Rao N Venkata, Pujar Basavaraj, Nimbal S K, Shantakumar S M, Satyanarayana S
Department of Pharmacology, V L College of Pharmacy, Raichur 584 103, India.
Indian J Exp Biol. 2008 Aug;46(8):591-8.
Nootropic effect of alcoholic (ALE; 50, 75, 100 mg/kg) and aqueous (AQE; 100, 200, 400 mg/kg) extracts of P. tuberosa was evaluated by using Elevated Plus Maze (EPM), scopolamine-induced amnesia (SIA), diazepam-induced amnesia (DIA), clonidine-induced (NA-mediated) hypothermia (CIH), lithium-induced (5-HT mediated) head twitches (LIH) and haloperidol-induced (DA- mediated) catalepsy (HIC) models. Piracetam was used as the standard drug. A significant increase in inflexion ratio (IR) was recorded in EPM, SIA and DIA models. A significant reversal effect was observed on rectal temperature in CIH model, reduction of head twitches in LIH models. However no significant reduction in catalepsy scores in HIC models were observed with test extracts and standard piracetam. The results indicate that nootropic activity observed with ALE and AQE of tuber extracts of P. tuberosa could be through improved learning and memory either by augmenting the noradrenaline (NA) transmission or by interfering with 5-hydroxytryptamine (5-HT) release. Further, the extracts neither facilitated nor blocked release of the dopamine (DA). Thus ALE and AQE elicited significant nootropic effect in mice and rats by interacting with cholinergic, GABAnergic, adrenergic and serotonergic systems. Phytoconstituents like flavonoids have been reported for their nootropic effect and these are present in both ALE and AQE extracts of tubers of P. tuberosa (Roxb) and these active principles may be responsible for nootropic activity.
通过高架十字迷宫（EPM）、东莨菪碱诱导的失忆（SIA）、地西泮诱导的失忆（DIA）、可乐定诱导的（去甲肾上腺素介导的）体温过低（CIH）、锂诱导的（5-羟色胺介导的）头部抽搐（LIH）和氟哌啶醇诱导的（多巴胺介导的）僵住症（HIC）模型，评估了块茎水黄皮的酒精提取物（ALE；50、75、100毫克/千克）和水提取物（AQE；100、200、400毫克/千克）的益智作用。吡拉西坦用作标准药物。在EPM、SIA和DIA模型中，转折率（IR）显著增加。在CIH模型中观察到对直肠温度有显著的逆转作用，在LIH模型中头部抽搐减少。然而，测试提取物和标准吡拉西坦在HIC模型中未观察到僵住症评分有显著降低。结果表明，块茎水黄皮的ALE和AQE提取物所观察到的益智活性可能是通过增强去甲肾上腺素（NA）传递或干扰5-羟色胺（5-HT）释放来改善学习和记忆。此外，提取物既不促进也不阻断多巴胺（DA）的释放。因此，ALE和AQE通过与胆碱能、GABA能、肾上腺素能和5-羟色胺能系统相互作用，在小鼠和大鼠中引发了显著的益智作用。据报道，类黄酮等植物成分具有益智作用，这些成分存在于块茎水黄皮（Roxb）的ALE和AQE提取物中，这些活性成分可能是益智活性的原因。
