Ameliorative Effects of α-Tocopherol and/or Coenzyme Q10 on Phenytoin-Induced Cognitive Impairment in Rats: Role of VEGF and BDNF-TrkB-CREB Pathway

Pregnenolone 16α-carbonitrile negatively regulates hippocampal cytochrome P450 enzymes and ameliorates phenytoin-induced hippocampal neurotoxicity

The central nervous system is susceptible to the modulation of various neurophysiological processes by the cytochrome P450 enzyme (CYP), which plays a crucial role in the metabolism of neurosteroids. The antiepileptic drug phenytoin (PHT) has been observed to induce neuronal side effects in patients, which could be attributed to its induction of CYP expression and testosterone (TES) metabolism in the hippocampus. While pregnane X receptor (PXR) is widely known for its regulatory function of CYPs in the liver, we have discovered that the treatment of mice with pregnenolone 16α-carbonitrile (PCN), a PXR agonist, has differential effects on CYP expression in the liver and hippocampus. Specifically, the PCN treatment resulted in the induction of cytochrome P450, family 3, subfamily a, polypeptide 11 (CYP3A11), and CYP2B10 expression in the liver, while suppressing their expression in the hippocampus. Functionally, the PCN treatment protected mice from PHT-induced hippocampal nerve injury, which was accompanied by the inhibition of TES metabolism in the hippocampus. Mechanistically, we found that the inhibition of hippocampal CYP expression and attenuation of PHT-induced neurotoxicity by PCN were glucocorticoid receptor dependent, rather than PXR independent, as demonstrated by genetic and pharmacological models. In conclusion, our study provides evidence that PCN can negatively regulate hippocampal CYP expression and attenuate PHT-induced hippocampal neurotoxicity independently of PXR. Our findings suggest that glucocorticoids may be a potential therapeutic strategy for managing the neuronal side effects of PHT.

Umbelliferone Ameliorates Memory Impairment and Enhances Hippocampal Synaptic Plasticity in Scopolamine-Induced Rat Model

Alzheimer's disease (AD) is a neurodegenerative disorder, characterized by memory loss and cognitive decline. Among the suggested pathogenic mechanisms of AD, the cholinergic hypothesis proposes that AD symptoms are a result of reduced synthesis of acetylcholine (ACh). A non-selective antagonist of the muscarinic ACh receptor, scopolamine (SCOP) induced cognitive impairment in rodents. Umbelliferone (UMB) is a Apiaceae-family-derived 7-hydeoxycoumarin known for its antioxidant, anti-tumor, anticancer, anti-inflammatory, antibacterial, antimicrobial, and antidiabetic properties. However, the effects of UMB on the electrophysiological and ultrastructure morphological aspects of learning and memory are still not well-established. Thus, we investigated the effect of UMB treatment on cognitive behaviors and used organotypic hippocampal slice cultures for long-term potentiation (LTP) and the hippocampal synaptic ultrastructure. A hippocampal tissue analysis revealed that UMB attenuated a SCOP-induced blockade of field excitatory post-synaptic potential (fEPSP) activity and ameliorated the impairment of LTP by the NMDA and AMPA receptor antagonists. UMB also enhanced the hippocampal synaptic vesicle density on the synaptic ultrastructure. Furthermore, behavioral tests on male SD rats (7-8 weeks old) using the Y-maze test, passive avoidance test (PA), and Morris water maze test (MWM) showed that UMB recovered learning and memory deficits by SCOP. These cognitive improvements were in association with the enhanced expression of BDNF, TrkB, and the pCREB/CREB ratio and the suppression of acetylcholinesterase activity. The current findings indicate that UMB may be an effective neuroprotective reagent applicable for improving learning and memory against AD.

Trends in the Use of Driving-Impairing Medicines According to the DRUID Category: A Population-Based Registry Study with Reference to Driving in a Region of Spain between 2015 and 2019

The European DRUID (Drive Under the Influence of drugs, alcohol, and medicines) program classifies medications into three categories according to their effect on one’s fitness to drive. The trend in the use of driving-impairing medicines (DIMs) in a region of Spain between 2015 and 2019 was analyzed through a population-based registry study. Pharmacy dispensing records for DIMs are provided. The use of DIMs on drivers was weighted according to the national driver’s license census. The analysis was performed considering the population distribution by age and sex, treatment length, and the three DRUID categories. DIMs were used by 36.46% of the population and 27.91% of drivers, mainly chronically, with considerable daily use (8.04% and 5.34%, respectively). Use was more common in females than in males (42.28% vs. 30.44%) and increased with age. Among drivers, consumption decreases after 60 years of age for females and after 75 years of age for males. There was a 34% increase in the use of DIMs between 2015 and 2019, with a focus on daily use (>60%). The general population took 2.27 ± 1.76 DIMs, fundamentally category II (moderate influence on fitness to drive) (20.3%) and category III (severe influence on fitness to drive) (19.08%). The use of DIMs by the general population and drivers is significant and has increased in recent years. The integration of the DRUID classification into electronic prescription tools would assist physicians and pharmacists in providing adequate information to the patient about the effects of prescribed medications on their fitness to drive.

Alpha-Tocopherol from people to plants is an essential cog in the metabolic machinery

SIGNIFICANCE

Protection from oxygen, a di-radical, became a necessity with the evolution of photosynthetic organisms about 2.7 billion years. α-Tocopherol plays an essential role in organisms from plants to people. An overview of human conditions that result in severe vitamin E (α-tocopherol) deficiency is provided.

RECENT ADVANCES

α-Tocopherol has a critical role in the oxygen protection system by stopping lipid peroxidation, its induced damage and cellular death by ferroptosis. Recent findings in bacteria and plants support the concept of why lipid peroxidation is so dangerous to life and why the family of tocochromanols are essential for aerobic organisms and for plants.

CRITICAL ISSUES

The hypothesis that prevention of the propagation of lipid peroxidation is the basis for the α-tocopherol requirement in vertebrates is proposed and further that its absence dysregulates energy metabolism, one-carbon metabolism and thiol homeostasis. By recruiting intermediate metabolites from adjacent pathways to sustain effective lipid hydroperoxide elimination, α-tocopherol function is linked not only to NADPH metabolism and its formation through the pentose phosphate pathway via glucose metabolism, but also to sulfur-containing amino acid metabolism, and to one-carbon metabolism.

FUTURE DIRECTIONS

Evidence from humans, animals and plants support the hypothesis but future studies are needed to assess the genetic sensors that detect lipid peroxidation and cause the ensuing metabolic dysregulation.

Curcumin-Nicotinate Attenuates Hippocampal Synaptogenesis Dysfunction in Hyperlipidemia Rats by the BDNF/TrkB/CREB Pathway: Involving Idol/LDLR Signaling to Eliminate Aβ Deposition

Hyperlipidemia has been demonstrated to evoke Alzheimer disease (AD) pathologies such as Amyloid-β (Aβ) deposition and synaptogenesis dysfunction in the hippocampus. Curcumin gives protection against anti-amyloid properties and synaptogenesis dysfunction. Curcumin-Nicotinate (CurTn), a new type of curcumin derivative, ameliorates cognitive impairment by rescuing autophagic flux in the CA1 hippocampus of diabetic rats. However, whether Curtn possesses an antagonistic effect on AD-related pathologies in the hippocampus induced by hyperlipidemia remains ill-defined. The present study aims to investigate whether CurTn alleviates synaptogenesis dysfunction by promoting the activation of brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB)/cAMP-response element binding protein (CREB) signaling and whether the underlying fundamental mechanism involves the elimination of Aβ deposition due to Idol/low-density lipoprotein receptor (LDLR) signaling in the hippocampus of high-fat diet (HFD)-induced hyperlipidemia rats. The results demonstrated that CurTn not only improved synaptogenesis dysfunction in the hippocampus of HFD rats, as evidenced by the increases in the expressions of synapse-related proteins postsynaptic density protein 95 (PSD-95), synapsin-1, and Glutamate receptor 1 (GluR1), but also activated BDNF/TrkB/CREB signaling, as evidenced by the elevation of the expressions of BDNF, pTrkB, and CREB. Moreover, CurTn modulated the Idol/LDLR pathway in the hippocampus of HFD rats, as evidenced by the decreased expression of Idol and the increased expression of LDLR. Furthermore, CurTn eliminated the deposition of Aβ, as evidenced by the reduction in the content of Aβ40 and Aβ42. These results reveal that CurTn may attenuate synaptogenesis dysfunction by activating BDNF/TrkB/CREB signaling, as the possible result of the modulation of Idol/LDLR signaling to eliminate Aβ deposition in the hippocampus of HFD rats.

Citicoline/Coenzyme Q10/Vitamin B3 Fixed Combination Exerts Synergistic Protective Effects on Neuronal Cells Exposed to Oxidative Stress

Background: The present study aimed to investigate the rationale and efficacy of using a citicoline, coenzyme Q10 (CAVAQ10) and vitamin B3 fixed combination in combating inflammation and oxidation in neuronal cells exposed to oxidative stress. Methods: HypoE22 cells and isolated hypothalamic specimens were selected as in vitro models to conduct the experiments. The efficacy of citicoline, CAVAQ10, and vitamin B3, with their fixed combination, were assayed after the exposure of hypothalamic cells to hydrogen peroxide (concentration range 1 nM–10 µM), in order to evaluate the biocompatibility of treatments. The activity of neuroprotective and pro-inflammatory factors, namely, brain-derived neurotrophic factor (BDNF), interleukin-6 (IL-6), and tumor necrosis factor-α (TNFα), involved in the neuronal cell damage in neurodegenerative diseases, were assayed in isolated hypothalamus. Results: Neither citicoline, CAVAQ10, nor vitamin B3 significantly altered hypothalamic cell viability, thus suggesting the biocompatibility of single ingredients and fixed combination in the concentration range considered for the study. In the same condition, citicoline and CAVAQ10 were also effective in reducing the gene expression of monoaminoxidase-B, involved in dopamine degradation. However, only citicoline demonstrated an ability to reduce dopamine levels. Conversely, all compounds were effective in reducing the gene expression of IL-6, and TNFα, and in inducing the gene expression of BDNF, with the co-administration of citicoline/CAVAQ10/vitamin B3 being generally more effective than single ingredients. Conclusions: The present findings support the beneficial and synergistic effects of citicoline, CAVAQ10, and vitamin B3 in fixed combination in reducing inflammation and oxidation, and in stimulating neurotrophin production in neuronal cells.

Metabolomics changes after rTMS intervention reveal potential peripheral biomarkers in methamphetamine dependence

Methamphetamine is one of the most commonly used drugs around the world, leading to serious public health and psychiatric problems. Due to the lackness of objective laboratory evaluation indicators, the molecular mechanisms of methamphetamine dependence still remain unclear. Previous evidence demonstrated that repetitive transcranial magnetic stimulation (rTMS) may be useful in treating drug addiction. The aim of this study was to identify and validate plasma metabolomics biomarkers in patients with methamphetamine use disorder before and after rTMS intervention. An untargeted gas chromatography-time-of-flight mass spectrometry (GC-TOFMS) based metabolomics approach was applied to characterize the metabolic profile of forty methamphetamine dependent subjects and thirty-eight healthy controls in peripheral blood mononuclear cells (PBMCs). Patients were randomized to receive either rTMS or sham over the DLPFC for four weeks (20 daily sessions, 900 pulses per day). Cognitive function were assessed before and after rTMS intervention. Eight PBMC metabolites responsible for distinguishing real rTMS from sham treatment were identified. These metabolites were mainly involved in energy metabolism and oxidative stress. Compared with baseline, the expression of three metabolites was reversed after rTMS intervention: alpha-tocopherol, glyceric acid and fumaric acid. Changes of the alpha-tocopherol were associated with cognitive function improvement following rTMS. These findings suggest that energy metabolism and oxidative stress system may be associated with the effect of rTMS on cognitive function in methamphetamine dependence, and warrant further investigation.

Association between the Serum Coenzyme Q10 Level and Seizure Control in Patients with Drug-Resistant Epilepsy

Drug-resistant epilepsy (DRE) is a chronic neurological disorder with somatic impacts and increased risk of metabolic comorbidities. Oxidative stress might play an important role in metabolic effects and as a regulator of seizure control, while coenzyme Q10 (CoQ10) could improve insulin sensitivity through antioxidant effects. We aimed to investigate the association between CoQ10 level and clinical outcome, represented by the seizure frequency and quality of life, in DRE patients. DRE patients (N = 33) had significantly higher serum insulin levels and lower scores on the physical domain of the World Health Organization Quality of Life questionnaire (WHOQoL) than gender-age matched controls. The serum CoQ10 level (2910.4 ± 1163.7 ng/mL) was much higher in DRE patients than the normal range. Moreover, the serum CoQ10 level was significantly correlated with the seizure frequency (r = −0.412, p = 0.037) and insulin level (r = 0.409, p = 0.038). Based on stratification by insulin resistance (HOMA-IR > 2.4), the subgroup analysis showed that patients with a greater HOMA-IR had higher CoQ10 levels and lower seizure frequency, and had a significantly worse quality of life. In summary, CoQ10 could be a mediator involved in the mechanism of epilepsy and serve as a biomarker of the clinical outcome in DER patients.

Exploring Molecular Approaches in Amyotrophic Lateral Sclerosis: Drug Targets from Clinical and Pre-Clinical Findings

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease (MND) characterized by the death of upper and lower motor neurons (corticospinal tract) in the motor cortex, basal ganglia, brain stem, and spinal cord. The patient experiences the sign and symptoms between 55 to 75 years of age, which include impaired motor movement, difficulty in speaking and swallowing, grip loss, muscle atrophy, spasticity, and sometimes associated with memory and cognitive impairments. Median survival is 3 to 5 years after diagnosis and 5 to 10% of the patients live for more than 10 years. The limited intervention of pharmacologically active compounds, that are used clinically, is majorly associated with the narrow therapeutic index. Pre-clinically established experimental models, where neurotoxin methyl mercury mimics the ALS like behavioural and neurochemical alterations in rodents associated with neuronal mitochondrial dysfunctions and downregulation of adenyl cyclase mediated cAMP/CREB, is the main pathological hallmark for the progression of ALS in central as well in the peripheral nervous system. Despite the considerable investigation into neuroprotection, it still constrains treatment choices to strong care and organization of ALS complications. Therefore, this current review specially targeted the investigation of clinical and pre-clinical features available for ALS to understand the pathogenic mechanisms and to explore the pharmacological interventions associated with the up-regulation of intracellular adenyl cyclase/cAMP/ CREB and activation of mitochondrial-ETC coenzyme-Q10 as a future drug target in the amelioration of ALS mediated motor neuronal dysfunctions.

Influence of progestational stress on BDNF and NMDARs in the hippocampus of male offspring and amelioration by Chaihu Shugan San

BACKGROUND

Progestational stress has been proven to be a risk for the neural development of offspring, especially in the hippocampus. However, whether Chaihu Shugan San (CSS) can ameliorate hippocampal neural development via the regulation of brain-derived neurotrophic factor (BDNF), and N-methyl-D-aspartate receptors (NMDAR) 2A (NR2A) and 2B (NR2B), and the mechanism of such action remains unclear.

METHODS

Thirty-six female rats were randomly allocated into control, chronic immobilization stress (CIS) and CSS groups according to the random number table, respectively. The male offspring were fed for 21 days after birth then randomly divided into the same three groups (6 rats/group) as the female rats. Female rats, except for the control group, underwent 21-day CIS to established a progestational stress anxiety-like model which was evaluated by body weight, the elevated plus-maze (EPM) test and serum dopamine (DA) measured using an enzyme-linked immunosorbent assay (ELISA). The expression levels of estrogen receptors (ERα/ERβ) and progesterone receptor (PR) in female rat ovaries were quantified by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. The hippocampal tissue in the 21-day offspring was observed by hematoxylin-eosin (HE) staining. The concentration of BDNF, NR2A, and NR2B were measured by RT-qPCR and immunohistochemistry in the CA3 and dentate gyrus (DG) regions of offsprings' hippocampus.

RESULTS

Compared with the female control group, significant differences in body weight, EPM test and DA concentration were observed in the CIS group, meanwhile, the concentration of ERα (P < 0.05), PR (P < 0.05) and ERβ in the ovaries were decreased. In the offsprings' hippocampus of the CIS group, the chromatin of the nucleus was edge set and with condensed and irregular morphology nucleus, and the cytoplasm was unevenly stained with spaces around the cells, moreover, the expression levels of BDNF, NR2A, and NR2B were also declined (P < 0.05). However, Chaihu Shugan San reversed these changes, especially the BDNF in the DG region (P < 0.05), and NR2A and NR2B in the CA3 and DG region (P < 0.05).

CONCLUSIONS

CSS could ameliorate the neural development of the hippocampus in offspring damaged by anxiety-like progestational stress in female rats via regulating the expression levels of ERα, ERβ, and PR in female rat ovaries and BDNF, NR2A, and NR2B in the hippocampus of their offspring.

An Insight into Molecular Mechanisms and Novel Therapeutic Approaches in Epileptogenesis

Epilepsy is the second most common neurological disease with abnormal neural activity involving the activation of various intracellular signalling transduction mechanisms. The molecular and system biology mechanisms responsible for epileptogenesis are not well defined or understood. Neuroinflammation, neurodegeneration and Epigenetic modification elicit epileptogenesis. The excessive neuronal activities in the brain are associated with neurochemical changes underlying the deleterious consequences of excitotoxicity. The prolonged repetitive excessive neuronal activities extended to brain tissue injury by the activation of microglia regulating abnormal neuroglia remodelling and monocyte infiltration in response to brain lesions inducing axonal sprouting contributing to neurodegeneration. The alteration of various downstream transduction pathways resulted in intracellular stress responses associating endoplasmic reticulum, mitochondrial and lysosomal dysfunction, activation of nucleases, proteases mediated neuronal death. The recently novel pharmacological agents modulate various receptors like mTOR, COX-2, TRK, JAK-STAT, epigenetic modulators and neurosteroids are used for attenuation of epileptogenesis. Whereas the various molecular changes like the mutation of the cell surface, nuclear receptor and ion channels focusing on repetitive episodic seizures have been explored by preclinical and clinical studies. Despite effective pharmacotherapy for epilepsy, the inadequate understanding of precise mechanisms, drug resistance and therapeutic failure are the current fundamental problems in epilepsy. Therefore, the novel pharmacological approaches evaluated for efficacy on experimental models of epilepsy need to be identified and validated. In addition, we need to understand the downstream signalling pathways of new targets for the treatment of epilepsy. This review emphasizes on the current state of novel molecular targets as therapeutic approaches and future directions for the management of epileptogenesis. Novel pharmacological approaches and clinical exploration are essential to make new frontiers in curing epilepsy.

Positive regulation of the CREB phosphorylation via JNK-dependent pathway prevents antimony-induced neuronal apoptosis in PC12 cell and mice brain

Antimony (Sb) is a potentially toxic chemical element abundantly found in the environment. We previously reported that Sb promoted neuronal deathvia reactive oxygen species-dependent autophagy. Here, we assessed the role of cyclic adenosine monophosphate response element-binding protein (CREB) in Sb-induced neuronal damage. We found that Sb treatment induced CREB phosphorylation and neuronal apoptosis both in vitro and in vivo. Interestingly, inhibition of CREB's transcriptional activity with 666-15 dramatically enhanced apoptosis in PC12 cells by downregulating B-cell lymphoma 2 (Bcl-2). Additionally, Sb activated ERK, JNK, and p38 signaling ; however, only JNK promoted CREB phosphorylation. In conclusion, our findings suggest that CREB phosphorylation by JNK attenuates Sb-induced neuronal apoptosis via Bcl-2 upregulation. These data suggest that JNK-dependent CREB activation prevents neurons from Sb-induced apoptosis and guides the development of novel strategies to prevent Sb-induced neurotoxicity.

Preventive Effects of Neuroprotective Agents in a Neonatal Rat of Photothrombotic Stroke Model

Neonatal ischemic stroke has a higher incidence than childhood stroke. Seizures are the first sign for the need for clinical assessment in neonates, but many questions remain regarding treatments and follow-up modalities. In the absence of a known pathophysiological mechanism, only supportive care is currently provided. Stroke-induced microglia activation and neuroinflammation are believed to play a central role in the pathological progression of neonatal ischemic stroke. We induced a photothrombotic infarction with Rose Bengal in neonatal rats to investigate the effects of pre- and post-treatment with Aspirin (ASA), Clopidogrel (Clop), and Coenzyme Q10 (CoQ10), which are known for their neuroprotective effects in adult stroke. Pre-stroke medication ameliorates cerebral ischemic injury and reduces infarct volume by reducing microglia activation, cellular reactive oxygen species (ROS) production, and cytokine release. Post-stroke administration of ASA, Clop, and CoQ10 increased motor function and reduced the volume of infarction, and the statistical evidence was stronger than that seen in the pre-stroke treatment. In this study, we demonstrated that ASA, Clop, and CoQ10 treatment before and after the stroke reduced the scope of stroke lesions and increased behavioral activity. It suggests that ASA, Clop, and CoQ10 medication could significantly have neuroprotective effects in the neonates who have suffered strokes.

Effect of Polydeoxyribonucleotide on Lipopolysaccharide and Sevoflurane-Induced Postoperative Cognitive dysfunction in Human Neuronal SH-SY5Y Cells

Purpose

Postoperative cognitive dysfunction (POCD) is a complication of surgery characterized by acute cognitive dysfunction, memory impairment, and loss of attention. The effect of polydeoxyribonucleotide (PDRN) on the POCD environment induced by lipopolysaccharide (LPS) and sevoflurane exposure were investigated in human neuronal SH-SY5Y cells.

Methods

The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and WST-8 assays were performed to determine cell viability. Cyclic adenosine-3,5′-monophosphate (cAMP), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 concentrations were measured using enzyme-linked immunoassay (ELISA). Immunocytochemistry was performed for vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF), and western blotting for TNF-α, IL-1β, IL-6, and cAMP response element-binding protein (CREB).

Results

Induction of the POCD environment reduced cell viability in the MTT and WST-8 assays. PDRN treatment reduced TNF-α, IL-1β, and IL-6 expression in POCD conditions, and significantly increased cAMP concentrations and the p-CREB/CREB ratio. PDRN treatment activated adenosine A2A receptors and then increased the expression of VEGF and BDNF, which had been reduced by LPS and sevoflurane exposure.

Conclusions

PDRN treatment showed a therapeutic effect on the LPS and sevoflurane-induced POCD environment. PDRN was shown to have an excellent therapeutic effect on POCD, not only by promoting rapid anti-inflammatory effects in damaged cells, but also by enhancing the expression of BDNF and VEGF.

PKA- and Ca2+-dependent p38 MAPK/CREB activation protects against manganese-mediated neuronal apoptosis

Although manganese (Mn) is an essential trace element, its excessive consumption may lead to neuronal death and neurodegenerative disorders. Human cells launch adaptive responses to attenuate Mn-induced neurotoxicity. However, the regulation of the responsive proteins and their function during Mn-stimulated neurotoxicity remain largely unknown. We report the role of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) in Mn-induced neuronal apoptosis. Mn increased CREB phosphorylation and cellular apoptosis in both PC12 cells and mouse brain tissue. Furthermore, downregulation of CREB with shRNA plasmid transfection significantly worsened the PC12 cell apoptosis by decreasing mRNA and protein expression of brain-derived neurotrophic factor (BDNF). Moreover, Mn enhanced protein kinase A (PKA) activation and activation of the p38 MAPK and JNK pathways. Inhibition of p38 MAPK rather than JNK effectively reduced the CREB phosphorylation. Subsequent analysis showed that a PKA inhibitor blocked p38 MAPK and CREB phosphorylation. Moreover, the intracellular Ca2+ chelator BAPTA-AM decreased the phosphorylation of p38 MAPK and CREB but failed to reduce PKA activation. In summary, p38 MAPK/CREB activation via PKA activation and increased cellular Ca²⁺ helped to alleviate Mn-induced neuronal apoptosis via BDNF regulation. These findings improve our understanding of Mn-induced neurotoxicity and the molecular targets to antagonise it.