Microglial Inhibitory Mechanism of Coenzyme Q10 Against Aβ (1-42) Induced Cognitive Dysfunctions: Possible Behavioral, Biochemical, Cellular, and Histopathological Alterations

Enhanced antichemobrain activity of amino acid assisted ferulic acid solid dispersion in adult zebrafish (Danio rerio)

Chemotherapy-induced cognitive impairment (CICI), also known as "chemobrain," is a common side effect of breast cancer therapy which causes oxidative stress and generation of reactive oxygen species (ROS). Ferulic acid (FA), a natural polyphenol, belongs to BCS class II is confirmed to have nootropic, neuroprotective and antioxidant effects. Here, we have developed FA solid dispersion (SD) in order to enhance its therapeutic potential against chemobrain. An amorphous ferulic acid loaded leucin solid dispersion (FA-Leu SD) was prepared by utilizing amino acid through spray-drying technique. The solid-state characterization was carried out via Fourier-transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and field emission scanning electron microscopy (FE-SEM). Additionally, in-vitro release studies and antioxidant assay were also performed along with in-vivo locomotor, biochemical and histopathological analysis. The physical properties showed that FA-Leu SD so formed exhibited spherical, irregular surface hollow cavity of along with broad melting endotherm as observed from FE-SEM and DSC results. The XRD spectra demonstrated absence of sharp and intense peaks in FA-Leu SD which evidenced for complete encapsulation of drug into carrier. Moreover, in-vitro drug release studies over a period of 5 h in PBS (pH 7.4) displayed a significant enhanced release in the first hr (68. 49 ± 5.39%) and in-vitro DPPH assay displayed greater antioxidant potential of FA in FA-Leu SD. Furthermore, the in-vivo behavioral findings of FA-Leu SD (equivalent to 150 mg/kg of free FA) exhibited positive results accompanied by in-vivo biochemical and molecular TNF-α showed a significant difference (p < 0.001) vis-à-vis DOX treated group upon DOX + FA-Leu SD. Additionally, histopathological analysis revealed neuroprotective effects of FA-Leu SD together with declined oxidative stress due to antioxidant potential of FA which was induced by anticancer drug doxorubicin (DOX). Overall, the above findings concluded that spray-dried FA-Leu SD could be useful for the treatment of chemotherapy induced cognitive impairment.

Coenzyme Q10 ameliorates chemotherapy-induced cognitive impairment in mice: a preclinical study

BACKGROUND

Among the three most used anticancer drugs, cyclophosphamide, Adriamycin, and 5-Fluorouracil (CAF), the most significant outcome is chemobrain, caused by increased oxidative stress, inflammatory insult, and mitochondrial dysfunction.

OBJECTIVE

In this study, endogenous antioxidant coenzyme Q10 (CoQ10) was evaluated for its neuroprotective effects in CICI.

MATERIALS AND METHODS

The chemobrain was induced in Swiss albino female mice by administering CAF (40 + 4 + 25 mg/kg) intraperitoneal (i.p.) in three cycles (single injection per week) followed by treatment with CoQ10 (40 mg/kg; p.o.) for up to 3 weeks followed by behavioral, biochemical, molecular and histopathological analysis.

RESULTS

Treatment with CoQ10 significantly improved cognition by improving exploring time in novel objects recognition test followed by increasing the time spent in the target quadrant in MWM test as compared to CAF-treated animals. Moreover, CoQ10 demonstrated antioxidant properties by reducing the expression of LPO while increasing levels of GSH, SOD, and catalase as compared to CAF-treated animals. While the levels of AChEs were significantly reduced after CoQ10 treatment in CAF-treated animals. In terms of its mechanism, it effectively counteracted the pro-inflammatory substances (TNF-α and IL-1β) triggered by CAF while also enhancing the levels of anti-inflammatory markers (IL-10 and Nrf2). Moreover, CoQ10 showed mitochondrial enhancers and it improved the level of Complex (I, II, and IV). Besides that, mitochondrial morphological analysis was done by TEM, and neuronal morphology along with quantification analysis was performed by H&E staining using Image J software to confirm the neuroprotective effect of CoQ10 over CAF-induced cognitive impairment.

CONCLUSION

This study suggests CoQ10 can protect the mitochondria by imposing antioxidant, and anti-inflammatory properties, which could be a potential therapy for CICI.

In-vitro and in-vivo studies of two-drug cocktail therapy targeting chemobrain via the Nrf2/NF-κB signaling pathway

Today, we critically need alternative therapeutic options for chemotherapy-induced cognitive impairment (CICI), often known as chemo brain. Mitochondrial dysfunction and oxidative stress are two of the primary processes that contribute to the development of chemobrain. Therefore, the purpose of this study was to investigate how CoQ10 and berberine shield neurons from chemotherapy-induced damage in in-vitro studies and memory loss in vivo studies. For the in-vitro investigation, we employed SH-SY5Y cell lines, and for the in-vivo study, we used female Swiss albino mice divided into seven different groups. Data from in-vitro studies revealed that treatment with coenzyme Q10 (CoQ10) and berberine improved chemotherapy-induced toxicity by reducing mitochondrial and total cellular ROS, as well as apoptosis-elicited markers (caspase 3 and 9). CoQ10 and berberine therapy inhibited the nuclear translocation of NF-κB and, consequently, the subsequent expressions of NLRP3 and IL-1β, implying the prevention of inflammasome formation. Furthermore, CoQ10 and berberine therapy boosted Nrf2 levels. This is a regulator for cellular resistance to oxidants. The in vivo results showed that treatment with CoQ10 (40 mg/kg) and berberine (200 mg/kg) improved the behavioral alterations induced by CAF (40/4/25 mg/kg) in both the Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests. Furthermore, biochemical and molecular evidence revealed the antioxidant, mitochondrial restorative, and anti-inflammatory potential of CoQ10 (40 mg/kg) and berberine (200 mg/kg) against CAF (40/4/25 mg/kg) subjected mice. In addition, the histological analysis using H&E staining and transmission electron microscopy (for mitochondrial morphology) showed that mice treated with the cocktails had an increased number of healthy neurons with intact mitochondria and a reduced presence of autophagic vacuoles in the hippocampal region of the brain. These findings back up our theory about this novel cocktail method for CAF-induced cognitive impairment.

Inhibition of lysyl oxidase by pharmacological intervention and genetic manipulation alleviates epilepsy-associated cognitive disorder

Epilepsy-associated cognitive disorder (ECD), a prevalent comorbidity in epilepsy patients, has so far uncharacterized etiological origins. Our prior work revealed that lysyl oxidase (Lox) acted as a novel contributor of ferroptosis, a recently discovered cell death mode in the regulation of brain function. However, the role of Lox-mediated ferroptosis in ECD remains unknown. ECD mouse model was established 2 months later following a single injection of kainic acid (KA) for. After chronic treatment with KA, mice were treated with different doses (30 mg/kg, 100 mg/kg and 300 mg/kg) of Lox inhibitor BAPN. Additionally, hippocampal-specific Lox knockout mice was also constructed and employed to validate the role of Lox in ECD. Cognitive functions were assessed using novel object recognition test (NOR) and Morris water maze test (MWM). Protein expression of phosphorylated cAMP-response element binding (CREB), a well-known molecular marker for evaluation of cognitive performance, was also detected by Western blot. The protein distribution of Lox was analyzed by immunofluorescence. In KA-induced ECD mouse model, ferroptosis process was activated according to upregulation of 4-HNE protein and a previously discovered ferroptosis in our group, namely, Lox was remarkably increased. Pharmacological inhibition of Lox by BAPN at the dose of 100 mg/kg significantly increased the discrimination index following NOR test and decreased escape latency as well as augmented passing times within 60 s following MWM test in ECD mouse model. Additionally, deficiency of Lox in hippocampus also led to pronounced improvement of deficits in ECD model. These findings indicate that the ferroptosis regulatory factor, Lox, is activated in ECD. Ablation of Lox by either pharmacological intervention or genetic manipulation ameliorates the impairment in ECD mouse model, which suggest that Lox serves as a promising therapeutic target for treating ECD in clinic.

The Protective Effects of High-Intensity Interval Training Combined with Q10 Supplementation on Learning and Memory Impairments in Male Rats with Amyloid-β-Induced Alzheimer's Disease

Background

Oxidative stress plays a major role in the progression of Alzheimer's disease (AD)-related cognitive deficits.

Objective

This study was done to determine the protective effects of coenzyme Q10 (CoQ10) and high-intensity interval training (HIIT) alone and in combination for eight continuous weeks, on oxidative status, cognitive functions, and histological changes in the hippocampus in amyloid-β (Aβ)-induced AD rats.

Methods

Ninety male Wistar rats were randomly assigned to the sham, control, Q10 (50 mg/kg of CoQ10; P.O.), HIIT (high intensity: 4 min running at 85-90% VO2max, low intensity: 3 min running at 50-60% VO2max), Q10 + HIIT, AD, AD+Q10, AD+HIIT, and AD+Q10 + HIIT groups.

Results

The results showed that Aβ injection reduced cognitive functions in the Morris water maze (MWM) test and recognition memory in the novel object recognition test (NORT), which was accompanied by a decrease in total thiol groups, catalase, and glutathione peroxidase activities, an increase in malondialdehyde levels, and neuronal loss in the hippocampus. Interestingly, pretreatment with CoQ10, HIIT, or both, could markedly improve the oxidative status and cognitive decline in the MWM and NOR tests, and hinder neuronal loss in the hippocampus of Aβ-induced AD rats.

Conclusion

Therefore, a combination of CoQ10 and HIIT can improve Aβ-related cognitive deficits, probably through an amelioration in hippocampal oxidative status and prevention of neuronal loss.

Spotlight on Coenzyme Q10 in scopolamine-induced Alzheimer's disease: oxidative stress/PI3K/AKT/GSK 3ß/CREB/BDNF/TrKB

OBJECTIVES

Excess amyloid beta (Aβ) and oxidative stress (OS) are inextricable hallmarks of the neuronal damage associated Alzheimer's disease. Aβ-induced cognitive and memory dysfunctions are mediated through different signalling pathways as phosphatidylinositol-3-kinase (PI3K) and their downstream intermediates including protein-kinase-B, known as Akt, glycogen-synthase-kinase-3β (GSK-3β), cAMP-response-element-binding-protein (CREB), brain-derived-neurotrophic factor (BDNF) and tropomyosin-related-kinase receptor-B (TrKB). The current work aims to investigate the protective potentials of CoQ10 against scopolamine (Scop)-induced cognitive disability and the contribution of PI3K/Akt/GSK-3β/CREB/BDNF/TrKB in the neuroprotection effects.

METHODS

The chronic co-administration of CQ10 (50, 100 and 200 mg/kg/day i.p.) with Scop in Wistar rats for 6 weeks were assayed both behaviourally and biochemically.

KEY FINDINGS

CoQ10 ameliorated the Scop-induced cognitive and memory defects by restoring alterations in novel object recognition and Morris water maze behavioural tests. CoQ10 favourably changed the Scop-induced deleterious effects in hippocampal malondialdehyde, 8-hydroxy-2' deoxyguanosine, antioxidants and PI3K/Akt/GSK-3β/CREB/BDNF/TrKB levels.

CONCLUSIONS

These results exhibited the neuroprotective effects of CoQ10 on Scop-induced AD and revealed its ability to inhibit oxidative stress, amyloid deposition and to modulate PI3K/Akt/GSK-3β/CREB/BDNF/TrKB pathway.

Coenzyme Q10 and Dementia: A Systematic Review

It is well known that coenzyme Q₁₀ (CoQ₁₀) has important antioxidant properties. Because one of the main mechanisms involved in the pathogenesis of Alzheimer's disease (AD) and other neurodegenerative diseases is oxidative stress, analysis of the concentrations of CoQ₁₀ in different tissues of AD patients and with other dementia syndromes and the possible therapeutic role of CoQ₁₀ in AD have been addressed in several studies. We performed a systematic review and a meta-analysis of these studies measuring tissue CoQ₁₀ levels in patients with dementia and controls which showed that, compared with controls, AD patients had similar serum/plasma CoQ₁₀ levels. We also revised the possible therapeutic effects of CoQ₁₀ in experimental models of AD and other dementias (which showed important neuroprotective effects of coenzyme Q₁₀) and in humans with AD, other dementias, and mild cognitive impairment (with inconclusive results). The potential role of CoQ₁₀ treatment in AD and in improving memory in aged rodents shown in experimental models deserves future studies in patients with AD, other causes of dementia, and mild cognitive impairment.

Non-Enzymatic Antioxidants against Alzheimer's Disease: Prevention, Diagnosis and Therapy

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive memory loss and cognitive decline. Although substantial research has been conducted to elucidate the complex pathophysiology of AD, the therapeutic approach still has limited efficacy in clinical practice. Oxidative stress (OS) has been established as an early driver of several age-related diseases, including neurodegeneration. In AD, increased levels of reactive oxygen species mediate neuronal lipid, protein, and nucleic acid peroxidation, mitochondrial dysfunction, synaptic damage, and inflammation. Thus, the identification of novel antioxidant molecules capable of detecting, preventing, and counteracting AD onset and progression is of the utmost importance. However, although several studies have been published, comprehensive and up-to-date overviews of the principal anti-AD agents harboring antioxidant properties remain scarce. In this narrative review, we summarize the role of vitamins, minerals, flavonoids, non-flavonoids, mitochondria-targeting molecules, organosulfur compounds, and carotenoids as non-enzymatic antioxidants with AD diagnostic, preventative, and therapeutic potential, thereby offering insights into the relationship between OS and neurodegeneration.

Idebenone Regulates Aβ and LPS-Induced Neurogliosis and Cognitive Function Through Inhibition of NLRP3 Inflammasome/IL-1β Axis Activation

Idebenone is an analogue of coenzyme Q10, an electron donor in the mitochondrial electron transport chain, and thus may function as an antioxidant to facilitate mitochondrial function. However, whether idebenone modulates LPS- and Aβ-mediated neuroinflammatory responses and cognitive function in vivo is unknown. The present study explored the effects of idebenone on LPS- or Aβ-mediated neuroinflammation, learning and memory and the underlying molecular mechanisms in wild-type (WT) mice and 5xFAD mice, a mouse model of Alzheimer’s disease (AD). In male and female WT mice, idebenone upregulated neuroprotective NRF2 expression, rescued LPS-induced spatial and recognition memory impairments, and reduced NLRP3 priming and subsequent neuroinflammation. Moreover, idebenone downregulated LPS-mediated neurogliosis, reactive oxygen species (ROS) levels, and mitochondrial function in BV2 microglial cells and primary astrocytes by inhibiting NLRP3 inflammasome activation. In 5xFAD mice, idebenone increased neuroprotective NRF2 expression and improved amyloid beta (Aβ)-induced cognitive dysfunction. Idebenone downregulated Aβ-mediated gliosis and proinflammatory cytokine levels in 5xFAD mice by modulating the vicious NLRP3/caspase-1/IL-1β neuroinflammation cycle. Taken together, our results suggest that idebenone targets neuroglial NLRP3 inflammasome activation and therefore may have neuroprotective effects and inhibit the pathological progression of neuroinflammation-related diseases.

Avicularin Attenuates Memory Impairment in Rats with Amyloid Beta-Induced Alzheimer's Disease

Amyloid-beta-induced Alzheimer's disease (AD) and its further complications are well-established models in preclinical studies and demonstrated by many researchers. Intracerebroventricular injection of Aβ produces brain malfunction, including neurodegeneration and memory impairment. Avicularin is a bioactive flavonoid that has been found to prevent oxidative stress and proinflammatory cytokines. Alzheimer's disease treatment may benefit from inhibiting amyloid-beta and its related complications. Hence, by considering multiple actions of avicularin, including antioxidant and anti-inflammatory, we demonstrated the neuroprotective action of avicularin against amyloid beta-induced neurotoxicity. Aβ_1-42 (1 µg/µl) was dissolved in phosphate buffer solution (pH7.4) and incubated at 37 °C for 3 days to induce aggregation. A single intracerebroventricular (i.c.v.) injection of the Aβ_1-42 was given to the animals utilizing stereotaxic equipment. Avicularin was dissolved in 0.5% sodium carboxymethyl cellulose (CMC), and treatment was given to the animals for 21 days at a dose of (25, 50, and 100 mg/kg, p.o.) after Aβ_1-42 peptide (i.c.v.) injection. Several behavioral studies, acetylcholinesterase activity, oxidative stress, TNFα, IL-6, IL-1β, and expression of BDNF and amyloid-beta were measured. Avicularin treatment (50 and 100 mg/kg) showed cognition enhancement activity in behavioral studies and could reverse the effects of amyloid beta-induced inflammatory response and excessive oxidative stress. Furthermore, the findings reveal that avicularin can halt AD progression by targeting BDNF and amyloid-beta levels in the brain, suggesting that avicularin could be used for Alzheimer's disease treatment.

Potential Protective Effect of Coenzyme Q10 on Doxorubicin-Induced Neurotoxicity and Behavioral Disturbances in Rats

The aim of this study was to investigate the potential neuroprotective efficacy of coenzyme Q10 (CoQ10) against doxorubicin (DOX) -induced behavioral disturbances in rats. Female rats were randomly assigned into 4 groups as control, CoQ10, DOX, and DOX plus CoQ10. The CoQ10 groups received CoQ10 (200 mg kg^-1) for 21 days, and the DOX groups received DOX (4 mg kg^-1) on days 7 and 14 of the study. The open field (OF) and elevated plus maze (EPM) tests were performed to assess locomotor activity and anxiety levels. Additionally, malondialdehyde (MDA), and protein carbonyl (PC) levels and acetylcholinesterase (AChE), and glutathione peroxidase (GPx) activities and total antioxidant capacity (TAC) were quantified in brain tissue. DOX administration caused alterations in locomotor activity, and anxiety-like behaviors. Moreover, DOX produced significant elevation in AChE activity . PC level and GPx activity tended to alter with DOX administration. Co-treatment with CoQ10 significantly attenuated DOX-induced behavioral alterations via improving AChE activity in the brain tissue of rats. CoQ10 treatment may be potential for the alleviation of DOX-induced behavioral disturbances. This improvement might be due to the inhibition of AChE activity.

Protective Effect of Dalbergia sissoo Extract Against Amyloid-β (1-42)-induced Memory Impairment, Oxidative Stress, and Neuroinflammation in Rats

Objectives

The ayurvedic literature reports that Dalbergia sissoo, a common medicinal plant for gastric and skin problems, has brain-revitalizing effects. However, the neuroprotective effect of this herb on an amyloid-β (Aβ) 1-42 model of Alzheimer's disease (AD) is yet unknown. The current study describes the protective effect of ethanolic extracts of D. sissoo leaves (EEDS) against Aβ (1-42)-induced cognitive deficit, oxidative stress, and neuroinflammation in rats.

Materials and Methods

EEDS (300 and 500 mg/kg) was orally administered to rats for 2 weeks prior to intracerebroventricular Aβ (1-42) treatment. The neuroprotective effect of EEDS was assessed by evaluating behavioral, biochemical, and neuroinflammatory parameters in the rat hippocampus. Memory function was assessed via the Morris water maze (MWM) task 2 weeks after Aβ (1-42) administration. After 3 weeks, surgery was performed, all biochemical parameters were evaluated, and histopathological examination of the tissues was carried out.

Results

EEDS improved the cognitive ability of Aβ (1-42)-administered rats in the MWM task. It reduced oxidative stress by significantly decreasing nitrite and malondialdehyde levels and increasing catalase activity and glutathione levels in the rat brain. Moreover, EEDS mitigated neuroinflammation in rats by decreasing the concentration of neuroinflammatory markers in a dose-dependent manner.

Conclusion

D. sissoo leaf extract has a beneficial role in alleviating cognitive deficits in AD by modulating cholinergic function, oxidative stress, and neuroinflammation.

Increasing Nrf2 Activity as a Treatment Approach in Neuropsychiatry

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor encoded by NFE2L2. Under oxidative stress, Nrf2 does not undergo its normal cytoplasmic degradation but instead travels to the nucleus, where it binds to a DNA promoter and initiates transcription of anti-oxidative genes. Nrf2 upregulation is associated with increased cellular levels of glutathione disulfide, glutathione peroxidase, glutathione transferases, thioredoxin and thioredoxin reductase. Given its key role in governing the cellular antioxidant response, upregulation of Nrf2 has been suggested as a common therapeutic target in neuropsychiatric illnesses such as major depressive disorder, bipolar disorder and schizophrenia, which are associated with chronic oxidative and nitrosative stress, characterised by elevated levels of reactive oxygen species, nitric oxide and peroxynitrite. These processes lead to extensive lipid peroxidation, protein oxidation and carbonylation, and oxidative damage to nuclear and mitochondrial DNA. Intake of N-acetylcysteine, coenzyme Q₁₀ and melatonin is accompanied by increased Nrf2 activity. N-acetylcysteine intake is associated with improved cerebral mitochondrial function, decreased central oxidative and nitrosative stress, reduced neuroinflammation, alleviation of endoplasmic reticular stress and suppression of the unfolded protein response. Coenzyme Q₁₀, which acts as a superoxide scavenger in neuroglial mitochondria, instigates mitohormesis, ameliorates lipid peroxidation in the inner mitochondrial membrane, activates uncoupling proteins, promotes mitochondrial biogenesis and has positive effects on the plasma membrane redox system. Melatonin, which scavenges mitochondrial free radicals, inhibits mitochondrial nitric oxide synthase, restores mitochondrial calcium homeostasis, deacetylates and activates mitochondrial SIRT3, ameliorates increased permeability of the blood-brain barrier and intestine and counters neuroinflammation and glutamate excitotoxicity.

Tert-butyl-(4-hydroxy-3-((3-(2-methylpiperidin-yl)propyl)carbamoyl)phenyl)carbamate Has Moderated Protective Activity in Astrocytes Stimulated with Amyloid Beta 1-42 and in a Scopolamine Model

Alzheimer's disease (AD) is a neurodegenerative disease with no cure nowadays; there is no treatment either to prevent or to stop its progression. In vitro studies suggested that tert-butyl-(4-hydroxy-3-((3-(2-methylpiperidin-yl)propyl)carbamoyl)phenyl) carbamate named the M4 compound can act as both β-secretase and an acetylcholinesterase inhibitor, preventing the amyloid beta peptide (Aβ) aggregation and the formation of fibrils (fAβ) from Aβ_1-42. This work first aimed to assess in in vitro studies to see whether the death of astrocyte cells promoted by Aβ_1-42 could be prevented. Second, our work investigated the ability of the M4 compound to inhibit amyloidogenesis using an in vivo model after scopolamine administration. The results showed that M4 possesses a moderate protective effect in astrocytes against Aβ_1-42 due to a reduction in the TNF-α and free radicals observed in cell cultures. In the in vivo studies, however, no significant effect of M4 was observed in comparison with a galantamine model employed in rats, in which case this outcome was attributed to the bioavailability of M4 in the brain of the rats.

Neuroprotective Methodologies of Co-Enzyme Q10 Mediated Brain Hemorrhagic Treatment: Clinical and Pre-Clinical Findings

Cerebral brain hemorrhage is associated with the highest mortality and morbidity despite only constituting approximately 10-15% of all strokes classified into intracerebral and intraventricular hemorrhage where most of the patients suffer from impairment in memory, weakness or paralysis in arms or legs, headache, fatigue, gait abnormality and cognitive dysfunctions. Understanding molecular pathology and finding the worsening cause of hemorrhage will lead to explore the therapeutic interventions that could prevent and cure the disease. Mitochondrial ETC-complexes dysfunction has been found to increase neuroinflammatory cytokines, oxidative free radicals, excitotoxicity, neurotransmitter and energy imbalance that are the key neuropathological hallmarks of cerebral hemorrhage. Coenzyme Q10 (CoQ10), as a part of the mitochondrial respiratory chain can effectively restore these neuronal dysfunctions by preventing the opening of mitochondrial membrane transition pore, thereby counteracting cell death events as well as exerts an anti-inflammatory effect by influencing the expression of NF-kB1 dependent genes thus preventing the neuroinflammation and energy restoration. Due to behavior and biochemical heterogeneity in post cerebral brain hemorrhagic pattern different preclinical autologous blood injection models are required to precisely investigate the forthcoming therapeutic strategies. Despite emerging pre-clinical research and resultant large clinical trials for promising symptomatic treatments, there are very less pharmacological interventions demonstrated to improve post operative condition of patients where intensive care is required. Therefore, in current review, we explore the disease pattern, clinical and pre-clinical interventions under investigation and neuroprotective methodologies of CoQ10 precursors to ameliorate post brain hemorrhagic conditions.

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.

Antidotal effects of thymoquinone against neurotoxic agents

Several plants which contain the active component thymoquinone (TQ) have been traditionally used in herbal medicine to treat various diseases. Several studies indicated the protective effects of TQ against neurotoxic agents. The present study was aimed to highlight the protective effects of TQ against neurotoxic agents. For this reason, the literature from 1998 to 2017 regarding the protective effects of TQ against neurotoxic agents and their involvement mechanisms has been studied. The present review suggests the protective effects of TQ against neurotoxic agents in experimental models. More clinical trial studies are however needed to confirm the antidotal effects of TQ in human intoxication.

Near-infrared photobiomodulation combined with coenzyme Q10 for depression in a mouse model of restraint stress: reduction in oxidative stress, neuroinflammation, and apoptosis

This study was aimed to evaluate the effects of near-infrared (NIR) photobiomodulation (PBM) combined with coenzyme Q₁₀ (CoQ₁₀) on depressive-like behavior, cerebral oxidative stress, inflammation, and apoptosis markers in mice. To induce a depressive-like model, mice were subjected to sub-chronic restraint stress for 5 consecutive days. NIR PBM (810 nm laser, 33.3 J/cm²) and/or CoQ₁₀ (500 mg/kg/day, gavage) were administered for five days concomitantly with immobilization. Behavior was evaluated by the forced swim test (FST), tail suspension test (TST), and open field test (OFT). Mitochondrial membrane potential as well as oxidative stress, neuroinflammatory, and markers of apoptosis were evaluated in the prefrontal cortex (PFC) and hippocampus (HIP). The serum levels of pro-inflammatory cytokines, cortisol, and corticosterone were also measured. PBM or CoQ₁₀, or the combination, ameliorated depressive-like behaviors induced by restraint stress as indicated by decreased immobility time in both the FST and TST. PBM and/or CoQ₁₀ treatments decreased lipid peroxidation and enhanced total antioxidant capacity (TAC), GSH levels, GPx and SOD activities in both brain areas. The neuroinflammatory response in the HIP and PFC was suppressed, as indicated by decreased NF-kB, p38, and JNK levels in PBM and/or CoQ₁₀ groups. Intrinsic apoptosis biomarkers, BAX, Bcl-2, cytochrome c release, and caspase-3 and -9, were also significantly down-regulated by both treatments. Furthermore, both treatments decreased the elevated serum levels of cortisol, corticosterone, TNF-α, and IL-6 induced by restraint stress. Transcranial NIR PBM and CoQ₁₀ therapies may be effective antidepressant strategies for the prevention of psychopathological and behavioral symptoms induced by stress.

Minocycline Attenuates Stress-Induced Behavioral Changes via Its Anti-inflammatory Effects in an Animal Model of Post-traumatic Stress Disorder

Accumulating evidences have suggested that anxiety-like behavior and impairment of learning and memory are key symptoms of post-traumatic stress disorder (PTSD), and pharmacological treatment can ameliorate anxiety and cognitive impairments. Recent studies have shown that minocycline exhibits anxiolytic effects. The aims of the present study were to determine whether minocycline administration would alter anxiety-like behavior and cognitive deficits induced by inescapable foot shock (IFS) and to explore the underlying mechanisms. Male Wistar rats were exposed to the IFS protocol for a period of 6 days to induce PTSD. The PTSD-like behavior was tested using the open field test, elevated plus maze test, and Morris water maze test. The effects of minocycline on pro-inflammatory cytokines, activation of microglia, and NF-κB in the PFC and hippocampus were also examined. Treatment with minocycline significantly reversed the IFS induced behavioral and cognitive parameters (impaired learning and memory function) in stressed rats. Additionally, IFS was able to increase pro-inflammatory cytokines, activate microglia, and enhance NF-κB levels, while minocycline significantly reversed these alterations. Taken together, our results suggest that the anxiolytic effect of minocycline is related to its ability to decrease the levels of pro-inflammatory cytokines and inhibit activation of microglia and NF-κB in the PFC and hippocampus.

Spirulina maxima Extract Ameliorates Learning and Memory Impairments via Inhibiting GSK-3β Phosphorylation Induced by Intracerebroventricular Injection of Amyloid-β 1-42 in Mice

Spirulina maxima, a microalga containing high levels of protein and many polyphenols, including chlorophyll a and C-phycocyanin, has antioxidant and anti-inflammatory therapeutic effects. However, the mechanisms where by Spirulina maxima ameliorates cognitive disorders induced by amyloid-β 1–42 (Aβ_1–42) are not fully understood. In this study, we investigated whether a 70% ethanol extract of Spirulina maxima (SM70EE) ameliorated cognitive impairments induced by an intracerebroventricular injection of Aβ_1–42 in mice. SM70EE increased the step-through latency time in the passive avoidance test and decreased the escape latency time in the Morris water maze test in Aβ_1–42-injected mice. SM70EE reduced hippocampal Aβ_1–42 levels and inhibited amyloid precursor protein processing-associated factors in Aβ_1–42-injected mice. Additionally, acetylcholinesterase activity was suppressed by SM70EE in Aβ_1–42-injected mice. Hippocampal glutathione levels were examined to determine the effects of SM70EE on oxidative stress in Aβ_1–42-injected mice. SM70EE increased the levels of glutathione and its associated factors that were reduced in Aβ_1–42-injected mice. SM70EE also promoted activation of the brain-derived neurotrophic factor/phosphatidylinositol-3 kinase/serine/threonine protein kinase signaling pathway and inhibited glycogen synthase kinase-3β phosphorylation. These findings suggested that SM70EE ameliorated Aβ_1–42-induced cognitive impairments by inhibiting the increased phosphorylation of glycogen synthase kinase-3β caused by intracerebroventricular injection of Aβ_1–42 in mice.

Topical Coenzyme Q10 demonstrates mitochondrial-mediated neuroprotection in a rodent model of ocular hypertension

Coenzyme Q10 (CoQ10) is a mitochondrial-targeted antioxidant with known neuroprotective activity. Its ocular effects when co-solubilised with α-tocopherol polyethylene glycol succinate (TPGS) were evaluated. In vitro studies confirmed that CoQ10 was significantly protective in different retinal ganglion cell (RGC) models. In vivo studies in Adult Dark Agouti (DA) rats with unilateral surgically-induced ocular hypertension (OHT) treated with either CoQ10/TPGS micelles or TPGS vehicle twice daily for three weeks were performed, following which retinal cell health was assessed in vivo using DARC (Detection of Apoptotic Retinal Cells) and post-mortem with Brn3a histological assessment on whole retinal mounts. CoQ10/TPGS showed a significant neuroprotective effect compared to control with DARC (p<0.05) and Brn3 (p<0.01). Topical CoQ10 appears an effective therapy preventing RGC apoptosis and loss in glaucoma-related models.

Curcumin Attenuates Beta-Amyloid-Induced Neuroinflammation via Activation of Peroxisome Proliferator-Activated Receptor-Gamma Function in a Rat Model of Alzheimer's Disease

Neuroinflammation is known to have a pivotal role in the pathogenesis of Alzheimer's disease (AD), and curcumin has been reported to have therapeutical effects on AD because of its anti-inflammatory effects. Curcumin is not only a potent PPARγ agonist, but also has neuroprotective effects on cerebral ischemic injury. However, whether PPARγ activated by curcumin is responsible for the anti-neuroinflammation and neuroprotection on AD remains unclear, and needs to be further investigated. Here, using both APP/PS1 transgenic mice and beta-amyloid-induced neuroinflammation in mixed neuronal/glial cultures, we showed that curcumin significantly alleviated spatial memory deficits in APP/PS1 mice and promoted cholinergic neuronal function in vivo and in vitro. Curcumin also reduced the activation of microglia and astrocytes, as well as cytokine production and inhibited nuclear factor kappa B (NF-κB) signaling pathway, suggesting the beneficial effects of curcumin on AD are attributable to the suppression of neuroinflammation. Attenuation of these beneficial effects occurred when co-administrated with PPARγ antagonist GW9662 or silence of PPARγ gene expression, indicating that PPARγ might be involved in anti-inflammatory effects. Circular dichroism and co-immunoprecipitation analysis showed that curcumin directly bound to PPARγ and increased the transcriptional activity and protein levels of PPARγ. Taking together, these data suggested that PPARγ might be a potential target of curcumin, acting to alleviate neuroinflammation and improve neuronal function in AD.

Protective effect of citicoline against aluminum-induced cognitive impairments in rats

The potential protective effect of citicoline on aluminum chloride-induced cognitive deficits was investigated in rats. In a Morris water maze, administration of aluminum chloride to rats for 90 days resulted in increased escape latency to reach the platform and decreased swimming speed in acquisition trials. Similarly, in probe trials, the time required to reach the hidden platform was increased and the time spent in the target quadrant was reduced. Also, administration of aluminum chloride to rats for 90 days increased the reference and working memory errors and time required to end the task in the radial arm maze. In addition, this treatment decreased the step-through latency in the passive avoidance test. Concurrently, treatment of rats with aluminum chloride for 90 days increased hippocampal glutamate, malondialdehyde, and nitrite levels and decreased intracellular reduced glutathione level. In the citicoline-treated group, aluminum chloride-induced learning and memory impairments as assessed by the Morris water maze, radial arm maze, and passive avoidance tests were inhibited. At the same time, treatment of rats with citicoline prevented the biochemical alterations induced by aluminum chloride in the hippocampus. It can be concluded that elevation of hippocampal glutamate level with consequent oxidative stress and nitric oxide (NO) overproduction may play an important role in aluminum-induced cognitive impairments. Also, our results suggest, for the first time, that citicoline can protect against the development of these cognitive deficits through inhibition of aluminum-induced elevation of glutamate level, oxidative stress, and NO overproduction in the hippocampus.