CELECOXIB, A SELECTIVE CYCLOOXYGENASE-2 INHIBITOR, IS ANTICONVULSIVE IN MES INDUCED SEIZURES BUT PROCONVULSIVE IN PTZ INDUCED SEIZURES IN MICE: A POSSIBLE ROLE OF EXCITATORY AMINO ACID IN THIS DIFFERENTIAL EFFECT

Epilepsy is an achronic neurological disorder characterized by recurrent seizures. There is a positive feedback cycle between epileptogenesis and brain inflammation. It has been proved that COX 2 is expressed constitutively in certain parts of the CNS and is further induced as a result of seizurogenic activity. Of the various experimental models of epilepsy, one is the maximal electroshock (MES) model, which is highly predictive of AED against GTCS. Other is the pentylenetetrazole (PTZ) model, which is useful in the AEDs activity against absence seizures. The present study was done to evaluate the antiepileptic effect of selective COX 2 inhibitor celecoxib in MES and PTZ models in mice and to see the differential effect of celecoxib in electrically chemically induced seizures. In the first part of the study, Celecoxib (2.5mg/kg, 5mg/kg & 10mg/kg) was injected intraperitoneally in albino mice. MES was induced, and durations of various phases were noted. Duration of Tonic hind limb extension was taken as an index of antiepileptic activity. The results indicated that celecoxibin, the dose of 10mg/kgi.p. Significantly reduced the duration of THLE. In the second part, celecoxib was injected in (10mg/kg & 20 mg/kg i.p.), in PTZ induced model, and the result displayed the proconvulsive activity in the PTZ seizure model. i.e., decrease in the latency to preclonic jerk and increase in the duration of clonus. This suggested the role of inflammation and COX2 isoenzyme in the pathophysiology of epilepsy and the clinical application of COX 2 inhibitors as a future therapeutic strategy for GTC seizures management.