Expression of selected long non-coding RNAs in gastric cancer cells treated with coumarin: Possible mechanisms for anti-cancer activity.

Long non-coding RNAs (lncRNAs) can be utilized as prognostic indicators of gastric cancer since they can affect several cancer-related processes. Coumarin is a natural product with some useful anti-cancer properties. Here, we measured the expression of selected lncRNAs (RuPAR, SNHG6, CASC11, and their targets, miR-340-5p, p21, E-cadherin, and CDK1) in AGS gastric cancer cells treated with coumarin. MTT test has been utilized for assessing the AGS cells' cell viability after exposure to coumarin. The expression of the lncRNAs (RuPAR, SNHG6, and CASC11) and miR-340-5p was evaluated via qRT-PCR. Western blot analysis has been utilized to determine changes in p21, E-cadherin, and CDK1 expression. Coumarin decreased AGS viability in a dose-dependent manner. The coumarin treated cells had lower levels of the mRNAs known to be targets of lncRNAs SNHG6 and CASC11 compared to control. Additionally, the coumarin group had increased levels of lncRNA RuPAR expression when compared with the control group. Some lncRNA targets, including p21, E-cadherin, and CDK1, showed lower expression in the coumarin group compared to the control by Western blotting. Coumarin could be a promising pharmacological candidate to be included in gastric cancer treatment regimens because it modulates lncRNAs and their targets.

Protection against Morphine-Induced Inhibitory Avoidance Memory Impairment in Rat by Curcumin: Possible Role of Nitric Oxide/ cAMP-Response Element Binding Protein Pathway.

Background: Although a substantial body of research suggests curcumin (CUR) has the preventive potential in memory impairment, the mechanism by which CUR prevents memory loss is still being investigated. This study employs an inhibitory avoidance (IA) model to investigate whether CUR can prevent morphine (Mor)-induced memory impairment as well as the possible role of cAMP-response element binding (CREB) protein, and nitric oxide (NO) signaling in this mechanism. Methods: This experimental study was conducted at the Animal Lab of the Physiology Research Center, Kashan University of Medical Sciences (Kashan, Iran) in 2018. Forty rats were randomly divided into four groups: control, CUR (pretreatment gavage of CUR [10 mg/Kg] for 35 days), Mor (7.5 mg/Kg, i.p.), and CUR+Mor (n=10 per group). Following the evaluation of the IA memory and locomotor activity of the animals, the CREB protein expression in the hippocampus and NO metabolites (NOx) level in the brain tissue were also investigated. The data were analyzed using Sigmaplot software (version 14.0) by using the ANOVA, Kruskal-Wallis, Holm-Sidak, and Dunn's post hoc tests. P<0.05 was considered to be statistically significant. Results: In the Mor group, the IA memory of the rats was significantly impaired (P=0.001). CUR prevented the Mor-induced IA memory impairment (P=0.075). While the Mor treatment decreased the phosphorylated CREB (p-CREB) expression, the CUR+Mor cotreatment increased p-CREB expression (P=0.010). Nevertheless, the Mor treatment increased the total CREB expression (P=0.010). The NOx concentration in the brain tissue was decreased following the Mor treatment (P=0.500) but increased after the CUR+Mor cotreatment (P=0.001). Conclusion: The present findings suggest that CUR prevents the memory impairment of rats, possibly through NO and its downstream CREB signaling.

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

In Iran, both Nepeta menthoides - the endemic species of Nepeta genus - and Lavandula officinalis are known as Ustukhuddoos and used widely as medicinal herbs. In Iranian traditional medicine, Ustukhuddoos has been recommended for several neuronal diseases including depression and epilepsy. While the antiepileptic effects of Lavandula officinalis have been investigated in a number of studies, no reports are available taking into account the effect of Nepeta menthoides on epilepsy. Since convulsion is an important side effect of some medicinal plants, a thorough study of the effects of Nepeta menthoides on epilepsy seems necessary. This study was designed to investigate the potential anti- or pro-convulsant activity of Nepeta menthoides and its effects on oxidative stress markers. Since an herbal medicine showed opposite effects in two animal models of epilepsy in our laboratory, authers decided to study Nepeta effects through several seizure tests including the intravenous pentylenetetrazol (i.v. PTZ) infusion, the maximal electroshock (MES), acute PTZ and PTZ-kindling tests. These seizure models are generally used for screening pro- or anti-epileptic drugs. Nepeta menthoides (400 mg/kg) significantly reduced the dose of PTZ necessary for clonus seizure induction. Combining either phenytoin (Phen) or Valproate (Val) with Nepeta decreased their antiepileptic effects. Therefore, Nepeta menthoides not only failed to prevent the seizures but also increased sensitivity to them. Nepeta raised brain NO levels in different seizure tests. It seems there is a relation between NO elevation by Nepeta and increased sensitivity to seizures that should be investigated later.

Effect of dextromethorphan/quinidine on pentylenetetrazole- induced clonic and tonic seizure thresholds in mice.

INTRODUCTION: This study aimed to investigate the effects of dextromethorphan (DM) or dextromethorphan/quinidine (DM/Q) against pentylenetetrazole (PTZ)- induced seizure threshold in mice and the probable involvement of N-methyl d-aspartate (NMDA), sigma-1 and serotonin 1A (5-HT1A) receptors. MATERIAL AND METHODS: NMRI male mice (25-30 g) received quinidine (10, 20, and 30 mg/kg), DM (5, 10, 25, and 50 mg/kg) or DM/Q (10/20, 25/20, and 50/20 mg/kg), 30 min before the infusion of PTZ. ketamine (1 and 5 mg/kg), BD-1047 (2.5 and 5 mg/kg) or WAY-100635 (0.5 and 1 mg/kg) were administrated as pre-treatment 30 min before the selected dose of DM/Q. Seizures were induced by intravenous PTZ infusion. All data were presented as means ± S.E.M. One-way ANOVA test was used to determine statistical significance (p < 0.05). RESULTS: DM (25 and 50 mg/kg) significantly increased PTZ- induced seizure threshold. DM/Q at doses of 10/20 and 25/20 mg/kg had anticonvulsant effect, while at a dose of 50/20 mg/kg attenuated anticonvulsant effect of DM 50 mg/kg. Ketamine (5 mg/kg) or WAY-100635 (1 mg/kg) potentiated, while BD-1047 (2.5 and 5 mg/kg) attenuated the anticonvulsant effect of DM/Q 10/20 mg/kg. CONCLUSION: The results of present study demonstrate that combination with quinidine potentiates the anticonvulsant effect of DM at lower doses, while attenuates it at higher dose. Meanwhile, the effects of DM/Q on seizure activity likely involve an interaction with NMDA, the sigma-1 or the 5-HT1A receptor which may be secondary to the elevation of DM levels.

Cardioprotective effects of cerebrolysin on the lesion severity and inflammatory factors in a rat model of isoproterenol-induced myocardial injury.

BACKGROUND: Myocardial injury (MI) is an important heart condition and a major cause of morbidity and mortality worldwide. The current study was designed to investigate the cardioprotective effects of cerebrolysin (CLY) on the lesion severity and inflammatory factors in male rats using isoproterenol (ISO)-induced MI model. METHODS: MI in rats was induced by injecting ISO (100 mg/kg) subcutaneously (sc) on the first 2 days. Then, CLY (5 ml/kg) was injected intraperitoneally (ip) post-treatment for 7 days. On the 3rd day, creatine phosphokinase (CK-MB) and cardiac troponin I (cTnI) levels in serum and, on the 10th day, the TNF-α and IL6 levels in serum and heart tissue were measured by enzyme-linked immunosorbent assay (ELISA). Finally, the heart of each rat was dissected out and stained for histopathological examination. RESULTS: On the 3rd day, the serum CK-MB and cTnI levels in the ISO and CLY + ISO groups were significantly increased compared with that in the control and CLY + Sal groups. One week after the induction of MI, ISO administration showed a significant increase in the serum level of TNF-α in the ISO group compared with that in the control and CLY + Sal groups. Also, our findings showed only a moderate reduction in inflammatory cell infiltration and extent of edema following CLY treatment in the CLY + ISO group. Also, CLY induced vascular proliferation in the heart tissue. CONCLUSIONS: We conclude that the severity of pathological changes induced by ISO in MI (e.g. inflammation and edema) can be limited by CLY treatment.

Anticonvulsant effects of thiamine on pentylenetetrazole-induced seizure in mice.

OBJECTIVES: Thiamine serves as a cofactor for several enzymes involved in brain function and neurotransmitters biosynthesis. Thiamine-dependent enzymes are important for oxidant stress defenses. Several studies have reported that thiamine deficiency in the central nervous system reduces seizure threshold. The present study was designed to investigate the effect of acute and chronic administration of thiamine alone and in combination with sub-effective dose of diazepam on pentylenetetrazole (PTZ)-induced tonic-clonic seizures in mice. METHODS: Animals were randomly divided into control and experimental groups. In experimental groups, thiamine (50, 100, and 200 mg/kg i.p.) was administered acutely or chronically (once a day, for 14 days). Slow intravenous infusion of PTZ (5 mg/ml) by infusion pump with a constant rate (0.3 ml/min) was used to induce clonic and tonic seizures. RESULTS: Acute injection of thiamine (50, 100, and 200 mg/kg i.p.) did not increase seizure threshold significantly, but chronic treatment with thiamine (200 mg/kg i.p.) increases the clonic and tonic seizure threshold. Moreover, the combination of sub-effective dose of thiamine (100 mg/kg) and diazepam (0.1 mg/kg) significantly increased seizure threshold and enhanced the anticonvulsant effect of diazepam at ineffective dose (0.1 mg/kg). DISCUSSION: Our results suggest that thiamine can be considered as a potential add-on treatment in deficient and non-deficient thiamine epileptic patients. Co-administration of this vitamin with classic antiepileptics to decrease the required doses of regular drugs may be recommended. Nevertheless, more well-designed studies may be executed to provide further accurate information.

Effect of acute caffeine administration on PTZ-induced seizure threshold in mice: Involvement of adenosine receptors and NO-cGMP signaling pathway.

PURPOSE: Caffeine is a non-selective antagonist of A1 and A2A adenosine receptors (ARs). In this regard, nitric oxide (NO) is partly involved in the central effects of caffeine. In this study, we examined the effect of acute caffeine administration on pentylenetetrazole (PTZ)-induced seizure threshold by focusing on A1Rs, A2ARs, and NO-cGMP signaling pathway. METHODS: NMRI male mice (25-30 g) received caffeine (5, 50, and 100 mg/kg) alone, whereas 8-CPT (1 and 5 mg/kg, a selective A1Rs antagonist), SCH-442416 (5 and 10 mg/kg, a selective A2ARs antagonist) or sildenafil (5 and 10 mg/kg, a phosphodiesterase 5 inhibitor) were administrated alone or as pre-treatment before caffeine. Seizure threshold was assessed by intravenous infusion of PTZ. Nitric oxide metabolites (NOx) were measured with the Griess method. RESULTS: When administrated alone, caffeine (5 and 50 mg/kg) and 8-CPT (1 and 5 mg/kg) significantly decreased seizure threshold, while 100 mg/kg of caffeine, SCH-442416 or sildenafil did not change it. Only pre-treatment with SCH-442416 (5 and 10 mg/kg) or sildenafil (5 and 10 mg/kg) before 100 mg/kg of caffeine significantly decreased seizure threshold. Moreover, NOx levels significantly decreased following alone administration of caffeine (100 mg/kg) or 8-CPT (5 mg/kg). CONCLUSION: The results of present study showed that 5 and 50 mg/kg of caffeine had a proconvulsant effect but caffeine at a dose of 100 mg/kg had no effect on seizure threshold. In addition, it seems that the effect caffeine on seizure threshold is partly mediated through ARs or modulation of the NO-cGMP signaling pathway.

The effect of sertraline and 8-OH-DPAT on the PTZ_induced seizure threshold: Role of the nitrergic system.

PURPOSE: Serotonin is a key regulatory neurotransmitter in the CNS which plays an important role in seizure through different receptors, especially the 5HT1A subtype. The role of sertraline through the 5HT1A receptor and nitric oxide interaction on the PTZ-induced seizure threshold was investigated in this study. METHOD: In this study, 70 white male mice were randomly divided into 10 groups including intact control, sham-control and eight experimental groups which received sertraline, 8-OH-DPAT, WAY100635, WAY100635+sertraline, WAY100635+8-OH-DPAT, L-NAME, L-NAME+sertraline and L-NAME+8-OH-DPAT. After 14days of treatment in different groups, the PTZ-induced seizure threshold was assessed and the measurement of nitric oxide metabolites in the brain tissue was done with the Greiss method. RESULTS: The seizure threshold was significantly increased in the sertraline and 8OH-DPAT receiving groups compared to the sham group (P<0.001). In the presence of WAY100635, the effect of both sertraline and 8-OH-DPAT in raising the seizure threshold was more prominent (P<0.001) but on the other hand, in the presence of L-NAME, an increase in the anticonvulsant effect of 8-OH-DPAT was observed, while L-NAME alone had no effect on the seizure threshold (P<0.001). The NOX concentration was significantly decreased in the 8-OH-DPAT_treated group (P<0.01), while the WAY100657 reversed it and the combination of 8-OH-DPAT with L-NAME reduced the NOX levels (P<0.001). CONCLUSIONS: These findings support the anticonvulsant effect of SSRIs and selective 5HT1A receptors, although serotonin receptors other than 5HT1A subtype may be involved and also it is probable that some anticonvulsant effects of the sertraline and 8-OH-DPAT are through the modulation of nitrergic system.

Lithium attenuates pain-related behavior in a rat model of neuropathic pain: possible involvement of opioid system.

Lithium is a major drug for bipolar disorder and mania. Recently, many studies have shown the neuroprotective effect of lithium in different models of neurodegenerative diseases. The present study was carried out to examine the effect of lithium in a rat model of neuropathic pain induced by partial sciatic nerve ligation and the possible role of opioid system in this effect. To do so, animals received acute injection of saline, lithium (5, 10 and 15 mg/kg,) and naloxone (1 mg/kg) or the combination of naloxone (1 mg/kg) with lithium (10 mg/kg) intraperitoneally on the testing days. Thermal hyperalgesia, mechanical and cold allodynia were measured on the days 3, 5, 7, 10 and 14 after surgery. Lithium decreased thermal hyperalgesia scores with dose of 5, 10 and 15 mg/kg and cold and mechanical allodynia scores with dose of 10 and 15 mg/kg, significantly. The opioid antagonist naloxone prevented the effect of lithium on thermal hyperalgesia and mechanical allodynia while it did not show any effect on the acetone-induced cold allodynia. Our results suggest that lithium can be considered as a therapeutic potential for the treatment of some aspects of neuropathic pain and that the opioid system may be involved in the lithium-induced attenuation of thermal hyperalgesia and mechanical allodynia.

Effects of short-term and subchronic lead poisoning on nitric oxide metabolites and vascular responsiveness in rat.

Chronic exposure to low levels of lead results in sustained hypertension in humans and experimental animals. The mechanism of lead-induced hypertension remains unclear. We investigated the short-term (4 and 8 weeks) and subchronic (12 weeks) effects of lead treatment on responsiveness of vascular adrenergic system and level of nitric oxide metabolites, that is, total nitrates and nitrites (NOx). Male Sprague-Dawley rats were treated with lead acetate (100 ppm in drinking water) for 12 weeks. Short-term lead administration resulted in marked elevation of blood pressure accompanied by significant reduction in serum NOx levels. In contrast, after subchronic lead administration the trend of decrease in NOx levels somehow reversed despite further increase in blood pressure. Both short-term and subchronic lead administration resulted in significant differences in vascular reactivity with respect to either vasoconstrictor (phenylephrine and clonidine) or vasodilator (isoproterenol) agents. We conclude that vascular adrenergic system and nitric oxide pathway change in short-term and subchronic phases of lead poisoning.