantly differed in cell counts compared to other groups (p < 0.001). Fluvoxamine also attenuated the weight loss caused by VPA (p < 0.0001). Our data suggested that fluvoxamine therapy attenuated the VPA-induced decrease in SGZ cellular proliferation, memory, and weight in rats.

Chitosan Nanoparticles Loaded with Quercetin and Valproic Acid: A Novel Approach for Enhancing Antioxidant Activity against Oxidative Stress in the SH-SY5Y Human Neuroblastoma Cell Line

BACKGROUND

Multiple drug-delivery systems obtained by loading nanoparticles (NPs) with different drugs that have different physicochemical properties present a promising strategy to achieve synergistic effects between drugs or overcome undesired effects. This study aims to develop a new NP by loading quercetin (Que) and valproic acid (VPA) into chitosan. In this context, our study investigated the antioxidant activities of chitosan NPs loaded with single and dual drugs containing Que against oxidative stress.

METHOD

The synthesis of chitosan NPs loaded with a single (Que or VPA) and dual drug (Que and VPA), the characterization of the NPs, the conducting of in vitro antioxidant activity studies, and the analysis of the cytotoxicity and antioxidant activity of the NPs in human neuroblastoma SH-SY5Y cell lines were performed.

RESULT

The NP applications that protected cell viability to the greatest extent against H2O2-induced cell damage were, in order, 96 µg/mL of Que-loaded chitosan NP (77.30%, 48 h), 2 µg/mL of VPA-loaded chitosan NP (70.06%, 24 h), 96 µg/mL of blank chitosan NP (68.31%, 48 h), and 2 µg/mL of Que- and VPA-loaded chitosan NP (66.03%, 24 h).

CONCLUSION

Our study establishes a successful paradigm for developing drug-loaded NPs with a uniform and homogeneous distribution of drugs into NPs. Chitosan NPs loaded with both single and dual drugs possessing antioxidant activity were successfully developed. The capability of chitosan NPs developed at the nanometer scale to sustain cell viability in SH-SY5Y cell lines implies the potential of intranasal administration of chitosan NPs for future studies, offering protective effects in central nervous system diseases.

Perampanel increases seizure threshold in pentylenetetrazole-kindled mice and improves behavioral dysfunctions by modifying mRNA expression levels of BDNF/TrkB and inflammatory markers

Perampanel (PER), a novel 3rd-generation antiseizure drug that modulates altered post-synaptic glutamatergic storming by selectively inhibiting AMPA receptors, is recently approved to treat intractable forms of seizures. However, to date, presumably consequences of long-term PER therapy on the comorbid deleterious psychiatric disturbances and its correlation with neuroinflammatory parameters are not fully investigated in chronic models of epilepsy. Therefore, we investigated the real-time effect of PER on brain electroencephalographic (EEG) activity, behavioral alterations, redox balance, and relative mRNA expression in pentylenetetrazole (PTZ) induced kindling. Male BALB/c mice were pretreated with PER (0.125, 0.25, and 0.5 mg/kg) for 3 weeks and challenged with 11 injections of PTZ at the sub-threshold dose of 40 mg/kg every other day. vEEG from implanted cortical electrodes was monitored to elucidate seizure propagation and behavioral manifestations. Recorded EEG signals exhibited that PER 0.5 mg/kg pretreatment exceptionally impeded the onset of sharp epileptic spike-wave discharges and associated motor symptoms. Additionally, qEEG analysis showed that PER prevented alterations in absolute mean spectral power and reduced RMS amplitude of epileptogenic spikes vs PTZ control. Furthermore, our outcomes illustrated that PER dose-dependently attenuated PTZ-evoked anxiety-like behavior, memory deficits, and depressive-like behavior that was validated by a series of behavioral experiments. Moreover PER, significantly reduced lipid peroxidation, AChE, and increased levels of SOD and total thiol in the mice brain via AMPAR antagonism. Post-PTZ kindling provoked overstimulation of BDNF/TrkB signaling and increased release of pro-inflammatory cytokines that were reversed by PER with suppression of iNOS in brain immune cells. In conclusion, our findings highlight that PER might play an auspicious preventive role in the proepileptic transformation of brain circuits via suppression of BDNF/TrkB signaling and reduced transcriptional levels of neuroinflammatory markers leading to improvised epilepsy-induced neurobehavioral and neurochemical effects.

Alterations in salivary biochemical composition and redox state disruption induced by the anticonvulsant valproic acid in male rat salivary glands

OBJECTIVE

To investigate the effects of the anticonvulsant valproic acid (VPA) on salivary glands in male rat using biochemical, functional, histomorphometric, and redox state parameters.

MATERIALS AND METHODS

Twenty-four male Wistar rats were randomly distributed into three groups (n = 8 per group): Control (0.9% saline solution), VPA100 (100 mg/kg), and VPA400 (400 mg/kg). After 21 consecutive days of treatment with by intragastric gavage. Pilocarpine-induced saliva was collected to determine salivary flow rate, pH, buffering capacity, and biochemical composition. Analyses of histomorphometric parameters and redox balance markers were performed on the parotid and submandibular glands.

RESULTS

Salivary flow rate, pH, buffering capacity, total protein, potassium, sodium, and chloride were similar between groups. However, phosphate and calcium were reduced in VPA400, while amylase was increased in both VPA100 and VPA400. We did not detect significant differences in the areas of acini, ducts, and connective tissue in the salivary glands between the groups. There were no significant changes in the redox status of the submandibular glands. In turn, in the parotid glands we detected reduced total oxidizing capacity and lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARs) and higher uric acid concentration in both the VPA100 and VPA400 groups, and increased superoxide dismutase (SOD) in the VPA400 group.

CONCLUSION

Chronic treatment with VPA modified the salivary biochemical composition and caused disruption in the redox state of the parotid gland in rats.

Increased levels of lipid and protein oxidation in rat prefrontal cortex after treatment by lithium, valproic acid, and olanzapine

Oxidative stress is widely accepted to contribute to the pathogenesis of several psychiatric diseases. Many antipsychotic drugs and mood stabilizers act through restoration of the dysregulated oxidative homeostasis in the brain. However, the long-term effect of these drugs per se in terms of their potential to interfere with the oxidative status in the brain remains largely controversial. The present study aimed to investigate the sole effect of three commonly used psychoactive drugs, lithium, valproic acid, and olanzapine, on lipid and protein oxidation status in the prefrontal cortex of healthy rats. A total of 80 adult male albino Wistar rats were used, and groups were treated with saline (control), lithium, valproic acid, or olanzapine daily for 30 days. Following sacrification, right prefrontal cortexes were dissected and homogenized. Lipid peroxidation (LPO) and protein oxidation (AOPP) assays were performed by ELISA. LPO levels were significantly higher in lithium and valproic acid-treated rats by 45% and 40%, respectively. Olanzapine treatment caused a mild 26% increase in LPO levels, but the effect was non-significant. Lithium, valproic acid, and olanzapine treatments significantly increased AOPP levels by 58%, 54%, and 36.5%, respectively. There was a strong positive correlation between the lipid peroxidation and protein oxidation levels. Our results call attention to the need to consider the pro-oxidative capacity of antipsychotic drugs per se and their potential to disturb the oxidative homeostasis in the brain during long-term medication for psychiatric diseases.

Time and Brain Region-Dependent Excitatory Neurochemical Alterations in Bilateral Common Carotid Artery Occlusion Global Ischemia Model

Strict metabolic regulation in discrete brain regions leads to neurochemical changes in cerebral ischemia. Accumulation of extracellular glutamate is one of the early neurochemical changes that take place during cerebral ischemia. Understanding the sequential neurochemical processes involved in cerebral ischemia-mediated excitotoxicity before the clinical intervention of revascularization and reperfusion may greatly influence future therapeutic strategies for clinical stroke recovery. This study investigated the influence of time and brain regions on excitatory neurochemical indices in the bilateral common carotid artery occlusion (BCCAO) model of global ischemia. Male Wistar rats were subjected to BCCAO for 15 and 60 min to evaluate the effect of ischemia duration on excitatory neurochemical indices (dopamine level, glutamine synthetase, glutaminase, glutamate dehydrogenase, aspartate aminotransferase, monoamine oxidase, acetylcholinesterase, and Na⁺ K⁺ ATPase activities) in the discrete brain regions (cortex, striatum, cerebellum, and hippocampus). BCCAO without reperfusion caused marked time and brain region-dependent alterations in glutamatergic, glutaminergic, dopaminergic, monoaminergic, cholinergic, and electrogenic homeostasis. Prolonged BCCAO decreased cortical, striatal, and cerebellar glutamatergic, glutaminergic, dopaminergic, cholinergic, and electrogenic activities; increased hippocampal glutamatergic, glutaminergic, dopaminergic, and cholinergic activities, increased cortical and striatal monoaminergic activity; decreased cerebellar and hippocampal monoaminergic activity; and decreased hippocampal electrogenic activity. This suggests that excitatory neurotransmitters play a major role in the tissue-specific metabolic plasticity and reprogramming that takes place between the onset of cardiac arrest-mediated global ischemia and clinical intervention of recanalization. These tissue-specific neurochemical indices may serve as diagnostic and therapeutic strategies for mitigating the progression of ischemic damage before revascularization.

Identification of Monomethyl Branched-Chain Lipids by a Combination of Liquid Chromatography Tandem Mass Spectrometry and Charge-Switching Chemistries

While various mass spectrometric approaches have been applied to lipid analysis, unraveling the extensive structural diversity of lipids remains a significant challenge. Notably, these approaches often fail to differentiate between isomeric lipids─a challenge that is particularly acute for branched-chain fatty acids (FAs) that often share similar (or identical) mass spectra to their straight-chain isomers. Here, we utilize charge-switching strategies that combine ligated magnesium dications with deprotonated fatty acid anions. Subsequent activation of these charge inverted anions yields mass spectra that differentiate anteiso-branched- from straight-chain and iso-branched-chain FA isomers with the predictable fragmentation enabling de novo assignment of anteiso branch points. The application of these charge-inversion chemistries in both gas- and solution-phase modalities is demonstrated to assign the position of anteiso-methyl branch-points in FAs and, with the aid of liquid chromatography, can be extended to de novo assignment of additional branching sites via predictable fragmentation patterns as methyl branching site(s) move closer to the carboxyl carbon. The gas-phase approach is shown to be compatible with top-down structure elucidation of complex lipids such as phosphatidylcholines, while the integration of solution-phase charge-inversion with reversed phase liquid chromatography enables separation and unambiguous identification of FA structures within isomeric mixtures. Taken together, the presented charge-switching MS-based technique, in combination with liquid chromatography, enables the structural identification of branched-chain FA without the requirement of authentic methyl-branched FA reference standards.

Caffeic acid phenethyl ester ameliorates imidacloprid-induced acute toxicity in the rat cerebral cortex

This study aimed to investigate the role of caffeic acid phenethyl ester (CAPE), a compound found in propolis, on imidacloprid (IMI), a nicotinic acetylcholine receptor agonist that causes cerebral toxicity. 60 adult rats were randomly divided into five groups: control, IMI (100 mg/kg), and IMI+CAPE (1, 5, 10 mg/kg). Cerebral cortex tissue was examined histopathologically, biochemically, spectrophotometrically and immunohistochemically. The results showed that IMI caused toxicity in the cerebral cortex. However, CAPE (5 and 10 mg/kg) attenuated the deteriorated histopathological score and normalized the apoptotic markers (Bax and Caspase-3). Additionally, CAPE dose-dependently normalized the levels of TNF-α, dopamin, GFAP and NGF, and at the highest dose (10 mg/kg) also normalized the balance of oxidative parameters (MDA, SOD, CAT, and GSH). In conclusion, the antioxidant, anti-inflammatory, and anti-apoptotic effects of CAPE may be a promising treatment for acute IMI-induced cerebral cortex toxicity.

Neuroprotective Effects of Natural Antioxidants Against Branched-Chain Fatty Acid-Induced Oxidative Stress in Cerebral Cortex and Cerebellum Regions of the Rat Brain

Valproic acid (VPA) is short branched-chain fatty acid (BCFA) derived from valeric acids which are naturally produced by Valeriana officinalis (flowering plant). Neurotoxicity caused by BCFA-like VPA may be mediated by oxidative stress, according to research involving the cerebral cortex and cerebellum. In the present study, we explored the possible protective effect of different antioxidants such as melatonin, quercetin, and piperine on VPA exposure by using a supernatant preparation of the cerebral cortex and cerebellum regions of the rat brain. The present study revealed that melatonin, quercetin, and piperine significantly prevented VPA-induced oxidative stress in the cerebral cortex and cerebellum regions. VPA was also observed to lower the level of reduced glutathione, and this effect was significantly mitigated by these antioxidants. Melatonin, quercetin, and piperine also ameliorated and altered the activities of AChE, Na⁺, K⁺ATPase, and MAO in the cerebral cortex and cerebellum. Results of this study also suggest that prior treatment of antioxidants like melatonin, quercetin, and piperine helps in combating the oxidative stress induced by VPA in the cerebral cortex and cerebellum region of the rat brain. Thus, sufficient dietary intake of these antioxidants by individuals at high risk of VPA exposure could prove beneficial in combating the adverse effect of VPA.

Crafting ɣ-L-Glutamyl-l-Cysteine layered Human Serum Albumin-nanoconstructs for brain targeted delivery of ropinirole to attenuate cerebral ischemia/reperfusion injury via "3A approach"

Treatment of Ischemic Stroke is inordinately challenging due to its complex aetiology and constraints in shuttling therapeutics across blood-brain barrier. Ropinirole hydrochloride (Rp), a propitious neuroprotectant with anti-oxidant, anti-inflammatory, and anti-apoptotic properties (3A) is repurposed for remedying ischemic stroke and reperfusion (I/R) injury. The drug's low bioavailability in brain however, limits its therapeutic efficacy. The current research work has reported sub-100 nm gamma-L-Glutamyl-L-Cysteine coated Human Serum Albumin nanoparticles encapsulating Rp (C-Rp-NPs) for active targeting in ischemic brain to encourage in situ activity and reduce unwanted toxicities. Confocal microscopy and brain distribution studies confirmed the enhanced targeting potentiality of optimized C-Rp-NPs. The pharmacokinetics elucidated that C-Rp-NPs could extend Rp retention in systemic circulation and escalate bioavailability compared with free Rp solution (Rp-S). Additionally, therapeutic assessment in transient middle cerebral occlusion (tMCAO) model suggested that C-Rp-NPs attenuated the progression of I/R injury with boosted therapeutic index at 1000 times less concentration compared to Rp-S via reinstating neurological and behavioral deficits, while reducing ischemic neuronal damage. Moreover, C-Rp-NPs blocked mitochondrial permeability transition pore (mtPTP), disrupted apoptotic mechanisms, curbed oxidative stress and neuroinflammation, and elevated dopamine levels post tMCAO. Thus, our work throws light on fabrication of rationally designed C-Rp-NPs with enormous clinical potential.

Effect of valproate and lithium on dementia onset risk in bipolar disorder patients

Although valproate and lithium are most commonly prescribed for bipolar disorder patients, studies comparing their effects on the risk of dementia are limited. Choosing a safer mood stabilizer is clinically crucial as elderly bipolar disorder patients are at high risk of dementia onset. Therefore, we aim to evaluate and compare the effects of valproate and lithium on the risk of dementia in elderly bipolar disorder patients. This study involved 4784 bipolar disorder patients aged 50 years or older from the Korean Health Insurance Review and Assessment Service database. We estimated the risk of dementia in valproate-only users, lithium-only users, and both users compared to both medication non-users using multivariable Cox proportional hazard models. Compared to non-users, valproate-only users and both users showed a higher risk of dementia (59% and 62%, respectively). In sub-group analysis, valproate increased the dementia risk when prescribed for at least 59 days or 23 cumulative defined daily doses. However, the dementia risk associated with lithium is unclear. Therefore, we concluded that lithium has the potential to be the safer choice as a mood stabilizer over valproate for elderly bipolar disorder patients considering the risk of dementia.

Effects of pramipexole on beta-amyloid1-42 memory deficits and evaluation of oxidative stress and mitochondrial function markers in the hippocampus of Wistar rat

Oxidative damage and mitochondrial dysfunction are two prominent pathological features and gradually understood as important pathogenic events for neurodegenerative diseases, including aging and Alzheimer's disease (AD). The present study was aimed to explore the prolonged treatment of pramipexole (PPX) following amyloid beta (Aβ_1-42)-induced cognitive deficits, oxidative stress, and mitochondrial dysfunction in Wistar rat model. We have found that PPX (1.0mg/kg, b.wt.) can rescue cognitive impairments of Aβ_1-42-infused rats in Morris water maze. At the same time, PPX attenuated Aβ_1-42-induced oxidative damage and increased reduced-glutathione content level, decreased lipid peroxidation rate and suppressed the activity of acetylcholinesterase and shows antioxidant effects. Additionally, PPX treatment has shown inhibition of mitochondrial reactive oxygen species production and restored mitochondrial membrane potential, oxidative phosphorylation, and enhanced ATP levels in Aβ_1-42 rats. Furthermore, PPX treatment reduced bioenergetics loss and dynamics alterations by regulating PGC-1α protein level and mitigating translocation of Bax and Drp-1 to mitochondria and cytochrome-c release into the cytoplasm. PPX also increased mitofusin-2 protein expression, a basic element of mitochondrial fusion process. We conclude that remedial role of PPX in mitigating oxidative damage and mitochondrial perturbation that are modulated in Aβ_1-42 rats may have the propensity in AD pathogenesis.

Comprehensive Analysis of Metabolic Changes in Male Mice Exposed to Sodium Valproate Based on GC-MS Analysis

Purpose

Sodium valproate (VPA) is the most widely used broad-spectrum antiepileptic first-line drug in clinical practice and is effective against various types of epilepsy. However, VPA can induce severe cardiotoxicity, nephrotoxicity, hepatotoxicity, and neurotoxicity, which limits its use. Metabolomic studies of VPA-induced toxicity have focused primarily on changes in serum and urine metabolites but have not evaluated changes in major organs or tissues.

Methods

Central target tissues (intestine, lung, liver, hippocampus, cerebral cortex, inner ear, spleen, kidney, heart, and serum) were analyzed using gas chromatography mass spectrometry to comprehensively evaluate VPA toxicity in mouse models.

Results

Multivariate analyses, including orthogonal projections of the latent structure and Student’s t test, indicated that depending on the matrix used in the study (the intestine, lung, liver, hippocampus, cerebral cortex, inner ear, spleen, kidney, heart or serum) the number of metabolites differed, the lung being the poorest and the kidney the richest in number.

Conclusion

These metabolites were closely related and were found to participate in 12 key pathways related to amino acid, fatty acid, and energy metabolism, revealing that the toxic mechanism of VPA may involve oxidative stress, inflammation, amino acid metabolism, lipid metabolism, and energy disorder.

Neuroprotective effects of catechin and quercetin in experimental Parkinsonism through modulation of dopamine metabolism and expression of IL-1β, TNF-α, NF-κB, IκKB, and p53 genes in male Wistar rats

The neurobehavioral, brain redox-stabilizing and neurochemical modulatory properties of catechin and quercetin in rotenone-induced Parkinsonism, and the involvement of NF-κB-mediated inflammation, were investigated. Male Wistar rats subcutaneously administered with multiple doses of 1.5mg/kg rotenone were post-treated with 5-20mg/kg catechin or quercetin. This was followed by neurobehavioral evaluation, biochemical estimations, and assessment of neurotransmitter metabolism in the striatum. Expression of genes involved in the canonical pathway for the activation of NF-κB mediated inflammation (IL-1β, TNF-α, NF-κB, and IκKB) and the pro-apoptotic gene, p53, in the striatum was determined by RT-qPCR. Catechin and quercetin mitigated neurobehavioral deficits caused by rotenone. Both flavonoids attenuated striatal redox stress and neurochemical dysfunction, optimized disturbed dopamine metabolism, and improved depletion of neuron density caused by rotenone toxicity. While administration of catechin produced a more pronounced attenuating effect on IL-1β, TNF-α, and p53 genes, the attenuating effect of quercetin (20mg/kg) was more pronounced on NF-κB and IκKB gene expressions when compared to the group administered with rotenone only. Comparatively, quercetin demonstrated superior protection against rotenone neurotoxicity. It is concluded that catechin and quercetin have potential relevance in Parkinson's disease therapy through amelioration of redox stress, optimization of dopamine metabolism, and modulation of anti-inflammatory and anti-apoptotic pathways.

N-acetyl-L-cysteine ameliorates mitochondrial dysfunction in ischemia/reperfusion injury via attenuating Drp-1 mediated mitochondrial autophagy

BACKGROUND AND PURPOSE

Ischemic reperfusion (I/R) injury causes a wide array of functional and structure alternations of mitochondria, associated with oxidative stress and increased the severity of injury. Despite the previous evidence for N-acetyl-L-cysteine (NAC) provide neuroprotection after I/R injury, it is unknown to evaluate the effect of NAC on altered mitochondrial autophagy forms an essential axis to impaired mitochondrial quality control in cerebral I/R injury.

METHODS

Male wistar rats subjected to I/R injury were used as transient Middle Cerebral Artery Occlusion (tMCAO) model. After I/R injury, the degree of cerebral tissue injury was detected by infarct volume, H&E staining and behavioral assessment. We also performed mitochondrial reactive oxygen species and mitochondrial membrane potential by flow cytometry and mitochondrial respiratory complexes to evaluate the mitochondrial dysfunction. Finally, we performed the western blotting analysis to measure the apoptotic and autophagic marker.

RESULTS

We found that NAC administration significantly ameliorates brain injury, improves neurobehavioral outcome, decreases neuroinflammation and mitochondrial mediated oxidative stress. We evaluated the neuroprotective effect of NAC against neuronal apoptosis by assessing its ability to sustained mitochondrial integrity and function. Further studies revealed that beneficial effects of NAC is through targeting the mitochondrial autophagy via regulating the GSK-3β/Drp1mediated mitochondrial fission and inhibiting the expression of beclin-1 and conversion of LC3, as well as activating the p-Akt pro-survival pathway.

CONCLUSION

Our results suggest that NAC exerts neuroprotective effects to inhibit the altered mitochondrial changes and cell death in I/R injury via regulation of p-GSK-3β mediated Drp-1 translocation to the mitochondria.

Melatonin Ameliorates Valproic Acid-Induced Neurogenesis Impairment: The Role of Oxidative Stress in Adult Rats

Background

Valproic acid (anticonvulsant medication) has been found to inhibit histone deacetylase activity and suppress hippocampal neurogenesis, which causes memory impairment in both humans and rodents. The neurohormone melatonin, which regulates mammalian seasonal and circadian physiology, has recently been shown to have neuroprotective properties, counteracting memory impairment associated with VPA-caused hippocampal neurogenesis reduction. This study is aimed at investigating the molecular mechanisms of melatonin associated with VPA-induced hippocampal neurogenesis and memory impairment.

Methods

Male Spraque-Dawley rats received VPA (300 mg/kg) twice daily or melatonin (8 mg/kg/day) or some rats were given melatonin for 14 days during VPA administration.

Results

The VPA-treated rats showed a significant increase in malondialdehyde (MDA) levels in the hippocampus and p21-positive cells in the subgranular zone (SGZ) of the dentate gyrus (DG) but decreased superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) activities. Moreover, VPA significantly decreased levels of nestin, Notchl, nuclear factor erythroid 2-related factor 2 (Nrf2), doublecortin (DCX), sex determining region Y-box 2 (SOX2), and brain-derived neurotrophic factor (BDNF).

Conclusions

We found that melatonin was able to counteract these neurotoxic effects, acting as a neuroprotectant in VPA-induced memory hippocampal neurogenesis impairment by preventing intracellular oxidative stress and increasing antioxidant activity.

Effect of vitamin B6 on brain damage in valproic acid induced toxicity

Valproic acid (VPA) is an efficient antiepileptic drug widely used for the treatment of epilepsy and other seizures in both children and adults. It is also reported to have side and toxic effects on many organs and tissues. Vitamin B₆ (Vit B₆ ) is a well-described water-soluble vitamin, which has an antioxidant effect. In this study, we aimed to investigate the protective effect of Vit B₆ on VPA-induced brain injury. Male Sprague-Dawley rats were divided into four groups. Group I, control animals; Group II, Vit B₆ (50 mg/kg/day) given rats; Group III, VPA (500 mg/kg/day) given rats; Group IV, VPA and Vit B₆ given rats at same dose and time. VPA and Vit B₆ were administered intraperitoneally and orally, respectively, for 7 days. At the end of the experiments, the rats were sacrificed and brain tissues were taken. Protein carbonyl and sialic acid levels, xanthine oxidase, adenosine deaminase, acetylcholine esterase, lactate dehydrogenase, myeloperoxidase activities, total oxidant status, and reactive oxygen species levels were found to be increased, while glutathione and total antioxidant capacity levels, catalase, superoxide dismutase, glutathione-S-transferase, paraoxonase, and glutathione reductase activities were found to be decreased in the VPA group. Administration of Vit B₆ reversed these defects in the VPA group. These findings indicate that Vit B₆ has a protective effect on VPA-induced brain damage.

Behavioural tagging: Effect of novelty exploration on plasticity related molecular signatures

Learning and memory are one of those frontier areas of neurobiology which attract us to investigate the intricacy of this process. Here, we aimed to investigate the general mechanism of "Behavioural Tagging and Capture" in long term memory (LTM) formation and to find the key factors playing role in consolidation of LTM. In this study, we've shown that not only plasticity related proteins (PRPs) but neurotransmitters and immediate early genes (IEGs) also play an important role in memory formation process. It's very well evident that memory traces can last longer if close in time novelty is introduced around memory encoding. Here our results point out that this novelty exploration acts as a modulator in memory consolidation by providing PRPs such as brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), enhancing neurotransmitters (Dopamine), IEGs (cFos) and some enzymes such as acetylcholinesterase (AChE), monoamine oxidase (MAO), sodium-potassium ATPase (Na⁺K⁺-ATPase). Therefore, by using a Novel Object Recognition task (NOR) in combination with novel task exposure, we evaluated the role of molecular markers in memory consolidation employing a behavioural tagging model. The purpose of the current study was first to evaluate the effect of novelty exposure around a single trail of NOR task in a critical time window on memory consolidation in rats after 24 h and second to determine the expression of BDNF, CREB, c-fos, AChE, MAO, Na⁺K⁺-ATPase as potential markers in the medial prefrontal cortex (mPFC) during memory formation. In the present study, to identify and validate the role of these molecular signatures in memory consolidation, infusion of the protein synthesis inhibitor Anisomycin (Ani) was done around the training session that causes a deficit in the formation of LTM when tested 24 h after weak encoding. Altogether, here we are providing the first comprehensive set of evidences indicating that BDNF, CREB, dopamine, some enzymes and c-fos role in modulating LTM by employing behavioural tagging model.

Melatonin Provides Neuroprotection Following Traumatic Brain Injury-Promoted Mitochondrial Perturbation in Wistar Rat

Excessive mitochondrial fission has been implicated in the etiology of neuronal cell death in traumatic brain injury (TBI). In the present study, we examined the efficacy of melatonin (Mel) as a neuroprotective agent against TBI-induced oxidative damage and mitochondrial dysfunction. We assessed the impact of Mel post-treatment (10 mg/kg b.wt., i.p.) at different time intervals in TBI-subjected Wistar rats. We found that the Mel treatment significantly attenuated brain edema, oxidative damage, mitochondrial fission, and promoted mitochondrial fusion. Additionally, Mel-treated rats showed restoration of mitochondrial membrane potential and oxidative phosphorylation with a concomitant reduction in cytochrome-c release. Further, Mel treatment significantly inhibited the translocation of Bax and Drp1 proteins to mitochondria in TBI-subjected rats. The restorative role of Mel treatment in TBI rats was supported by the mitochondrial ultra-structural analysis, which showed activation of mitochondrial fusion mechanism. Mel enhanced mitochondrial biogenesis by upregulation of PGC-1α protein. Our results demonstrated the remedial role of Mel in ameliorating mitochondrial dysfunctions that are modulated in TBI-subjected rats and provided support for mitochondrial-mediated neuroprotection as a putative therapeutic agent in the brain trauma.

Melatonin attenuates branch chain fatty acid induced apoptosis mediated neurodegeneration

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.

The effects of chard on brain damage in valproic acid-induced toxicity

Valproic acid (VPA; 2-propyl valeric acid) is a potent drug widely used in treating anxiety disorders, migraine as well as epileptic diseases. In the ongoing study chard protective effect was investigated, on the damaged VPA rat brain. Sprague Dawley rats (females) were grouped as follows: control, VPA (500 mg kg-1 day-1 VPA intraperitoneal), chard (100 mg/kg day chard extract by gavage), VPA + chard (500 mg kg-1 day-1 VPA + 100 mg kg-1 day-1 chard extract). Aqueous chard leaves extract was given 1 hr before apply VPA for a period of 7 days. Lipid peroxidation, advanced oxidation protein products and protein carbonyl content, and superoxide dismutase, glutathione peroxidase, glutathione-S-transferase, and glutathione reductase activities increased in the VPA group. Reduced glutathione levels, paraoxanase, and acetylcholinesterase activities were significantly diminished in the VPA animals. Chard extract application curatively reverted the studied biochemical parameters. The results obtained, it has been found the chard has a protective and antioxidant effect on brain damage induced by VPA. PRACTICAL APPLICATIONS: Valproic acid is a comparably safe pharmaceutical agent, but it can cause severe adverse effects on biological metabolism when it is used in high amount. There are not many studies declared that VPA stimulate the generation of ROS, which is liable for the life-threatening adverse effects of VPA therapy including hepatotoxicity neurotoxicity and teratogenicity. Chard is a plant which has antimicrobial, antibacterial, antiinflammatory, antioxidant, antitumor, antiacetylcholinesterase activities, and hepatoprotective effects. In the current study we examined the protection of the VPA damaged rat brain by chard.

Nrf2/HO-1 mediates the neuroprotective effects of pramipexole by attenuating oxidative damage and mitochondrial perturbation after traumatic brain injury in rats

Pramipexole (PPX), a D2-like receptor agonist, is generally used in the treatment of Parkinson's disease and restless leg syndrome. Its neuroprotective effects have been shown against various neurological disorders. Recent research work has demonstrated that PPX exerts neuroprotection through mitochondria. However, the neuromodulator-related effects of PPX against traumatic brain injury (TBI) remain unexplored. The present study, therefore, investigated the mechanism of neuroprotection by PPX against oxidative stress, mitochondrial dysfunction and neuronal damage following TBI in rats. We hypothesized that the neuroprotection by PPX in TBI-subjected rats might involve activation of the Nrf2/HO-1 (also known as Nfe2l2/Hmox1) signaling pathway. PPX was injected intraperitoneally (0.25 mg/kg body weight and 1.0 mg/kg body weight) at different time intervals post-TBI. Several neurobehavioral parameters were assessed at 48 h post-TBI, and the brain was isolated for molecular and biochemical analysis. The results demonstrated that PPX treatment significantly improved the behavioral deficits, decreased the lipid peroxidation rate, increased glutathione levels and decreased 4-hydroxynonenal levels in TBI-subjected rats. PPX also increased the activities of glutathione peroxidase and superoxide dismutase enzymes. In addition, PPX treatment inhibited mitochondrial reactive oxygen species production, restored mitochondrial membrane potential and increased ATP levels after a TBI. Further, PPX treatment reduced the Bax/Bcl2 ratio and translocation of Bax to mitochondria and cytochrome-c to the cytosol. Finally, PPX treatment greatly accelerated the translocation of Nrf2 to the nucleus and upregulated HO-1 protein expression. We conclude that the neuroprotective effects of PPX are mediated by activation of the Nrf2/HO-1 signaling pathway following TBI.This article has an associated First Person interview with the first author of the paper.

Prophylaxis with a multicomponent nutraceutical abates transient cerebral ischemia/reperfusion injury

The effect of a multicomponent nutraceutical on cerebral ischemia/reperfusion injury in male Wistar rats was investigated. Animals were administered with the nutraceutical, Trévo™, for 7 days before 30 min of bilateral common carotid artery occlusion-induced cerebral ischemia and 24 hr of reperfusion. Behavioral assessment, biochemical estimations in the brain cortex, striatum, and hippocampus, and hippocampal histopathological evaluation were carried out after treatments. Results showed that ischemia/reperfusion-induced motor and cognitive deficits were abated in rats pretreated with Trévo™. Additionally, prophylaxis with Trévo™ blunted ischemia/reperfusion-induced redox stress, proinflammatory events, disturbances in neurotransmitter metabolism, mitochondrial dysfunction, and histoarchitectural aberrations in the discreet brain regions. In summary, supplementation with Trévo™ provided neuroprotection to rats against transient cerebral ischemia/reperfusion injury and could be explored as a promising approach in stroke prevention. PRACTICAL APPLICATIONS: There is a worldwide increase in the incidence of cerebral ischemia or stroke. Although an advanced health care system and effective control of risk factors have led to the declining incidence in developed nations, a definitive cure for stroke remains elusive and the situation is growing worse in developing nations. The results of the present study revealed that supplementation with Trévo™ ameliorated neurobehavioral, neurochemical, and histopathological consequences of brain ischemia/reperfusion injury and could, therefore, be beneficial in stroke prevention and management.

Lipopolysaccharide-Induced Systemic Inflammation in the Neonatal Period Increases Microglial Density and Oxidative Stress in the Cerebellum of Adult Rats

Inflammatory processes occurring in the perinatal period may affect different brain regions, resulting in neurologic sequelae. Injection of lipopolysaccharide (LPS) at different neurodevelopmental stages produces long-term consequences in several brain structures, but there is scarce evidence regarding alterations in the cerebellum. The aim of this study was to evaluate the long-term consequences on the cerebellum of a systemic inflammatory process induced by neonatal LPS injection. For this, neonatal rats were randomly assigned to three different groups: naïve, sham, and LPS. Saline (sham group) or LPS solution (1 mg/kg) was intraperitoneally injected on alternate postnatal days (PN) PN1, PN3, PN5, and PN7. Spontaneous activity was evaluated with the open field test in adulthood. The cerebellum was evaluated for different parameters: microglial and Purkinje cell densities, oxidative stress levels, and tumor necrosis factor alpha (TNF-α) mRNA expression. Our results show that administration of LPS did not result in altered spontaneous activity in adult animals. Our data also indicate increased oxidative stress in the cerebellum, as evidenced by an increase in superoxide fluorescence by dihydroethidium (DHE) indicator. Stereological analyses indicated increased microglial density in the cerebellum that was not accompanied by Purkinje cell loss or altered TNF-α expression in adult animals. Interestingly, Purkinje cells ectopically positioned in the granular and molecular layers of the cerebellum were observed in animals of the LPS group. Our data suggest that neonatal LPS exposure causes persistent cellular and molecular changes to the cerebellum, indicating the susceptibility of this region to systemic inflammatory insults in infancy. Further investigation of the consequences of these changes and the development of strategies to avoid those should be subject of future studies.

Effect of valproic acid on oxidative stress parameters of glutamate-induced excitotoxicity in SH-SY5Y cells

Glutamate-induced excitotoxicity has been reported to be involved in the pathophysiology of neurodegenerative disorders. It has been proposed that valproic acid (VPA), which is used in epileptic and bipolar disorders, may be protective against excitotoxic insult. The aim of the present study was to investigate the effects of VPA against the glutamate excitotoxicity in the SH-SY5Y human neuroblastoma cell line and determine its anti-oxidant capacity by measuring oxidative and anti-oxidant biochemical parameters. SH-SY5Y human neuroblastoma cells were pre-treated with 1, 5 or 10 mM VPA prior to exposure to 15 mM glutamate. The MTT assay was performed to determine cell viability. To detect oxidative insult in glutamate toxicity and the potential anti-oxidant effect of VPA, the cell catalase (CAT), superoxide dismutase (SOD), malondialdehyde and hydrogen peroxide (H₂O₂) activity was determined. A progressive decline in cell viability was observed with increasing glutamate concentrations (1-50 mM). Treatment with 1 mM VPA was revealed to be effective in increasing the viability of cells exposed to glutamate for 24 h. Oxidative damage, including an increase in H₂O₂ and MDA, was observed in SH-SY5Y cells treated with glutamate and was reduced by pre-treatment with VPA. CAT activity was decreased following glutamate exposure, but VPA did not prevent this decrease. SOD activity was increased by treatment with VPA alone and was not affected by glutamate exposure. Overall, the present results confirmed the critical role of oxidative stress in glutamate-induced excitotoxicity. They also suggested that VPA may exert an anti-oxidant effect against glutamate-induced excitotoxicity by decreasing oxidative parameters, including H₂O₂ and MDA, but only had a slight effect on CAT and SOD activity, which have an anti-oxidant capacity.

Enzymatic, Non-enzymatatic Antioxidant Levels and Heat Shock Protein Expression as Indicators of Metal Induced Toxicity and Reproductive Modulation in Female Indian Major Carp Cirrhinus cirrhosus

Effects of zinc (Zn) and lead (Pb) exposure on oxidative biomarkers and heat shock protein (HSP) expression, and their possible relation to ovarian steroidogenesis in fish were investigated. Female Cirrhinus cirrhosus were exposed to 1/10th of LC₅₀ of metals for 30 days, and kept for another 30 days without metal exposure. Metal concentrations, antioxidants, HSPs, 17β-estradiol and steroidogenic enzymes were analysed in brain and ovary after 15 and 30 days of exposure and a 15 and 30 day recovery period. Activities of enzymatic and non-enzymatic antioxidants showed duration dependent variation in both exposure and recovery period. HSP70 and HSP90 expressions increased following metal exposure, with the expression being higher in brain than ovary. 17β-Estradiol, steroidogenic enzymes decreased significantly (p < 0.05) after metal exposure. The present study suggests that metals have differential and tissue specific influence on oxidative status and manipulate ovarian steroidogenesis probably through the modulation of HSPs.

Iron overload: Effects on cellular biochemistry

Iron is an essential element for human life. However, it is a pro-oxidant agent capable of reacting with hydrogen peroxide. An iron overload can cause cellular changes, such as damage to the plasma membrane leading to cell death. Effects of iron overload in cellular biochemical processes include modulating membrane enzymes, such as the Na, K-ATPase, impairing the ionic transport and inducing irreversible damage to cellular homeostasis. To avoid such damage, cells have an antioxidant system that acts in an integrated manner to prevent oxidative stress. In addition, the cells contain proteins responsible for iron transport and storage, preventing its reaction with other substances during absorption. Moreover, iron is associated with cellular events coordinated by iron-responsive proteins (IRPs) that regulate several cellular functions, including a process of cell death called ferroptosis. This review will address the biochemical aspects of iron overload at the cellular level and its effects on important cellular structures.

A transcriptomics-based analysis of the toxicity mechanisms of gabapentin to zebrafish embryos at realistic environmental concentrations

Gabapentin (GPT) has become an emerging contaminant in aquatic environments due to its wide application in medical treatment all over the world. In this study, embryos of zebrafish were exposed to gabapentin at realistically environmental concentrations, 0.1 μg/L and 10 μg/L, so as to evaluate the ecotoxicity of this emergent contaminant. The transcriptomics profiling of deep sequencing was employed to illustrate the mechanisms. The zebrafish (Danio rerio) embryo were exposed to GPT from 12 hpf to 96 hpf resulting in 136 and 750 genes differentially expressed, respectively. The results of gene ontology (GO) analysis and the Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis illustrated that a large amount of differentially expressed genes (DEGs) were involved in the antioxidant system, the immune system and the nervous system. RT-qPCR was applied to validate the results of RNA-seq, which provided direct evidence that the selected genes involved in those systems mentioned above were all down-regulated. Acetylcholinesterase (AChE), lysozyme (LZM) and the content of C-reactive protein (CRP) were decreased at the end of exposure, which is consistent with the transcriptomics results. The overall results of this study demonstrate that GPT simultaneously affects various vital functionalities of zebrafish at early developmental stage, even at environmentally relevant concentrations.

Phytanic acid induced neurological alterations in rat brain synaptosomes and its attenuation by melatonin

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.

Postnatal treatment using curcumin supplements to amend the damage in VPA-induced rodent models of autism

Background

Valproic acid (VPA) is used as a first-line antiepileptic agent and is undergoing clinical trials for use as a treatment for many disorders. Mothers undergoing VPA treatment during early pregnancy reportedly show increased rates of autism among their offspring. The benefits of curcumin supplementation were investigated using an animal model of VPA-induced autism.

Methods

The study was performed using a rodent model of autism by exposing rat fetuses to valproic acid (VPA) on the 12.5th day of gestation. At 7 days from their birth, the animals were supplemented with a specific dose of curcumin. Forty neonatal male Western Albino rats were divided into four groups. Rats in group I received only phosphate-buffered saline, rats in group II were the prenatal VPA exposure newborns, rats in group III underwent prenatal VPA exposure supplemented with postnatal curcumin, and rats in group IV were given only postnatal curcumin supplements.

Results

VPA rats exhibited delayed maturation and lower body and brain weights with numerous signs of brain toxicity, such as depletion of IFN-γ, serotonin, glutamine, reduced glutathione, glutathione S-transferase, lipid peroxidase with an increase in CYP450, IL-6, glutamate, and oxidized glutathione. A curcumin supplement moderately corrected these dysfunctions and was especially noticeable in improving delayed maturation and abnormal weight.

Conclusions

Curcumin plays a significant therapeutic role in attenuating brain damage that has been induced by prenatal VPA exposure in rats; however, its therapeutic role as a dietary supplement still must be certified for use in humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1763-7) contains supplementary material, which is available to authorized users.

Progesterone induces neuroprotection following reperfusion-promoted mitochondrial dysfunction after focal cerebral ischemia in rats

Organelle damage and increases in mitochondrial permeabilization are key events in the development of cerebral ischemic tissue injury because they cause both modifications in ATP turnover and cellular apoptosis/necrosis. Early restoration of blood flow and improvement of mitochondrial function might reverse the situation and help in recovery following an onset of stroke. Mitochondria and related bioenergetic processes can be effectively used as pharmacological targets. Progesterone (P4), one of the promising neurosteroids, has been found to be neuroprotective in various models of neurological diseases, through a number of mechanisms. This influenced us to investigate the possible role of P4 in the mitochondria-mediated neuroprotective mechanism in an ischemic stroke model of rat. In this study, we have shown the positive effect of P4 administration on behavioral deficits and mitochondrial health in an ischemic stroke injury model of transient middle cerebral artery occlusion (tMCAO). After induction of tMCAO, the rats received an initial intraperitoneal injection of P4 (8 mg/kg body weight) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 12 and 18 h. Behavioral assessment for functional deficits included grip strength, motor coordination and gait analysis. Findings revealed a significant improvement with P4 treatment in tMCAO animals. Staining of isolated brain slices from P4-treated rats with 2,3,5-triphenyltetrazolium chloride (TTC) showed a reduction in the infarct area in comparison to the vehicle group, indicating the presence of an increased number of viable mitochondria. P4 treatment was also able to attenuate mitochondrial reactive oxygen species (ROS) production, as well as block the mitochondrial permeability transition pore (mPTP), in the tMCAO injury model. In addition, it was also able to ameliorate the altered mitochondrial membrane potential and respiration ratio in the ischemic animals, thereby suggesting that P4 has a positive effect on mitochondrial bioenergetics. In conclusion, these results demonstrate that P4 treatment is beneficial in preserving the mitochondrial functions that are altered in cerebral ischemic injury and thus can help in defining better therapies.

Summary: Progesterone treatment is beneficial in preserving the altered mitochondrial functions in cerebral ischemic injury and thus can help in defining better therapies.