Tropisetron attenuates neuroinflammation and chronic neuropathic pain via α7nAChR activation in the spinal cord in rats

Unraveling the Interplay of 5-hydroxytryptamine-3 and N-methyl-d-aspartate Receptors in Seizure Susceptibility

BACKGROUND

Epilepsy, a prevalent neurological disorder characterized by recurrent seizures, presents significant challenges in treatment and management. This study aimed to evaluate the effect of tropisetron, a selective 5-HT3 receptor antagonist on pentylenetetrazole (PTZ) - induced seizure in mice by exploring the potential role of the NMDA receptor and inflammatory responses.

METHODS

For this purpose, seizures were induced by intravenous PTZ infusion. Tropisetron at 1-, 2-, 3-, 5-, 10- mg/kg were administered intraperitoneally 30 minutes before PTZ. To evaluate probable role of NMDA signaling, selective NMDAR antagonists, ketamine and MK-801, were injected 15 minutes before tropisetron. Also, TNF-α level of hippocampus were measured following administration of mentioned drugs in mice.

RESULTS

Our results demonstrate that tropisetron displayed a dose-dependent impact on seizure threshold, with certain doses (5 and 10 mg/kg) exhibiting anticonvulsant properties. In addition, the noncompetitive NMDAR antagonists, ketamine (1 mg/kg) and MK-801 (0.5 mg/kg), at doses that had no effect on seizure threshold, augmented the anticonvulsant effect of tropisetron (3 mg/kg). Also, tropisetron led to a reduction in hippocampal TNF-α levels, indicating its anti-inflammatory potential independent of 5-HT receptor activity.

CONCLUSION

In conclusion, we demonstrated that the anticonvulsant effect of tropisetron is mediated by the inhibition of NMDA receptors and a decline in hippocampal TNF-α level. These findings highlight a potential connection between 5-HT3 and NMDA receptors in the pharmacological treatment of inflammatory diseases, such as seizure, warranting further investigation into their combined therapeutic effects.

Effect of Prophylactic Tropisetron on Post-Operative Nausea and Vomiting in Patients Undergoing General Anesthesia: Systematic Review and Meta-Analysis with Trial Sequential Analysis

This systematic review and meta-analysis of randomized controlled trials (RCTs) with trial sequential analysis (TSA) aimed to comprehensively evaluate and compare the efficacy of the prophylactic administration of tropisetron in the prevention of the incidence of post-operative nausea and vomiting (PONV) in patients undergoing surgery under general anesthesia. This study was registered with PROSPERO (CRD42024372692). RCTs comparing the efficacy of the perioperative administration of tropisetron with that of a placebo, other anti-emetic agents, or a combination of anti-emetic injections were retrieved from the databases of Ovid-MEDLINE, Ovid-EMBASE, the Cochrane Central Register of Controlled Trials, and Google Scholar. The frequency of rescue anti-emetic use (RA) and the incidence of PON, POV, and PONV (relative risk [RR]: 0.718; 95% confidence interval [CI] 0.652-0.790; I2 = 0.0, RR: 0.587; 95% CI 0.455-0.757; I2 = 63.32, RR: 0.655; 95% CI 0.532-0.806; I2 = 49.09, and RR: 0.622; 95% CI 0.552-0.700; I2 = 0.00, respectively) in the tropisetron group were lower than those in the control group; however, the incidence of complete response (CR) was higher in the tropisetron group (RR: 1.517;95% CI 1.222-1.885; I2 = 44.14). TSA showed the cumulative Z-curve exceeded both the conventional test and trial sequential monitoring boundaries for RA, PON, POV, and PONV between the tropisetron group and the control group. Thus, the prophylactic administration of tropisetron exhibited superior efficacy in the prevention of PON, POV, and PONV. Furthermore, a lower incidence of RA and a higher incidence of CR were observed with its use.