Proconvulsant effects of Nepeta menthoides hydro alcoholic extract in different seizure tests: behavioral and biochemical studies

Evaluation of Cytotoxic and Antioxidant Potential of Green-Synthesized Silver and Gold Nanoparticles From Nepeta leucophylla Benth

In the present study, silver (AgNPs) and gold (AuNPs) nanoparticles (NPs) have been prepared using the ethanolic extract of Nepeta leucophylla (NLe). This plant was considered owing to its richness in natural polyphenols and antioxidants that are well known for their reducing potential. Different techniques, such as UV (ultraviolet-visible spectrophotometer), FTIR (Fourier transform infrared radiation), and XRD (X-ray diffraction), were utilized for the characterization of NPs. The UV absorption peak was observed at 434 and 535 nm for NLe-AgNPs and NLe-AuNPs, respectively. FTIR suggested about the possible classes of biomolecules involved in the formation of metal NPs. XRD pattern confirmed the crystalline structure of gold and silver NPs and validated that the crystal structure under consideration is a face-centered cubic (FCC) pattern. High-resolution transmission electron microscopy (HR-TEM) images revealed that the NLe-AgNPs and NLe-AuNPs NPs were spherical in shape, with average diameter of 11.4 and 7.8 nm, respectively. The antioxidant potential was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, which revealed that NLe exhibited the highest antioxidant potential (79.37%) compared to synthesized metal NPs. Further, cytotoxic potential was evaluated using MTT assay against Hep G2 cell lines. The IC50 values were determined to be 5.97 µg/mL for NLe, 12.31 µg/mL for NLe-AgNPs, and 34.58 µg/mL for NLe-AuNPs, demonstrating their effectiveness in inhibiting cancer cell proliferation. The present results revealed that NLe may play a promising role in the cure of different deteriorative diseases. In future, more detailed studies based on animal model may be useful to support the present results and to evaluate further health benefits of NLe.

Anticonvulsant effects of ivermectin on pentylenetetrazole- and maximal electroshock-induced seizures in mice: the role of GABAergic system and KATP channels

INTRODUCTION

Ivermectin (IVM) is an antiparasitic medicine that exerts its function through glutamate-gated chloride channels and GABAA receptors predominantly. There is paucity of information on anti-seizure activity of IVM. Moreover, the probable pharmacological mechanisms underlying this phenomenon have not been identified.

MATERIALS AND METHODS

In this study, pentylenetetrazole (PTZ)-induced clonic seizures and maximal electroshock (MES)-induced tonic-clonic seizure models, respectively in mice was utilized to inquire whether IVM could alter clonic seizure threshold (CST) and seizure susceptibility. To assess the underlying mechanism behind the anti-seizure activity of IVM, we used positive and negative allosteric modulators of GABAA (diazepam and flumazenil, respectively) as well as KATP channel opener and closer (cromakalim and glibenclamide, respectively). Data are provided as mean ± S.E.M. After the performance of the variance homogeneity test, a one-way and two-way analysis of variance was used. Fisher's exact test was performed in case of MES. P-value less than 0.05 considered statistically significant.

RESULTS

and Discussion: Our data showed that IVM (0.5, 1, 5, and 10 mg/kg, i.p.) increased CST. Furthermore, flumazenil 0.25 mg/kg, i.p. and glibenclamide 1 mg/kg, i.p., could inhibit the anticonvulsant effects of IVM. Supplementary, an ineffective dose of diazepam 0.02 mg/kg, i.p. or cromakalim 10 μg/kg, i.p. were able to enhance the anticonvulsant effects of IVM. Besides, we figure out that the IVM (1 and 5 mg/kg, i.p.) could delay the onset of first clonic seizure and also might decrease the frequency of clonic seizures induced by PTZ (85 mg/kg, i.p.). Finally, IVM could prevent the incidence and death in MES-induced tonic-clonic seizures.

CONCLUSION

Based on the obtained results, it can be concluded that IVM may exert anticonvulsant effects against PTZ- and MES-induced seizures in mice that might be mediated by GABAA receptors and KATP channels.

The Role of 5-HT1A Receptors and Neuronal Nitric Oxide Synthase in a Seizur Induced Kindling Model in Rats

BACKGROUND AND OBJECTIVE

Dentate gyrus (DG) has a high density of 5-HT1A receptors. It has neural nitric oxide synthase (nNOS), which is involved in neural excitability. The purpose of this study was to investigate the role of 5-HT1A receptors and nNOS of DG in perforant path kindling model of epilepsy.

MATERIAL AND METHODS

To achieve this purpose, a receptor antagonist (WAY100635, 0.1 mg/kg, intracerebroventricular, i.c.v) and neuronal nitric oxide synthase inhibitor (7-NI, 15 mg/kg, intraperitoneal, i.p.) were injected during kindling aquisition. Adult male Wistar rats (280 ± 20 g) were used in this study Animals were kindled through the daily administration of brief electrical stimulations (10 stimulations per day) to the perforant pathway. Field potential recordings were performed for 20 min in DG beforehand. Additionally, glial fibrillary acidic protein (GFAP) expression rate in the DG was determined using immunohistochemistry as a highly specific marker for glia.

RESULTS

WAY100635 (0.1 mg/kg) significantly attenuated the kindling threshold compared to the kindled + vehicle group (P < 0.001). The co-administration of WAY100635 with 7-NI, exerted a significant anticonvulsive effect. Furthermore, the slope of field Excitatory Post Synaptic Potentials (fEPSP) at the end of 10 days in the kindled + 7-NI + WAY100635 group was significantly lower than in the kindled + vehicle group (P < 0.001). Furthermore, immunohistochemistry showed that the density of GAFP⁺ cells in the kindled + 7-NI + WAY100635 group was significantly higher than in the kindled + vehicle group (P < 0.001).

CONCLUSION

Our data demonstrate that antagonists of 5-HT1A receptors have proconvulsive effects and that astrocyte cells are involved in this process, while nNOS has an inhibitory effect on neuronal excitability.