雷公藤内酯醇对人肺癌细胞增殖抑制及放疗增敏作用

目的:探讨雷公藤内酯醇对人肺癌细胞A549增殖抑制及放疗增敏作用。方法:以人肺癌细胞株A549为研究对象,用CCK-8法和流式细胞技术检测雷公藤内酯醇对肺癌细胞增殖的影响和肺癌细胞放射敏感性的改变。结果:CCK-8法检测雷公藤内酯醇对A549的生长有显著抑制作用且具有剂量依赖性,与阴性对照组对比差异有统计学意义(p0.05)。雷公藤内酯醇能使处于G0/G1、G2/M期的细胞减少,S期细胞增加。同时,雷公藤内酯醇对A549放疗具有增敏作用。结论:雷公藤内酯醇可抑制人肺癌细胞增殖,可能与影响细胞周期有关;雷公藤内酯醇能增强肺癌细胞放射敏感性。     

雷公藤内酯醇对 PC12细胞增殖的抑制作用及机制初探

目的:研究雷公藤内酯醇(triptolide)对PC12细胞增殖的影响及其作用的机制,为其在临床上治疗肿瘤提供实验依据.方法:利用形态学观察、四甲基偶氮唑(MTT)比色分析、流式细胞术和逆转录聚合酶链式反应(RTPCR)检测雷公藤内酯醇对体外培养的嗜铬细胞瘤细胞(PC12 cell)增殖的影响.结果:雷公藤内酯醇(5×103、25×103 g/L)与PC12细胞作用24 h、48 h或72 h均可抑制PC12细胞的增殖,并且这种抑制作用可随着雷公藤内酯醇浓度的增加而增强.但低浓度的雷公藤内酯醇(1×103g/L)对PC12细胞增殖无明显影响.5×103 g/L雷公藤内酯醇与PC12细胞作用24 h后,可使细胞周期中的G0～G1期比例增加,S期比例下降.PC12细胞与雷公藤内酯醇作用后,细胞的翻译延伸因子2A3-2的表达减弱,而且作用48 h与作用24 h相比,2A3-2的表达减弱更为明显.结论:雷公藤内酯醇可抑制PC12细胞的增殖,该抑制可能是通过改变2A3-2基因的表达从而阻止细胞的G0～G1期向S期过渡来实现的.     

双氯雷公藤内酯四醇的分离与结构研究

从雷公藤（Ｔｒｉｐｔｅｒｙｇｉｕｍ ｗ ｉｌｆｏｒｄｉｉＨｏｏｋ．ｆ．）的叶中分离出１个新的含氯环氧二萜内酯化合物。据其理化数据和光谱分析,并结合分子图形学和分子力学计算,确定了它的化学结构,命名为双氯雷公藤内酯四醇（ｄｉｃｈｌｏｒｏｔｒｉｐｔｅｔｒａｏｌｉｄｅ）。     

抗褐变剂对雷公藤愈伤组织生长和次生代谢产物含量的影响

以雷公藤（Tripterygium wilfordii Hook f.）根愈伤组织为材料,以NT为基本培养基,添加不同浓度硫代硫酸钠、抗坏血酸、柠檬酸、硝酸银、聚乙烯吡咯烷酮以及活性炭,探讨抗褐变剂对雷公藤愈伤组织生长、抗褐化和雷公藤内酯醇及总生物碱含量的影响。结果表明：除较低浓度柠檬酸以外,其他抗褐变剂均不同程度抑制雷公藤愈伤组织的生长。培养基中添加不同浓度硫代硫酸钠、抗坏血酸、柠檬酸、聚乙烯吡咯烷酮以及活性炭,雷公藤愈伤组织褐化程度不但没有得到控制,反而使褐化加重。但所有处理中,愈伤组织中内酯醇含量明显升高,其中加入50mg/L柠檬酸处理的内酯醇含量为对照的2.4倍。培养基中加入10～50mg/L硝酸银不仅能抑制雷公藤愈伤组织褐变,内酯醇的含量也随着硝酸银浓度的增加而增加。供试抗褐变剂中除较低浓度硫代硫酸钠以外,其他处理对雷公藤总生物碱的合成起抑制作用。     

雷公藤内酯醇C14位羟基结构修饰及抗肿瘤活性研究进展

雷公藤是我国资源丰富的一种传统中草药,具有抗炎、抗肿瘤、免疫抑制等多种生物活性。本文综述了近年来雷公藤内酯醇C14位羟基的结构修饰和抗肿瘤活性的研究进展。     

昆明山海棠茎中化合物的分离及其抗炎活性

从昆明山海棠茎的氯仿提取物中分离得到6个化合物,经鉴定为雷公藤内酯甲(Ⅰ)、昆明山海棠二萜内酯(Ⅱ)、雷公藤内酯乙(Ⅲ)、雷酚二萜酸(Ⅳ)、雷公藤碱(Ⅴ)及3-epikatonic acid(Ⅵ)。其中,化合物Ⅲ及Ⅵ为首次从该植物中分离得到,化合物Ⅴ为首次从该植物茎中分离得到。药理实验显示化合物Ⅰ和Ⅱ对大鼠足跖部角叉菜胶炎症模型具有明显的抑制作用。     

雷公藤内酯醇阳离子聚合物肝细胞毒性及其对乳腺癌干细胞影响的研究

该文观察了雷公藤内酯醇阳离子聚合物(TPL-PEI-Cy D)对乳腺癌干细胞的影响。采用CCK-8测定TPL-PEI-Cy D、雷公藤内酯醇(TPL)对HL-7702细胞的毒性,用TGF-β1孵育培养MCF-7细胞,流式细胞仪检测其中CD_(44)~+CD_(24)~–标志的细胞比例;免疫磁珠法分选其中CD_(44)~+CD_(24)~–细胞群;TPL-PEI-Cy D作用于MCF-7干细胞后,流式细胞术检测其中CD_(44)~+CD_(24)~–细胞比例的变化。雷公藤内酯醇在接入聚乙烯亚胺–环糊精后,对肝细胞的毒性较雷公藤内酯醇单体显著降低(P0.05),用TGF-β1培养能富集高比例的乳腺癌干细胞;免疫磁珠分选法从中分离出肿瘤干细胞;TPL-PEI-Cy D较TPL更高效地抑制MCF-7干细胞后中CD_(44)~+CD_(24)~–细胞的比例(P0.05)。结果说明,TPL-PEI-Cy D的肝细胞毒性降低且能高效地抑制乳腺癌干细胞的性能,有望开发成为治疗乳腺癌的中药新制剂。     

摇瓶培养条件下雷公藤不定根生长及次生代谢产物含量的研究

以雷公藤(Tripterygium wilfordii Hook. f.)不定根为材料,研究摇瓶悬浮培养条件下接种密度、装液比例、逐级放大、消泡剂、大孔吸附树脂种类及浓度对雷公藤不定根增长量、不定根及培养基中雷公藤内酯醇、雷公藤吉碱、雷公藤次碱含量的影响。结果显示,接种密度在15 g/L (FW)时较适合不定根的继代培养和次生代谢产物的积累。250 m L摇瓶中装入100 m L培养基,即装液量为2/5时,培养基利用率最高。随着摇瓶体积的逐渐放大,不定根增长量和3种次生代谢产物含量略有下降,5 L摇瓶中不定根增长量为对照的91.6%,内酯醇、吉碱和次碱的含量分别为对照的91.8%、91.7%和96.9%。6种大孔吸附树脂中,XAD-7处理对不定根的生长有明显促进作用,培养结束时,3种次生代谢产物产量显著提高,当XAD-7浓度为0.5 g/瓶时不定根增长量为对照的1.2倍,内酯醇、吉碱和次碱产量最高,分别为对照的2.9、2.4和2.2倍。培养基中添加消泡剂后不定根增长量、3种次生代谢产物总产量均不同程度下降,其中,LX-603处理后,虽然不定根增长量为对照的85%,内酯醇、吉碱和次碱产量分别为对照的78%、64%和87%,但明显抑制了培养过程中泡沫的产生。研究结果表明筛选的摇瓶逐级放大培养雷公藤不定根的方法效果较好,可为雷公藤不定根生物反应器放大培养奠定基础。     

雷公藤不定根两相培养初步研究

以雷公藤(Tripterygium wilfordii)不定根为材料,通过两相培养技术,研究有机溶剂邻苯二甲酸二丁酯(DBP)不同浓度及培养时间对雷公藤不定根生长及次生代谢产物含量的影响。结果显示,DBP浓度为6%、培养至第6 d时,不定根增长量达1.14 g/瓶,为对照(1.08 g/瓶)的1.06倍;DBP浓度为2%、培养至第8 d时,内酯醇含量达74.96μg/g,为对照(53.67μg/g)的1.40倍;DBP浓度为2%、培养至第2 d时,所收获的内酯醇总产量最高(0.40 mg/瓶),且为对照(0.27 mg/瓶)的1.48倍。本研究结果表明,在培养基中添加一定浓度DBP,虽然适合雷公藤内酯醇的形成,但不适合雷公藤生物碱的形成;不论添加DBP浓度大小、培养时间长短,不定根中吉碱和次碱含量及每瓶总产量均低于对照。     

东北雷公藤三萜成分的研究

从东北雷公藤(Tripterygium regeli)根的乙醇提取物分得10种三萜化合物,经波谱分析和化学转化,鉴定为雷公藤内酯甲(wilforlide A 1)、雷公藤内酯乙(wilfo rlide B 2)、黑蔓内酯(regelide 3)、3β-羟基-11,13(18)-齐墩果二烯(3β-hydroxy-olean-11,13(18)-diene4)、orthosphenic acid(5)、salaspermic acid(6)、3-epikatonic acid(7)、maytenfolic acid(8)、3β-acecyl-oleanolic acid(9)和南蛇藤素(celastrol 10)。化合物3—10首次从该植物分得,3是新化合物.     

Triptolide derivatives as potential multifunctional anti-Alzheimer agents: Synthesis and structure–activity relationship studies

Owning to the promising neuroprotective profile and the ability to cross the blood–brain barrier, triptolide has attracted extensive attention. Although its limited solubility and toxicity have greatly hindered clinical translation, triptolide has nonetheless emerged as a promising candidate for structure–activity relationship studies for Alzheimer’s disease. In the present study, a series of triptolide analogs were designed and synthesized, and their neuroprotective and anti-neuroinflammatory effects were then tested using a cell culture model. Among the triptolide derivatives tested, a memantine conjugate, compound 8, showed a remarkable neuroprotective effect against Aβ_1–42 toxicity in primary cortical neuron cultures as well as an inhibitory effect against LPS-induced TNF-α production in BV2 cells at a subnanomolar concentration. Our findings provide insight into the different pharmacophores that are responsible for the multifunctional effects of triptolide in the central nervous system. Our study should help in the development of triptolide-based multifunctional anti-Alzheimer drugs.     

异戊烯基焦磷酸转运对雷公藤甲素生物合成的影响

雷公藤甲素是一种具有显著抗炎、抗肿瘤和免疫抑制活性的天然产物,市场需求量大,临床应用前景广阔.文中以雷公藤悬浮细胞为实验材料,通过对不同培养时期(7d、14 d)的细胞外源性添加D,L-甘油醛(DLG)以阻断异戊烯基焦磷酸(IPP)转运,分析诱导前后的细胞活性及生物量、雷公藤甲素累积量及其生物合成上游途径关键酶基因的变...     

Triptolide Preserves Cognitive Function and Reduces Neuropathology in a Mouse Model of Alzheimer's Disease

Triptolide, a major bioactive ingredient of a widely used herbal medicine, has been shown to possess multiple pharmacological functions, including potential neuroprotective effects pertinent to Alzheimer''s disease (AD) in vitro. However, the therapeutic potential of triptolide for AD in vivo has not been thoroughly evaluated. In the present study, we investigated the impact of peripherally administered triptolide on AD-related behavior and neuropathology in APP_swe/PS1_ΔE9 (APP/PS1) mice, an established model of AD. Our results showed that two-month treatment with triptolide rescued cognitive function in APP/PS1 mice. Immunohistochemical analyses indicated that triptolide treatment led to a significant decrease in amyloid-β (Aβ) deposition and neuroinflammation in treated mice. In contrast to previous findings in vitro, biochemical analyses showed that triptolide treatment did not significantly affect the production pathway of Aβ in vivo. Intriguingly, further analyses revealed that triptolide treatment upregulated the level of insulin-degrading enzyme, a major Aβ-degrading enzyme in the brain, indicating that triptolide treatment reduced Aβ pathology by enhancing the proteolytic degradation of Aβ. Our findings demonstrate that triptolide treatment ameliorates key behavioral and neuropathological changes found in AD, suggesting that triptolide may serve as a potential therapeutic agent for AD.     

Activation of Nrf2 Protects against Triptolide-Induced Hepatotoxicity

Triptolide, the major active component of Tripterygium wilfordii Hook f. (TWHF), has a wide range of pharmacological activities. However, the toxicities of triptolide, particularly the hepatotoxicity, limit its clinical application. The hepatotoxicity of triptolide has not been well characterized yet. The aim of this study was to investigate the role of NF-E2-related factor 2 (Nrf2) in triptolide-induced toxicity and whether activation of Nrf2 could protect against triptolide-induced hepatotoxicity. The results showed that triptolide caused oxidative stress and cell damage in HepG2 cells, and these toxic effects could be aggravated by Nrf2 knockdown or be counteracted by overexpression of Nrf2. Treatment with a typical Nrf2 agonist, sulforaphane (SFN), attenuated triptolide-induced liver dysfunction, structural damage, glutathione depletion and decrease in antioxidant enzymes in BALB/C mice. Moreover, the hepatoprotective effect of SFN on triptolide-induced liver injury was associated with the activation of Nrf2 and its downstream targets. Collectively, these results indicate that Nrf2 activation protects against triptolide-induced hepatotoxicity.     

Triptolide Induces Growth Inhibition and Apoptosis of Human Laryngocarcinoma Cells by Enhancing p53 Activities and Suppressing E6-Mediated p53 Degradation

Triptolide, an active compound extracted from Chinese herb Leigongteng (Tripterygium wilfordii Hook F.), shows a broad-spectrum of anticancer activity through its cytotoxicity. However, the efficacy of triptolide on laryngocarcinoma rarely been evaluated, and the mechanism by which triptolide-induced cellular apoptosis is still not well understood. In this study, we found that triptolide significantly inhibited the laryngocarcinoma HEp-2 cells proliferation, migration and survivability. Triptolide induces HEp-2 cell cycle arrest at the G1 phase and apoptosis through intrinsic and extrinsic pathways since both caspase-8 and -9 are activated. Moreover, triptolide enhances p53 expression by increasing its stability via down-regulation of E6 and E6AP. Increased p53 transactivates down-stream target genes to initiate apoptosis. In addition, we found that short time treatment with triptolide induced DNA damage, which was consistent with the increase in p53. Furthermore, the cytotoxicity of triptolide is decreased by p53 knockdown or use of caspases inhibitor. In conclusion, our results demonstrated that triptolide inhibits cell proliferation and induces apoptosis in laryngocarcinoma cells by enhancing p53 expression and activating p53 functions through induction of DNA damage and suppression of E6 mediated p53 degradation. These studies indicate that triptolide is a potential anti-laryngocarcinoma drug.     

Fluorination of triptolide and its analogues and their cytotoxicity

The reaction of triptolide and its analogues with a fluorinating agent, that is, bis(2-methoxyethyl)aminosulfur trifluoride (Deoxo-Fluor) or (diethylamino)sulfur trifluoride (DAST), was studied. One of the fluorinated products, 14beta-dehydroxy-14beta-fluoro triptolide, was found to be more cytotoxic than the parent natural triptolide.     

Triptolide (PG-490) induces apoptosis of dendritic cells through sequential p38 MAP kinase phosphorylation and caspase 3 activation

Dendritic cells (DCs) are the most potent antigen-presenting cells that play crucial roles in the regulation of immune response. Triptolide, an active component purified from the medicinal plant Tripterygium wilfordii Hook F., has been demonstrated to act as a potent immunosuppressive drug capable of inhibiting T cell activation and proliferation. However, little is known about the effects of triptolide on DCs. The present study shows that triptolide does not affect phenotypic differentiation and LPS-induced maturation of murine DCs. But triptolide can dramatically reduce cell recovery by inducing apoptosis of DCs at concentration as low as 10ng/ml, as demonstrated by phosphatidylserine exposure, mitochondria potential decrease, and nuclear DNA condensation. Triptolide induces activation of p38 in DCs, which precedes the activation of caspase 3. SB203580, a specific kinase inhibitor for p38, can block the activation of caspase 3 and inhibit the resultant apoptosis of DCs. Our results suggest that the anti-inflammatory and immunosuppressive activities of triptolide may be due, in part, to its apoptosis-inducing effects on DCs.     

Triptolide attenuate the oxidative stress induced by LPS/D-GalN in mice

Triptolide, a diterpene triepoxide, is one of the major components of most functional extracts of Tripterygium wilfordii Hook f, which is known to have various biological effects, including immunosuppressive, anti-inflammatory and anti-tumor functions. We studied the inhibitory effect of triptolide on endotoxemia (ETM)-induced oxidative stress, which was induced in C57BL/6 mice by lipopolysaccharide (LPS) and D-galactosamine (D-GalN). Pretreatment with triptolide decreased the reactive oxygen species (ROS) levels, mortality rate and liver injury after LPS/D-GalN injection. We utilized comprehensive proteomics to identify alterations in liver protein expression during pretreatment with triptolide or N-acetylcysteine (NAC) after LPS/D-GalN injection, 44 proteins were found to be related to oxidative stress, mitochondria, metabolism and signal transduction, and 23 proteins of them seemed to be significantly up- or down-regulated. Furthermore, both triptolide and NAC inhibited activation of c-jun NH2-terminal kinases (JNK) and mitogen-activated protein kinase p38 (p38), phosphorylation of inhibitor of nuclear factor-kappa B (IκB) and activation of nuclear factor-κB (NF-κB). These results demonstrated that triptolide inhibited the activation of JNK and p38 by decreasing ROS levels, which in turn inhibited the hepatic injury. In addition, we set and validated the phosphorylation model of extracellular signal-regulated kinase (ERK) and proposed that triptolide probably induced ERK phosphorylation through inhibiting its dephosphorylation rates. These results showed that triptolide can effectively reduce the oxidative stress and partially rescue the damage in the liver induced by LPS/D-GalN.     

Autophagy in pancreatic cancer

Pancreatic cancer, the fourth leading cause of cancer-related death in the United States, is resistant to current chemotherapies. Therefore, identification of different pathways of cell death is important to develop novel therapeutics. Our previous study has shown that triptolide, a diterpene triepoxide, inhibits the growth of pancreatic cancer cells in vitro and prevents tumor growth in vivo. However, the mechanism by which triptolide kills pancreatic cancer cells was not known, hence, this study aimed at elucidating it. Our study reveals that triptolide kills diverse types of pancreatic cancer cells by two different pathways; it induces caspase-dependent apoptotic death in some cell lines and death via a caspase-independent autophagic pathway in the other cell lines tested. Triptolide-induced autophagy requires autophagy-specific genes, atg5 or beclin 1, and its inhibition results in cell death via the apoptotic pathway, whereas inhibition of both autophagy and apoptosis rescues triptolide-mediated cell death. Our study shows for the first time that induction of autophagy by triptolide has a pro-death role in pancreatic cancer cells. Since triptolide kills diverse pancreatic cancer cells by different mechanisms, it makes an attractive chemotherapeutic agent for future use against a broad spectrum of pancreatic cancers.