The Effects of Adenosinergic Modulation on Cytokine Levels in a Pentylenetetrazole-Induced Generalized Tonic-Clonic Seizure Model.

OBJECTIVE: It has been suggested that the adenosinergic system and cytokines play a role in the pathogenesis of epilepsy. Although the role of the adenosinergic system in the modulation of seizure activity is well known, the mechanism of this modulation needs to be described in detail. We performed this study to determine the contribution of the proinflammatory cytokines to the generalized seizure activity during adenosine and caffeine treatment. METHODS: We induced generalized tonic-clonic seizures with the administration of 60 mg/kg pentylenetetrazole (PTZ) in male Wistar Albino rats. Adenosine (500 mg/kg) or caffeine (5 mg/kg) was administered before PTZ injection. We monitored seizure activity and then determined the TNF-α, IL-1ß, and IL-6 levels in the cortical and thalamic brain regions of rats by ELISA. RESULTS: Adenosine pretreatment significantly extended seizure latency (p < 0.05), but did not affect seizure duration and entry time to stage 4 seizure. Caffeine pretreatment did not change seizure latency and seizure duration. PTZ treatment did not change brain cytokine levels significantly (p > 0.05) compared to the control group. Whereas adenosine pretreatment decreased brain TNF-α, IL-1ß, and IL-6 levels significantly (p < 0.05), caffeine pretreatment reduced brain cytokine levels slightly but nonsignificantly (p > 0.05). CONCLUSION: Our results show that there is a clear relation between adenosinergic system and brain tissue cytokine levels. Our findings indicated that TNF-α, IL-1ß, and IL-6 participate in the pathogenesis of generalized seizures, and the inhibition of TNF-α, IL-1ß, and IL-6 with adenosinergic modulation may decrease seizure severity.

Effects of caffeine on behavioral and inflammatory changes elicited by copper in zebrafish larvae: Role of adenosine receptors.

This study investigated the effects of caffeine in the behavioral and inflammatory alterations caused by copper in zebrafish larvae, attempting to correlate these changes with the modulation of adenosine receptors. To perform a survival curve, 7dpf larvae were exposed to 10µM CuSO4, combined to different concentrations of caffeine (100µM, 500µM and 1mM) for up to 24h. The treatment with copper showed lower survival rates only when combined with 500µM and 1mM of caffeine. We selected 4 and 24h as treatment time-points. The behavior evaluation was done by analyzing the traveled distance, the number of entries in the center, and the length of permanence in the center and the periphery of the well. The exposure to 10µM CuSO4 plus 500µM caffeine at 4 and 24h changed the behavioral parameters. To study the inflammatory effects of caffeine, we assessed the PGE2 levels by using UHPLC-MS/MS, and TNF, COX-2, IL-6 and IL-10 gene expression by RT-qPCR. The expression of adenosine receptors was also evaluated with RT-qPCR. When combined to copper, caffeine altered inflammatory markers depending on the time of exposure. Adenosine receptors expression was significantly increased, especially after 4h exposure to copper and caffeine together or separately. Our results demonstrated that caffeine enhances the inflammation induced by copper by decreasing animal survival, altering inflammatory markers and promoting behavioral changes in zebrafish larvae. We also conclude that alterations in adenosine receptors are related to those effects.