Phyllathin From Phyllanthus Amarus Ameliorates Epileptic Convulsion and Kindling Associated Post-Ictal Depression in Mice via Inhibition of NF-κB/TLR-4 Pathway

Phyllanthus niruri L. Administration during pregnancy and breastfeeding: Maternal evaluation and effects on initial development and adult behavior of male rat offspring

The leaves of Phyllanthus niruri L. are used in folk medicine in many countries to treat various diseases. However, despite the enormous therapeutic potential, use of the plant is contraindicated during pregnancy and breastfeeding. Reports on the impacts of exposure to this plant on the development of the offspring of rats are still scarce and controversial. The aim of this study is to evaluate the effects of the administration of P. niruri aqueous extract, during pregnancy and lactation, on maternal toxicity, on postnatal physical development, and on behavioral aspects in adult male offspring. Pregnant rats were divided into three experimental groups (n = 8/group) and treated daily during pregnancy and lactation, (gavage), with vehicle and doses of 75 and 150 mg/kg of aqueous extract of P. niruri. To assess maternal toxicity; weight gain, feed intake, reproductive outcomes, and biochemical profiles were analyzed. The male pups were evaluated for physical development through the end of lactation and submitted to tests evaluating their behavior in adulthood. Treatment with the aqueous extract of P. niruri (AEPN) did not cause significant changes in the maternal and reproductive parameters analyzed. However, changes in the biochemical markers of liver function were observed. In the male offspring, the extract did not alter postnatal physical growth, but caused early opening of the ear canal and eyes. In the evaluation of adult male offspring, it was found that the groups exposed to AEPN presented behavioral changes predictive of anxiolytic effect. Brain malondialdehyde levels of male offspring whose mothers were treated with AEPN were significantly reduced. Our results demonstrate that exposure to P. niruri extract did not induce significant changes sufficiently to indicate occurrence of maternal or postnatal toxicity. In addition, in the male offspring exposed to the extract, anticipation of physical maturation parameters and anxiolytic-like behavior was observed.

Phytotherapeutic options for the treatment of epilepsy: pharmacology, targets, and mechanism of action

Epilepsy is one of the most common, severe, chronic, potentially life-shortening neurological disorders, characterized by a persisting predisposition to generate seizures. It affects more than 60 million individuals globally, which is one of the major burdens in seizure-related mortality, comorbidities, disabilities, and cost. Different treatment options have been used for the management of epilepsy. More than 30 drugs have been approved by the US FDA against epilepsy. However, one-quarter of epileptic individuals still show resistance to the current medications. About 90% of individuals in low and middle-income countries do not have access to the current medication. In these countries, plant extracts have been used to treat various diseases, including epilepsy. These medicinal plants have high therapeutic value and contain valuable phytochemicals with diverse biomedical applications. Epilepsy is a multifactorial disease, and therefore, multitarget approaches such as plant extracts or extracted phytochemicals are needed, which can target multiple pathways. Numerous plant extracts and phytochemicals have been shown to treat epilepsy in various animal models by targeting various receptors, enzymes, and metabolic pathways. These extracts and phytochemicals could be used for the treatment of epilepsy in humans in the future; however, further research is needed to study the exact mechanism of action, toxicity, and dosage to reduce their side effects. In this narrative review, we comprehensively summarized the extracts of various plant species and purified phytochemicals isolated from plants, their targets and mechanism of action, and dosage used in various animal models against epilepsy.

Aqueous leaf extract of Phyllanthus amarus protects against oxidative stress and misfiring of dopaminergic neurons in Paraquat-induced Parkinson's disease-like model of adult Wistar rats

BACKGROUND OF THE STUDY

Phyllanthus amarus has high nutritional value and is beneficial in managing and treating diverse ailments. This study assessed the role of aqueous leaf extract of Phyllanthus amarus on Paraquat (PQ) induced neurotoxicity in the substantia nigra of Wistar rats.

MATERIALS AND METHODS

The role of aqueous leaves extract of Phyllanthus amarus was assessed using an open field test (OFT) for motor activity, oxidative stress biomarkers [Catalase (CAT), and Superoxide Dismutase (SOD)], histological examination (H and E stained) for cytoarchitectural changes and immunohistochemical studies using tyrosine hydroxylase (TH) as a marker for dopaminergic neurons. Forty-two (42) rats were categorized into six groups (n = 7); group 1: control was administered 0.5 ml/kg distilled water, group 2: received 10 mg/kg PQ + 10 mg/kg L-dopa as reference drug, group 3; received 10 mg/kg PQ, while group 4: received 10 mg/kg PQ + 200 mg/kg P. amarus, group 5: received 10 mg/kg PQ + 300 mg/kg P. amarus, and group 6: received 10 mg/kg PQ + 400 mg/kg P. amarus respectively, for 14 days. All administrations were done orally; a significant difference was set at p < 0.05.

RESULTS AND DISCUSSION

The study's open field test (OFT) revealed no motor activity deficit with Paraquat (PQ) exposure. Also, cytoarchitectural distortions were not observed with Paraquat (PQ) only treatment group compared to the control and other groups pretreated with P. amarus and L-dopa. Moreover, the Paraquat (PQ) only treatment group showed oxidative stress by significantly decreasing the antioxidant enzyme (SOD) compared to the control and L-dopa pretreated group. A significant decrease in tyrosine hydroxylase (TH) expressing dopaminergic neurons was also observed in Paraquat (PQ) only treatment. However, P. amarus treatment showed therapeutic properties by significantly increasing tyrosine hydroxylase (TH) expressing dopaminergic neuron levels relative to control.

CONCLUSION

Aqueous leaf extract of Phyllanthus amarus possesses therapeutic properties against Paraquat (PQ) induced changes in the substantia nigra of Wistar rats.

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.

Insights into the potential benefits of triphala polyphenols toward the promotion of resilience against stress-induced depression and cognitive impairment

In response to environmental challenges, stress is a common reaction, but dysregulation of the stress response can lead to neuropsychiatric disorders, including depression and cognitive impairment. Particularly, there is ample evidence that overexposure to mental stress can have lasting detrimental consequences for psychological health, cognitive function, and ultimately well-being. In fact, some individuals are resilient to the same stressor. A major benefit of enhancing stress resilience in at-risk groups is that it may help prevent the onset of stress-induced mental health problems. A potential therapeutic strategy for maintaining a healthy life is to address stress-induced health problems with botanicals or dietary supplements such as polyphenols. Triphala, also known as Zhe Busong decoction in Tibetan, is a well-recognized Ayurvedic polyherbal medicine comprising dried fruits from three different plant species. As a promising food-sourced phytotherapy, triphala polyphenols have been used throughout history to treat a variety of medical conditions, including brain health maintenance. Nevertheless, a comprehensive review is still lacking. Here, the primary objective of this review article is to provide an overview of the classification, safety, and pharmacokinetics of triphala polyphenols, as well as recommendations for the development of triphala polyphenols as a novel therapeutic strategy for promoting resilience in susceptible individuals. Additionally, we summarize recent advances demonstrating that triphala polyphenols are beneficial to cognitive and psychological resilience by regulating 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF) receptors, gut microbiota, and antioxidant-related signaling pathways. Overall, scientific exploration of triphala polyphenols is warranted to understand their therapeutic efficacy. In addition to providing novel insights into the mechanisms of triphala polyphenols for promoting stress resilience, blood brain barrier (BBB) permeability and systemic bioavailability of triphala polyphenols also need to be improved by the research community. Moreover, well-designed clinical trials are needed to increase the scientific validity of triphala polyphenols' beneficial effects for preventing and treating cognitive impairment and psychological dysfunction.

The Neuroprotective Effect Associated with Echinops spinosus in an Acute Seizure Model Induced by Pentylenetetrazole

Echinops spinosus (ES) is a medicinal plant with a wide range of pharmacological and biological effects. It is a medicinal herb having a variety of therapeutic characteristics, including antioxidant, anti-inflammatory, and antibacterial capabilities. The primary goal of this research is to investigate the neuroprotective and anticonvulsant characteristics of E. spinosa extract (ESE) against pentylenetetrazole (PTZ)-induced acute seizures. Negative control rats, ESE treatment rats, PTZ acute seizure model rats, ESE + PTZ rats, and Diazepam + PTZ rats were used in the study. The rats were given a 7-day treatment. ESE pretreatment elevated the latency to seizure onset and lowered seizure duration after PTZ injection. By reducing Bax levels and enhancing antiapoptotic Bcl-2 production, ESE prevented the release of interleukin-1β, tumor necrosis factor-α, and cyclooxygenase-2, as well as preventing hippocampal cell death after PTZ injection. ESE corrected the PTZ-induced imbalance in gamma-aminobutyric acid levels and increased the enzyme activity of Na⁺/K⁺-ATPase. Echinops spinosus is a potent neuromodulatory, antioxidant, antiinflammatory, and antiapoptotic plant that could be employed as a natural anticonvulsant in the future.

An insight into the potent medicinal plant Phyllanthus amarus Schum. and Thonn

Phyllanthus amarus Schum. and Thonn., a globally distributed herb is known for its several therapeutic potentials. P. amarus has a long history of use in the traditional system of medicine for over 2000 years owing to its wide array of secondary metabolites that confer significant medicinal attributes. Research on various aspects including ethnobotany, phytochemistry to bioactivity, or pharmacological studies has been conducted over the past several decades on this potent herb. P. amarus extracts have shown a broad range of pharmacological activities like hepatoprotective, antioxidant, antiviral, antimicrobial, antidiabetic, anti-inflammatory, anticancer, antimalarial, nephroprotective, diuretic, and several other properties. The present review compiles and covers literature and research of several groups across past decades to date and focuses on how the therapeutic significance of this plant can be further explored for future research either as herbal formulations, alternative medicine, or in the pharmaceutical industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13237-022-00409-z.

Transcription factors are potential therapeutic targets in epilepsy

Academics generally believe that imbalance between excitation and inhibition of the nervous system is the root cause of epilepsy. However, the aetiology of epilepsy is complex, and its pathogenesis remains unclear. Many studies have shown that epilepsy is closely related to genetic factors. Additionally, the involvement of a variety of tumour‐related transcription factors in the pathogenesis of epilepsy has been confirmed, which also confirms the heredity of epilepsy. In this review, we summarize the existing research on a variety of transcription factors and epilepsy and present relevant evidence related to transcription factors that may be targets in epilepsy. This information is of great significance for revealing the in‐depth molecular and cellular mechanisms of epilepsy.

Neuroprotective Effect of Otostegia limbata Against PTZ-Induced Mice Model of Epilepsy by Attenuated Expression of p-NFκB and TNF-α

Epilepsy is a chronic neurological disorder characterized by recurrent unprovoked seizures. Currently available antiepileptic drugs have severe side effects and do not offer complete cure. Herbal remedies have been used for centuries to treat many neurodegenerative disorders. Otostegia limbata L. belongs to the largest and medicinally important family Lamiaceae and is distributed in hilly areas of Pakistan. This study was designed to assess the antioxidant, anti-inflammatory, and anticonvulsant potential of O. limbata. The methanolic extract showed significant antioxidant activity assessed by (1,1-diphenyl 2-picrylhydrazyl) free-radical scavenging assay, nitric oxide scavenging, and iron chelation antioxidant assays. The methanolic extract was evaluated for its anticonvulsant effect, employing the pentylenetetrazole (PTZ)-induced mice model of epilepsy. Three different doses of O. limbata (100, 200, and 300 mg/kg) were administered orally 30 min before PTZ [50 mg/kg, intraperitoneal (i.p.)] injection, while diazepam was used as a positive control. The extract at 300 mg/kg significantly decreased the duration and increased the latency of the PTZ-induced seizures. The expression of inflammatory cytokines tumor necrosis factor α (p-TNF-α) and phosphorylated transcription factor nuclear factor kappa B (p-NF-κB), in the cortex and hippocampus of the brains of treated mice were analyzed through enzyme-linked immunosorbent assay and western blot analysis. The morphological changes and number of surviving neurons were recorded through hematoxylin and eosin staining. The seizure score and survival rate of the treated group showed considerable differences as compared to the PTZ group. TNF-α and p-NF-K b expression were downregulated as compared to the PTZ group. The anticonvulsant effect may be the outcome of the antioxidant potential and high levels of phenols and flavonoids detected in the methanolic plant extract through Fourier transform infrared spectrophotometer and gas chromatography–mass spectrometry analysis.

Selenium Nanoparticles with Prodigiosin Rescue Hippocampal Damage Associated with Epileptic Seizures Induced by Pentylenetetrazole in Rats

Simple Summary

Epilepsy is a chronic neurological disease characterized by neuronal hyper electrical activity and the development of unprovoked seizures. Although several antiepileptic drugs are currently available, their application is associated with undesirable adverse effects. In an attempt to find a novel antiepileptic medication with minimum side effects, we have investigated the potential neuroprotective activity of prodigiosin, a red pigment produced by bacterial species that have important pharmaceutical and biological activities biosynthesized with selenium formulation (SeNPs-PDG) against a murine epileptic model mediated by pentylenetetrazole. The main recorded findings revealed that SeNPs-PDG delayed the onset of epileptic seizures and decreased their duration significantly. Additionally, SeNPs-PDG prevented hippocampal cell loss, oxidative stress, neuroinflammation, restored the balance between excitatory and inhibitory neurotransmitters, and notably normalized the monoaminergic and cholinergic transmission. These promising findings indicate that SeNPs-PDG might serve as a naturally derived anticonvulsant agent due to their active antioxidant, anti-inflammatory, anti-apoptotic, and neuromodulatory properties.

Abstract

Background: Prodigiosin (PDG) is a red pigment synthesized by bacterial species with important pharmaceutical and biological activities. Here, we investigated the neuroprotective and anticonvulsant activities of green biosynthesized selenium formulations with PDG (SeNPs-PDG) versus pentylenetetrazole (PTZ)-induced epileptic seizures. Methods: Rats were assigned into six experimental groups: control; PTZ (60 mg/kg, epileptic model); sodium valproate (200 mg/kg) + PTZ; PDG (300 mg/kg) + PTZ; sodium selenite (0.5 mg/kg) + PTZ; and SeNPs-PDG (0.5 mg/kg) + PTZ. The treatment duration is extended to 28 days. Results: SeNPs-PDG pre-treatment delayed seizures onset and reduced duration upon PTZ injection. Additionally, SeNPs-PDG enhanced the antioxidant capacity of hippocampal tissue by activating the expression of nuclear factor erythroid 2–related factor 2 and innate antioxidants (glutathione and glutathione derivatives, in addition to superoxide dismutase and catalase) and decreasing the levels of pro-oxidants (lipoperoxidation products and nitric oxide). SeNPs-PDG administration inhibited inflammatory reactions associated with epileptic seizure development by suppressing the production and activity of glial fibrillary acidic protein and pro-inflammatory mediators, including interleukin-1 beta, tumor necrosis factor-alpha, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor kappa B. Moreover, SeNPs-PDG protected against hippocampal cell loss following PTZ injection by decreasing the levels of cytosolic cytochrome c, Bax, and caspase-3 and enhancing the expression of anti-apoptotic Bcl-2. Interestingly, SeNPs-PDG restored the PTZ-induced imbalance between excitatory and inhibitory amino acids and improved monoaminergic and cholinergic transmission. Conclusions: These promising antioxidative, anti-inflammatory, anti-apoptotic, and neuromodulatory activities indicate that SeNPs-PDG might serve as a naturally derived anticonvulsant agent.

Biology of cyclooxygenase-2: An application in depression therapeutics

Depressive Disorder is a common mood disorder or affective disorder that is dominated by depressed mood. It is characterized by a high incidence and recurrence. The onset of depression is related to genetic, biological and psychosocial factors. However, the pathogenesis is still unclear. In recent years, there has been an increasing amount of research on the inflammatory hypothesis of depression, in which cyclo-oxygen-ase 2 (COX-2), a pro-inflammatory cytokine, is closely associated with depression. A variety of chemical drugs and natural products have been found to exert therapeutic effects by modulating COX-2 levels. This paper summarizes the relationship between COX-2 and depression in terms of neuroinflammation, intestinal flora, neurotransmitters, HPA axis, mitochondrial dysfunction and hippocampal neuronal damage, which can provide a reference for further preventive control, clinical treatment and scientific research on depression.

The Role of Microglia in the Development of Neurodegenerative Diseases

Microglia play an important role in the maintenance and neuroprotection of the central nervous system (CNS) by removing pathogens, damaged neurons, and plaques. Recent observations emphasize that the promotion and development of neurodegenerative diseases (NDs) are closely related to microglial activation. In this review, we summarize the contribution of microglial activation and its associated mechanisms in NDs, such as epilepsy, Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD), based on recent observations. This review also briefly introduces experimental animal models of epilepsy, AD, PD, and HD. Thus, this review provides a better understanding of microglial functions in the development of NDs, suggesting that microglial targeting could be an effective therapeutic strategy for these diseases.

Neuroprotective Effect of Fisetin Through Suppression of IL-1R/TLR Axis and Apoptosis in Pentylenetetrazole-Induced Kindling in Mice

Epilepsy is a complex neurological disorder, characterized by frequent electrical activity in brain regions. Inflammation and apoptosis cascade activation are serious neurological sequelae during seizures. Fisetin (3, 3',4',7-tetrahydroxyflavone), a flavonoid molecule, is considered for its effective anti-inflammatory and anti-apoptotic properties. This study investigated the neuroprotective effect of fisetin on experimental epilepsy. For acute studies, increasing current electroshock (ICES) and pentylenetetrazole (PTZ)-induced seizure tests were performed to evaluate the antiseizure activity of fisetin. For the chronic study, the kindling model was established by the administration of PTZ in subconvulsive dose (25 mg/kg, i.p.). Mice were treated with fisetin (5, 10, and 20 mg/kg, p.o.) to study its probable antiseizure mechanism. The kindled mice were evaluated for seizure scores. Their hippocampus and cortex were assessed for neuronal damage, inflammation, and apoptosis. Histological alterations were observed in the hippocampus of the experimental mice. Levels of high mobility group box 1 (HMGB1), Toll-like receptor-4 (TLR-4), interleukin-1 receptor 1 (IL-1R1), interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed in the hippocampus and cortex by ELISA. The immunoreactivity and mRNA expressions of nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), cytochrome C, and caspase-3 were quantified by immunohistochemical analysis and real-time PCR. Phosphorylation ELISA was performed to evaluate AkT/mTOR (mammalian target of rapamycin) activation in the hippocampus and cortex of the kindled mice. The results showed that fisetin administration increased the seizure threshold current (STC) in the ICES test. In PTZ-induced seizures, fisetin administration increased the latency for myoclonic jerks (MJs) and generalized seizures (GSs). In the PTZ-induced kindling model, fisetin administration dose-dependently suppressed the development of kindling and the associated neuronal damage in the experimental mice. Further, fisetin administration ameliorated kindling-induced neuroinflammation as evident from decreased levels of HMGB1, TLR-4, IL-1R1, IL-1β, IL-6, and TNF-α in the hippocampus and cortex of the kindled mice. Also, the immunoreactivity and mRNA expressions of inflammatory molecules, NF-κB, and COX-2 were decreased with fisetin administration in the kindled animals. Decreased phosphorylation of the AkT/mTOR pathway was reported with fisetin administration in the hippocampus and cortex of the kindled mice. The immunoreactivity and mRNA expressions of apoptotic molecules, cytochrome C, and caspase-3 were attenuated upon fisetin administration. The findings suggest that fisetin shows a neuroprotective effect by suppressing the release of inflammatory and apoptosis molecules and attenuating histological alterations during experimental epilepsy.