Mahomed Ismail M, Ojewole John A O
Department of Pharmacology, Faculty of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa.
Brain Res Bull. 2006 Mar 15;69(1):57-62. doi: 10.1016/j.brainresbull.2005.10.010. Epub 2005 Nov 15.
Harpagophytum procumbens DC [family: Pedaliaceae] is widely used in South African traditional medicine for the treatment, management and/or control of a variety of human ailments. In the present study, we have examined the anticonvulsant activity of Harpagophytum procumbens secondary root aqueous extract (HPE, 50-800 mg/kg i.p.) against pentylenetetrazole (PTZ)-, picrotoxin (PCT)- and bicuculline (BCL)-induced seizures in mice. Phenobarbitone and diazepam were used as reference anticonvulsant drugs for comparison. Like the reference anticonvulsant agents used, H. procumbens secondary root aqueous extract (HPE, 100-800 mg/kg i.p.) significantly (P<0.05-0.001) delayed the onset of, and antagonized, pentylenetetrazole (PTZ)-induced seizures. The plant's extract (HPE, 100-800 mg/kg i.p.) also profoundly antagonized picrotoxin (PCT)-induced seizures, but only partially and weakly antagonized bicuculline (BCL)-induced seizures. Although the data obtained in the present study do not provide conclusive evidence, it would appear that H. procumbens secondary root aqueous extract (HPE) produces its anticonvulsant activity by enhancing GABAergic neurotransmission and/or facilitating GABAergic action in the brain. In general, the average onset of convulsion was delayed, while the average duration of convulsion was markedly reduced. The plant's extract also depressed the central nervous system (CNS). It is, therefore, thought that the anticonvulsant property of the herb may be linked, at least in part, to its ability to depress the central nervous system. However, the results of this experimental animal study indicate that H. procumbens secondary root aqueous extract possesses anticonvulsant activity, and thus lend pharmacological support to the suggested folkloric, ethnomedical uses of the plant's extract in the treatment, management and/or control of epilepsy and childhood convulsions in some rural communities of South Africa.
南非钩果草（Harpagophytum procumbens DC，列当科）在南非传统医学中被广泛用于治疗、处理和/或控制多种人类疾病。在本研究中，我们检测了南非钩果草次生根水提取物（HPE，腹腔注射50 - 800毫克/千克）对小鼠戊四氮（PTZ）、印防己毒素（PCT）和荷包牡丹碱（BCL）诱导惊厥的抗惊厥活性。苯巴比妥和地西泮用作参考抗惊厥药物进行比较。与所使用的参考抗惊厥剂一样，南非钩果草次生根水提取物（HPE，腹腔注射100 - 800毫克/千克）显著（P<0.05 - 0.001）延迟了戊四氮（PTZ）诱导惊厥的发作并起到拮抗作用。该植物提取物（HPE，腹腔注射100 - 800毫克/千克）也对印防己毒素（PCT）诱导的惊厥有显著拮抗作用，但仅对荷包牡丹碱（BCL）诱导的惊厥有部分且较弱的拮抗作用。尽管本研究获得的数据未提供确凿证据，但南非钩果草次生根水提取物（HPE）似乎是通过增强大脑中的γ-氨基丁酸能神经传递和/或促进γ-氨基丁酸能作用来产生其抗惊厥活性。总体而言，惊厥的平均发作时间延迟，而惊厥的平均持续时间显著缩短。该植物提取物还抑制中枢神经系统（CNS）。因此，人们认为该草药的抗惊厥特性可能至少部分与其抑制中枢神经系统的能力有关。然而，这项实验动物研究的结果表明，南非钩果草次生根水提取物具有抗惊厥活性，从而为该植物提取物在南非一些农村社区治疗、处理和/或控制癫痫和儿童惊厥方面的民间、民族医学用途提供了药理学支持。
