Kulkarni S K, Akula Kiran Kumar, Dhir Ashish
Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160 014, India.
Indian J Exp Biol. 2008 Jun;46(6):465-9.
Withania somnifera (ashwagandha) is a widely used herb in the Ayurvedic system of medicine. The objective of the present study was to elucidate the effect of W. somnifera root extract (Ws) alone or in combination with exogenous gamma-amino butyric acid (GABA), a GABA receptor agonist or with diazepam, a GABA receptor modulator against pentylenetetrazol (PTZ, iv) seizure threshold in mice. Minimal dose of PTZ (iv, mg/kg) needed to induce different phases (myoclonic jerks, generalized clonus and tonic extension) of convulsions were recorded as an index of seizure threshold. Ws (100 or 200 mg/kg, po) increased the PTZ seizure threshold for the onset of tonic extension phase whereas a lower dose (50 mg/kg, po) did not show any effect on the seizure threshold. Co-administration of a sub-effective dose of Ws (50 mg/kg, po) with a sub-protective dose of either GABA (25 mg/kg, ip) or diazepam (0.5 mg/kg, ip) increased the seizure threshold. The results suggested that the anticonvulsant effect of W. somnifera against PTZ seizure threshold paradigm involved the GABAAergic modulation.
南非醉茄（印度人参）是阿育吠陀医学体系中一种广泛使用的草药。本研究的目的是阐明南非醉茄根提取物（Ws）单独使用或与外源性γ-氨基丁酸（GABA，一种GABA受体激动剂）或地西泮（一种GABA受体调节剂）联合使用对小鼠戊四氮（PTZ，静脉注射）惊厥阈值的影响。将诱导惊厥不同阶段（肌阵挛性抽搐、全身性阵挛和强直性伸展）所需的最小PTZ剂量（静脉注射，mg/kg）记录为惊厥阈值指标。Ws（100或200mg/kg，口服）提高了强直性伸展期开始时的PTZ惊厥阈值，而较低剂量（50mg/kg，口服）对惊厥阈值没有任何影响。将无效剂量的Ws（50mg/kg，口服）与亚保护剂量的GABA（25mg/kg，腹腔注射）或地西泮（0.5mg/kg，腹腔注射）联合使用可提高惊厥阈值。结果表明，南非醉茄对PTZ惊厥阈值模型的抗惊厥作用涉及GABAA能调节。
