Article

Tropisetron ameliorates ischemic brain injury in an embolic model of stroke.

Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran.
Brain research (Impact Factor: 2.83). 03/2011; 1392:101-9. DOI: 10.1016/j.brainres.2011.03.053
Source: PubMed

ABSTRACT Tropisetron is widely used to counteract chemotherapy-induced emesis. Evidence obtained from human and animal studies shows that tropisetron possesses anti-inflammatory properties. In this study, we assessed the effect of tropisetron on brain damage in a rat thromboembolic model of stroke. Stroke was rendered in rats by introduction of an autologous clot into the middle cerebral artery (MCA). Tropisetron (1 or 3mg/kg); m-chlorophenylbiguanide (mCPBG), a selective 5-HT(3) receptor agonist (15 mg/kg); tropisetron (3mg/kg) plus mCPBG (15 mg/kg); granisetron (3mg/kg); tacrolimus (1mg/kg); or tacrolimus (1mg/kg) plus tropisetron (3mg/kg) were administered intraperitoneally 1h prior to embolization. Behavioral scores and infarct volume as well as myeloperoxidase (MPO) activity and tumor necrosis factor-alpha (TNF-α) level were determined in the ipsilateral cortex 4h and 48 h following stroke induction. Forty-eight hours after embolization, tropisetron (1 or 3mg/kg), tropisetron (3mg/kg) plus mCPBG (15 mg/kg), tacrolimus (1mg/kg), or tacrolimus (1mg/kg) plus tropisetron (3mg/kg) significantly curtailed brain infarction, improved behavioral scores, diminished elevated tissue MPO activity, and reduced TNF-α levels compared to control group (n=6; P<0.05). mCPBG or granisetron had no effect on the mentioned parameters. Tropisetron attenuates brain damage after a thromboembolic event. Beneficial effects of tropisetron in this setting are receptor independent.

Download full-text

Full-text

Available from: Reza Rahimian, Jul 04, 2015
0 Followers
 · 
131 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: 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<0.001). Interestingly, co-administration of non-effective doses of NTX and l-NAME (1 and 0.5mg/kg, respectively) reverses epileptogenesis of H/I (P<0.001). In the same way, co-administration of non-effective doses of NTX and AG (1 and 5mg/kg, respectively), reverses epileptogenesis of H/I (P<0.001). Indeed, the histological studies performed on mice exposed to H/I confirmed our previous data. These findings suggest hyper-susceptibility to PTZ induced seizure following H/I is mediated by interaction of opioidergic, and iNOS/NO pathways. Therefore, our results identify new pharmacological targets and provide the rationale for a novel strategy to promote recovery after stroke and possibly other brain injuries. Copyright © 2014 Elsevier B.V. All rights reserved.
    11/2014; DOI:10.1016/j.ejphar.2014.11.005,
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nephrotoxicity is one of the most important complications of cisplatin, a potent chemotherapeutic agent used in the treatment of various malignancies. 5-HT3 antagonists are widely used to counteract chemotherapy-induced emesis and new studies reveal that they posses notable anti-inflammatory properties. In current study, we investigated the effects of 5-HT3 antagonists on cisplatin induced nephrotoxicity in mice. To identify the underlying mechanism of renal protection by tropisetron, we investigated the probable involvement of alpha7 nicotinic acetylcholine receptor (α7nAChR) A single injection of cisplatin (20mg/kg; i.p) induced nephrotoxicity, 5-HT3 antagonists (tropisetron, granisetron and ondansetron,) were given twice daily for 3 day (3mg/kg; i.p). Finally animals were euthanized and blood sample were collected to measure urea and creatinin level. Also kidneys were removed for histopatological examination and biochemical measurements including glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD) activity, inducible nitric oxide synthase (iNOS) expression and inflammatory cytokines. tropisetron decreased the expression of inflammatory molecules including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta ( IL-1β) and iNOS and improved histopathalogical damage and renal dysfunction. However other 5-HT3 antagonists, granisetron or ondansetron do not have elicit any effects on biochemical markers and histological damages. Since methyllycaconitine, antagonist of α7nAChR, was unable to reverse the beneficial effect of tropisetron, we concluded that this effect of tropisetron is not mediated α7nAChR.Our results showed that tropisetron treatment markedly ameliorated the experimental cisplatin induced-nephrotoxicity and this effect might be 5-HT3 receptor and α7nAChR independent.
    European Journal of Pharmacology 06/2014; 738. DOI:10.1016/j.ejphar.2014.05.050 · 2.68 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Vincristine (VCR) peripheral neuropathy is a dose-limiting side effect. Several studies have shown that tropisetron, a 5-HT3 receptor antagonist, exerts anti-inflammatory and immunomodulatory properties. Current study was designed to investigate a suppressive effect of tropisetron on VCR-induced neuropathy and whether this effect exerts through the 5-HT3 receptor or not. Neuropathy was induced in rats by administration of vincristine (0.5 mg/kg, 3 intraperitoneal injections on alternate days) and in treatment group, tropisetron (3mg/kg); m-chlorophenylbiguanide (mCPBG), a selective 5-HT3 receptor agonist (15mg/kg); tropisetron (3mg/kg) plus mCPBG (15mg/kg); granisetron, another selective 5-HT3 receptor antagonist (3mg/kg) were administered intraperitoneally 1h prior to vincristine injection. Hot plate, open field tests (total distance moved, mean velocity and percentage of total duration of the movement) and Motor Nerve Conduction Velocity (MNCV) were performed to evaluate the sensory and motor neuropathy. Further, plasma levels of tumor necrosis factor-alpha (TNF-α) and interleukin-2 (IL-2) and the level of TNF-α in sciatic nerve were assessed as well as histological examination. In only VCR-treated rats hot plate latencies were significantly increased, total distance moved, mean velocity, total duration of the movement and sciatic MNCV significantly decreased compared with control. In tropisetron and tropisetron plus mCPBG groups, one injection of tropisetron prior to each VCR injection robustly diminished TNF-α and IL-2 levels, and also prevented mixed sensory-motor neuropathy, as indicated by less mortality rate, better general conditions, behavioral and electrophysiological studies. Moreover, pathological evidence confirmed the results obtained from other findings. But granisetron and mCPBG had no significant effect on the mentioned parameters. In conclusion, these studies demonstrate that tropisetron significantly suppressed VCR-induced neuropathy and could be a neuroprotective agent for prevention of VCR-induced neuropathy via a receptor-independent pathway.
    NeuroToxicology 12/2013; 41. DOI:10.1016/j.neuro.2013.12.002 · 3.05 Impact Factor