雷公藤减毒研究进展

雷公藤为治疗类风湿性关节炎常用中药,具有清热解毒,祛风除湿,消肿止痛,杀虫止痒的功用,现代药理研究表明其具有抗炎、镇痛、抗肿瘤及免疫调节等作用,临床主要用于治疗免疫性疾病、肾脏性疾病、皮肤性疾病等,对类风湿性关节炎的疗效尤为显著。但严重的毒副作用,尤其是肝肾毒性,限制了其临床应用,成为迫切需要解决的难题,故雷公藤的减毒研究成为近年来的研究热点。本课题组主要研究雷公藤的经皮给药对其减毒增效的作用,但目前雷公藤的应用困境仍然没有得到改善,故对2006年至2016年近10年来雷公藤减毒研究的相关文献进行检索,包括传统的炮制减毒、配伍减毒和现代的制剂减毒、结构修饰减毒、生物技术减毒以及其相互的联合应用等,分析雷公藤的减毒现状和困境,对比现存减毒方式间的差异,为雷公藤减毒增效研究提供思路,促进其合理开发和临床安全应用,也为其他有毒中药的合理应用提供参考。     

从自噬角度研究雷公藤甲素引起HepG2细胞肝毒性的机制

目的:探讨雷公藤甲素(TP)对HepG2细胞的过氧化损伤及对自噬的调控作用。方法:将质量浓度为0.003 2,0.016,0.08,0.4,2 g·L~(-1)的TP作用于体外培养的HepG2细胞48 h,另设空白组做对比,采用噻唑蓝(MTT)法检测细胞生长活性,采用酶联免疫吸附测定(ELISA)法检测超氧化物歧化酶(SOD),谷胱甘肽过氧化物酶(GSH-Px)的活性,采用蛋白质免疫印迹(Western blot)法检测自噬相关蛋白微管相关蛋白轻链3(LC3Ⅱ)与Beclin1蛋白的表达情况,用免疫荧光法检测自噬相关蛋白LC3的表达情况。结果:与空白组比较,随着TP质量浓度的增加,HepG2活性下降(P0.05,P0.01);检测细胞上清中SOD,GSH-Px的活性,均较空白组降低(P0.05,P0.01);Western blot表明TP可上调LC3Ⅱ与Beclin1蛋白水平的表达(P0.05,P0.01),免疫荧光法同样表明TP能够引起自噬相关蛋白LC3表达的增多(P0.05,P0.01),均具有一定的浓度依赖性。结论:一定质量浓度的TP可造成肝细胞损伤,其损伤机制可能与过氧化损伤以及过氧化损伤导致的自噬过度激活有关。     

经皮穴位电刺激不同时间对雷公藤甲素致大鼠急性肝损伤的影响

目的 观察经皮穴位电刺激（transcutanclus electrical acupoint stimulation,TEAS）不同刺激时间对雷公藤甲素致大鼠急性肝损伤的保护作用。方法 将50只SD大鼠随机分为空白组、模型组、TEAS Ⅰ组（刺激20 min）,TEAS Ⅱ组（刺激30 min）、TEAS Ⅲ组（刺激40 min）,以雷公藤甲素灌胃法复制急性肝损伤模型。TEAS各组刺激“足三里”穴,每日1次,连续5 d。观察肝脏组织形态学变化,检测血清天冬氨酸氨基转移酶（aspartate aminotransferase,AST）、丙氨酸氨基转移酶（alanine aminotransferase,ALT）及肝组织丙二醛（malondialdehyde,MDA）、肿瘤坏死因子- α（tumor necrosis factor- α,TNF- α）、白介素- 10（interleukin- 10,IL- 10）、硫化氢的含量。结果 模型组大鼠肝索排列紊乱,肝窦扩张,肝细胞水肿、脂肪变性、坏死;各TEAS组肝脏病理变化较模型组减轻。与空白组比较,模型组大鼠血清ALT、AST及肝组织MDA、TNF- α含量明显升高（P＜0.05）,硫化氢含量明显降低（P＜0.05）,肝组织IL- 10含量无明显变化（P＞0.05）。与模型组比较,TEAS Ⅰ、Ⅱ、Ⅲ组大鼠血清AST、ALT含量和肝组织MDA、TNF- α含量明显降低（P<0.05）或呈降低趋势（P>0.05）,硫化氢含量明显升高（P<0.05）。其中TEAS Ⅲ组与TEAS Ⅰ、Ⅱ组各指标比较,差异均具有统计学意义（P＜0.05）。结论 TEAS能减轻雷公藤甲素对肝组织的损伤,且较长时间（40 min）刺激的保护作用更为明显。     

Modulation of IL-37 expression by triptolide and triptonide in THP-1 cells

IL-37 is an anti-inflammatory cytokine that was only recently identified, and it is highly expressed in tissues from patients with inflammatory and autoimmune diseases. Inflammatory cytokines and inflammatory stimuli can induce the upregulation of IL-37. However, it has not been reported whether anti-inflammatory medications induce the expression of IL-37. In this work, we uncovered, for the first time, that two main bioactive components, triptolide and triptonide, from the herb Tripterygium wilfordii Hook f. (TwHF), which possess anti-inflammatory activity, upregulate the expression of IL-37, and this expression was suppressed by ERK1/2 and p38 MAPK inhibitors. Overall, our research demonstrated, for the first time, that anti-inflammatory active components (triptolide and triptonide) upregulated the expression of IL-37 most likely via activation of the ERK1/2 and p38 MAPK pathways.     

Triptolide inhibits human breast cancer MCF-7 cell growth via downregulation of the ERα-mediated signaling pathway

Aim:

To investigate the anticancer mechanisms of triptolide, a diterpenoid isolated from the plant Tripterygium wilfordii Hook F, against human breast cancer cells and the involvement of the estrogen receptor-α (ERα)-mediated signaling pathway in particular.

Methods:

Human breast cancer ERα-positive MCF-7 cells and ERα-negative MDA-MB-231 cells were tested. PrestoBlue assay was used to evaluate the cell viability. The levels of ERα mRNA and protein were detected with real-time PCR and immunoblotting, respectively. Mouse models of MCF-7 or MDA-MB-231 xenograft tumors were treated with triptolide (0.4 mg·kg⁻¹·d⁻¹, po) or a selective estrogen receptor modulator tamoxifen (mg·kg⁻¹·d⁻¹, po) for 3 weeks, and the tumor weight and volume were measured.

Results:

Triptolide (5–200 nmol/L) dose-dependently inhibited the viability of both MCF-7 and MDA-MB-231 cells, with a more potent inhibition on MCF-7 cells. Knockdown of ERα in MCF-7 cells by siRNA significantly attenuated the cytotoxicity of triptolide, whereas overexpression of ERα in MDA-MB-231 cells markedly enhanced the cytotoxicity. Triptolide dose-dependently decreased the expression of ERα in MCF-7 cells and MCF-7 xenograft tumors. Furthermore, treatment of MCF-7 cells with triptolide inhibited the phosphorylation of ERK1/2 in dose- and time-dependent manners. In the mice xenografted with MCF-7 cells, treatment with triptolide or tamoxifen resulted in significant reduction in the tumor weight and volume. Similar effects were not obtained in the mice xenografted with MDA-MB-231 cells.

Conclusion:

The anticancer activity of triptolide against ERα-positive human breast cancer is partially mediated by downregulation of the ERα-mediated signaling pathway.     

雷公藤内酯醇的细胞内定位研究?

目的：检测雷公藤内酯醇的细胞内定位,探讨其在细胞内的作用位点。方法采用4-溴甲基-7-甲氧基香豆素标记雷公藤内酯醇,与人肝癌细胞孵育;并与细胞核染料 PI 或细胞质膜染料 DiI 行双色荧光染色,用荧光显微镜观察。结果与对照相比,香豆素标记在紫外激发下呈特异性的淡蓝色荧光;与 DiI 共定位显示,香豆素标记在细胞质(膜)存在;与 PI 共定位显示,香豆素标记在细胞核存在,且荧光强于细胞质(膜)。结论雷公藤内酯醇在细胞内主要位于细胞核,其次是细胞质(膜),提示雷公藤内酯醇可能主要在细胞核内起作用,其次是在细胞质(膜)上起作用。     

UPLC-MS/MS法测定大鼠血浆中雷公藤内酯醇及其药代动力学

目的建立大鼠血浆中雷公藤内酯醇的超高效液相色谱质谱联用(ultra performance liquid chromatography-mass spectrometer/mass spectrometer,UPLC-MS/MS)法测定大鼠灌胃给药与静脉注射给药后的血浆药物浓度,并进行药代动力学参数评价。方法 Sprague Dawley大鼠分别经灌胃与尾静脉注射给药,经颈静脉取血,测定不同时间的大鼠血浆药物浓度,并计算其主要药代动力学参数。结果在0.1~200.0 ng/m L质量浓度范围内,血浆雷公藤内酯醇线性关系良好,血浆中雷公藤内酯醇的定量限为0.1 ng/m L,该药稳定性良好,回收率均在95%以上,日内与日间差异均小于15%。口服与静脉给药后,雷公藤内酯醇在大鼠体内的消除均较快,口服生物利用度为9.5%。结论本实验操作简便、稳定可靠、检测限低、效率高、重现性好,可以可靠地用于雷公藤内酯醇血药浓度测定及其药代动力学研究,本研究结果为雷公藤内酯醇的结构优化、剂型改进以及临床应用提供了实验依据。     

Effects of triptolide on hippocampal microglial cells and astrocytes in the APP/PS1 double transgenic mouse model of Alzheimer’s disease

The principal pathology of Alzheimer's disease includes neuronal extracellular deposition of amyloid-beta peptides and formation of senile pl aques,which in turn induce neuroinflammation in the brain.Triptolide,a natural extract from the vine-like herb Tripterygium wilfordii Hook F,has potent anti-inflammatory and immunosuppressive efficacy.Therefore,we determined if triptolide can inhibit activation and proliferation of microglial cells and astrocytes in the APP/PS1 double transgenic mouse model of Alzheimer's disease.We used 1 or 5 μg/kg/d triptolide to treat APP/PS1 double transgenic mice(aged 4–4.5 months) for 45 days.Unbiased stereology analysis found that triptolide dose-dependently reduced the total number of microglial cells,and transformed microglial cells into the resting state.Further,triptolide(5 μg/kg/d) also reduced the total number of hippocampal astrocytes.Our in vivo test results indicate that triptolide suppresses activation and proliferation of microglial cells and astrocytes in the hippocampus of APP/PS1 double transgenic mice with Alzheimer's disease.     

雷公藤配伍白芍对雷公藤提取物透皮吸收的影响

目的:考察雷公藤与白芍配伍后对雷公藤甲素和2种生物碱类成分(雷公藤吉碱、雷公藤次碱)透皮吸收的影响,从经皮转运的角度探讨雷公藤与白芍配伍减毒的机制。方法:采用改良Franz扩散池,以小鼠离体腹部皮肤为透皮屏障,以20%乙醇生理盐水为接收介质,通过HPLC测定接收液中雷公藤甲素(流动相乙腈-水梯度洗脱,检测波长220 nm)和雷公藤吉碱、雷公藤次碱[流动相乙腈-0.1%磷酸水溶液(57∶43),检测波长230 nm]的含量,计算其累积渗透量和稳态透皮速率等渗透动力学参数。结果:与雷公藤乳膏相比,雷公藤-白芍配伍乳膏均能降低雷公藤吉碱、雷公藤次碱的累积通过量,但对雷公藤甲素的累积透过量无影响;其中雷公藤-白芍以比例1∶2和1∶3配伍的乳膏中雷公藤吉碱和雷公藤次碱的24 h累积透过量呈明显的降低趋势。结论:雷公藤与白芍配伍经皮给药能降低毒性成分的透过量,同时不影响主要活性物质雷公藤甲素的透过量,从而达到了减毒增效的作用。