Ondansetron attenuates cisplatin-induced behavioral and cognitive impairment through downregulation of NOD-like receptor inflammasome pathway.

Cisplatin is an effective and commonly used chemotherapeutic drug; however, its use is accompanied by several adverse effects, including chemobrain. Ondansetron is a 5-HT3 antagonist, commonly used in prophylactic against chemotherapy-induced nausea and vomiting. Moreover, it has been identified as a novel neuroprotective agent in different animal models. However, its protective role against chemotherapy-induced chemobrain has not been investigated. The current study was the first study that explored the potential neuroprotective effect of ondansetron against cisplatin-induced chemobrain in rats. Cisplatin (5 mg/Kg) was injected intraperitoneally, once weekly, for 4 weeks with the daily administration of ondansetron (0.5 and 1 mg/Kg). Compared to the cisplatin-treated group, ondansetron administration showed a significant decrease in the latency time and a significant increase in ambulation, rearing, and grooming frequency in the open field test (OFT). Moreover, a significant improvement in the latency time in the rotarod and passive avoidance tests, following ondansetron administration. In addition, ondansetron treatment increased the percentage of alternation in the Y-maze test. Also, ondansetron showed a remarkable enhancement in the biochemical parameters in the hippocampus. It increased the acetylcholine (Ach) level and decreased the level of the acetylcholine esterase enzyme (AchE). Ondansetron significantly decreased interleukin-1ß (Il-1ß), tumor necrosis factor-alpha (TNF-α), toll-like receptor-4 (TLR-4), NOD-like receptor-3 (NLRP3) inflammasome as well as caspase-1 and caspase-3 levels. Furthermore, ondansetron significantly decreased the levels of copper transporter-1(CTR1) expression in the hippocampus. Collectively, these findings suggest that ondansetron may exhibit a neuroprotective and therapeutic activity against cisplatin-induced chemobrain.

Protective effects of morin against depressive-like behavior prompted by chronic unpredictable mild stress in rats: Possible role of inflammasome-related pathways.

Depression is a common mental illness that possesses a noteworthy effect on patients' lives. Many theories are recently studied for their plausible involvement in depression pathogenesis, especially oxidative stress and inflammation. Morin (2',3,4',5,7-pentahydroxyflavone), a natural flavonoid, is characterized by its potent anti-inflammatory, and anti-oxidant activities. Accordingly, the aim of the current study was to investigate its potential protective anti-depressant effect in the model of chronic unpredictable mild stress (CUMS) in experimental rats. Moreover, the conceivable neuro-protective mechanisms, especially those related to the inflammasome pathway, were explored. Several, mild, unpredictable stressors were applied for 4 weeks concomitantly with the oral administration of morin (15 and 30 mg/Kg). Morin hydrate supplementations exhibited a significant improvement in the scores of the forced swimming and sucrose preference tests. In addition, it prompted a marked elevation in the ambulation, rearing as well as grooming scores of the open field test. The morin-treated groups showed a great improvement in the biochemical parameters in both the cortex and hippocampus, where it significantly elevated the serotonin, epinephrine, and norepinephrine levels. Also, it significantly increased reduced glutathione levels and decreased malondialdehyde levels. Regarding the inflammasome pathway, morin significantly decreased the tissue levels of tumor necrosis factor-alpha, toll-like receptor-4, interleukin-1beta, NOD-like receptor pyrin domain-containing protein-3, and caspase-1 levels. Morin also significantly decreased the level of the key apoptotic marker, caspase-3. In conclusion, these findings propose that morin might show a promising anti-depressant effect.