Effect of different extracts of Centella asiatica on cognition and markers of oxidative stress in rats.

Centella asiatica, a plant mentioned in Indian literature has been described to possess CNS effects such as stimulatory-nervine tonic, rejuvenant, sedative, tranquilizer and intelligence promoting property. In the present study aqueous, methanolic and chloroform extracts of C. asiatica were investigated for their effect on cognitive functions in rats. Male Wistar rats of 200-250 g were used to study the effect on learning and memory by using shuttle box, step through, step down and elevated plus maze paradigms. Only the aqueous extract of whole plant (200 mg/kg for 14 days) showed an improvement in learning and memory in both shuttle box and step through paradigms. Therefore, further experiments were conducted with aqueous extract using 100, 200 and 300 mg/kg doses in different paradigms of learning and memory. All doses of aqueous extract increased the number of avoidances in shuttle box and prolonged the step through latency in step through apparatus in a dose dependent manner, while only two doses 200 and 300 mg/kg of aqueous extract showed significant increase in the step down latency in step down apparatus and transfer latency (TL) in elevated plus maze. Among doses of aqueous extract tested on oxidative stress parameters, only 200 and 300 mg/kg showed a significant decrease in the brain levels of malondialdehyde (MDA) with simultaneous significant increase in levels of glutathione. There was a significant increase in the levels of catalase at the 300 mg/kg but no significant change in superoxide dismutase (SOD) levels were observed. The present findings indicate that the aqueous extract of C. asiatica has cognitive enhancing effect and an antioxidant mechanism is involved.     

积雪草总苷对小鼠抑郁行为和脑内氨基酸含量的影响

目的：采用小鼠强迫游泳抑郁症模型，观察积雪草总苷的抗抑作用。方法：昆明种小鼠随机分为空白对照组、模型组、阳性对照丙咪嗪组和积雪草总苷组，分析药物对小鼠强迫游泳不动时间及脑内氨基酸含量的影响。结果：丙咪嗪组和积雪草总苷低、中、高3个剂量能够显著缩短小鼠强迫游泳不动时间，改善强迫游泳所致小鼠脑内氨基酸含量的失调。结论：积雪草总苷具有抗抑郁活性。     

Beneficial effects of Centella asiatica aqueous extract against arsenic-induced oxidative stress and essential metal status in rats

The efficacy of an aqueous extract of Centella asiatica (100, 200 and 500 mg/kg for 5 consecutive days) was studied in the depletion of arsenic and in the recovery of a few altered biochemical variables in arsenic pre-exposed rats (20 ppm in drinking water for 5 weeks). Exposure to arsenic significantly depleted delta-aminolevulinic acid dehydratase (ALAD) activity, reduced glutathione (GSH) level, superoxide dismutase (SOD) and increased thiobarbituric acid reactive substance (TBARS) activity in red blood cells. Significant depletion of ALAD activity, GSH level, glutathione peroxidase (GPx), SOD and catalase (CAT) activities and an increase in TBARS levels in liver tissues was also noted. There was a significant depletion of SOD, CAT and GPx activities in kidneys and an increased TBARS levels in kidney and brain accompanied by increased arsenic concentration in blood and soft tissues. Treatment with aqueous extract of Centella asiatica provided significant protection against ALAD, GSH and TBARS levels, particularly at doses of 200 and 500 mg. Centella asiatica also provided significant recovery in the inhibited liver ALAD and G6PD activities. Arsenic concentration in blood and soft tissues remained uninfluenced after Centella asiatica administration. The present study thus suggests a beneficial effect of Centella asiatica against arsenic-induced oxidative stress but possesses no chelating property.     

Wound-healing activity of St. John's Wort (Hypericum perforatum L.) on chicken embryonic fibroblasts

Wound-healing effect of St. John's Wort (Hypericum perforatum L.) extract was evaluated by comparing with dexpanthenol and titrated extract of Centella asiatica (TECA) on cultured chicken embryonic fibroblasts. Chicken embryonic fibroblasts from fertilized eggs were incubated with the plant extract, dexpanthenol and TECA. Using microscopical methods by staining cells, mitotic ability, morphologic changes and collagen production in the cultured fibroblasts were evaluated as parameters to approach its mechanism of action in wound repair. Findings obtained in the present study indicated that Hypericum perforatum extract exhibited a wound-healing activity whose mechanism of action is similar to that of TECA. Wound-healing activity of Hypericum perforatum extract seems to be mainly due to the increase in the stimulation of fibroblast collagen production and the activation of fibroblast cells in polygonal shape, which plays a role in wound repair by closing damaged area. The findings demonstrated the wound-healing activity of Hypericum perforatum, which has previously been based on ethnomedical data.     

Screening of Indian medicinal plants for acetylcholinesterase inhibitory activity

The cholinergic hypothesis of Alzheimer's disease (AD) has provided the rationale for the current pharmaco-therapy of this disease, in an attempt to reduce the cognitive decline caused by cholinergic deficits. Nevertheless, the search for potent and long-acting acetylcholinesterase (AChE) inhibitors that exert minimal side effects in AD patients is still ongoing. AChE inhibitors are currently the only approved therapy for the treatment of Alzheimer's disease; only a limited number of drugs are commercially available. Hydroalcohol extracts of six herbs, Andrographis paniculata, Centella asiatica, Evalvulus alsinoides, Nardostachys jatamansi, Nelumbo nucifera, Myristica fragrans used in Indian systems of medicine, were tested for in vitro acetylcholinesterase inhibitory activity based on Ellman's method in 96-well microplates using AChE obtained from bovine erythrocytes. The results showed that the hydroalcohol extract from Centella asiatica, Nardostachys jatamansi, Myristica fragrans, Evalvulus alsinoides inhibited 50% of AChE activity at concentrations of 100-150 microg/mL. Andrographis paniculata and Nelumbo nucifera extracts showed a weak inhibition of acetylcholinesterase with IC(50) values of 222.41 +/- 19.87 microg/mL and 185.55 +/- 21.24 microg/mL, respectively. Physostigmine was used as a standard and showed inhibition of acetylcholinesterase with an IC(50) value of 0.076 +/- 0.0042 microg/mL.     

积雪草化学成分和药理作用研究进展及其质量标志物预测分析

积雪草为伞形科植物积雪草的干燥全草，应用历史悠久、药理作用广泛。本文通过查询相关文献对积雪草的化学成分、药理作用进行综述分析，并结合中药Q-Marker概念，从传统药性、传统药效、化学成分可测性、不同复方配伍中表达组分等角度对积雪草Q-Marker进行预测，发现积雪草具有促进创伤愈合及抑制瘢痕增生、抗阿尔茨海默病、改善肾肺损伤及关节炎等活性，主要含有三萜皂苷类、黄酮类、挥发油类及多炔烯烃类等成分，主要活性物质为三萜皂苷类成分，建议将积雪草苷、积雪草酸、羟基积雪草苷、羟基积雪草酸和积雪草苷B等三萜皂苷类，芦丁、槲皮素、山柰酚、黄芩素、木犀草素等黄酮类化合物及挥发油类成分作为积雪草Q-Marker的主要选择，有利于完善积雪草质量评价标准并建立科学全面的专属质量控制体系，为积雪草临床用药及其资源的开发利用提供理论依据。     

4种中药体外抗结核分枝杆菌H37RV的研究

目的研究中药夏枯草、积雪草、筋骨草和青蒿素的体外抗结核分枝杆菌H37RV的活性。方法采用改良罗氏固体培养基试管培养法进行活性检测。结果夏枯草醇提物抗结核效果明显;积雪草苷片、筋骨草及青蒿素均无效。结论夏枯草醇提物抗结核菌效果优于水提物;积雪草醇提物有微弱抑制结核杆菌活性,但其有效成分可能不是积雪草苷;青蒿素及二氢青蒿素无抑制结核分枝杆菌的活性。     

HPLC-ELSD测定积雪草提取物中积雪草苷的含量

目的：用HPLC-ELSD测定积雪草提取中积雪草苷的含量。方法：色谱柱为HiQ siL KYA-C18分析柱,流动相为乙腈-水,梯度洗脱；漂移管温度105 ℃；载气流速2.9 L·min^-1。结果：积雪草苷在0.35～7.0 μg呈良好线性关系；积雪草提取物中积雪草苷的回收率为94.9％(RSD 1.7%)。结论：该方法简便、准确、分离效果好,无干扰,可用于积雪草提取物中积雪草苷的质量评价。     

RE-HPLC测定积雪草中积雪草甙、羟基积雪草甙的含量

目的测定不同产地的中药积雪草甙和羟基积雪草甙的含量.方法采有RE-HPLC法进行测定.结果不同产地的积雪草中积雪草甙和羟基积雪草甙的含量有很大差异.结论方法简便,准确灵敏.     

积雪草总苷对实验性抑郁症大鼠血清皮质酮和单胺类神经递质的影响

目的:探讨积雪草总苷抗抑郁症可能的作用机制.方法:采用荧光法检测积雪草总苷对实验性抑郁症大鼠血清皮质酮的影响;HPLC-ECD法检测积雪总苷对大鼠皮质、海马和下丘脑单胺类神经递质含量的影响.结果:积雪草总苷降低抑郁症大鼠的血清皮质酮水平,增加脑内5-HT,NE和DA及其代谢产物的含量.结论:积雪草总苷的抗抑郁活性与改善下丘脑-垂体-肾上腺轴功能和增加胺神经递质的水平有关.