Toosendanin-induced change of dopamine level detected by microdialysisin vivo at rat striatum

To investigate the effect on central nervous transmission of toosendanin (TSN), a presynaptic blocker, rat striatum was perfusedin vivo with a TSN-containing artificial cerebrospinal fluid (ACSF) and the level of dopamine (DA) as well as related metabolites in the collected dialysates has been determined by a microbore HPLC with electrochemical detection (microbore HPLC-ECD). The results are as follows: ( i ) TSN induced a biphasic change of DA from its basal level;( ii ) the basal contents of two metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) increased in turn and stayed at a higher level than basal control for a long period. The basal level of 5-hydroxyindoleacetic acid (5-HIAA), a metabolite of 5-hydroxytryptamine(5-HT), had a change similar to that of HVA; ( iii ) after perfusion with TSN-containing ACSF, high K₊-evoked DA release was inhibited. These results show that TSN does not selectively affect acetylcholine (ACh) release, but probably acts on a common mechanism responsible for transmitter release at different synapses by interfering with the proteins involved in fusian and resulting in diffusion of the vesicular contents into the cytoplasm and blockade of normal exocytosis.     

川楝素抗肿瘤作用机制研究进展

川楝素(toosendanin)是从楝属植物的根茎及川楝果实(川楝子)中提取的一种三萜化合物。经研究证明其通过影响K+、Ca2+通道活性作用于神经系统、呼吸系统、神经肌肉接头及消化系统。近年来研究证明其通过诱导细胞分化及凋亡从而具有抗肿瘤作用,本文综述了川楝素的抗肿瘤作用及机制,为临床开发应用提供参考。     

川楝素对骨骼肌、平滑肌和心肌收缩的作用

川楝素能轻度可逆地增强箭毒化及去神经骨骼肌由直接刺激引起的收缩反应.当用Sr~(2+)代替溶液中的Ca~(2+)时,这种正肌力作用仍能出现.川楝素对豚鼠平滑肌的自发收缩亦有增强作用,但川楝素对大鼠心肌由直接电刺激引起的收缩反应则具有负肌力作用.     

RP-HPLC法测定川楝子水提醇沉提取物中川楝素的含量

建立川楝子水提醇沉提取物中川楝素含量测定的反相高效液相色谱法。采用Diamonsil TMC18柱(250×4.6 mm,5μm);流动相为乙腈-水(40∶60);流速为1.2 mL.min-1;检测波长为220 nm,柱温为25℃,进样量20μL。川楝素检测浓度在(10.39～249.36)μg.mL-1范围内与川楝素峰面积呈良好的线性关系(r=0.999 9,n=6);平均加样回收率为99.52%,RSD为0.81%。建立了简便、快速、准确、重复性好的川楝子水体醇沉提取物中川楝素的RP-HPLC含量测定方法。     

微波辅助提取川楝素的方法研究

利用微波效应，以水为溶剂提取川楝素．研究了微波功率、微波占空比、微波作用时间、溶剂用量等因素对川楝素提取率的影响．确定最佳的提取工艺条件为：微波功率300W，微波作用时间10min，固液比为1：30，微波占空比50％．提供了一条以水为溶剂、微波为热源提取川楝素的绿色化学途径。     

超声波提取川楝素的方法研究

运用超声波技术从川楝树韧皮中提取川楝素,并与常规方法进行了比较,超声波提取川楝素具有省时、节能、提取率高等优点.实验条件:超声波协助提取法的最佳工艺参数为:固液比为1/20,提取时间为30 min,提取3次.在优化条件下,川楝素的提取率为3.25 mg·g-1.