Carveol Attenuates Seizure Severity and Neuroinflammation in Pentylenetetrazole-Kindled Epileptic Rats by Regulating the Nrf2 Signaling Pathway

The Interplay of Carveol and All-Trans Retinoic Acid (ATRA) in Experimental Parkinson's Disease: Role of Inflammasome-Mediated Pyroptosis and Nrf2

Parkinson's disease (PD) is a debilitating and the second most common neurodegenerative disorder with a high prevalence. PD has a multifaceted etiology characterized by an altered redox state and an excessive inflammatory response. Extensive research has consistently demonstrated the role of the nuclear factor E2-related factor (Nrf2) and inflammasomes, notably NLRP3 in neurodegenerative diseases. In this study, our focus was on exploring the potential neuroprotective properties of carveol in Parkinson's disease. Our findings suggest that carveol may exhibit these effects through Nrf2 and by suppressing pyroptosis. Male albino mice were treated with carveol, and the animal PD model was induced through a single intranigral dose of 2 µg/2µl lipopolysaccharide (LPS). To further demonstrate the essential role of the Nrf2 pathway, we utilized all-trans retinoic acid (ATRA) to inhibit the Nrf2. Our finding showed the induction of pyroptosis as evidenced by increased levels of NLRP3 and other inflammatory mediators, including IL-1β, iNOS, p-NFKB, and apoptotic cell death indicated by positive fluoro Jade B (FJB) staining. Moreover, increased levels of lipid peroxides and reactive oxygen species indicated a significant rise in oxidative stress due to LPS. The administration of carveol mitigates oxidative stress and suppresses inflammatory pathways through the augmentation of intrinsic antioxidant defenses, primarily via the activation of the Nrf2. Conversely, ATRA reversed carveol protective effects by increasing FJB-positive cells, inflammatory and oxidative biomarkers. Taken together, our findings suggest that carveol mitigated LPS-induced Parkinson-like symptoms, partially through the activation of the Nrf2 and downregulation of pyroptosis notably NLRP3.

Neuroprotective role of chlorogenic acid against hippocampal neuroinflammation, oxidative stress, and apoptosis following acute seizures induced by pentylenetetrazole

This study investigated the neuroprotective effect of chlorogenic acid (CGA) on pentylenetetrazole (PTZ)-induced acute epileptic seizures in mice. Epileptic animals received CGA (200 mg/kg) or sodium valproate (standard antiepileptic agent, 200 mg/kg) for four weeks. Results revealed that pre-administration of CGA significantly reversed the behavioral changes following pentylenetetrazole (PTZ) injection. Further, CGA pre-treatment caused significant increases in acetylcholinesterase (AChE) activity and brain-derived neurotrophic factor (BDNF) levels, along with marked increases in dopamine, norepinephrine, and serotonin levels. Additionally, the increased antioxidant enzymes activities, along with higher glutathione (GSH) contents and upregulated nuclear factor erythroid 2-related factor 2 (Nrf2) gene expression, were indicative of a notable improvement in the cellular antioxidant defense in mice treated with CGA. These results were associated with lowered malondialdehyde (MDA) and nitric oxide (NO) levels. Moreover, epileptic mice that received CGA showed significant declines in the content of interleukin-1 beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), and nuclear factor kappa-B (NF-κB), besides downregulating inducible nitric oxide synthase (iNOS) expression. Remarkably, CGA counteracted hippocampal apoptosis by lessening the levels of pro-apoptotic biomarkers [Bcl-2-associated X protein (Bax) and caspase-3] and increasing the anti-apoptogenic marker level of B-cell lymphoma 2 (Bcl-2). The hippocampal histopathological findings corroborated the abovementioned changes. In sum, these findings suggest that CGA could mediate the neuroprotective effect against PTZ-induced epilepsy via modulation of neurotransmitters, oxidative damage, neuroinflammation, and apoptosis. CGA, therefore, could be considered a valuable antiepileptic therapeutic supplement.

Metabolomic Profiling and In Vivo Antiepileptic Effect of Zygophyllum album Aerial Parts and Roots Crude Extracts against Pentylenetetrazole-Induced Kindling in Mice

The chemical profiles of both Zygophyllum album (Z. album) aerial parts and roots extracts were evaluated with LC-ESI-TOF-MS/MS analysis. Twenty-four compounds were detected. Among them, some are detected in both the aerial parts and the roots extracts, and others were detected in the aerial parts only. The detected compounds were mainly flavonoids, phenolic compounds, triterpenes and other miscellaneous compounds. Such compounds contribute to the diverse pharmacological activities elicited by the Z. album species. This study aimed to elucidate the antiepileptic effect of Z. album aerial parts and roots crude extracts against pentylenetetrazole (PTZ)-induced kindling in mice. Male albino mice were divided into four groups, eight animals each. All groups, except the control group, were kindled with PTZ (35 mg/kg i.p.), once every alternate day for a total of 15 injections. One group was left untreated (PTZ group). The remaining two groups were treated prior to PTZ injection with either Z. album aerial parts or roots crude extract (400 mg/kg, orally). Pretreatment with either extract significantly reduced the seizure scores, partially reversed the histological changes in the cerebral cortex and exerted antioxidant/anti-inflammatory efficacy evinced by elevated hippocampal total antioxidant capacity and SOD and catalase activities, parallel to the decrement in MDA content, iNOS activity and the TXNIB/NLRP3 axis with a subsequent decrease in caspase 1 activation and a release of IL-1β and IL-18. Moreover, both Z. album extracts suppressed neuronal apoptosis via upregulating Bcl-2 expression and downregulating that of Bax, indicating their neuroprotective and antiepileptic potential. Importantly, the aerial parts extract elicited much more antiepileptic potential than the roots extract did.

Quercetin attenuated ischemic stroke induced neurodegeneration by modulating glutamatergic and synaptic signaling pathways

Ischemic strokes originate whenever the circulation to the brain is interrupted, either temporarily or permanently, resulting in a lack of oxygen and other nutrients. This deprivation primarily impacts the cerebral cortex and striatum, resulting in neurodegeneration. Several experimental stroke models have demonstrated that the potent antioxidant quercetin offers protection against stroke-related damage. Multiple pathways have been associated with quercetin's ability to safeguard the brain from ischemic injury. This study examines whether the administration of quercetin alters glutamate NMDA and GluR1 receptor signaling in the cortex and striatum 72 h after transient middle cerebral artery occlusion. The administration of 10 mg/kg of quercetin shielded cortical and striatal neurons from cell death induced by ischemia in adult SD rats. Quercetin reversed the ischemia-induced reduction of NR2a/PSD95, consequently promoting the pro-survival AKT pathway and reducing CRMP2 phosphorylation. Additionally, quercetin decreased the levels of reactive oxygen species and inflammatory pathways while increasing the expression of the postsynaptic protein PSD95. Our results suggest that quercetin may be a promising neuroprotective drug for ischemic stroke therapy as it recovers neuronal damage via multiple pathways.

Titanium-Mediated Dehydroxylative Cross-Coupling of Allylic Alcohols with Electron-Deficient Olefins

Herein we report a Ti(III)-mediated dehydroxylative cross-coupling reaction of allylic alcohols with electron-deficient olefins. This reaction is amenable to various synthetically versatile allylic alcohols, including geraniol and farnesol, providing a general method for dehydroxylative C-C bond formation. We demonstrated the reaction's utility by simplifying the syntheses of eight useful building blocks that are otherwise laborious to prepare.

Plant Monoterpenes and Essential Oils as Potential Anti-Ageing Agents: Insights from Preclinical Data

Ageing is a natural process characterized by a time-dependent decline of physiological integrity that compromises functionality and inevitably leads to death. This decline is also quite relevant in major human pathologies, being a primary risk factor in neurodegenerative diseases, metabolic disorders, cardiovascular diseases and musculoskeletal disorders. Bearing this in mind, it is not surprising that research aiming at improving human health during this process has burst in the last decades. Importantly, major hallmarks of the ageing process and phenotype have been identified, this knowledge being quite relevant for future studies towards the identification of putative pharmaceutical targets, enabling the development of preventive/therapeutic strategies to improve health and longevity. In this context, aromatic plants have emerged as a source of potential bioactive volatile molecules, mainly monoterpenes, with many studies referring to their anti-ageing potential. Nevertheless, an integrated review on the current knowledge is lacking, with several research approaches studying isolated ageing hallmarks or referring to an overall anti-ageing effect, without depicting possible mechanisms of action. Herein, we aim to provide an updated systematization of the bioactive potential of volatile monoterpenes on recently proposed ageing hallmarks, and highlight the main mechanisms of action already identified, as well as possible chemical entity-activity relations. By gathering and categorizing the available scattered information, we also aim to identify important research gaps that could help pave the way for future research in the field.

Exploring the neuroprotective potential of antimicrobial peptides from Dinoponera quadriceps venom against pentylenetetrazole-induced seizures in vivo

Epilepsy affects around 50 million people worldwide and 30% of patients have difficulty controlling the disease. The search for substances that can fill the existing gaps in the treatment of epilepsy is of great importance. Arthropod venoms are promising sources for this purpose due to the presence of small peptides that modulate the activity of ion channels and neuron receptors. The aim of this study was to investigate dinoponeratoxins from the Dinoponera quadriceps ant venom (M-PONTX-Dq3a, M-PONTX-Dq3b and M-PONTX-Dq3c) as potential anticonvulsants. We evaluated them in a seizure model induced by pentylenetetrazole (PTZ) in male swiss mice. Interestingly, intraperitoneal treatment with each peptide increased the time until the first seizure and the percentage of survival, with M-PONTX-Dq3b showing the best results. M-PONTX-Dq3a was discarded due to the appearance of some signs of toxicity with the increase in malondialdehyde (MDA) levels in the striatum. Both, M-PONTX-Dq3b and M-PONTX-Dq3c decreased iNOS and TNF-α in the hippocampus. Notably, M-PONTX-Dq3c treatment decreased the levels of MDA and nitrite in the cortex and hippocampus. Our results indicate that, M-PONTX-Dq3b and M-PONTX-Dq3c have anticonvulsant activity and exhibit anti-inflammatory effects in epilepsy, offering new perspectives for biopharmaceutical development.

Dissecting the Relationship Between Neuropsychiatric and Neurodegenerative Disorders

Neurodegenerative diseases (NDDs) and neuropsychiatric disorders (NPDs) are two common causes of death in elderly people, which includes progressive neuronal cell death and behavioral changes. NDDs include Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, and motor neuron disease, characterized by cognitive defects and memory impairment, whereas NPDs include depression, seizures, migraine headaches, eating disorders, addictions, palsies, major depressive disorders, anxiety, and schizophrenia, characterized by behavioral changes. Mounting evidence demonstrated that NDDs and NPDs share an overlapping mechanism, which includes post-translational modifications, the microbiota-gut-brain axis, and signaling events. Mounting evidence demonstrated that various drug molecules, namely, natural compounds, repurposed drugs, multitarget directed ligands, and RNAs, have been potentially implemented as therapeutic agents against NDDs and NPDs. Herein, we highlighted the overlapping mechanism, the role of anxiety/stress-releasing factors, cytosol-to-nucleus signaling, and the microbiota-gut-brain axis in the pathophysiology of NDDs and NPDs. We summarize the therapeutic application of natural compounds, repurposed drugs, and multitarget-directed ligands as therapeutic agents. Lastly, we briefly described the application of RNA interferences as therapeutic agents in the pathogenesis of NDDs and NPDs. Neurodegenerative diseases and neuropsychiatric diseases both share a common signaling molecule and molecular phenomenon, namely, pro-inflammatory cytokines, γCaMKII and MAPK/ERK, chemokine receptors, BBB permeability, and the gut-microbiota-brain axis. Studies have demonstrated that any alterations in the signaling mentioned above molecules and molecular phenomena lead to the pathophysiology of neurodegenerative diseases, namely, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, and neuropsychiatric disorders, such as bipolar disorder, schizophrenia, depression, anxiety, autism spectrum disorder, and post-traumatic stress disorder.

Daytime-Restricted Feeding Ameliorates Oxidative Stress by Increasing NRF2 Transcriptional Factor in the Rat Hippocampus in the Pilocarpine-Induced Acute Seizure Model

Seizure-mediated oxidative stress is a crucial mechanism in the pathophysiology of epilepsy. This study evaluated the antioxidant effects of daytime-restricted feeding (DRF) and the role of the Nrf2 signaling pathway in a lithium-pilocarpine model seizure model that induces status epilepticus (SE). We performed a lipoperoxidation assay and dihydroethidium fluorescence to measure oxidative stress markers in the hippocampus (malondialdehyde and reactive oxygen species). The protein content of Nrf2 and its downstream protein SOD2 was evaluated using Western blotting. The cellular distribution of the Nrf2 and SOD2 proteins in the pyramidal cell layer of both the CA1 and CA3 hippocampal subfields and astrocytes (GFAP marker) were quantified using immunofluorescence and immunohistochemistry, respectively. Our results indicate that DRF reduced the malondialdehyde levels and the production of reactive oxygen species. Furthermore, a significant increase in Nrf2 and SOD2 protein content was observed in animals subjected to restrictive diet. In addition, DRF increased the relative intensity of the Nrf2 fluorescence in the perinuclear and nuclear compartments of pyramidal neurons in the CA1 subfield. Nrf2 immunoreactivity and the astrocyte marker GFAP also increased their colocalization under DRF conditions. Additionally, SOD2 immunoreactivity was increased in CA1 pyramidal neurons but not in the CA3 region. Our findings suggest that DRF partially prevents oxidative stress by increasing the Nrf2 transcriptional factor and the SOD2 enzyme during the development of SE.

Bee venom ameliorates oxidative stress and histopathological changes of hippocampus, liver and testis during status epileptics

The unrelenting progression of neurodegenerative diseases has a negative impact on affected individuals, their families, and society. Recurrent epileptic seizures are the hallmark of epilepsy, and treating it effectively remains difficult. Clarify and understanding effects of the antiepileptic drugs (AEDs) in epilepsy by comparing the therapeutic effects between rats receiving valproic acid (VPA) and Bee venom (BV) was aimed throughout the present study. Four male Wistar rat groups were included: control, epileptic group receiving pilocarpine (PILO), epileptic group treated with VPA and BV respectively. Cognitive functions were assessed by evaluating latency time in hot plate, despair swim test, grooming, rearing and ambulation frequency in the open field. BV has ameliorative effect on electrolytes balancing, assured by decreasing lipid peroxidation, nitric oxide and increasing catalase, superoxide dismutase and glutathione peroxidase activities. BV enhanced restoration of liver functions indicated by alanine transaminase (ALT) and aspartate transaminase (AST), total proteins, and albumin; hormonal parameters total and free testosterone, follicle stimulating hormone (FSH) and Luteinizing hormone (LH) were preserved by BV with great recovery of hippocampus, liver and testicular histopathology and ultrastructure comparing with the epileptic rats. The present findings suggested that BV and its active components offer fresh options for controlling epilepsy and prospective methods via minimize or manage the severe consequences.

A Compared Study of Eicosapentaenoic Acid and Docosahexaenoic Acid in Improving Seizure-Induced Cognitive Deficiency in a Pentylenetetrazol-Kindling Young Mice Model

Epilepsy is a chronic neurological disorder that is more prevalent in children, and recurrent unprovoked seizures can lead to cognitive impairment. Numerous studies have reported the benefits of docosahexaenoic acid (DHA) on neurodevelopment and cognitive ability, while comparatively less attention has been given to eicosapentaenoic acid (EPA). Additionally, little is known about the effects and mechanisms of DHA and EPA in relation to seizure-induced cognitive impairment in the young rodent model. Current research indicates that ferroptosis is involved in epilepsy and cognitive deficiency in children. Further investigation is warranted to determine whether EPA or DHA can mitigate seizure-induced cognitive deficits by inhibiting ferroptosis. Therefore, this study was conducted to compare the effects of DHA and EPA on seizure-induced cognitive deficiency and reveal the underlying mechanisms focused on ferroptosis in a pentylenetetrazol (PTZ)-kindling young mice model. Mice were fed a diet containing DHA-enriched ethyl esters or EPA-enriched ethyl esters for 21 days at the age of 3 weeks and treated with PTZ (35 mg/kg, i.p.) every other day 10 times. The findings indicated that both EPA and DHA exhibited ameliorative effects on seizure-induced cognitive impairment, with EPA demonstrating a superior efficacy. Further mechanism study revealed that supplementation of DHA and EPA significantly increased cerebral DHA and EPA levels, balanced neurotransmitters, and inhibited ferroptosis by modulating iron homeostasis and reducing lipid peroxide accumulation in the hippocampus through activating the Nrf2/Sirt3 signal pathway. Notably, EPA exhibited better an advantage in ameliorating iron dyshomeostasis compared to DHA, owing to its stronger upregulation of Sirt3. These results indicate that DHA and EPA can efficaciously alleviate seizure-induced cognitive deficiency by inhibiting ferroptosis in PTZ-kindled young mice.

Antioxidant Therapy Reduces Oxidative Stress, Restores Na,K-ATPase Function and Induces Neuroprotection in Rodent Models of Seizure and Epilepsy: A Systematic Review and Meta-Analysis

Epilepsy is a neurological disorder characterized by epileptic seizures resulting from neuronal hyperexcitability, which may be related to failures in Na,K-ATPase activity and oxidative stress participation. We conducted this study to investigate the impact of antioxidant therapy on oxidative stress, Na,K-ATPase activity, seizure factors, and mortality in rodent seizure/epilepsy models induced by pentylenetetrazol (PTZ), pilocarpine (PILO), and kainic acid (KA). After screening 561 records in the MEDLINE, EMBASE, Web of Science, Science Direct, and Scopus databases, 22 were included in the systematic review following the PRISMA guidelines. The meta-analysis included 14 studies and showed that in epileptic animals there was an increase in the oxidizing agents nitric oxide (NO) and malondialdehyde (MDA), with a reduction in endogenous antioxidants reduced glutathione (GSH) and superoxide dismutase (SO). The Na,K-ATPase activity was reduced in all areas evaluated. Antioxidant therapy reversed all of these parameters altered by seizure or epilepsy induction. In addition, there was a percentage decrease in the number of seizures and mortality, and a meta-analysis showed a longer seizure latency in animals using antioxidant therapy. Thus, this study suggests that the use of antioxidants promotes neuroprotective effects and mitigates the effects of epilepsy. The protocol was registered in the Prospective Register of Systematic Reviews (PROSPERO) CRD42022356960.

miR-10a induces inflammatory responses in epileptic hippocampal neurons of rats via PI3K/Akt/mTOR signaling pathway

Epilepsy is a common chronic neurological disorder worldwide. MicroRNAs (miRNAs) play an important role in the pathogenesis of epilepsy. However, the mechanism of the regulatory effect of miR-10a on epilepsy is unclear. In this study, we investigated the effect of miR-10a expression on the PI3K/Akt/mTOR signaling pathway and inflammatory cytokines in epileptic hippocampal neurons of rats. The miRNA differential expression profile of rat epileptic brain was analyzed using bioinformatic approaches. Neonatal Sprague-Dawley rat hippocampal neurons were prepared as epileptic neuron models in vitro by replacing culture medium with magnesium-free extracellular solution. The hippocampal neurons were transfected with miR-10a mimics, and transcript levels of miR-10a, PI3K, Akt and mTOR were detected by quantitative reverse transcription-PCR, and PI3K, mTOR, Akt, TNF-α, IL-1β, IL-6 protein expression levels were detected by Western blot. Cytokines secretory levels were detected by ELISA. Sixty up-regulated miRNAs were identified in the hippocampal tissue of epileptic rats and might affect the PI3K-Akt signaling pathway. In the epileptic hippocampal neurons model, the expression levels of miR-10a were significantly increased, with decreasing levels of PI3K, Akt and mTOR, and increasing levels of TNF-α, IL-1β and IL-6. The miR-10a mimics promoted the expression of TNF-α, IL-1β and IL-6. Meanwhile, miR-10a inhibitor activated PI3K/Akt/mTOR pathway and inhibited cytokines secretion. Finally, cytokine secretion was increased by treated with PI3K inhibitor and miR-10a inhibitor. The miR-10a may promote inflammatory responses in rat hippocampal neurons by inhibiting the PI3K/Akt/mTOR pathway, suggesting that miR-10a may be one of the target therapeutic molecules for epilepsy treatment.

Natural Products as Modulators of Nrf2 Signaling Pathway in Neuroprotection

Neurodegenerative diseases (NDs) affect the West due to the increase in life expectancy. Nervous cells accumulate oxidative damage, which is one of the factors that triggers and accelerates neurodegeneration. However, cells have mechanisms that scavenge reactive oxygen species (ROS) and alleviate oxidative stress (OS). Many of these endogenous antioxidant systems are regulated at the gene expression level by the transcription factor Nrf2 (nuclear factor erythroid 2-related factor 2). In the presence of prooxidant conditions, Nrf2 translocates to the nucleus and induces the transcription of genes containing ARE (antioxidant response element). In recent years, there has been an increase in the study of the Nrf2 pathway and the natural products that positively regulate it to reduce oxidative damage to the nervous system, both in in vitro models with neurons and microglia subjected to stress factors and in vivo models using mainly murine models. Quercetin, curcumin, anthocyanins, tea polyphenols, and other less studied phenolic compounds such as kaempferol, hesperetin, and icariin can also modulate Nrf2 by regulating several Nrf2 upstream activators. Another group of phytochemical compounds that upregulate this pathway are terpenoids, including monoterpenes (aucubin, catapol), diterpenes (ginkgolides), triterpenes (ginsenosides), and carotenoids (astaxanthin, lycopene). This review aims to update the knowledge on the influence of secondary metabolites of health interest on the activation of the Nrf2 pathway and their potential as treatments for NDs.

Monosodium glutamate induces cortical oxidative, apoptotic, and inflammatory challenges in rats: the potential neuroprotective role of apigenin

Monosodium glutamate (MSG) is used as a flavor, and a taste enhancer was reported to evoke marked neuronal impairments. This study investigated the neuroprotective ability of flavonoid apigenin against neural damage in MSG-administered rats. Adult male rats were allocated into four groups: control, apigenin (20 mg/kg b.wt, orally), MSG (4 g/kg b.wt, orally), and apigenin + MSG at the aforementioned doses for 30 days. Regarding the levels of neurotransmitters, our results revealed that apigenin augmented the activity of acetylcholinesterase (AChE) markedly, and levels of brain monoamines (dopamine, norepinephrine, and serotonin) accompanied by lessening the activity of monoamine oxidase (MAO) as compared to MSG treatment. Moreover, apigenin counteracted the MSG-mediated oxidative stress by decreasing the malondialdehyde (MDA) levels together with elevating the glutathione (GSH) levels. In addition, pretreatment with apigenin induced notable increases in the activities of cortical superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR). Furthermore, apigenin attenuated the cortical inflammatory stress as indicated by lower levels of pro-inflammatory mediators such as interleukin-1 b (IL-1b), tumor necrosis factor-α (TNF-α), and nitric oxide (NO) as well as downregulated inducible nitric oxide synthase (iNOS) expression levels. Histopathological screening validated the abovementioned results and revealed that apigenin restored the distorted cytoarchitecture of the brain cortex. Thus, the present findings collectively suggest that apigenin exerted significant protection against MSG-induced neurotoxicity by enhancing the cellular antioxidant response and attenuating inflammatory machineries in the rat brain cortex.

DHA and EPA Prevent Seizure and Depression-Like Behavior by Inhibiting Ferroptosis and Neuroinflammation via Different Mode-of-actions in a Pentylenetetrazole-Induced Kindling Model in Mice

SCOPE

It has been reported that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have anticonvulsant effects, yet the respective mechanism of EPA and DHA on epilepsy are still unclarified. This study aimed to investigate the effect of EPA and DHA on pentylenetetrazol (PTZ) induced seizures and depression.

METHODS AND RESULTS

The administration of EPA and DHA at a dose of 1% (w/w) significantly inhibited PTZ-induced seizures and depressive-like behavior, whereas EPA outcompetes DHA. Further mechanistic studies revealed that the higher effect of EPA can be partly attributed to the promotion of M2 polarization, inhibition of M1 polarization of microglia, and lower iron content in the brain, resulting from the stronger activation of nuclear factor E2-related factor 2 (Nrf2). We found that DHA and EPA comparably inhibited NLRP3 inflammasome activation but with different mode-of-actions: EPA preferred to inhibit the binding of NLRP3 and ASC, while DHA decreased the protein levels of ASC and Caspase-1.

CONCLUSIONS

These results indicated that DHA and EPA could efficaciously alleviate PTZ-induced seizure and depressive-like behavior but with different efficiency and molecular mechanisms. This article is protected by copyright. All rights reserved.

Neuroprotective Effect of Natural Compounds in Paclitaxel-Induced Chronic Inflammatory Pain

The current study explored the effects of natural compounds, berbamine, bergapten, and carveol on paclitaxel-associated neuroinflammatory pain. Berbamine, an alkaloid obtained from BerberisamurensisRuprhas been previously researched for anticancer and anti-inflammatory potential. Bergapten is 5-methoxsalenpsoralen previously investigated in cancer, vitiligo, and psoriasis. Carveol obtained from caraway is a component of essential oil. The neuropathic pain model was induced by administering 2 mg/kg of paclitaxel (PTX) every other day for a week. After the final PTX injection, a behavioral analysis was conducted, and subsequently, tissue was collected for molecular analysis. Berbamine, bergapten, and carveol treatment attenuated thermal hypersensitivity, improved latency of falling, normalized the changes in body weight, and increased the threshold for pain sensation. The drugs increased the protective glutathione (GSH) and glutathione S-transferase (GST) levels in the sciatic nerve and spinal cord while lowering inducible nitric oxide synthase (iNOS) and lipid peroxidase (LPO). Hematoxylin and eosin (H and E) and immunohistochemistry (IHC) examinations confirmed that the medication reversed the abnormal alterations. The aforementioned natural substances inhibited cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κb) overexpression, as evidenced by enzyme-linked immunosorbant assay (ELISA) and Western blot and hence provide neuroprotection in chronic constriction damage.

Neuroprotective effects of carvacrol against cadmium-induced neurotoxicity in rats: role of oxidative stress, inflammation and apoptosis

Cadmium (Cd), is a heavy metal reported to be associated with oxidative stress and inflammation. In this paper, we investigated the possible protective effects of carvacrol against Cd-induced neurotoxicity in rats. Adult male Sprague Dawley rats were treated orally with Cd (25 mg/kg body weight) and with carvacrol (25 and 50 mg/kg body weight) for 7 days. Carvacrol decreased the levels of malondialdehyde (MDA), glial fibrillary acidic protein (GFAP) and monoamine oxidase (MAO), and significantly increased the levels of glutathione (GSH) and activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in brain tissue. Additionally, carvacrol alleviated the in levels of inflammation and apoptosis related proteins involving p38 mitogen-activated protein kinase (p38 MAPK), cyclooxygenase-2 (COX-2), nuclear factor kappa B (NF-κB), B-cell lymphoma-3 (Bcl-3), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), myeloperoxidase (MPO), prostaglandin E2 (PGE2), neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), cysteine aspartate specific protease-3 (caspase-3) and Bcl-2 associated X protein (Bax) in the Cd-induced neurotoxicity. Carvacrol also decreased the mRNA expression of matrix metalloproteinases (MMP9 and MMP13), as well as 8-hydroxy-2'-deoxyguanosine (8 - OHdG) level, a marker of oxidative DNA damage. Collectively, our findings indicated that carvacrol has a beneficial effect in ameliorating the Cd-induced neurotoxicity in the brain of rats.

Carveol Promotes Nrf2 Contribution in Depressive Disorders through an Anti-inflammatory Mechanism

Major depressive disorder (MDD) is a progressive deteriorating mental state with a feeling of worthlessness and frequent mood swings. Several studies reported the favorable effects of natural drug substances on MMD associated oxidative stress and neuroinflammation. The present study is attempted to examine whether carveol could affect lipopolysaccharide- (LPS-) induced depression, and if so, how nuclear factor E2-related factor (Nrf2) contributed to the neuroprotective effects of carveol mechanistically. Two experimental cohorts were used using the SD rats: first to evaluate the promising dose of carveol (whether 20 mg/kg or 50 mg/kg) and secondly to determine the effect of carveol on Nrf2-mediated antidepression. Significant neuronal alterations were noticed in the cortex and hippocampus regions in the LPS-treated group, accompanied by elevated inflammatory cytokine levels such as tumor necrosis factor-alpha (TNF-α), cyclooxygenase (COX-2), and c-Jun N-terminal kinase (p-JNK). Moreover, amassing of free radicals exacerbated lipid peroxidase (LPO) and oxidative stress with a limited antioxidant capacity. Carveol (20 mg/kg) significantly ameliorated these detrimental effects by promoting the antioxidant Nrf2 gene and protein, which critically regulate the downstream antioxidant and anti-inflammatory pathway. To further elaborate our hypothesis, we employed all-trans retinoic acid (ATRA), an Nrf2 inhibitor, and we found that ATRA exaggerated LPS-induced depressive-like effects associated with elevated neuroinflammatory markers. Our results demonstrated that carveol (20 mg/kg) could activate the endogenous antioxidant Nrf2, which regulates the downstream antioxidant signaling pathway, eventually leading to amelioration of LPS-induced neuroinflammation and neurodegeneration.

Neurovascular unit dysfunction as a mechanism of seizures and epilepsy during aging

The term neurovascular unit (NVU) describes the structural and functional liaison between specialized brain endothelium, glial and mural cells, and neurons. Within the NVU, the blood‐brain barrier (BBB) is the microvascular structure regulating neuronal physiology and immune cross‐talk, and its properties adapt to brain aging. Here, we analyze a research framework where NVU dysfunction, caused by acute insults or disease progression in the aging brain, represents a converging mechanism underlying late‐onset seizures or epilepsy and neurological or neurodegenerative sequelae. Furthermore, seizure activity may accelerate brain aging by sustaining regional NVU dysfunction, and a cerebrovascular pathology may link seizures to comorbidities. Next, we focus on NVU diagnostic approaches that could be tailored to seizure conditions in the elderly. We also examine the impending disease‐modifying strategies based on the restoration of the NVU and, more in general, the homeostatic control of anti‐ and pro‐inflammatory players. We conclude with an outlook on current pre‐clinical knowledge gaps and clinical challenges pertinent to seizure onset and conditions in an aging population.

1,3,4, Oxadiazole Compound A3 Provides Robust Protection Against PTZ-Induced Neuroinflammation and Oxidative Stress by Regulating Nrf2-Pathway

Background

Epilepsy is a common neurological disorder that is characterized by recurrent episodes of seizures. Various studies have demonstrated a direct association between oxidative stress and inflammation in several neurological disorders including epilepsy. This study aimed to investigate the neuroprotective effects of a synthetic 1,3,4, oxadiazole compound A3 against pentylenetetrazole (PTZ)-induced kindling and seizure model.

Methodology

PTZ was administered in a sub-convulsive dose of 40 mg/kg for 15 days, at 48-hour intervals to male Swiss-Albino mice until animals were fully kindled. Two different doses of A3 (10 mg/kg and 30 mg/kg) were administered to find out the effective dose of A3 and to further demonstrate the relative role of nuclear factor E2-related factor (Nrf2) in the PTZ-induced kindled model.

Results

Our results demonstrated a compromised antioxidant capacity associated with a low level of catalase (CAT), superoxide dismutase (SOD), glutathione (GST), and glutathione S-transferase (GSH) in the kindled group. However, the PTZ-induced group demonstrated an elevated level of lipid peroxidation (LPO) level parallel to pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α), mediators as cyclooxygenase (COX-2), and nuclear factor kappa B (NFκB). Furthermore, the A3 treatment reversed these changes and overexpressed the antioxidant Nrf2 gene and its downstream HO-1. To further investigate the involvement of Nrf2, we employed an Nrf2-inhibitor, ie, all-trans retinoic acid (ATRA), that further aggravated the PTZ toxicity. Moreover, vascular endothelial growth factor (VEGF) expression was evaluated to assess the extent of BBB disruption.

Conclusion

The findings of this study suggest that A3 could mediate neuroprotection possibly by activating Nrf2 dependent downregulation of inflammatory cascades.

Investigation of 1, 3, 4 Oxadiazole Derivative in PTZ-Induced Neurodegeneration: A Simulation and Molecular Approach

Objective

The study investigated the effect 5-[(naphthalen-2-yloxy) methyl]-1,3,4-oxadiaszole2-thiol (B3) in animal model of acute epileptic shock.

Methods

The pharmacokinetics profile of B3 was checked through SwissADME software. The binding affinities of B3, diazepam, and flumazenil (FLZ) were obtained through Auto Dock and PyRx. Post docking analysis and interpretation of hydrogen bonds were performed through Discovery Studio Visualizer 2016. Molecular dynamics simulations of three complexes were carried out through Desmond software package. B3 was then proceeded in PTZ-induced acute seizures models. Flumazenil was used in animal studies for elucidation of possible mechanism of B3. After behavioral studies, the animals were sacrificed, and the brain samples were isolated and stored in 4% formalin for molecular investigations including H and E staining, IHC staining and Elisa etc.

Results

The results demonstrate that B3 at 20 and 40 mg/kg prolonged the onset time of generalized seizures. B3 considerably increased the expression of protective glutathione S-transferase and glutathione reductase and reduced lipid peroxidation and inducible nitric oxide synthase (P < 0.001) in the cortex. B3 significantly suppressed (P < 0.01) the over expression of the inflammatory mediator tumor necrosis factor–α, whose up-regulation is reported in acute epileptic shocks.

Conclusion

Hence, it is concluded from the aforementioned results that B3 provides neuroprotective effects PTZ-induced acute epileptic model. FLZ pretreatment resulted in inhibition of the anticonvulsant effect of B3. B3 possesses anticonvulsant effect which may be mediated through GABA_A mediated antiepileptic pathway.