Methamphetamine-induced dopaminergic toxicity prevented owing to the neuroprotective effects of salicylic acid

Role of Thrombosis in Neurodegenerative Diseases: An Intricate Mechanism of Neurovascular Complications

Thrombosis, the formation of blood clots in arteries or veins, poses a significant health risk by disrupting the blood flow. It can potentially lead to major cardiovascular complications such as acute myocardial infarction or ischemic stroke (arterial thrombosis) and deep vein thrombosis or pulmonary embolism (venous thrombosis). Nevertheless, over the course of several decades, researchers have observed an association between different cardiovascular events and neurodegenerative diseases, which progressively harm and impair parts of the nervous system, particularly the brain. Furthermore, thrombotic complications have been identified in numerous clinical instances of neurodegenerative diseases, particularly Alzheimer's disease, Parkinson's disease, multiple sclerosis, and Huntington's disease. Substantial research indicates that endothelial dysfunction, vascular inflammation, coagulation abnormalities, and platelet hyperactivation are commonly observed in these conditions, collectively contributing to an increased risk of thrombosis. Thrombosis can, in turn, contribute to the onset, pathogenesis, and severity of these neurological disorders. Hence, this concise review comprehensively explores the correlation between cardiovascular diseases and neurodegenerative diseases, elucidating the cellular and molecular mechanisms of thrombosis in these neurodegenerative diseases. Additionally, a detailed discussion is provided on the commonly employed antithrombotic medications in the context of these neuronal diseases.

Pharmacological Assessment of Aqueous Ethanolic Extract of Thalictrum Foetidum Against Haloperidol-Induced Parkinson's Like Symptoms in Animal Model: A Dose-Dependent Study With Mechanistic Approach

Introduction: Parkinson's disease (PD) is characterized by dopamine deficiency in the corpus striatum due to the degeneration of dopaminergic neurons in the substantia nigra. Symptoms include bradykinesia, resting tremors, unstable posture, muscular rigidity, and a shuffled gait. Thalictrum foetidum is traditionally used for neurodegenerative disorders. Objectives: This study aimed to explore the therapeutic potential of aqueous ethanolic extract of Thalictrum foetidum (AETF) against Parkinson-like symptoms and to investigate its underlying mechanism. Methodology: Thirty-six albino mice were randomly divided into 6 groups (n = 6): normal control, disease control, standard treatment (levodopa/carbidopa, 100/25 mg/kg), and 3 treatment groups (AETF at 200, 400, and 600 mg/kg). One hour before treatment, haloperidol (1 mg/kg, i. p.) was administered to induce Parkinson's disease in all groups except the normal control group. Results: Behavioral analysis showed significant improvement (P < .001) in motor function, muscular coordination, and reduced muscular rigidity and tremors. AETF also reduced oxidative stress. Histological examination of the brain showed reduced Lewy bodies, neurofibrillary tangles, and plaque formation. Conclusion: AETF alleviated PD symptoms by reducing neurodegeneration, modulating oxidative stress, and inhibiting the expression of nuclear factor-κB (NF-κB) and associated inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).

Repercussion of Primary Nucleation Pathway: Dementia and Cognitive Impairment

Neurodegenerative diseases, such as Alzheimer's, Parkinson's, and prion disease, are characterized by the conversion of normally soluble proteins or peptides into aggregated amyloidal fibrils. These diseases result in the permanent loss of specific types of neurons, making them incurable and devastating. Research on animal models of memory problems mentioned in this article contributes to our knowledge of brain health and functionality. Neurodegenerative disorders, which often lead to cognitive impairment and dementia, are becoming more prevalent as global life expectancy increases. These diseases cause severe neurological impairment and neuronal death, making them highly debilitating. Exploring and understanding these complex diseases offer significant insights into the fundamental processes essential for maintaining brain health. Exploring the intricate mechanisms underlying neurodegenerative diseases not only holds promise for potential treatments but also enhances our understanding of fundamental brain health and functionality. By unraveling the complexities of these disorders, researchers can pave the way for advancements in diagnosis, treatment, and ultimately, improving the lives of individuals affected by neurodegenerative diseases.

Differential Cellular Interactome in Schizophrenia and Bipolar Disorder-Discriminatory Biomarker Role

Schizophrenia (SCH) and bipolar disorder (BD) are two of the most important psychiatric pathologies due to their high population incidence and disabling power, but they also present, mainly in their debut, high clinical similarities that make their discrimination difficult. In this work, the differential oxidative stress, present in both disorders, is shown as a concatenator of the systemic alterations-both plasma and erythrocyte, and even at the level of peripheral blood mononuclear cells (PBMC)-in which, for the first time, the different affectations that both disorders cause at the level of the cellular interactome were observed. A marked erythrocyte antioxidant imbalance only present in SCH generalizes to oxidative damage at the plasma level and shows a clear impact on cellular involvement. From the alteration of protein synthesis to the induction of death by apoptosis, including proteasomal damage, mitochondrial imbalance, and autophagic alteration, all the data show a greater cellular affectation in SCH than in BD, which could be linked to increased oxidative stress. Thus, patients with SCH in our study show increased endoplasmic reticulum (ER)stress that induces increased proteasomal activity and a multifactorial response to misfolded proteins (UPR), which, together with altered mitochondrial activity, generating free radicals and leading to insufficient energy production, is associated with defective autophagy and ultimately leads the cell to a high apoptotic predisposition. In BD, however, oxidative damage is much milder and without significant activation of survival mechanisms or inhibition of apoptosis. These clear differences identified at the molecular and cellular level between the two disorders, resulting from progressive afflictions in which oxidative stress can be both a cause and a consequence, significantly improve the understanding of both disorders to date and are essential for the development of targeted and preventive treatments.

Association between 23 drugs and Parkinson's disease: A two-sample Mendelian randomization study

BACKGROUND

Parkinson's disease (PD) is a common degenerative nervous system disease. At present, there are certain limitations in various treatment options aimed at preventing or delaying the progression of PD. Therefore, the exploration of new drugs for PD is beneficial. Mendelian randomization (MR) analysis can be used to explore the association between drugs and diseases. In this study, MR analysis was adopted to investigate the causal relationship between 23 drugs and PD. These drugs have been approved for the treatment of different diseases, such as salicylic acid and derivatives (collectively called salicylates, e.g., aspirin, used for fever and pain relief), antithrombotic agents (e.g., warfarin, aspirin, used for preventing thrombotic events).

METHODS

The GWAS data for the 23 drugs were obtained from the UK Biobank (UKB) project, while the GWAS data for PD were sourced from FinnGen. Single-Nucleotide Polymorphisms (SNPs) were selected as instrumental variables (IVs). We first performed a series of quality control steps (including MR-PRESSO) to select the appropriate SNPs. Two-sample MR analysis was performed using five different methods, including inverse variance weighting (IVW) with random-effects model, weighted median, MR-Egger, simple model, and weighted model. At the same time, sensitivity analysis was carried out using the MR-Egger and Cochran's Q test to ensure the authenticity and reliability of the results.

RESULTS

In MR-PRESSO, salicylates and antithrombotic agents showed statistically significant associations with PD, respectively. In the main MR analysis (IVW), there was a negative causal relationship between salicylates and PD (OR = 0.73, 95% CI = 0.54-0.98, p = .039). Similarly, there was a negative causal relationship between antithrombotic agents and PD (OR = 0.70, 95%CI = 0.52-0.96, p = .027). No statistically significant association was found between the remaining 21 drugs and PD.

CONCLUSION

This MR study demonstrated that salicylates and antithrombotic agents can reduce the risk of PD, thus providing a novel avenue for future drug exploration in PD.

Consequence of Dementia and Cognitive Impairment by Primary Nucleation Pathway

An acquired loss of cognition in several cognitive domains that is severe enough to interfere with social or professional functioning is called dementia. As well as a moderately in-depth mental status examination by a clinician to identify impairments in memory, language, attention, visuospatial cognition, such as spatial orientation, executive function, and mood, the diagnosis of dementia requires a history evaluating for cognitive decline and impairment in daily activities, with confirmation from a close friend or family member. The start and organization of the cognitive assessment can be helped by short screening tests for cognitive impairment. Clinical presentations show that neurodegenerative diseases are often incurable because patients permanently lose some types of neurons. It has been determined through an assessment that, at best, our understanding of the underlying processes is still rudimentary, which presents exciting new targets for further study as well as the development of diagnostics and drugs. A growing body of research suggests that they also advance our knowledge of the processes that are probably crucial for maintaining the health and functionality of the brain. We concentrate on a number of the animal models of memory problems that have been mentioned in this review article because dementia has numerous etiologies. Serious neurological impairment and neuronal death are the main features of neurodegenerative illnesses, which are also extremely crippling ailments. The most prevalent neurodegenerative disorders are followed by those primary nucleation pathways responsible for cognitive impairment and dementia.

A Schematic Colorimetric Assay for Sialic Acid Assay Based on PEG-Mediated Interparticle Crosslinking Aggregation of Gold Nanoparticles

Sialic acid (SA) is a well-known component of glycoproteins, which have applications in various functional processes on the cell's surface. The colorimetric is a simpler and more convenient method for measuring SA due to its low-cost apparatus and visual signal changes. This work focused on the unpredictable interparticle crosslinking aggregation of the functionalized gold nanoparticles (AuNPs) in complex media. We proposed a balance of the Derjaguin-Landau-Verwey-Overbeek (DLVO)-type aggregation and molecule-based interaction method to solve this problem. Here, we report a novel colorimetric assay for the determination of SA using 4-mercaptophenyl boronic acid (4-MPBA) as an analyte's recognition molecule, and negative charge PEG₄₀₀ was used to repulsive the interparticle crosslinking. The proposed sensing platform shows a linear relationship between the ratio of the absorbance intensity (A₅₂₅/A₆₆₀) and concentration of SA from 0.05 to 8 mM (R² = 0.997) and a detection limit of 48 μM was observed. The novel gold-based colorimetric sensor is easy to fabricate, reproducible in its test performance and has been successfully applied for the detection of SA in biological and healthcare product samples.

Targeting Aβ and p-Tau Clearance in Methamphetamine-Induced Alzheimer’s Disease-Like Pathology: Roles of Syntaxin 17 in Autophagic Degradation in Primary Hippocampal Neurons

Methamphetamine (Meth), a central nervous system (CNS) stimulant with strong neurotoxicity, causes progressive cognitive impairment with characterized neurodegenerative changes. However, the mechanism underlying Meth-induced pathological changes remains poorly understood. In the current study, Meth elicited a striking accumulation of the pathological proteins hyperphosphorylated tau (p-tau) and amyloid beta (Aβ) in primary hippocampal neurons, while the activation of autophagy dramatically ameliorated the high levels of these pathological proteins. Interestingly, after the Meth treatment, Aβ was massively deposited in autophagosomes, which were remarkably trapped in early endosomes. Mechanistically, syntaxin 17 (Stx17), a key soluble n-ethylmaleimide-sensitive fusion protein (NSF) attachment protein receptor (SNARE) protein responsible for autophagosome and mature endosome/lysosome fusion, was significantly downregulated and hindered in combination with autophagosomes. Notably, adenovirus overexpression of Stx17 in primary neurons facilitated autophagosome-mature endosome/lysosome fusion, which dramatically reversed the Meth-induced increases in the levels of p-tau, Aβ, beta-secretase (Bace-1), and C-terminal fragments (CTFs). Immunofluorescence assays showed that Stx17 retarded the Meth-induced Aβ, p-tau, and Bace-1 accumulation in autophagosomes and facilitated the translocation of these pathological proteins to lysosomes, which indicated the importance of Stx17 via enhanced autophagosome-mature endosome/lysosome fusion. Therefore, the current study reveals a novel mechanism involving Meth-induced high levels of pathological proteins in neurons. Targeting Stx17 may provide a novel therapeutic strategy for Meth-induced neurodegenerative changes.

Phenolic Acids and Prevention of Cognitive Decline: Polyphenols with a Neuroprotective Role in Cognitive Disorders and Alzheimer's Disease

Cognitive impairment, also known as cognitive decline, can occur gradually or suddenly and can be temporary or more permanent. It represents an increasingly important public health problem and can depend on normal aging or be linked to different neurodegenerative disorders, including Alzheimer's disease (AD). It is now well-established that lifestyle factors including dietary patterns play an important role in healthy aging as well as in the prevention of cognitive decline in later life. Among the natural compounds, dietary polyphenols including phenolic acids have been recently the focus of major attention, with their supplementation being associated with better cognitive status and prevention of cognitive decline. Despite their therapeutic potential, human studies investigating the relation between phenolic acids intake and cognitive outcomes are rather scarce. In this review, we provide preclinical evidence that different dietary polyphenols such as rosmarinic acid, ellagic acid, and cinnamic aldehyde can exert neuroprotective and pro-cognitive activities through different molecular mechanisms including the modulation of pro-oxidant and antioxidant machinery as well as inflammatory status. Future and more numerous in vivo studies are needed to strengthen the promising results obtained at the preclinical level. Despite the excellent pharmacokinetic properties of phenolic acids, which are able to be accumulated in the brain at pharmacologically relevant levels, future studies should also identify which among the different metabolites produced as a consequence of phenolic acids' consumption may be responsible for the potential neuroprotective effects of this subgroup of polyphenols.

Phenolic Acids and Prevention of Cognitive Decline: Polyphenols with a Neuroprotective Role in Cognitive Disorders and Alzheimer's Disease

Cognitive impairment, also known as cognitive decline, can occur gradually or suddenly and can be temporary or more permanent. It represents an increasingly important public health problem and can depend on normal aging or be linked to different neurodegenerative disorders, including Alzheimer's disease (AD). It is now well-established that lifestyle factors including dietary patterns play an important role in healthy aging as well as in the prevention of cognitive decline in later life. Among the natural compounds, dietary polyphenols including phenolic acids have been recently the focus of major attention, with their supplementation being associated with better cognitive status and prevention of cognitive decline. Despite their therapeutic potential, human studies investigating the relation between phenolic acids intake and cognitive outcomes are rather scarce. In this review, we provide preclinical evidence that different dietary polyphenols such as rosmarinic acid, ellagic acid, and cinnamic aldehyde can exert neuroprotective and pro-cognitive activities through different molecular mechanisms including the modulation of pro-oxidant and antioxidant machinery as well as inflammatory status. Future and more numerous in vivo studies are needed to strengthen the promising results obtained at the preclinical level. Despite the excellent pharmacokinetic properties of phenolic acids, which are able to be accumulated in the brain at pharmacologically relevant levels, future studies should also identify which among the different metabolites produced as a consequence of phenolic acids' consumption may be responsible for the potential neuroprotective effects of this subgroup of polyphenols.

Uncovering the mechanism of the Shenzhi Jiannao formula against vascular dementia using a combined network pharmacology approach and molecular biology

BACKGROUND

Shenzhi Jiannao formula (SZJNF) is a herbal prescription which is used for detoxification, dredging collaterals, and activating blood circulation and Qi flow in traditional Chinese medicine. SZJNF is a clinical effective prescription for the treatment of vascular dementia (VD) first formulated based on the classical theory of traditional Chinese medicine, but its anti-VD mechanism remains ambiguous.

PURPOSE

The aim of this study was to elucidate the multi-target mechanisms of SZJNF against VD using a network pharmacology approach and verify its effects through biological experiments.

STUDY DESIGN AND METHODS

We utilized network pharmacology-based prediction and molecular docking techniques to uncover the potential micro-mechanism of SZJNF against VD. We identified active components and potential targets, and performed network analysis, functional annotation, and pathway enrichment analysis. Subsequently, glutamate-induced PC12 cells and VD rats were used to verify the molecular mechanisms of SZJNF.

RESULTS

Seventeen active compounds were identified in SZJNF rat plasma; moreover, 773 predicted targets and 1544 VD-related targets were found. Various networks, including the PPI, herb-compound-target, and compound-target-pathway network were constructed. A total of 188 shared targets were identified by network topological analysis, which were closely associated to the anti-VD effects of SZJNF. They were also enriched in various biological processes through hypoxia reaction, promotion of cell proliferation, inhibition of apoptosis, neuroactive ligand-receptor interaction, and calcium signaling pathway, as evaluated by the analysis of advanced functions and pathways. SZJNF components docked well with the key targets. Treatment with SZJNF promoted cell proliferation, ameliorated apoptosis and oxidative stress injury, and improved neurological and cognitive abilities.

CONCLUSION

This study comprehensively demonstrated the multi-target mechanisms of SZJNF in VD using network pharmacology and molecular biology experiments. This provides evidence for further mechanistic studies and for the development of SZJNF as a potential treatment for patients with VD.

Neuroprotective Effects of Anti-high Mobility Group Box-1 Monoclonal Antibody Against Methamphetamine-Induced Dopaminergic Neurotoxicity

High mobility group box-1 (HMGB1) is a ubiquitous non-histone nuclear protein that plays a key role as a transcriptional activator, with its extracellular release provoking inflammation. Inflammatory responses are essential in methamphetamine (METH)-induced acute dopaminergic neurotoxicity. In the present study, we examined the effects of neutralizing anti-HMGB1 monoclonal antibody (mAb) on METH-induced dopaminergic neurotoxicity in mice. BALB/c mice received a single intravenous administration of anti-HMGB1 mAb prior to intraperitoneal injections of METH (4 mg/kg × 2, at 2-h intervals). METH injections induced hyperthermia, an increase in plasma HMGB1 concentration, degeneration of dopaminergic nerve terminals, accumulation of microglia, and extracellular release of neuronal HMGB1 in the striatum. These METH-induced changes were significantly inhibited by intravenous administration of anti-HMGB1 mAb. In contrast, blood-brain barrier disruption occurred by METH injections was not suppressed. Our findings demonstrated the neuroprotective effects of anti-HMGB1 mAb against METH-induced dopaminergic neurotoxicity, suggesting that HMGB1 could play an initially important role in METH toxicity.

Methamphetamine-induced dopaminergic neurotoxicity as a model of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease with a high prevalence, approximately 1 % in the elderly population. Numerous studies have demonstrated that methamphetamine (MA) intoxication caused the neurological deficits and nigrostriatal damage seen in Parkinsonian conditions, and subsequent rodent studies have found that neurotoxic binge administration of MA reproduced PD-like features, in terms of its symptomatology and pathology. Several anti-Parkinsonian medications have been shown to attenuate the motor impairments and dopaminergic damage induced by MA. In addition, it has been recognized that mitochondrial dysfunction, oxidative stress, pro-apoptosis, proteasomal/autophagic impairment, and neuroinflammation play important roles in inducing MA neurotoxicity. Importantly, MA neurotoxicity has been shown to share a common mechanism of dopaminergic toxicity with that of PD pathogenesis. This review describes the major findings on the neuropathological features and underlying neurotoxic mechanisms induced by MA and compares them with Parkinsonian pathogenesis. Taken together, it is suggested that neurotoxic binge-type administration of MA in rodents is a valid animal model for PD that may provide knowledge on the neuropathogenesis of PD.

Effects of prenatal synthetic cannabinoid exposure on the cerebellum of adolescent rat offspring

Cannabis is the most commonly used illicit drug worldwide. Recently, cannabis use among young pregnant women has greatly increased. However, prenatal cannabinoid exposure leads to long-lasting cognitive, motor, and behavioral deficits in the offspring and alterations in neural circuitry through various mechanisms. Although these effects have been studied in the hippocampus, the effects of prenatal cannabinoid exposure on the cerebellum are not well elucidated. The cerebellum plays an important role in balance and motor control, as well as cognitive functions such as attention, language, and procedural memories. The aim of this study was to investigate the effects of prenatal cannabinoid exposure on the cerebellum of adolescent offspring. Pregnant rats were treated with synthetic cannabinoid agonist WIN55,212-2, and the offspring were evaluated for various cerebellar markers of oxidative stress, mitochondrial function, and apoptosis. Additionally, signaling proteins associated with glutamate dependent synaptic plasticity were examined. Administration of WIN55,212-2 during pregnancy altered markers of oxidative stress by significantly reducing oxidative stress and nitrite content. Mitochondrial Complex I and Complex IV activities were also enhanced following prenatal cannabinoid exposure. With regard to apoptosis, pP38 levels were significantly increased, and proapoptotic factor caspase-3 activity, pERK, and pJNK levels were significantly decreased. CB1R and GluA1 levels remained unchanged; however, GluN2A was significantly reduced. There was a significant decrease in MAO activity although tyrosine hydroxylase activity was unaltered. Our study indicates that the effects of prenatal cannabinoid exposure on the cerebellum are unique compared to other brain regions by enhancing mitochondrial function and promoting neuronal survival. Further studies are required to evaluate the mechanisms by which prenatal cannabinoid exposure alters cerebellar processes and the impact of these alterations on behavior.

Psychoactive Drugs-From Chemical Structure to Oxidative Stress Related to Dopaminergic Neurotransmission. A Review

Nowadays, more and more young people want to experience illegal, psychoactive substances, without knowing the risks of exposure. Besides affecting social life, psychoactive substances also have an important effect on consumer health. We summarized and analyzed the published literature data with reference to the mechanism of free radical generation and the link between chemical structure and oxidative stress related to dopaminergic neurotransmission. This review presents data on the physicochemical properties, on the ability to cross the blood brain barrier, the chemical structure activity relationship (SAR), and possible mechanisms by which neuronal injuries occur due to oxidative stress as a result of drug abuse such as "bath salts", amphetamines, or cocaine. The mechanisms of action of ingested compounds or their metabolites involve intermediate steps in which free radicals are generated. The brain is strongly affected by the consumption of such substances, facilitating the induction of neurodegenerative diseases. It can be concluded that neurotoxicity is associated with drug abuse. Dependence and oxidative stress are linked to inhibition of neurogenesis and the onset of neuronal death. Understanding the pathological mechanisms following oxidative attack can be a starting point in the development of new therapeutic targets.

Design, synthesis and bioactivity study of N-salicyloyl tryptamine derivatives as multifunctional agents for the treatment of neuroinflammation

Because of the complex etiology in neuroinflammatory process, the design of multifunctional agents is a potent strategy to cure neuroinflammatory diseases including AD and PD. Herein, based on the combination principles, 23 of N-salicyloyl tryptamine derivatives as multifunctional agents were designed and their new application for anti-neuroinflammation was disclosed. In cyclooxygenase assay, two compounds 3 and 16 displayed extremely preferable COX-2 inhibition than N-salicyloyl tryptamine. In LPS-induced C6 and BV2 cell models, some compounds decreased the production of proinflammatory mediators NO, PGE₂, TNF-α, iNOS, COX-2 and ROS, while increased the production of IL-10. Among them, compound 3 and 16 showed approximately six-fold better inhibition on nitric oxide production than N-salicyloyl tryptamine in C6. Besides, compounds 3, 13 and 16 attenuated the activation of BV2 and C6 cells. More importantly, in vivo, compounds 3 and 16 reduced GFAP and Iba-1 levels in the hippocampus, and displayed neuroprotection in Nissl staining. Besides, both compounds 3 and 16 had high safety (LD₅₀ > 1000 mg/kg). Longer plasma half-life of compounds 3 and 16 than melatonin supported combination strategy. All these results demonstrated that N-salicyloyl tryptamine derivatives are potential anti-neuroinflammation agents for the treatment of neurodegenerative disorder.

Concurrent nicotine exposure to prenatal alcohol consumption alters the hippocampal and cortical neurotoxicity

Aims

This study investigated the neurotoxic effects of prenatal alcohol and nicotine exposure in the cortex and hippocampus of rodents.

Main methods

Behavioral alterations, electrophysiological changes, and biochemical markers associated with cholinergic neurotransmission, neural oxidative stress, mitochondrial function, and apoptosis were evaluated.

Key findings

Prenatal alcohol exposure induced the generation of ROS, nitrite and lipid peroxide, decreased mitochondrial Complex-I and IV activities, increased Caspase-1 and 3 activities, had no effect on cholinergic neurotransmission, increased expression of PSD-95, decreased LTP and decreased performance on spatial memory tasks. However, nicotine exposure, in addition to alcohol exposure, was found to mitigate the negative effects of alcohol alone on ROS generation and spatial memory task performances. Furthermore, we also studied the role of ILK in prenatal alcohol and nicotine exposure.

Significance

Prenatal Smoking and/or drinking is a major health concern around the world. Thus, our current study may lead to better insights into the molecular mechanisms of fetal alcohol and nicotine exposure on the developing offspring.

Psychotropic and neurological medication effects on mitochondrial complex I and IV in rodent models

Mitochondrial complex I (NADH-dehydrogenase) and complex IV (cytochrome-c-oxidase) are reported to be affected by drugs used to treat psychiatric or neurodegenerative diseases, including antidepressants, antipsychotics, anxiolytics, mood stabilizers, stimulants, antidementia, and antiparkinsonian drugs. We conducted meta-analyses examining the effects of each drug category on complex I and IV. The electronic databases Pubmed, EMBASE, CENTRAL, and Google Scholar were searched for studies published between 1970 and 2018. Of 3105 screened studies, 68 articles covering 53 drugs were included in the meta-analyses. All studies assessed complex I and IV in rodent brain at the level of enzyme activity. Results revealed that selected antidepressants increase or decrease complex I and IV, antipsychotics and stimulants decrease complex I but increase complex IV, whereas anxiolytics, mood stabilizers, antidementia, and antiparkinsonian drugs preserve or even enhance both complex I and IV. Potential contributions to the drug effects were found to be related to the drugs' neurotransmitter receptor profiles with adrenergic (α1B), dopaminergic (D1/2), glutaminergic (NMDA1,3), histaminergic (H1), muscarinic (M1,3), opioid (OP1-3), serotonergic (5-HT_2A, 5-HT_2C, 5-HT_3A) and sigma (σ1) receptors having the greatest effects. The findings are discussed in relation to pharmacological mechanisms of action that might have relevance for clinical and research applications.

Protein kinase Cδ mediates methamphetamine-induced dopaminergic neurotoxicity in mice via activation of microsomal epoxide hydrolase

We previously demonstrated that activation of protein kinase Cδ (PKCδ) is critical for methamphetamine (MA)-induced dopaminergic toxicity. It was recognized that microsomal epoxide hydrolase (mEH) also induces dopaminergic neurotoxicity. It was demonstrated that inhibition of PKC modulates the expression of mEH. We investigated whether MA-induced PKCδ activation requires mEH induction in mice. MA treatment (8 mg/kg, i.p., × 4; 2 h interval) significantly enhanced the level of phosphorylated PKCδ in the striatum of wild type (WT) mice. Subsequently, treatment with MA resulted in significant increases in the expression of cleaved PKCδ and mEH. Treatment with MA resulted in enhanced interaction between PKCδ and mEH. PKCδ knockout mice exhibited significant attenuation of the enhanced mEH expression induced by MA. MA-induced hyperthermia, oxidative stress, proapoptotic potentials, and dopaminergic impairments were attenuated by PKCδ knockout or mEH knockout in mice. However, treating mEH knockout in mice with PKCδ inhibitor, rottlerin did not show any additive beneficial effects, indicating that mEH is a critical mediator of neurotoxic potential of PKCδ. Our results suggest that MA-induced PKCδ activation requires mEH induction as a downstream signaling pathway and that the modulation of the PKCδ and mEH interaction is important for the pharmacological intervention against MA-induced dopaminergic neurotoxicity.

Doxorubicin-induced neurotoxicity is associated with acute alterations in synaptic plasticity, apoptosis, and lipid peroxidation

Cognitive deficits are commonly reported by patients following treatment with chemotherapeutic agents. Anthracycline-containing chemotherapy regimens are associated with cognitive impairment and reductions in neuronal connectivity in cancer survivors, and doxorubicin (Dox) is a commonly used anthracycline. Although it has been reported that Dox distribution to the central nervous system (CNS) is limited, considerable Dox concentrations are observed in the brain with co-administration of certain medications. Additionally, pro-inflammatory cytokines, which are overproduced in cancer or in response to chemotherapy, can reduce the integrity of the blood-brain barrier (BBB). Therefore, the aim of this study was to evaluate the acute neurotoxic effects of Dox on hippocampal neurons. In this study, we utilized a hippocampal cell line (H19-7/IGF-IR) along with rodent hippocampal slices to evaluate the acute neurotoxic effects of Dox. Hippocampal slices were used to measure long-term potentiation (LTP), and expression of proteins was determined by immunoblotting. Cellular assays for mitochondrial complex activity and lipid peroxidation were also utilized. We observed reduction in LTP in hippocampal slices with Dox. In addition, lipid peroxidation was increased as measured by thiobarbituric acid reactive substances content indicating oxidative stress. Caspase-3 expression was increased indicating an increased propensity for cell death. Finally, the phosphorylation of signaling molecules which modulate LTP including extracellular signal-regulated kinase 1/2 (ERK1/2), p38 mitogen-activated protein kinase, and Akt were increased. This data indicates that acute Dox exposure dose-dependently impairs synaptic processes associated with hippocampal neurotransmission, induces apoptosis, and increases lipid peroxidation leading to neurotoxicity.

The Main Molecular Mechanisms Underlying Methamphetamine- Induced Neurotoxicity and Implications for Pharmacological Treatment

Methamphetamine (METH) is a popular new-type psychostimulant drug with complicated neurotoxicity. In spite of mounting evidence on METH-induced damage of neural cell, the accurate mechanism of toxic effect of the drug on central nervous system (CNS) has not yet been completely deciphered. Besides, effective treatment strategies toward METH neurotoxicity remain scarce and more efficacious drugs are to be developed. In this review, we summarize cellular and molecular bases that might contribute to METH-elicited neurotoxicity, which mainly include oxidative stress, excitotoxicity, and neuroinflammation. We also discuss some drugs that protect neural cells suffering from METH-induced neurotoxic consequences. We hope more in-depth investigations of exact details that how METH produces toxicity in CNS could be carried out in future and the development of new drugs as natural compounds and immunotherapies, including clinic trials, are expected.

Evaluation of behavioral parameters, hematological markers, liver and kidney functions in rodents exposed to Deepwater Horizon crude oil and Corexit

The 2010 Deepwater Horizon (DWH) oil spill is the largest marine oil spill in US history. In the aftermath of the spill, the response efforts used a chemical dispersant, Corexit, to disperse the oil spill. The health impacts of crude oil and Corexit mixture to humans, mammals, fishes, and birds are mostly unknown. The purpose of this study is to investigate the in vivo effects of DWH oil, Corexit, and oil-Corexit mixture on the general behavior, hematological markers, and liver and kidney functions of rodents. C57 Bl6 mice were treated with DWH oil (80 mg/kg) and/or Corexit (95 mg/kg), and several hematological markers, lipid profile, liver and kidney functions were monitored. The results show that both DWH oil and Corexit altered the white blood cells and platelet counts. Moreover, they also impacted the lipid profile and induced toxic effects on the liver and kidney functions. The impacts were more pronounced when the mice were treated with a mixture of DWH-oil and Corexit. This study provides preliminary data to elucidate the potential toxicological effects of DWH oil, Corexit, and their mixtures on mammalian health. Residues from the DWH spill continue to remain trapped along various Gulf Coast beaches and therefore further studies are needed to fully understand their long-term impacts on coastal ecosystems.

Assessment of the cerebellar neurotoxic effects of nicotine in prenatal alcohol exposure in rats

The adverse effects of prenatal nicotine and alcohol exposure on human reproductive outcomes are a major scientific and public health concern. In the United States, substantial percentage of women (20-25%) of childbearing age currently smoke cigarettes and consume alcohol, and only a small percentage of these individuals quit after learning of their pregnancy. However, there are very few scientific reports on the effect of nicotine in prenatal alcohol exposure on the cerebellum of the offspring. Therefore, this study was conducted to investigate the cerebellar neurotoxic effects of nicotine in a rodent model of Fetal Alcohol Spectrum Disorder (FASD). In this study, we evaluated the behavioral changes, biochemical markers of oxidative stress and apoptosis, mitochondrial functions and the molecular mechanisms associated with nicotine in prenatal alcohol exposure on the cerebellum. Prenatal nicotine and alcohol exposure induced oxidative stress, did not affect the mitochondrial functions, increased the monoamine oxidase activity, increased caspase expression and decreased ILK, PSD-95 and GLUR1 expression without affecting the GSK-3β. Thus, our current study of prenatal alcohol and nicotine exposure on cerebellar neurotoxicity may lead to new scientific perceptions and novel and suitable therapeutic actions in the future.

Differential effects of MDMA and cocaine on inhibitory avoidance and object recognition tests in rodents

INTRODUCTION

Drug addiction continues being a major public problem faced by modern societies with different social, health and legal consequences for the consumers. Consumption of psychostimulants, like cocaine or MDMA (known as ecstasy) are highly prevalent and cognitive and memory impairments have been related with the abuse of these drugs.

AIM

The aim of this work was to review the most important data of the literature in the last 10 years about the effects of cocaine and MDMA on inhibitory avoidance and object recognition tests in rodents.

DEVELOPMENT

The object recognition and the inhibitory avoidance tests are popular procedures used to assess different types of memory. We compare the effects of cocaine and MDMA administration in these tests, taking in consideration different factors such as the period of life development of the animals (prenatal, adolescence and adult age), the presence of polydrug consumption or the role of environmental variables. Brain structures involved in the effects of cocaine and MDMA on memory are also described.

CONCLUSIONS

Cocaine and MDMA induced similar impairing effects on the object recognition test during critical periods of lifetime or after abstinence of prolonged consumption in adulthood. Deficits of inhibitory avoidance memory are observed only in adult rodents exposed to MDMA. Psychostimulant abuse is a potential factor to induce memory impairments and could facilitate the development of future neurodegenerative disorders.

Chronic treatment with Tempol during acquisition or withdrawal from CPP abolishes the expression of cocaine reward and diminishes oxidative damage

In previous studies, we reported that pretreatment with the antioxidant Tempol attenuated the development and expression of cocaine-induced psychomotor sensitization in rats and diminished cocaine-induced oxidative stress (OS) in the prefrontal cortex (PFC) and nucleus accumbens (NAc), suggesting a potential role for Tempol in interfering with cocaine-related psychomotor sensitization. The aim of the current study was to examine the role of Tempol in reward and reinforcement using the conditioned place preference (CPP) paradigm. We found that administration of Tempol during the conditioning session abolished the expression of cocaine-induced CPP. We also found that OS was significantly elevated following the establishment of CPP, and that cocaine-induced OS was significantly diminished by pretreatment with Tempol during conditioning. Furthermore, we found that repeated, but not single, administration of Tempol for seven days during withdrawal from CPP resulted in significant attenuation in the expression of CPP. Moreover, Tempol did not affect the expression of food reward. Taken together, these findings provide evidence for the involvement of Tempol in regulating cocaine rewarding properties without affecting natural rewards. Since Tempol was found to be effective in reducing OS and expression of CPP following withdrawal, it may be a potential treatment for cocaine addiction.

Role of Mitochondria in Methamphetamine-Induced Dopaminergic Neurotoxicity: Involvement in Oxidative Stress, Neuroinflammation, and Pro-apoptosis-A Review

Methamphetamine (MA), an amphetamine-type psychostimulant, is associated with dopaminergic toxicity and has a high abuse potential. Numerous in vivo and in vitro studies have suggested that impaired mitochondria are critical in dopaminergic toxicity induced by MA. Mitochondria are important energy-producing organelles with dynamic nature. Evidence indicated that exposure to MA can disturb mitochondrial energetic metabolism by inhibiting the Krebs cycle and electron transport chain. Alterations in mitochondrial dynamic processes, including mitochondrial biogenesis, mitophagy, and fusion/fission, have recently been shown to contribute to dopaminergic toxicity induced by MA. Furthermore, it was demonstrated that MA-induced mitochondrial impairment enhances susceptibility to oxidative stress, pro-apoptosis, and neuroinflammation in a positive feedback loop. Protein kinase Cδ has emerged as a potential mediator between mitochondrial impairment and oxidative stress, pro-apoptosis, or neuroinflammation in MA neurotoxicity. Understanding the role and underlying mechanism of mitochondrial impairment could provide a molecular target to prevent or alleviate dopaminergic toxicity induced by MA.

The Neuroprotective Effects of Phenolic Acids: Molecular Mechanism of Action

The neuroprotective role of phenolic acids from food has previously been reported by many authors. In this review, the role of phenolic acids in ameliorating depression, ischemia/reperfusion injury, neuroinflammation, apoptosis, glutamate-induced toxicity, epilepsy, imbalance after traumatic brain injury, hyperinsulinemia-induced memory impairment, hearing and vision disturbances, Parkinson’s disease, Huntington’s disease, anti-amyotrophic lateral sclerosis, Chagas disease and other less distributed diseases is discussed. This review covers the in vitro, ex vivo and in vivo studies concerning the prevention and treatment of neurological disorders (on the biochemical and gene expression levels) by phenolic acids.

Extended-access methamphetamine self-administration elicits neuroinflammatory response along with blood-brain barrier breakdown

Methamphetamine (METH) is a highly addictive psychostimulant drug that can lead to neurological and psychiatric abnormalities. Several studies have explored the central impact of METH use, but the mechanism(s) underlying blood-brain barrier (BBB) dysfunction and associated neuroinflammatory processes after chronic METH consumption are still unclear. Important findings in the field are mainly based on in vitro approaches and animal studies using an acute METH paradigm, and not much is known about the neurovascular alterations under a chronic drug use. Thus, the present study aimed to fill this crucial gap by exploring the effect of METH-self administration on BBB function and neuroinflammatory responses. Herein, we observed an increase of BBB permeability characterized by Evans blue and albumin extravasation in the rat hippocampus and striatum triggered by extended-access METH self-administration followed by forced abstinence. Also, there was a clear structural alteration of blood vessels showed by the down-regulation of collagen IV staining, which is an important protein of the endothelial basement membrane, together with a decrease of intercellular junction protein levels, namely claudin-5, occludin and vascular endothelial-cadherin. Additionally, we observed an up-regulation of vascular cell and intercellular adhesion molecule, concomitant with the presence of T cell antigen CD4 and tissue macrophage marker CD169 in the brain parenchyma. Rats trained to self-administer METH also presented a neuroinflammatory profile characterized by microglial activation, astrogliosis and increased pro-inflammatory mediators, namely tumor necrosis factor-alpha, interleukine-1 beta, and matrix metalloproteinase-9. Overall, our data provide new insights into METH abuse consequences, with a special focus on neurovascular dysfunction and neuroinflammatory response, which may help to find novel approaches to prevent or diminish brain dysfunction triggered by this overwhelming illicit drug.

Synthesis and protective effect of new ligustrazine-vanillic acid derivatives against CoCl2-induced neurotoxicity in differentiated PC12 cells

Ligustrazine-vanillic acid derivatives had been reported to exhibit promising neuroprotective activities. In our continuous effort to develop new ligustrazine derivatives with neuroprotective effects, we attempted the synthesis of several ligustrazine-vanillic acid amide derivatives and screened their protective effect on the injured PC12 cells damaged by CoCl₂. The results showed that most of the newly synthesized derivatives exhibited higher activity than ligustrazine, of which, compound VA-06 displayed the highest potency with EC₅₀ values of 17.39 ± 1.34 μM. Structure-activity relationships were briefly discussed.Graphical abstractNew series of ligustrazine-vanillic acid amide derivatives were synthesized and evaluated for their protective effect on the injured PC₁₂ cells damaged by CoCl₂. VA-06 was found to be the most active one.

Proteomic studies associated with Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) is an insidious disorder affecting more than 1-2% of the population over the age of 65. Understanding the etiology of PD may create opportunities for developing new treatments. Genomic and transcriptomic studies are useful, but do not provide evidence for the actual status of the disease. Conversely, proteomic studies deal with proteins, which are real time players, and can hence provide information on the dynamic nature of the affected cells. The number of publications relating to the proteomics of PD is vast. Therefore, there is a need to evaluate the current proteomics literature and establish the connections between the past and the present to foresee the future. Areas covered: PubMed and Web of Science were used to retrieve the literature associated with PD proteomics. Studies using human samples, model organisms and cell lines were selected and reviewed to highlight their contributions to PD. Expert commentary: The proteomic studies associated with PD achieved only limited success in facilitating disease diagnosis, monitoring and progression. A global system biology approach using new models is needed. Future research should integrate the findings of proteomics with other omics data to facilitate both early diagnosis and the treatment of PD.