Curcumin ameliorates cognitive dysfunction and oxidative damage in phenobarbitone and carbamazepine administered rats.

The antiepileptic drugs, phenobarbitone and carbamazepine are well known to cause cognitive impairment on chronic use. The increase in free radical generation has been implicated as one of the important mechanisms of cognitive impairment by antiepileptic drugs. Curcumin has shown antioxidant, anti-inflammatory and neuro-protective properties. Therefore, the present study was carried out to investigate the effect of chronic curcumin administration on phenobarbitone- and carbamazepine-induced cognitive impairment and oxidative stress in rats. Pharmacokinetic interactions of curcumin with phenobarbitone and carbamazepine were also studied. Vehicle/drugs were administered daily for 21days to male Wistar rats. Passive avoidance paradigm and elevated plus maze test were used to assess cognitive function. At the end of study period, serum phenobarbitone and carbamazepine, whole brain malondialdehyde and reduced glutathione levels were estimated. The administration of phenobarbitone and carbamazepine for 21days caused a significant impairment of learning and memory as well as an increased oxidative stress. Concomitant curcumin administration prevented the cognitive impairment and decreased the increased oxidative stress induced by these antiepileptic drugs. Curcumin co-administration did not cause any significant alteration in the serum concentrations of both phenobarbitone as well as carbamazepine. These results show that curcumin has beneficial effect in mitigating the deterioration of cognitive functions and oxidative damage in rats treated with phenobarbitone and carbamazepine without significantly altering their serum concentrations. The findings suggest that curcumin can be considered as a potential safe and effective adjuvant to phenobarbitone and carbamazepine therapy in preventing cognitive impairment associated with these drugs.

Reeta KH ，Mehla J ，Gupta YK 《-》

Curcumin is protective against phenytoin-induced cognitive impairment and oxidative stress in rats.

Reeta KH ，Mehla J ，Gupta YK 《-》

Pharmacokinetic and pharmacodynamic interactions of valproate, phenytoin, phenobarbitone and carbamazepine with curcumin in experimental models of epilepsy in rats.

The present study investigates the interaction of curcumin with four antiepileptic drugs (AEDs) in male Wistar rats. In the first protocol, seizures were induced using pentylenetetrazole (PTZ) and valproate was injected intraperitoneally (i.p.) in therapeutic and sub-therapeutic doses 30min before PTZ administration. Curcumin was co-administered with sub-therapeutic dose of valproate 60min before PTZ injection. In the second protocol, seizures were induced by maximal-electroshock. Phenytoin, phenobarbitone and carbamazepine were injected in their therapeutic and sub-therapeutic doses 120, 60 and 30min, respectively, before seizure induction. Curcumin was administered along with sub-therapeutic doses of phenytoin, phenobarbitone and carbamazepine, 60min before induction of seizures. Behavioral parameters were assessed using elevated plus maze test and passive avoidance paradigm. Rat brain oxidative stress parameters were assessed and the serum levels of the AEDs were estimated. The AEDs in their therapeutic doses produced complete protection against seizures. However, sub-therapeutic doses of these AEDs failed to completely protect against seizures. Co-administration of curcumin with sub-therapeutic dose of valproate significantly increased the latency to myoclonic jerks. The percentage protection against seizures with sub-therapeutic doses of valproate, phenytoin, phenobarbitone and carbamazepine was also enhanced by concomitant curcumin administration. Both PTZ and MES induced seizures caused significant impairment of cognitive functions. Co-administration of curcumin with these AEDs in their sub-therapeutic doses prevented the impairment of learning and memory due to seizures whereas no such improvement was observed in the groups administered the sub-therapeutic doses of the AEDs alone. Additionally, curcumin reversed the oxidative stress due to seizures. However, curcumin co-administration did not cause any significant alteration in the serum levels of the AEDs. The results thus suggest the potential of curcumin as an adjunct to these AEDs in epilepsy with the advantage of increasing the efficacy, reducing the dose and side effects of the AEDs.

Reeta KH ，Mehla J ，Pahuja M ，Gupta YK ... -  《-》

Protective effect of curcumin against seizures and cognitive impairment in a pentylenetetrazole-kindled epileptic rat model.

Epilepsy as well as chronic use of most antiepileptic drugs predisposes to cognitive impairment. Curcumin has been reported to possess antioxidant, anticonvulsant as well as neuroprotective potential. Hence, this study was conducted to evaluate the effect of curcumin against seizures, cognitive impairment and oxidative stress in pentylenetetrazole-induced kindling in rats. The effect of pretreatment with curcumin (100, 200 and 300 mg/kg, orally) on pentylenetetrazole (PTZ)-induced kindling, kindling-induced cognitive impairment and oxidative stress was evaluated. Male Wistar rats were injected PTZ (30 mg/kg, i.p.) once every alternate day (48±1h) until the development of kindling. Cognitive impairment was assessed using elevated plus maze and passive avoidance test while the oxidative stress parameters (malondialdehyde and glutathione) were estimated in the whole brain at the end of experiments. PTZ, 30 mg/kg, induced kindling in rats after 31.0±1.4 days. Curcumin showed dose-dependent anti-seizure effect. Curcumin (300 mg/kg) significantly increased the latency to myoclonic jerks, clonic seizures as well as generalized tonic-clonic seizures, improved the seizure score and decreased the number of myoclonic jerks. PTZ kindling induced a significant oxidative stress and cognitive impairment which was reversed by pretreatment with curcumin in a dose-dependent manner. The results indicate that pretreatment with curcumin ameliorates seizures, oxidative stress and cognitive impairment in PTZ induced kindling in rats. These results thus suggest the potential of curcumin as an adjuvant in epilepsy both to prevent seizures as well as to protect against seizure induced memory impairment.

Mehla J ，Reeta KH ，Gupta P ，Gupta YK ... -  《-》

Effect of carbamazepine and lamotrigine on cognitive function and oxidative stress in brain during chemical epileptogenesis in rats.

Arora T ，Mehta AK ，Sharma KK ，Mediratta PK ，Banerjee BD ，Garg GR ，Sharma AK ... -  《-》