No abstract

Epilepsy is one of the most common neurologic disorders. Though there are effective medications available to reduce the symptoms of the disease, their side effects have limited their usage. Palmitoylethanolamide (PEA) has been shown to attenuate seizure in different animal models. The objective of the current study was to evaluate the role of CB1 and CB2 receptors in this attenuation. Male wistar rats were used for the current experiment. PTZ was injected to induce chemical kindling in animals. After verification of kindling in animals, treatment was performed with PEA, AM251 and AM630 in different groups. Latency to induce seizure, seizure stages and latency and duration of fifth stage of seizure was recorded for each animal. Injection of PTZ led to seizure in the animals. Pretreatment with PEA increased the latency to initiate seizures and reduced the duration of seizure. Pretreatment with different dosages of AM251 had contrary effects so that at lower doses they increased the seizure in animals but at higher doses led to the attenuation of seizure. AM630 increased seizures in a dose dependent manner. Combination of the antagonists increased the seizure parameters and attenuated the effect of PEA on seizure. PEA attenuated the PTZ-induced seizures and pretreatment with CB1 and CB2 antagonists diminished this effect of PEA, but still PEA was effective, which might be attributed to the contribution of other receptors in PEA anti-epileptic properties. Findings of the current study implied that endocannabinoid signaling pathway might have an important role in the effects of PEA.

No abstract

Pyridoxine (vitamin B6) toxicity is a well-known model for peripheral neuropathy. GABA and glutamate are two neurotransmitters in neural pathways involved in the peripheral neuropathy. Cichorium intybus (Chicory) contains glycosides and triterpenoids, which inhibit glutamatergic transmission and enhance GABAergic transmission. The present study was aimed at studying the effect of chicory extract (CE) on the pyridoxine-induced peripheral neuropathy with a particular focus on glutamatergic and GABAergic systems. In this experimental study, a high dose of pyridoxine (800 mg/kg, i.p.) was injected for 14 days to induce neuropathy in male rats. To evaluate the behavioral symptoms, three tests including rotarod, hot plate, and foot fault were used. After the induction of neuropathy, CE (50 mg/kg i.p.) was injected intraperitoneally for 10 consecutive days. Morphologically, the sciatic nerve and the DRG neurons were evaluated in the control, neuropathy, and chicory groups by H&E staining. For evaluating the mechanism, picrotoxin (1 mg/kg) and MK-801 (0.1 mg/kg) were also individually injected 15 min before the extract administration. The concentration of TNF-α in rat sciatic nerve and DRG neurons were also measured by enzyme-linked-immunoassay (ELISA). Morphological and physiological changes occurred in the DRG and sciatic nerve following pyridoxine intoxication. The CE exerted an anti-neuropathic effect on the sciatic nerve and DRG neurons and also decreased reaction time in hot plate test (p < 0.05), increased balance time in rotarod test (p < 0.001), and improved foot fault performance (p < 0.01). Moreover, CE administration reduced TNF-α level in DRG (p < 0.001) and sciatica nerve (p < 0.001). Picrotoxin, unlike MK-801, showed a significant difference in all three behavioral tests and reduced TNF-α content in comparison with group received extraction alone (with p < 0.001 for all three tests). Our results showed beneficial effects of CE on pyridoxine-induced peripheral neuropathy. Modulating of the GABAergic system mediated by TNF-α may be involved in the anti-neurotoxic effect of CE.

No abstract