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Aims Although approving new anticonvulsants was a major breakthrough in the field of epilepsy control, so far we have met limited success in almost one third of patients suffering from epilepsy and a definite and reliable method is yet to be found. Levosimendan demonstrated neuroprotective effects and reduced mortality in conditions in which seizure can be an etiology of death; however, the underlying neuroprotective mechanisms of levosimendan still eludes us. In the light of evidence suggesting levosimendan can be a K ATP channel opener and nitrergic pathway activator, levosimendan may exert antiseizure effects through K ATP channels and nitrergic pathway. Main methods In this study, the effects of levosimendan on seizure susceptibility was studied by PTZ-induced seizures model in mice. Key findings Administration of a single effective dose of levosimendan significantly increased seizures threshold and the nitrite level in the hippocampus and temporal cortex. Pretreatment with noneffective doses of glibenclamide (a K ATP channel blocker) and L-NAME (a non-selective NOS inhibitor) neutralize the anticonvulsant and nitrite elevating effects of levosimendan. While 7-NI (a neural NOS inhibitor) blocked the anticonvulsant effect of levosimendan, Aminoguanidine (an inducible NOS inhibitor) failed to affect the anticonvulsant effects of levosimendan. Cromakalim (a K ATP channel opener) or l -arginine (an NO precursor) augmented the anticonvulsant effects of a subeffective dose of levosimendan. Moreover, co-administration of noneffective doses of Glibenclamide and L-NAME demonstrated a synergistic effect in blocking the anticonvulsant effects of levosimendan. Significance Levosimendan has anticonvulsant effects possibly via K ATP /nNOS/NO pathway activation in the hippocampus and temporal cortex.

Cannabinoid and PPAR receptors show well established interactions in a set of physiological effects. Regarding the seizure-modulating properties of both classes of receptors, the present study aimed to evaluate the roles of the PPAR-gamma, PPAR-alpha and CB1 receptors on the anticonvulsant effects of WIN 55,212-2 (WIN, a non selective cannabinoid agonist). The clonic seizure thresholds after intravenous administration of pentylenetetrazole (PTZ) were assessed in mice weighing 23-30 g. WIN increased the seizure threshold dose dependently. Pretreatment with pioglitazone, as a PPARγ agonist, potentiated the anticonvulsant effects of WIN, while PPARγ antagonist inhibited these anticonvulsant effects partially. On the other hand PPARα antagonist reduced the anticonvulsant effects of WIN significantly. Finally the combination of CB1 antagonist and PPARα antagonist could completely block the anticonvulsant properties of WIN. Taken together, these results show for the first time that a functional interaction exists between cannabinoid and PPAR receptors in the modulation of seizure susceptibility.

Stroke is a leading cause of death, disability, and socioeconomic loss worldwide. All attempts at pharmacological reduction of the complications of stroke (e.g. post-stroke seizure, and brain׳s vulnerability to hypoxic/ischemic injury) have failed. Endogenous opioids and nitric oxide (NO) overproduction has been documented in brain hypoxia/ischemia (H/I), which can exert pro-convulsive effects. In this study, we aimed to examine the possible involvement of opioidergic and nitrergic pathways in the pathogenesis of post-stroke seizure. H/I was induced by right common carotid ligation and sham-operated mice served as controls. We demonstrated that right common carotid ligation decreases the threshold for clonic seizures induced by pentylenetetrazole (PTZ), a GABA antagonist. Furthermore, pro-convulsive effect of H/I following right common carotid ligation was blocked by naltrexone (NTX) (3mg/kg), NG-Nitro-l-arginine methyl ester (l-NAME) (10mg/kg), and aminoguanidine (AG) (100mg/kg) administration (P

Sumatriptan has been among the top choices in the management of migraine headaches. The association between migraine and epilepsy highlights the possible effect of sumatriptan on seizures. In this regard, we investigated sumatriptan effects on PTZ-induced seizures thresholds and delineated the modulatory role of 5-HT1B/D receptors and NOS/NO pathway. Our data revealed the anti-convulsant effects of lower doses of sumatriptan, and pro-convulsant effects of higher doses of sumatriptan. GR 127935, a selective 5-HT1B/D antagonist, could abolish the sumatriptan anti-convulsant effects, but it was ineffective against the sumatriptan pro-convulsant effects. Serotonin depletion by consecutive administration of p-CPA, a selective irreversible inhibitor of tryptophan hydroxylase, could not affect the anti-convulsant effects of sumatriptan. The anti-convulsant effects of sumatriptan was potentiated by L-NAME, a non-selective NOS inhibitor, 7-NI, a selective nNOS inhibitor, but not AG, an iNOS inhibitor. It was also neutralized by L-ARG, a NO precursor. The pro-convulsant effects of sumatriptan were blocked by L-NAME and AG, but not 7-NI. It was also potentiated by L-ARG. Our data revealed that anti-convulsive effects of sumatriptan is mediated by interaction between non-serotonergic 5-HT1B/D receptors and nNOS/NO pathway. Besides, the pro-convulsive effect of sumatriptan is mediated by iNOS/NO pathway independent of 5-HT1B/D receptors. For the first time, this study reported the biphasic effect of sumatriptan on an animal model of GCS and its modulatory pathways.

There are prominently similar symptoms, effectors, and commonalities in the majority of characteristics between ovarian aging and polycystic ovarian syndrome (PCOS). Despite the approved role of oxidative stress in the pathogenesis of PCOS and aging, to our knowledge, the link between the PCO(S) and aging has not been investigated yet. In this study we investigated the possible exhibition of ovarian aging phenotype in murine model of PCO induced by daily oral administration of letrozole (1 mg/kg body weight) for 21 consecutive days in the female Wistar rats. Hyperandrogenization showed irregular cycles and histopathological characteristics of PCO which was associated with a significant increase in lipid peroxidation (LPO) and reactive oxygen species (ROS) and decrease in total antioxidant capacity (TAC) in serum and ovary. Moreover, serum testosterone, insulin and tumor necrosis factor-alpha (TNF-α) levels, and ovarian matrix metalloproteinase-2 (MMP-2) were increased in PCO rats compared with healthy controls, while estradiol and progesterone diminished. Almost all of these findings are interestingly found to be common with the characteristics identified with (ovarian) aging showing that hyperandrogenism-induced PCO in rat is associated with ovarian aging-like phenotypes. To our knowledge, this is the first report that provides evidence regarding the phenomenon of aging in PCO.

Influenza virus belongs to orthomyxoviridae family. This virus is a major public health problems, with high rates of morbidity and mortality. Despite a wide range of pharmacotherapeutic choices inhibiting specific sequences of pathological process of influenza, developing more effective therapeutic options is an immediate challenge. In this paper, a comprehensively review of natural polyphenolic products used worldwide for the management of influenza infection is presented. Cellular and molecular mechanisms of the natural polyphenols on influenza infection including suppressing virus replication cycle, viral hemagglutination, viral adhesion and penetration into the host cells, also intracellular transductional signaling pathways have been discussed in detail. Based on cellular, animal, and human evidence obtained from several studies, the current paper demonstrates that natural polyphenolic compounds possess potential effects on both prevention and treatment of influenza, which can be used as adjuvant therapy with conventional chemical drugs for the management of influenza and its complications.

Histamine regulates release of neurotransmitters such as dopamine, serotonin, gamma-aminobutyric acid (GABA), glutamate and also is involved in several functions in central nervous system (CNS). It has been shown that histamine participates in disorders like seizure. It has been well documented that morphine dose-dependently induces anti or proconvulsant effects. In the current study, we firstly showed that morphine (1mg/kg) exerts anticonvulsant effects which significantly reversed by naltrexone administration. Secondly, we determined seizure threshold for H1 and H3 receptors agonists and antagonists in mouse model of pentylenetetrazole (PTZ)-induced clonic seizures. Our results showed that activation of H1 receptors by 2-(2-Pyridyl)-ethylamine exerts anticonvulsant properties while inhibition of H1 receptors by pyrilamine maleate induced proconvulsant effects. Furthermore, we showed that immepip dihydrobromide, a H3 receptor agonist, increased seizure susceptibility to PTZ whereas thioperamide, a H3 receptor antagonist increased seizure threshold. We also revealed that pretreatment with morphine potently reversed the effects of histaminergic system on seizure threshold suggesting the involvement of opioid system in alteration of seizure threshold by histaminergic drugs.

Aim Aluminum phosphide (AlP) is a widely used fumigant and rodenticide. While AlP ingestion leads to high mortality, its exact mechanism of action is unclear. There are ample evidences suggesting cardioprotective effects of triiodothyronine (T3). In this study, we aimed to examine the potential of T3 in the protection of a rat model of AlP induced cardiotoxicity. Main methods In order to induce AlP intoxication animals were intoxicated with AlP (12 mg/kg; LD50) by gavage. In treatment groups, T3 (1, 2 and 3 μg/kg) was administered intra-peritoneally 30 min after AlP administration. Animals were connected to the electronic cardiovascular monitoring device simultaneously after T3 administration. Then, electrocardiogram (ECG), blood pressure (BP), and heart rate (HR) were monitored for 180 min. Additionally, 24 h after AlP intoxication, rats were deceased and the hearts were dissected out for evaluation of oxidative stress, cardiac mitochondrial function (complexes I, II and IV), ATP/ADP ratio, caspases 3 & 9, and apoptosis by flow cytometry. Key findings The results demonstrated that AlP intoxication causes cardiac toxicity presenting with changes in ECG patterns such as decrement of HR, BP and abnormal QRS complexes, QTc and ST height. T3 at a dose of 3 μg/kg significantly improved ECG and also oxidative stress parameters. Furthermore, T3 administration could increase mitochondrial function and ATP levels within the cardiac cells. In addition, administration of T3 showed a reduction in apoptosis through diminishing the caspase activities and improving cell viability. Significance Overall, the present data demonstrate the beneficial effects of T3 in cardiotoxicity of AlP.

Chronic low-grade inflammation and oxidative stress (OS) appear to be two main pathways involved in the pathogenesis of polycystic ovary (PCO) syndrome. Therefore, targeting these pathways by means of anticytokine and antioxidant agents might be a therapeutic alternative approach to the current treatments of PCO syndrome. In this study, we investigated the protective effects of pentoxifylline (PTX), a drug with antioxidant and anti–tumor necrosis factor alpha (TNF-α) properties, in hyperandrogenism-induced PCO rats. The inflammatory and OS responses and their connections with ovarian functionality in induced PCO rats were investigated through ovarian histopathologic examination and a series of biochemical measurements including serum estradiol, progesterone, testosterone, insulin, and TNF-α, ovarian and serum lipid peroxidation, total antioxidant power, and reactive oxygen species. Experimental PCO was induced in rats by oral administration of letrozole (1 mg/kg body weight) for 21 consecutive days. In a different group, PTX was administrated orally (50 mg/kg/d) for 21 days simultaneous with letrozole to assess its potential protective effects. The letrozole-induced PCOs were characterized by irregular cycles, high incidence of subcapsular ovarian cysts with diminished or scant granulosa cell layers, increased number of atretic preantral and antral follicles, and absence of CL. In addition, the letrozole-induced PCO rats exhibited notable increase in lipid peroxidation and reactive oxygen species of serum and ovary, serum testosterone, insulin, and TNF-α and significant decline in total antioxidant power, serum estradiol, and serum progesterone. Our results indicated that all the identified pathologic parameters and biochemical characteristics in letrozole-induced PCO rats in this study were preserved close to normal levels by simultaneous PTX treatments. Present results demonstrate that there is a direct connection between ovarian dysfunction and increased OS and inflammation in PCO. For the first time, the beneficial effects of PTX as a powerful antioxidant and TNF-α blocker in hyperandrogenism-induced PCO are reported.

Thalidomide is an old glutamic acid derivative which was initially used as a sedative medication but withdrawn from the market due to the high incidence of teratogenicity. Recently, it has reemerged because of its potential for counteracting number of diseases, including neurodegenerative disorders. Other than the antiemetic and hypnotic aspects, thalidomide exerts some anticonvulsant properties in experimental settings. However, the underlying mechanisms of thalidomide actions are not fully realized yet. Some investigations revealed that thalidomide could elicit immunomodulatory or neuromodulatory properties by affecting different targets, including cytokines (such as TNF α), neurotransmitters, and nitric oxide (NO). In this regard, we used a model of clonic seizure induced by pentylenetetrazole (PTZ) in male NMRI mice to investigate whether the anticonvulsant effect of thalidomide is affected through modulation of the l-arginine-nitric oxide pathway or not. Injection of a single effective dose of thalidomide (10 mg/kg, i.p. or higher) significantly increased the seizure threshold (P0.05). On the one hand, pretreatment with low and per se noneffective dose of l-arginine [NO precursor] (10, 30 and 60 mg/kg) prevented the anticonvulsant effect of thalidomide. On the other hand, NOS inhibitors [l-NAME and 7-NI] augmented the anticonvulsant effect of a subeffective dose of thalidomide (1 and 5 mg/kg, i.p.) at relatively low doses. Meanwhile, several doses of aminoguanidine [an inducible NOS inhibitor] (20, 50 and 100 mg/kg) failed to alter the anticonvulsant effect of thalidomide significantly. In summary, our findings demonstrated that the l-arginine-nitric oxide pathway can be involved in the anticonvulsant properties of thalidomide, and the role of constitutive nNOS is prominent in the reported neuroprotective feature.

The interaction between the immune and nervous systems suggests invaluable mechanisms for several pathological conditions, especially neurodegenerative disorders. Multiple sclerosis (MS) is a potentially disabling chronic autoimmune disease, characterized by chronic inflammation and neurodegenerative pathology of the central nervous system. Toll-like receptors (TLRs) are an important family of receptors involved in host defense and in recognition of invading pathogens. The role of TLRs in the pathogenesis of autoimmune disorders such as MS is only starting to be uncovered. Recent studies suggest an ameliorative role of TLR3 and a detrimental role of other TLRs in the onset and progression of MS and experimental autoimmune encephalomyelitis, a murine model of MS. Thus, modulating TLRs can represent an innovative immunotherapeutic approach in MS therapy. This article outlines the role of these TLRs in MS, also discussing TLR-targeted agonist or antagonists that could be used in the different stages of the disease.