摘要
BACKGROUND： Previous studies have demonstrated that scorpion venom in the scorpion can inhibit epilepsy and apoptosis. However, it remains unclear whether ethanol extracts of scorpion （EES） exhibit similar effects. OBJECTIVE： To investigate the effects of EES on hippocampal apoptosis and caspase-3 expression, and to compare the effects on sodium valproate （positive control drug） in a rat model of status epilepticus induced by lithium chloride-pilocarpine. DESIGN, TIME AND SETTING： This randomized, controlled study was conducted at the Drug Research and Development Center, Kanghong Pharmaceuticals Group, and the Department of Pathology, Sichuan Academy of Medical Sciences ＆ Sichuan Provincial People＇s Hospital, China from May 2007 to April 2008. MATERIALS： EES were prepared by Huashen Pharmaceutical, China. Sodium valproate （Hunan Xiangzhong Pharmaceutical, China） and lithium chloride-pilocarpine （Sigma, USA） were also used in the present study. METHODS： From a total of 156 rats, six served as normal controls. The remaining rats were intraperitoneally injected with lithium chloride-pilocarpine to establish status epileptlcus models, and then assigned to five groups （n = 30, respectively）. Animals in each group were administered drugs at 15 minutes after epileptic seizure by gavage, i.e. in the normal control and model groups, rats were treated with 1 mL/0.1 kg saline. The sodium valproate group was administered 120 mg/kg/d sodium valproate. The low-, moderate-, and high-dose EES groups received treatments of 290, 580 and 1 160 mg/kg/d EES. The dispensed concentration was 1 mL/0.1 kg. Rat seizure behavior was observed. If status epilepticus did not terminated after 1 hour, the rats were intraperitoneally administered atropine （1 mg/kg） and diazepam （10 mg/kg） to terminate seizure. These rats were continuously observed for 6 hours to ensure seizure termination. Then rats were treated with the above-mentioned drugs at 8：00 am each day until sacrifice, which took place 4 hours after drug administration. MAIN OUTCOME MEASURES： Terminal dUTP nick end labeling （TUNEL）-positive cells and caspase-3 expression were, respectively, determined by TUNEL and immunohistochemistry at 6, 24 48, and 72 hours, as well as 7 days, after status epilepticus. Behavioral changes were also measured. RESULTS： A few caspase-3-positive cells were observed. TUNEL- and caspase-3-positive ceils were mainly visible in the hippocampal CA1 and CA3 regions 6 hours following status epilepticus in the model and drug intervention groups. The number of TUNEL-positive cells reached a peak at 48 hours following status epilepticus in the sodium valproate group, as well as the moderate- and high-dose EES groups, and number of TUNEL-positive cells reached a peak at 72 hours in the model and low-dose EES groups. The number of caspase-3-positive cells reached a peak at 48 hours in each group. Following treatment of sodium valproate and EES, the number of TUNEL- and caspase-3-positive cells significantly decreased compared with the model group at various time points （P 〈 0.05）. The number of TUNEL- and caspase-3-positive cells was greatest in the low-dose EES group, followed by the moderate- and high-dose EES groups. The number of TUNEL- and caspase-3-positive cells was similar between the sodium valproate and high-dose EES groups. Epileptic seizure was significantly improved in the sodium valproate group, as well as the moderate- and high-dose EES groups, compared with the model group （P〈 0.05 or P〈 0.01）. Treatment with sodium valproate and high-dose EES resulted in the best outcome, although the results were similar （P 〉 0.05）. CONCLUSION： A dose of 1 160 mg/kg/d EES significantly inhibited status epilepticus. This outcome corresponded to a decreased number of apoptotlc cells and caspase-3-positive cells, which was similar to sodium valproate. These results suggest that it is not necessary to extract a component from the scorpion for the treatment of epilepsy. The high dose of EES significantly inhibited epilepsy, which correlated with decreased hippocampal caspase-3 expression.
BACKGROUND： Previous studies have demonstrated that scorpion venom in the scorpion can inhibit epilepsy and apoptosis. However, it remains unclear whether ethanol extracts of scorpion （EES） exhibit similar effects. OBJECTIVE： To investigate the effects of EES on hippocampal apoptosis and caspase-3 expression, and to compare the effects on sodium valproate （positive control drug） in a rat model of status epilepticus induced by lithium chloride-pilocarpine. DESIGN, TIME AND SETTING： This randomized, controlled study was conducted at the Drug Research and Development Center, Kanghong Pharmaceuticals Group, and the Department of Pathology, Sichuan Academy of Medical Sciences ＆ Sichuan Provincial People＇s Hospital, China from May 2007 to April 2008. MATERIALS： EES were prepared by Huashen Pharmaceutical, China. Sodium valproate （Hunan Xiangzhong Pharmaceutical, China） and lithium chloride-pilocarpine （Sigma, USA） were also used in the present study. METHODS： From a total of 156 rats, six served as normal controls. The remaining rats were intraperitoneally injected with lithium chloride-pilocarpine to establish status epileptlcus models, and then assigned to five groups （n = 30, respectively）. Animals in each group were administered drugs at 15 minutes after epileptic seizure by gavage, i.e. in the normal control and model groups, rats were treated with 1 mL/0.1 kg saline. The sodium valproate group was administered 120 mg/kg/d sodium valproate. The low-, moderate-, and high-dose EES groups received treatments of 290, 580 and 1 160 mg/kg/d EES. The dispensed concentration was 1 mL/0.1 kg. Rat seizure behavior was observed. If status epilepticus did not terminated after 1 hour, the rats were intraperitoneally administered atropine （1 mg/kg） and diazepam （10 mg/kg） to terminate seizure. These rats were continuously observed for 6 hours to ensure seizure termination. Then rats were treated with the above-mentioned drugs at 8：00 am each day until sacrifice, which took place 4 hours after drug administration. MAIN OUTCOME MEASURES： Terminal dUTP nick end labeling （TUNEL）-positive cells and caspase-3 expression were, respectively, determined by TUNEL and immunohistochemistry at 6, 24 48, and 72 hours, as well as 7 days, after status epilepticus. Behavioral changes were also measured. RESULTS： A few caspase-3-positive cells were observed. TUNEL- and caspase-3-positive ceils were mainly visible in the hippocampal CA1 and CA3 regions 6 hours following status epilepticus in the model and drug intervention groups. The number of TUNEL-positive cells reached a peak at 48 hours following status epilepticus in the sodium valproate group, as well as the moderate- and high-dose EES groups, and number of TUNEL-positive cells reached a peak at 72 hours in the model and low-dose EES groups. The number of caspase-3-positive cells reached a peak at 48 hours in each group. Following treatment of sodium valproate and EES, the number of TUNEL- and caspase-3-positive cells significantly decreased compared with the model group at various time points （P 〈 0.05）. The number of TUNEL- and caspase-3-positive cells was greatest in the low-dose EES group, followed by the moderate- and high-dose EES groups. The number of TUNEL- and caspase-3-positive cells was similar between the sodium valproate and high-dose EES groups. Epileptic seizure was significantly improved in the sodium valproate group, as well as the moderate- and high-dose EES groups, compared with the model group （P〈 0.05 or P〈 0.01）. Treatment with sodium valproate and high-dose EES resulted in the best outcome, although the results were similar （P 〉 0.05）. CONCLUSION： A dose of 1 160 mg/kg/d EES significantly inhibited status epilepticus. This outcome corresponded to a decreased number of apoptotlc cells and caspase-3-positive cells, which was similar to sodium valproate. These results suggest that it is not necessary to extract a component from the scorpion for the treatment of epilepsy. The high dose of EES significantly inhibited epilepsy, which correlated with decreased hippocampal caspase-3 expression.
基金
the National Natural Science Foundation of China,No.30740035
the Tackle Key Program of Sichuan Province,No.05SG1672
