Melissa officinalis L. ameliorates oxidative stress and inflammation and upregulates Nrf2/HO-1 signaling in the hippocampus of pilocarpine-induced rats

Medicinal plants for epileptic seizures: Phytoconstituents, pharmacology and mechanisms revisited

ETHNOPHARMACOLOGICAL RELEVANCE

Epilepsy is a neurological disorder that presents with recurring and spontaneous seizures. It is prevalent worldwide, affecting up to 65 million people, with 80% of cases found in lower-income countries. Medicinal plants are commonly employed for managing and treating epilepsy and convulsions due to their unique therapeutic properties. With increasing research and clinical application, medicinal plants are gaining attention globally due to their potent therapeutic effects and fewer side effects. The development of new plant-based antiepileptic/anticonvulsant agents has become a major focus in the pharmaceutical industry.

AIM OF THE REVIEW

This article summarizes recent research on medicinal plants with reported antiepileptic/anticonvulsant effects. It provides pharmacological and molecular mechanism of action information for the crude extracts and related active constituents evaluated in preclinical research for the treatment of epilepsy and convulsions, and offers a reference for the development of future related studies in this area.

MATERIALS AND METHODS

Articles related to ethnopharmacological and antiepileptic studies on plants or natural products from 2018 to 2023 were collected from PubMed, Web of Science and Scopus, etc. using keywords related to epilepsy, medicinal plants, and natural products, etc. RESULTS: Eighty plant species are commonly used to treat epilepsy and convulsions in African and Asian countries. Sixty natural products showing potential for antiepileptic/anticonvulsant effects have been identified from these medicinal plants. These products can be broadly classified as alkaloids, coumarins, flavonoids, saponins, terpenoids and other compounds. The antiepileptic action of plant extracts and their active ingredients can be classified according to their abilities to modulate the GABAergic and glutamatergic systems, act as antioxidants, exhibit anti-neuroinflammatory effects, and provide neuroprotection. In addition, we highlight that some medicinal plants capable of pharmacologically relieving epilepsy and cognition may be therapeutically useful in the treatment of refractory epilepsy.

CONCLUSIONS

The review highlights the fact that herbal medicinal products used in traditional medicine are a valuable source of potential candidates for antiepileptic drugs. This confirms and encourages the antiepileptic/anticonvulsant activity of certain medicinal plants, which could serve as inspiration for further development. However, the aspects of structural modification and optimization, metabolism, toxicology, mechanisms, and clinical trials are not fully understood and need to be further explored.

Melissa officinalis extract palliates redox imbalance and inflammation associated with hyperthyroidism-induced liver damage by regulating Nrf-2/ Keap-1 gene expression in γ-irradiated rats

BACKGROUND

Melissa officinalis (MO) is a well-known medicinal plant species used in the treatment of several diseases; it is widely used as a vegetable, adding flavour to dishes. This study was designed to evaluate the therapeutic effect of MO Extract against hyperthyroidism induced by Eltroxin and γ-radiation.

METHODS

Hyperthyroidism was induced by injecting rats with Eltroxin (100 µg/kg/ day) for 14 days and exposure to γ-radiation (IR) (5 Gy single dose). The hyperthyroid rats were orally treated with MO extract (75 mg/kg/day) at the beginning of the second week of the Eltroxin injection and continued for another week. The levels of thyroid hormones, liver enzymes and proteins besides the impaired hepatic redox status and antioxidant parameters were measured using commercial kits. The hepatic gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein-1(Keap-1) in addition to hepatic inflammatory mediators including tumor necrosis factor-α (TNF- α), Monocyte chemoattractant protein-1 (MCP-1) and fibrogenic markers such as transforming growth factor-beta1 (TGF-β1) were determined.

RESULTS

MO Extract reversed the effect of Eltroxin + IR on rats and attenuated the thyroid hormones. Moreover, it alleviated hyperthyroidism-induced hepatic damage by inhibiting the hepatic enzymes' activities as well as enhancing the production of proteins concomitant with improving cellular redox homeostasis by attenuating the deranged redox balance and modulating the Nrf2/Keap-1 pathway. Additionally, MO Extract alleviated the inflammatory response by suppressing the TNF- α and MCP-1 and prevented hepatic fibrosis via Nrf2-mediated inhibition of the TGF-β1/Smad pathway.

CONCLUSION

Accordingly, these results might strengthen the hepatoprotective effect of MO Extract in a rat model of hyperthyroidism by regulating the Nrf-2/ Keap-1 pathway.

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.

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.

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.

Mentha piperita Oil Exerts an Antiepileptic Effect in Pilocarpine and Pentylenetetrazol-Induced Seizures in Mice

Introduction

Epilepsy is a progressive, chronic neurological disorder characterized by recurrent seizures. Peppermint (Mentha piperita L.) (MP) is one of the most commonly ingested herbal teas or tisanes with a single component.

Aim

We aimed to assess the potential antiepileptic and neuroprotective features of MP essential oil (MPO) in pilocarpine (P) and pentylenetetrazol (PTZ) models of epilepsy.

Methods

The study used eight groups of mice to assess the anticonvulsant activity of MPO in both the P and PTZ acute models in mice. P (350 mg/kg, i.p.) was given 30 minutes after MPO (1.6, 3.2, and 6.4 ml/kg, i.p.). As a positive control group, diazepam (1 mg/kg, i.p) was used. PTZ (95 mg/kg, i.p.) was given 30 minutes after MPO (6.4 ml/kg, i.p.). The first convulsion's latency time, the number of convulsions, the latency time to death, and the percentage of deaths were calculated in all groups.

Results

MPO significantly (P < 0.05) increases the first convulsion's latency time and the death's latency time. Moreover, the essential oil significantly decreases the number of convulsions and reduces the mortality rate compared to the negative control group.

Conclusion

MPO at 3.2 and 6.4 ml/kg doses can reduce the percentage and the number of convulsions and increase the latency time of both the first convulsion and death so that it can be used as a supplement in the treatment of epilepsy.