科研资料整理

Neuroreport. 2003 May 23;14(7):1091-5

Microglia are believed to participate in the mediation of neurodegeneration through producing a variety of cytotoxic factors upon activation. Pharmacological intervention in microglial activation may therefore exert a neuroprotective effect. In exploring pharmacological agents that can affect microglial activation, we found in this study that triptolide possesses a powerful inhibitory influence over microglia. Pretreatment with triptolide was able to dose-dependently reduce the lipopolysaccharide (LPS)-induced nitrite accumulation and tumor necrosis factor-alpha and interleukin-1beta release from LPS-activated microglia as revealed by Griess reaction and ELISA, respectively. Triptolide reduced LPS-stimulated mRNA expression of all three inflammatory factors. The results obtained from this study demonstrate that triptolide can inhibit inflammatory responses of microglia to inflammatory stimulation via a mechanism involving the inhibition of the synthesis and release of inflammatory factors

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J Biol Chem. 2001 Jan 19;276(3):2221-7. Epub 2000 Oct 26

Triptolide (PG490), a diterpene triepoxide, is a potent immunosuppressive agent extracted from the Chinese herb Tripterygium wilfordii. We have previously shown that triptolide blocks NF-kappaB activation and sensitizes tumor necrosis factor (TNF-alpha)-resistant tumor cell lines to TNF-alpha-induced apoptosis. We show here that triptolide enhances chemotherapy-induced apoptosis. In triptolide-treated cells, the expression of p53 increased but the transcriptional function of p53 was inhibited, and we observed a down-regulation of p21(waf1/cip1), a p53-responsive gene. The increase in levels of the p53 protein was mediated by enhanced translation of the p53 protein. Additionally, triptolide induced accumulation of cells in S phase and blocked doxorubicin-mediated accumulation of cells in G(2)/M and doxorubicin-mediated induction of p21. Our data suggest that triptolide, by blocking p21-mediated growth arrest, enhances apoptosis in tumor cells.

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J Biol Chem. 1999 May 7;274(19):13451-5.Click here to read
Progress in the treatment of solid tumors has been slow and sporadic. The efficacy of conventional chemotherapy in solid tumors is limited because tumors frequently have mutations in the p53 gene. Also, chemotherapy only kills rapidly dividing cells. Members of the tumor necrosis factor (TNF) family, however, induce apoptosis regardless of the p53 phenotype. Unfortunately, the cytotoxicity of TNF-alpha is limited by its activation of NF-kappaB and activation of NF-kappaB is proinflammatory. We have identified a compound called PG490, that is composed of purified triptolide, which induces apoptosis in tumor cells and sensitizes tumor cells to TNF-alpha-induced apoptosis. PG490 potently inhibited TNF-alpha-induced activation of NF-kappaB. PG490 also blocked TNF-alpha-mediated induction of c-IAP2 (hiap-1) and c-IAP1 (hiap-2), members of the inhibitor of apoptosis (IAP) family. Interestingly, PG490 did not block DNA binding of NF-kappaB, but it blocked transactivation of NF-kappaB. Our identification of a compound that blocks TNF-alpha-induced activation of NF-kappaB may enhance the cytotoxicity of TNF-alpha on tumors in vivo and limit its proinflammatory effects.

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雷公藤为卫矛科Celastraceae植物雷公藤Tripterygium wilfordii Hook.f.的根,叶、花及果实也入药。

　　【分布】
　　生于山地林缘阴湿处。分布于长江流域以南各地及西南地区。

　　【采集】
　　根秋季采，叶夏季采，花、果夏秋采。

　　【化学成分】
　　从根中分离出生物碱类：雷公藤碱(tripterygine)、雷公藤定碱(wilfordine)、雷公藤精碱(wilforgine)、雷公藤灵碱 (wilforine)、雷公藤春碱(wilfortrine)、雷公藤辛碱(wilforzine)、雷公藤酸(wilfordic acid)、羟基雷公藤酸(hydroxy wilfordic acid)。自石油醚提取物中分离出雷公藤红（tripterin或celustrol），并从残渣的醇提取物中分离出卫矛醇（甜醇dulcitol），果糖和葡萄糖。近据报道：雷公藤根皮中含雷酚萜(tri-ptonoterpene)、雷酚萜甲醚(triptonoterpene methylether)、雷醇内酯(trip-tolidenol)、polounonic acid、雷二羟酸甲酯、雷公藤三萜内酯A(triototriterpenoidal lactone A)、雷酚萜、雷酚萜甲醚及雷醇内酯。
　　近年来又从雷公藤多甙中分离一新单体为雷公藤氯内酯醇(tripcheorolide)，另含一种双环氧二萜化合物为雷藤内酯三醇(triptriolide)。
　　雷公藤所含成分复杂，其有效成分为生物碱，而毒性主要是内酯部分：雷藤酮(triptonide)、雷藤甲素(triptolide)、雷藤乙素 (tripdiolide)和山海棠素(hypolide)、山海棠素甲醚(hypolide methyl ether)、雷藤酮内酯(triptonolide)、异雷酚新内酯(isoneotriptophenolide)及雷藤素 (wilforonide)。 茎、叶也含雷藤甲素、雷藤乙素、雷藤酮及一种新的二萜化合物雷公藤内酯二醇酮(tripdioltonide)。

【药理作用】
　　1.抗肿瘤：雷公藤碱、雷公藤定碱对小鼠白血病L1210，L388有明显的抗肿瘤活性，并对人鼻咽癌有抑制作用。
　　2.雷公藤多甙有抗生育作用，16mg/kg用药4周时能使动物怀孕率明显下降；用药5周时即产生不育。用药5周大鼠精子密度和活率明显降低，畸形率增高。
　　3.雷公藤总甙能抑制小鼠血清溶血素的形成,对体液免疫和细胞免疫均有明显的抑制作用。
　　4.能延长戊巴比妥钠致小鼠睡眠时间。5.雷公藤可降低实验性肾病大鼠尿总蛋白及白蛋白排出量，可能有阻止或修复嘌呤霉素所致肾小球滤过膜病变的作用。 6.雷公藤总甙、总萜和总生物碱在中毒剂量下，均可引起大鼠睾丸生殖上皮退行性变性，以总碱最为明显。7.雷公藤甲素能诱发较明显的小鼠骨髓细胞畸变。 8.雷公藤煎剂对正常小鼠具有明显的降血糖作用，能对抗肾上腺素和四氧嘧啶致小鼠糖尿病作用。9.毒性：雷公藤对各种动物的毒性殊不相同。对昆虫有触杀效能，对人、狗、猪的胃肠道有局部刺激作用，吸收后对中枢神经系统有损害，并可引起肝、心的出血与坏死，可导致死亡；但是对羊、兔、猫、鱼等却无毒性。
　　及树缝中的皮分。主要成份含雷公藤定碱、雷公藤扔碱、雷公藤晋碱、雷公藤春碱和雷公藤增碱等生物碱。此外还含南蛇藤醇、卫矛醇、雷公藤甲素等。另据报道认为雷公藤属植物涂含有生物碱外，尚含有雷公藤内酯、雷公藤羟内酯二醇和雷公藤羟内酯酮。昆明山海棠报中尚含有二萜内酯化合物山海棠素。此外，雷公藤属等尚含有雷公藤三萜醇（雷公红素）以及扁葫藤素。雷公藤碱性质稳定经100℃高温不被破坏。但经过炮制处理后（取报彻底剥去内外二层及树缝中的皮，反复洗涤至无原液汁后切片晒干），另据认为雷公藤有抗癌和抗菌作用。根皮煎浓计杀蛆，灭了螺。昆明山海棠有剧毒，能续筋接骨、祛风通络、杀虫，并有抗癌活性，已制成片剂诊疗类风湿性关节炎、肾炎、红斑狼疮等。其毒性比雷公藤小。
　　雷公藤使用时必须严格控制剂量，超量内服或食入雷公藤嫩牙数个、或误服大量雷公藤农药，或因泡制不当（根皮朱副、原波汁未洗净），均可导致中毒，甚至死亡，民间服嫩芽7个板皮30一60g即可致死。雷公藤对各种动物毒性不同，对人、犬、猫及昆虫的毒性很大，可以导致中毒甚至死亡，但是对羊、兔、猫、鼠、鱼都无毒性，故可用羊血解毒。
　　雷公藤接触皮肤后可引起局部刺激作用，内服后首先刺激胃肠道，吸收后则损害中枢神经系统包括机丘、中脑、延髓、小脑及脊髓，并引起肝、心的出血与坏死。有人认为雷公藤主要毒害动物的心脏，（但对其他平滑肌及横纹肌亦有损害）

　　【功能与主治】
　　雷公藤有杀虫、消炎、解毒之效，是我国江浙一带菜园中广泛使用的杀虫剂，有祛风，解毒，杀虫功能。也用来治疗类风湿性关节炎、结核、麻风等。其根、叶、花均可捣烂外敷，但用根敷后，过半小时须取去，否则起泡。

　　【中毒症状】
　　潜伏期一般2小时左右如煎服或同时饮酒的症状就出现更早，且更严重。一般死亡时间约在24小时左右，最多不超过4天。中毒开始出现头晕头痛、心悸乏力、恶心呕吐、腹痛腹胀、肌肉疼痛、嚎叫挣扎、四肢麻木或抽搐、肝肾区疼痛。血便、少尿、浮肿，偶有血尿、尿储留、血压下降、唇甲发绀，严重时有脱水、电解质紊乱及休克、急性肾功能衰竭和尿毒症。偶因心肌损害并发心律失常、心源性脑缺血综合征、鼻出血、吐血水、全身及寒丸疼痛，后期毛发脱落，皮肤接触时可引起炎症。

　　【解救方法】
　　服毒后能度过5天，预后较好。接触中毒者应立即脱离现场。
　　2．治疗中出现恶心呕吐、腹痛腹胀、肝肾区疼痛、尿中出现蛋白及血清转氨酶升高时应立即停药。尽快催吐、洗胃、导泻、灌肠。静脉输入10％葡萄糖水或5％葡萄糖盐水。
　　３．对症治疗：如肺水肿、心原性脑缺血综合征、急性肾功能衰竭、高血钾及严重尿毒症等均应按常规方法进行抢救。急性肾功能衰竭、高血钾及严重尿毒症时，立即应用透析疗法常有良效。腹痛用阿托品，神经症状可用安定等。杨梅（树梅）根60g，水前内服。

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雷公藤常用中药制剂有哪些？
　
　　常用的雷公藤制剂主要有：目前市场上销售的雷公藤制剂主要有雷公藤糖浆、复方雷公藤冲剂、雷公藤多甙片及雷公藤片，以后两种制剂在临床上最为多用。成人的具体用法如下：雷公藤多甙片每次10—20mg，每日3次；雷公藤片每次2片，每日3次；雷公藤糖浆每次10ml(每毫升含生药1g)，每日3次；复方雷公藤冲剂每次10g，每日2次。

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Proc Natl Acad Sci U S A. 2007 Mar 13;104(11):4389-94. Epub 2007 Mar 6

During kidney organogenesis, tubular epithelial cells proliferate until a functional tubule is formed as sensed by cilia bending in response to fluid flow. This flow-induced ciliary mechanosensation opens the calcium (Ca(2+)) channel polycystin-2 (PC2), resulting in a calcium flux-mediated cell cycle arrest. Loss or mutation of either PC2 or its regulatory protein polycystin-1 (PC1) results in autosomal dominant polycystic kidney disease (ADPKD), characterized by cyst formation and growth and often leading to renal failure and death. Here we show that triptolide, the active diterpene in the traditional Chinese medicine Lei Gong Teng, induces Ca(2+) release by a PC2-dependent mechanism. Furthermore, in a murine model of ADPKD, triptolide arrests cellular proliferation and attenuates overall cyst formation by restoring Ca(2+) signaling in these cells. We anticipate that small molecule induction of PC2-dependent calcium release is likely to be a valid therapeutic strategy for ADPKD

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Immunobiology. 2007;212(7):549-56. Epub 2007 Apr 11

Triptolide is a naturally occurring diterpene triepoxide whose anti-inflammatory effects correlate with transcriptional inhibition of various cytokines. Despite its use in herbal medicine for thousands of years, the cellular target and mode of action of this drug are unknown. [3H]-triptolide was prepared and a filtration assay designed to measure binding to cells and cellular extracts. Triptolide bound specifically and irreversibly to a single, 90 kDa protein in nuclear extracts from stimulated and non-stimulated monocytic and epithelial cell lines. Thiol reactivity of one or more of the epoxides on triptolide was necessary for the covalent binding, since thiol oxidizing agents dithiodipyridine and diamide, and the thiol alkylating agent N-ethylmaleimide all reduced the binding of [3H]-triptolide to nuclear extract. Neither glutathione nor the pro-oxidant tert-butylhydroperoxide affected the binding of [3H]-triptolide to the nuclear protein, ruling out a general oxidant effect. The number of epoxide moieties correlated with the ability to compete with radiolabeled triptolide for binding to the nuclear extract and with the potency of inhibition of TNFalpha secretion from monocytes, IL-2 secretion from Jurkat cells, and with inhibition of RNA synthesis. The correlation between the structure-activity relationship and observed binding suggests that identification of the triptolide binding protein could provide insight into the cellular mode of action of this anti-inflammatory natural product.

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