Embelin ameliorates cognitive dysfunction and progression of kindling in pentylenetetrazol-induced kindling in mice by attenuating brain inflammation

Astragalus polysaccharides ameliorate epileptogenesis, cognitive impairment, and neuroinflammation in a pentylenetetrazole-induced kindling mouse model

Background: Epilepsy is a prevalent neurological disease where neuroinflammation plays a significant role in epileptogenesis. Recent studies have suggested that Astragalus polysaccharides (APS) have anti-inflammatory properties, which make them a potential candidate for neuroprotection against central nervous system disease. Nevertheless, the extent of their effectiveness in treating epilepsy remains enigmatic. Therefore, our study aims to investigate the potential of APS to mitigate epileptogenesis and its comorbidities by exploring its underlying mechanism. Methods: Initially, we employed pentylenetetrazol-induced seizure mice to validate APS' effectiveness. Subsequently, we employed network pharmacology analysis to probe the possible targets and signaling pathways of APS in treating epilepsy. Ultimately, we verified the key targets and signaling pathways experimentally, predicting their mechanisms of action. Results: APS have been observed to disturb the acquisition process of kindling, leading to reduced seizure scores and a lower incidence of complete kindling. Moreover, APS has been found to improve cognitive impairments and prevent hippocampal neuronal damage during the pentylenetetrazole (PTZ)-kindling process. Subsequent network pharmacology analysis revealed that APS potentially exerted their anti-epileptic effects by targeting cytokine and toll-like receptor 4/nuclear factor kappa B (TLR4/NF-κB) signaling pathways. Finally, experimental findings showed that APS efficiently inhibited the activation of astrocytes and reduced the release of pro-inflammatory mediators, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). In addition, APS impeded the activation of the TLR4/NF-κB signaling cascade in a PTZ-induced kindling mouse model. Conclusion: The outcomes of our study suggest that APS exerts an impact on epileptogenesis and mitigates cognitive impairment by impeding neuroinflammatory processes. The mechanism underlying these observations may be attributed to the modulation of the TLR4/NF-κB signaling pathway, resulting in a reduction of the release of inflammatory mediators. These findings partially agree with the predictions derived from network pharmacology analyses. As such, APS represents a potentially innovative and encouraging adjunct therapeutic option for epileptogenesis and cognitive deficit.

Mechanistic Study on the Possible Role of Embelin in Treating Neurodegenerative Disorders

Embelin (EMB) (2,5-Dihydroxy-3-undecyl-1,4-benzoquinone) is a natural benzoquinone extracted mainly from Embelia ribes (ER) and appear as vivid orange dots beneath the fruit's pericarp. It is being used to treat various diseases since ancient times in India. It has been ascribed as one of the 32 ayurvedic drugs of national importance in the National Medicinal Plant Board set up by the Government of India under the Ministry of Indian System of Medicine and Homeopathy. Embelin prevents neuronal oxidative damage by decreasing the peroxidation of lipids. Along with having antioxidant properties, it also prevents the production of amyloid-protein-related fibrils and blocks the progression of inflammatory cascades. Due to embelin's ability to cross the blood-brain barrier, its neuroprotective effects have been studied in the past using in vitro models of neuronal disorders such as convulsion and epilepsy, Alzheimer's disease, anxiety and depression, traumatic brain injury, cerebral ischemia, Huntington's disease, and multiple sclerosis. In addition to its neuroprotective effects, its role as an antitubercular, anti-cancer, antioxidant, astringent, anti-inflammatory, anti-bacterial, contraceptive, carminative, diuretic, and anthelmintic agent has also been studied. With docking studies and recent advancements in formulations of embelin including polyethylene and embelin micelles and embelin noisome preparations, embelin can prove to be a promising compound for its therapeutic actions in a wide range of diseases and disorders. The findings of docking studies suggest the binding ability of embelin to be similar to the standard drug in their respective disorders. In this review and docking analysis, we bring an outline of scientific evidence concerning the neuroprotective actions of embelin, still, further research is required for its prospective as a chief compound in clinical approaches.

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.

PTZ kindling model for epileptogenesis, refractory epilepsy, and associated comorbidities: relevance and reliability

Pentylenetetrazole (PTZ)-induced seizure is one of the gold standard mouse models for rapid evaluation of novel anticonvulsants. Synchronically, PTZ induced kindling in mice is also a simple and well accepted model of chronic epilepsy. PTZ kindling has been explored for studying epileptogenesis, epilepsy-associated comorbidities, and refractory epilepsy. This review summarizes the potential of PTZ kindling in mice and its modifications for its face, construct, and predictive validity to screen antiepileptogenic drugs, combined or add on novel and safe therapies for treatment of epilepsy-associated depression and cognitive impairment as well as effective interventions for pharmacoresistant epilepsy.

Baicalin Rescues Cognitive Dysfunction, Mitigates Neurodegeneration, and Exerts Anti-Epileptic Effects Through Activating TLR4/MYD88/Caspase-3 Pathway in Rats

Purpose

This study aims to evaluate the beneficial effects of anti-epileptic mechanisms of baicalin (BA) on cognitive dysfunction and neurodegeneration in pentylenetetrazol (PTZ)-induced epileptic rats.

Methods

First, PTZ-induced epileptic rats were administered intraperitoneally a sub-convulsive dose of PTZ (40 mg/kg) daily, and the seizure susceptibility (the degree of seizures and latency) was evaluated using Racine’s criterion. Then, classical behavioral experiments were performed to test whether BA ameliorated cognitive dysfunction. Neurodegeneration was assessed using Fluoro Jade-B (FJB), and NeuN staining was used to determine whether BA offered a neuroprotective role. After BA had been proven to possess anti-epileptic effects, its possible mechanisms were analyzed through network pharmacology. Finally, the key targets for predictive mechanisms were experimentally verified.

Results

The epileptic model was successfully established, and BA had anti-epileptic effects. Epileptic rats displayed significant cognitive dysfunction, and BA markedly ameliorated cognitive dysfunction. Further, we also discovered that BA treatment mitigated neurodegeneration of the hippocampus CA3 regions, thereby ameliorated cognitive dysfunction of epileptic rats. Subsequent network pharmacology analysis was implemented to reveal a possible mechanism of BA in the anti-epileptic process and the TLR4/MYD88/Caspase-3 pathway was predicted. Finally, experimental studies showed that BA exerted an anti-epileptic effect by activating the TLR4/MYD88/Caspase-3 pathway in PTZ-induced epileptic rats.

Conclusion

In conclusion, BA had a protective effect against PTZ-induced seizures. BA improved cognitive dysfunction and exerted a neuroprotective action. The anti-epileptic effects of BA may be potentially through activation of the TLR4/MYD88/Caspase-3 pathway.