Aim To investigate the synergistic effect of the combination of pinellia total alkaloid （PTA） and uncaria total alkaloid （UTA）, and explore the mechanism of anticonvulsant action. Methods Anticonvulsant and toxic ...Aim To investigate the synergistic effect of the combination of pinellia total alkaloid （PTA） and uncaria total alkaloid （UTA）, and explore the mechanism of anticonvulsant action. Methods Anticonvulsant and toxic effect profiles of combinations of PTA with UTA, alone and at three fixed ratios of 1：4, 1 ：1, 4：1, were evaluated in maximal electroshock （MES）-induced seizures and acute toxicity test in mice. Respective ED50 and LD50 were calculated with Bliss＇s method. Their synergistic effect were evaluated by isobolographic analysis and allowed the determination of benefit indices （BI） for respective combinations. The model of convulsive rats kindled by penicillin topically injected into cortex was used to investigated the content of Glu, Asp, Gly and GABA in hippocampus using high performance liquid chromatography （HPLC）. Results Combinations of PTA and UTA at the ratio of 4：1 were synergistic in MES test and antagonistic in acute toxicity test, showing the best profile for combinations of PTA with UTA. In contrast, the ratios of 1 ：4 and 1 ： 1, despite synergistic in MES test, were additive in acute toxicity test. The 4：1 combination and two drugs alone significantly decreased Glu level and increased GABA level in the hippocampus, but the GABA level in the 4：1 combination group was higher than that in the two drugs alone groups. They did not have significant influence on the levels of ASp and Gly. Conclusion Combinations of PTA and UTA at 4：1 ratio demonstrated synergistic effect in anticonvulsant action and antagonistic effect in toxicity. The anticonvulsant mechanism might be related to decreasing the excitability of Glutamatergic neurons and increasing the inhibition of GABAergic neurons.展开更多
神经退行性疾病（Degenerative diseases of the central nervous system，ND）是一组以原发性神经元变性为基础的慢性进行性神经系统疾病。该类疾病主要包括阿尔茨海默氏病（Alzheimer’s disease，AD）、帕金森病（Parkinson’s dise...神经退行性疾病（Degenerative diseases of the central nervous system，ND）是一组以原发性神经元变性为基础的慢性进行性神经系统疾病。该类疾病主要包括阿尔茨海默氏病（Alzheimer’s disease，AD）、帕金森病（Parkinson’s disease，PD）、Huntington舞蹈病（Huntington disease）、不同类型脊髓小脑共济失调（spinal cerebellar ataxias）、肌萎缩侧索硬化症（amyotrophic lateral sclerosis）及脊髓肌萎缩症（spinal muscular atrophy）等。研究发现，ND是由多种不同原因导致的，包括神经元或神经胶质细胞不能提供充分的营养、轴突传递功能受损、谷氨酸受体活性过高、活性氧水平过高、代谢通路受损、线粒体能量产生减少、折叠错误的蛋白质形成增加或降解不充分、炎症过程、病毒感染、细胞核或线粒体DNA突变以及RNA或蛋白质的加工过程不正确所致的特殊蛋白质或脂质部分功能的损失或增加等因素。虽然诱发这些疾病的病因和病变部位不尽相同，但它们都有一个共同的特征，即发生神经元的退行性病变和凋亡，并最终导致个体死亡。目前对神经退行性疾病的机理及治疗已进行了大量的研究，但至今尚无有效成熟的方法和药物来防治这种疾病。展开更多
基金Natural Science Foundation of Shanxi Province(No 20041109).
文摘Aim To investigate the synergistic effect of the combination of pinellia total alkaloid （PTA） and uncaria total alkaloid （UTA）, and explore the mechanism of anticonvulsant action. Methods Anticonvulsant and toxic effect profiles of combinations of PTA with UTA, alone and at three fixed ratios of 1：4, 1 ：1, 4：1, were evaluated in maximal electroshock （MES）-induced seizures and acute toxicity test in mice. Respective ED50 and LD50 were calculated with Bliss＇s method. Their synergistic effect were evaluated by isobolographic analysis and allowed the determination of benefit indices （BI） for respective combinations. The model of convulsive rats kindled by penicillin topically injected into cortex was used to investigated the content of Glu, Asp, Gly and GABA in hippocampus using high performance liquid chromatography （HPLC）. Results Combinations of PTA and UTA at the ratio of 4：1 were synergistic in MES test and antagonistic in acute toxicity test, showing the best profile for combinations of PTA with UTA. In contrast, the ratios of 1 ：4 and 1 ： 1, despite synergistic in MES test, were additive in acute toxicity test. The 4：1 combination and two drugs alone significantly decreased Glu level and increased GABA level in the hippocampus, but the GABA level in the 4：1 combination group was higher than that in the two drugs alone groups. They did not have significant influence on the levels of ASp and Gly. Conclusion Combinations of PTA and UTA at 4：1 ratio demonstrated synergistic effect in anticonvulsant action and antagonistic effect in toxicity. The anticonvulsant mechanism might be related to decreasing the excitability of Glutamatergic neurons and increasing the inhibition of GABAergic neurons.
