大鼠颈总动脉闭塞性休克时对海马结构SOD、MDA、AChE水平影响的研究

目的：观察乙酰酸胆硷酯酶在脑缺血损伤中的作用及作用机理。方法：采用大鼠颈总动脉闭塞性休克模型，测定大鼠海马结构内MDA的含量及SOD、AChE的活性。统计学处理采用t检验。结果：休克组与对照组比较，海马组织MDA含量升高，SOD活性降低，AChE光密度明显升高。结论：①脑缺血后迅速发生了组织低灌流及神经细胞膜功能损害。②AChE不仅参与胆硷能神经递质的传递，还可能参与了脑缺血早期对神经元损伤的保护作用。

Effect of Transgenic Bt plus CpTI Cotton on Carboxylesterase and Acetylcholinesterase of Cotton Aphid Aphis gossypii

[Objective] The research aimed to assess the effect of transgenic Bt plus CpTI cotton variety SGK321 on carboxylesterase and acetylcholinesterase of cotton aphid Aphis gossypii and provide theoretical basis for studying the biosafety of transgenic cotton.[Method] Cotton aphids were fed with SGK321 and Shiyuan321（normal parental varieties） for over 40 generations.Enzyme activities were compared between cotton aphids feeding on SGK321 for 1,2,3,41,42 and 43 generations with those on Shiyuan321.[Result] The carboxylesterase activity of cotton aphids feeding on SGK321 for 1 generation was significantly higher than those feeding on Shiyuan321.Acetylcholinesterase activity of cotton aphids feeding on SGK321 for 1,2 and 3 generations were significantly higher than those feeding on Shiyuan321 in the same generation.But there was no significant difference of enzyme activity between cotton aphids feeding on SGK321 for a long term and those feeding on parental cotton.[Conclusion] The cotton aphid that feeding on transgenic Bt plus CpTI cotton SGK321 for a long time has adaptivity to SGK321 by regulating the detoxifying enzyme.

Acute toxicity of organochlorine insecticide endosulfan to the giant freshwater prawn Macrobrochium rosenbergii

Endosulfan, an organochlorine pesticide, is highly toxic and effective at controlling pests in agriculture, horticulture, and public health programs. In this study, static bioassays were used to evaluate the toxicity of endosulfan to freshwater prawns( Macrobrachium rosenbergii) of various lengths(1.5±0.03,4±0.08, and 7±0.06 cm). Additionally, the activities of peroxidase(POD), acid phosphatase(ACP),alkaline phosphatase, acetylcholinesterase(AChE), and Na + /K +-ATPase were analyzed to refl ect the effects of endosulfan exposure. The 96 h LC 50 of endosulfan for prawns 1.5, 4, and 7 cm long were 1.86, 4.53,and 6.09μg/L, respectively, improved tolerance to endosulfan with growth. The POD activities of test organisms exposed to low concentrations of endosulfan were inhibited, indicating the presence of oxygen damaged tissue. Moreover, a notable decrease in AChE activity was observed due to overstimulation of neurotransmission, which might result in abnormal behavior. The effect caused by endosulfan on phosphatase production in the hepatopancreas of prawns 1.5, 4, and 7 cm long was different because the ability of nonspecifi c immune regulation increased with growth. The 96 h LC 50 values obtained in this study could be used in the formulation of water-quality criteria in China. Moreover, the changes in enzymes activities of M. rosenbergii under stress of endosulfan could be applied in the establishment of early warning indicators for bio-safety.

Development of a Zebrafish Model for Rapid Drug Screening against Alzheimer＇s Disease

Alzheimer＇s disease, the leading cause of dementia in the elderly, is a complex neurodegenerative disorder which leads to a progressive decline in cognitive functions. A rapid screening model is highly demanded for identification and evaluation of novel anti-Alzheimer＇s disease drugs from a large numbers of compounds. Until now, numerous studies utilized zebrafish model for drug discovery. Since aluminum can induce a similar biological activity in zebrafish as in Alzheimer patients, in this study, we developed a novel animal model using 3 to 5 day post-fertilization larval zebrafish by optimizing the doses and duration of aluminum chloride exposure. Six anti-Alzheimer＇s disease drugs with a variety of mechanisms were tested to validate the newly developed zebrafish model. Importantly, Rivastigmine, ThT, Flurbiprofen and AM-117 could increase the value of Dyskinesia Recovery Rate by 53.4-64%, 169.4-200%, 54.5-96% and 70.9-121%, respectively. Rivastigmine, Memantine, ThT, Flurbiprofen, Rosiglitazone and AM-117 improved the value of Response Efficiency by 86.6-175.1%, 28.2-66.6%, 127.2-236.5%, 118.3-323.7%, 26.6-140.8% and 70.2-161.4%, respectively. Our results suggest that the zebrafish model developed in this study could be a useful tool for high throughput screening of potential novel anti-Alzheimer＇s disease leading compounds targeting acetylcholinesterase, N-methyl-D-aspartic acid receptor, γ-secretase, peroxisome proliferator-activated receptor-γand amyloid-β.

In vitro studies on the multi-target anti-Alzheimer activities of berberine-like alkaloids from Coptidis Rhizoma

Coptidis Rhizoma, a well known heat-clearing Chinese Materia Medica, exhibited multi-target anti-Alzheimer effectsin vitro through inhibition of AI342 aggregation, ACHE, and BACE1. Six berberine-like alkaloids were found to be the majoractive constituents of Coptidis Rhizoma by HPLC analysis along with activity assays. A standard combination of the six majoralkaloids was demonstrated to fully reproduce the in vitro effects of Coptidis Rhizoma. Molecular docking studies revealed thatberberine-like alkaloids could directly bind at the active sites of AI342, ACHE, and BACE1 through hydrophobic interactions,aromatic stacking, and electrostatic interactions.