Effects Of Kava On Absence-like Seizures In The Tremor Rats And On Tonic Seizures In The Spontaneously Epileptic Rats

IntroductionEpilepsy is a chronic brain disease that results from several causes. It is characterized by sudden, repeating and temporary disturbance in the CNS caused by brain neuron's excessive firing. In the past half century, Chinese medicine and western medicine have had their own advantages and continuously developed new drugs in the antiepileptic drugs investigation. Antiepileptic western drugs are strong and fast effect, but they have toxic and adverse effect, such as neurologic system. Antiepileptic effect of the traditional Chinese medicine displays properties on safe, small adverse effect and strong efficiency, so the investigation about antiepileptic traditional Chinese medicine is attentioned. The major component of kava, kavalactone, may basically modulate brain sensibility centrum. Recent reports suggested that kava might have anti - anxiety, antidepressant properties and can also improve sleep. Furthermore, some reports demonstrated that kava have muscle relax, anticonvulsant and immune enforcement properties. But there have not been reports about its antiepileptic effect. We chronically implanted electrodes in cortical and hippocampus of tremor rats and then recorded the electroencephalograms ( EEG) to observe effects of kava on absence - like seizures in tremor rats. Meanwhile, we observed the effects of kava on tonic seizures in the spontaneously epileptic rats (SER) by giving puff stimuli on the face of the rats.Methods1. chronically implanting electrode in cortical and hippocampus of tremor ratsWe selected 25 tremor rats and randomly divided them into five groups; normal saline control group, valproate group (0. 036 g/kg) , low dose kava group (0. 27 g/kg) , middle dose kava group (0. 54 g/kg) , high dose kava group (1. 08 g/kg) , Each group included 5 rats. The animals were anaesthetized with 3 % sodium pentobarbital (40 mg/kg, ip). We fixed the rat onto the stereotaxic apparatus and cut the skin of the midline. Then scratched out muscles and periosteum, stanched and sanitized. Three bores were drilled at the following sites of ( - 3 mm, 3 mm) (3 mm, 3 mm) ( - 2 mm, - 4 mm) from the bregma and implanted cortical electrode, reference electrode and hippocampal e-lectrode, respectively. Finally the electrodes were embed with dental cement.2. Mensuration of the EEGAfter a 7 - d recovery period, we measured the EEG of tremor rats before administration by pen -tracing polygrph. The five groups including A,B,C,D, E animals were orally administrated normal saline, VPA, low, middle, and high dose kava ,respectively (10 ml/kg). The rats were administrated two times every day and added up to 4 days. And the EEG of the rats were record at lh aftet administration for 15 minutes.3. stimulating tonic seizures in SERWe selected 10 SER and randomly divided them into two groups. The rats were placed in a soundproof box (40 40 40cm). After rats were habituated to the box for 30 min, given puff stimuli strongly and recorded the state of tonic convulsion. Rats were given a puff every 5 min and 6 times. After administration high dose kava of 4 days, the same stimuli were given rats and the times of seizures were recorded.Results1. The effects of every group on duration of each absence - like seizure in tremor ratsThe duration of each absence - like seizure in tremor rats significantly was decreased to (11. 58 0.63) s from (16. 99 1. 73 ) s at 1 h after VPA administration of 4 days. Low dose kava had no suppressive effect. Middle dose kava decreased the duration from (17.95 4.41 )s to (11. 36 0.64) sand (11.25 0. 84) s at lh after administration of 3 days and 4 days. High dose kava significantly decreased the duration from (17. 39 2. 19) s to (13.62 1.32)s and (10. 16 0. 49) s at 1h after administration of 3 days and 4 days.2. The effects of every group on total duration of absence -like seizures in 15 minutes in tremor ratsThe total duration of absence - like seizures in 15 minutes in tremor rats was significantly reduced to (252. 76 27. 35} s from (309.96 12.74) s at lh after 4 days by VPA administration. Low dose kava had no suppressive effect. Middle dose kava decreased total duration from (350. 48 79. 16) s to (267. 44 57. 60) s and (223. 32 46.74) s at 1h after administration of 3 days and 4 days. High dose kava significantly decreased total duration from (321. 64 33. 17) s to (253. 96 21. 88) s and (190. 60 32. 58) s at lh after administration of 3 days and 4 days.3. Compare the effects of each group on different guidelines of abnormal EEG in tremor ratsHigh dose kava had more significant suppressive effect on duration of each absence - like seizure and total duration in 15 min compared with middle dose kava and VPA4 days after administration.4. The effects of kava on tonic seizures in SERthe times of tonic seizures in SER were significantly decreased to (4. 60 0. 55) s from (5. 80 0.45) s after administration.