微波辅助提取金钗石斛多糖的工艺研究

目的:考察金钗石斛多糖的最佳提取工艺。方法:应用微波辅助提取技术,采用单因素试验和正交试验,以多糖的提取率为评价指标,对影响石斛多糖提取工艺的因素进行研究。结果:金钗石斛多糖最佳提取工艺为:微波频率为1470MHz,加30倍量水,浸提3h,微波10m in,在此条件下,金钗石斛粗多糖得率为4.23%。结论:金钗石斛多糖的提取中,微波辅助提取具有提取时间短、提取率高的优点。

金钗石斛多糖减轻脂多糖诱导的大鼠学习记忆减退及机制研究

目的:观察金钗石斛多糖(Dendrobium nobile polysaccharides,DNP)对脂多糖(lipopolysaccharide,LPS)诱导的大鼠学习记忆减退及神经炎症的改善作用。方法:DNP(40、80、160 mg·kg-1·d-1)预防性给药7 d,侧脑室注射20μg LPS制备大鼠学习记忆减退模型。制模后d 5开始,Morris水迷宫法检测大鼠的空间辨别学习记忆能力。行为学检测结束后,HE染色观察大鼠海马神经元的细胞形态改变,RT-PCR及Western Blot分别检测大鼠海马组织中肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)、白介素1β(interleukine-1β,IL-1β)、转化生长因子β1(transforming growth factor-β1,TGF-β1)的m RNA及蛋白表达。结果:与假手术组比较,模型组大鼠在定位航行实验中逃避潜伏期明显延长,在空间探索实验中其校正潜伏期明显缩短;大鼠海马神经元排列散乱,部分神经元丢失,出现核固缩,嗜伊红染色;大鼠海马组织中TNF-α、IL-1β、TGF-β1 m RNA及其蛋白的表达量明显增加。DNP(40、80、160 mg·kg-1·d-1)给药组能改善大鼠学习记忆能力,对抗LPS引起的大鼠海马CA1区神经元损伤,并降低大鼠海马组织中TNF-α、IL-1β、TGF-β1的m RNA及蛋白表达。结论:DNP可减轻LPS诱导的大鼠学习记忆减退及神经元损伤,抑制其海马的炎症反应。

Dendrobium nobile Lindl. alkaloids alleviate Mn-induced neurotoxicity via PINK1/Parkinmediated mitophagy in PC12 cells

OBJECTIVE Activation of the PINK1/Parkin-mediated autophagy pathway has been proposed to play a protective role in the development of neurological disorders through the elimination of damaged macromolecules or organelles.Exposure to excessive manganese(Mn) causes neurotoxicity and can produce a Parkinson disease(PD)-like neurological disorder.Mitochondrial dysfunction and oxidative stress are implicated in the mechanism of Mn induced neurotoxicity.The present study was designed to determine whether Dendrobium nobile Lindl.alkaloids(DNLA),a Chinese medicinal herb extract,confers protective function over Mn-induced cell toxicity,and to investigate whether the modulation of PINK1/Parkin-mediated autophagy is involved in the mechanism of DNLA-mediated cell protection over Mn toxicity.METHODS AND RESULTS Rat adrenal pheochromocytoma PC12 cells were utilized as an in vitro model of Mn cell toxicity.It was found that the treatment of the PC12 cells with Mn resulted in concentration-dependent cell death,accompanied by a decrease in mitochondrial respiration capacity and an increase in ROS generation,whereas pretreatment of cells with DNLA significantly alleviated cell toxicity induced by Mn and improved mitochondrial function and oxidative status.Mn treatment enhanced apoptotic cells along with a marked increase in the protein expression of Bax and a decrease in the expression of Bcl-2 protein.On the contrary,DNLA increased Bcl-2 expression,and concomitantly dramatically decreased the Bax/Bcl-2 ratio.Analysis of the expression of PINK1 and Parkin revealed that pretreatment of cells with DNLA significantly alleviated the decrease in protein levels of both PINK1 and Parkin caused by Mn.Furthermore,cells treated with Mn exhibited increased expression of LC3-Ⅱ and a decrease in accumulation of P62,which was noticeably reversed by the pretreatment of cells with DNLA.CONCLUSION DNLA inhibits Mn induced cytotoxicity,which may be mediated through modulating PINK1/Parkin-mediated autophagic flux and improving mitochondrial function.

不同施肥处理对金钗石斛光合特性的影响

以贵州省赤水市金钗石斛(Dendrobium nobile Lindl)苗为试验材料,通过不同施肥处理进行单因素分析和正交试验,采用Li-6400型便携式光合作用测量系统(Li-Cor,USA),对金钗石斛光合特性的有关参数进行测试。结果表明,施用Hoaglan营养液能有效改善金钗石斛的净光合速率,光合速率的快慢与金钗石斛气孔导度呈正相关,气孔导度日变化与蒸腾速率日变化有直接关系,所有因子中钾肥对净光合速率、蒸腾速率影响较大,均达显著水平,而影响气孔导度的是氮肥,生产中应合理施用钾肥、氮肥。

中药体外抑制大肠杆菌实验研究

目的:探讨中药提取物对大肠杆菌的体外抑菌作用。方法:选用五倍子、白芷、金钗石斛、丁香、川芎、当归6种中药,采用醇提法和水提法提取其有效成分,并使用平板打孔法和二倍比稀释法测定中药提取物对大肠杆菌的抑菌效果。结果:五倍子和丁香的醇提取物和水提取物都有显著的抑菌效果,最小抑菌浓度分别为0.390 625 g·L^(-1)、0.781 25g·L^(-1),金叉石斛的醇提取物也有显著的抑菌效果,其最低抑菌浓度为6.25 g·L^(-1),而其他3种药物抑菌作用相对较弱。结论:6味中药对大肠杆菌均有不同程度的抑制作用,其中五倍子的作用最强,其次是丁香和金叉石斛,其他3种抑菌效果弱。

基于表型性状的金钗石斛种质资源多样性评价

金钗石斛是我国重要的经济作物,具有药用和观赏价值。对收集的17个居群的野生金钗石斛植株形态、花、气孔、有效成分含量等表型性状进行统计分析和多样性评价,并进行亲缘关系的系统聚类分析。结果表明,不同居群金钗石斛在表型性状上存在明显差异,种质资源具有丰富的遗传多样性;以变异系数较低的7个表型性状为参数进一步进行系统聚类分析,当欧式距离为10时,金钗石斛居群分成三组,其中海南白沙居群独立成一组,表明岛屿隔离阻碍了基因交流,对金钗石斛的生物多样性的贡献较大,因此岛屿为金钗石斛种质资源的就地保护和遗传资源有效维护提供了重要场所,为金钗石斛种质资源的保护和利用奠定了理论基础。