冬凌草素抗肿瘤机制研究进展

冬凌草是一种颇具研究价值的药用植物,其有效活性成分冬凌草甲素、乙素具有多种药理作用,尤其是抗肿瘤活性。本文拟对其化学成分、药理作用和抗肿瘤分子机制研究方面作一综述,冬凌草的药用价值值得进一步研究、开发、利用。     

鲁山冬凌草素的结构研究

冬凌草甲素和乙素〔rubescensin A(=oridonin),B(=ponicidin)〕为冬凌草〔Rabdosia rubescens(Hemsl.)Hara〕中的两个抗癌有效成份,对多种动物移植性肿瘤有一定的抗肿瘤作用,对食管癌、肝癌等有一定疗效。为了进一步探讨不同产地冬凌草的抗癌活性成份,我们对河南省鲁山县地区产的冬凌草进行了研究。从叶的乙醚提取物中除分离到α-amyrin和ursolic acid外,还分离得到了一个新的二萜苦味成份,命名为鲁山冬凌草素(lushanrubescensin)(1),药理实验(另报)表明,(1)具有一定的抗肿瘤活性,为冬凌草中的另一抗癌有效成份。文本报道其结构研究。     

冬凌草甲素抗炎作用参与多种疾病治疗的新进展

冬凌草甲素是冬凌草的主要活性成分,具有广泛的药理作用。研究表明,冬凌草甲素在炎症性疾病方面表现出较好的疗效。综述国内外关于冬凌草甲素抗炎作用参与多种疾病治疗的研究进展,并分析研究的方向,为研究与开发以冬凌草为原料的抗炎新药提供参考。     

冬凌草甲素抗炎机制研究进展

冬凌草为唇形科香茶属植物，性微寒，有活血止痛、解热降噪和清热解毒的功效，近年来研究发现其主要活性成分冬凌草甲素具有降压、抗氧化、抗菌、抗肿瘤、抗凋亡、增强机体免疫等多种药理作用。基于现代医学研究，从核因子κB(NF-κB)、丝裂原活化蛋白激酶（MAPK）和NOD样受体热蛋白结构域相关蛋白3(NLRP3)等信号通路方面，对冬凌草甲素在呼吸系统炎症、消化系统炎症、神经性炎症、肾损伤性炎症、血管炎等疾病抗炎作用机制的研究进展进行综述，为研究与开发以冬凌草甲素为原料的抗炎新药提供参考。     

抑制自噬促进冬凌草甲素诱导的多发性骨髓瘤细胞凋亡涉及胞内ROS产生

目的本实验主要研究冬凌草甲素诱导多发性骨髓瘤发生自噬、凋亡,两者之间的关系以及所涉及的相关机制。方法利用MTT比色法检测冬凌草甲素对多发性骨髓瘤RPMI8226细胞的增殖活性影响;透视电镜观察细胞内凋亡和自噬的形态学改变;TUNEL检测细胞凋亡;分别利用以下技术检测处理后的细胞内的自噬变化:使用QDs605nm-Anti-LC3荧光探针以及免疫荧光技术定位细胞胞内LC3Ⅰ和LC3Ⅱ蛋白,利用western blot免疫印记技术检测Beclin 1蛋白表达水平;利用DCFH-DA探针以及流式细胞术检测细胞胞内ROS水平。结果冬凌草甲素能明显抑制RPMI8226细胞增殖,其抑制作用呈时间、剂量依赖性;冬凌草甲素能同时诱发细胞凋亡、自噬和胞内ROS产生;NAC完全抑制胞内ROS产生后冬凌草甲素诱导的细胞凋亡消失;3-MA抑制自噬后,冬凌草甲素诱导的胞内ROS产生进一步增多,凋亡增多。结论冬凌草甲素能明显抑制RPMI8226细胞增殖;冬凌草甲素同时诱发细胞凋亡和自噬;胞内ROS产生介导冬凌草甲素诱导的凋亡;凋亡为细胞死亡的主要途径,而自噬通过下调胞内ROS产生抑制凋亡。     

磷脂酶Dα1与H2S参与冬凌草甲素对拟南芥的化感作用

以拟南芥哥伦比亚野生型(WT)、磷脂酶Dα1(PLDα1)缺失型突变体pldα1、D-/L-半胱氨酸脱巯基酶(D-/L-CDes)缺失型突变体d-cdes和l-cdes幼苗为试验材料,60 μmol·L^-1冬凌草甲素为处理浓度,研究了拟南芥响应二萜类化合物冬凌草甲素的化感作用中磷脂酶Dα1(PLDα1)与气体信号分子硫化氢(H₂S)的信号关系。结果表明: 冬凌草甲素显著提高了野生型拟南芥幼苗H₂S含量、PLD和D-/L-CDes酶的活性及其基因表达;冬凌草甲素处理下,pldα1突变体幼苗的D-CDes和L-CDes活性明显低于WT,外源添加磷脂酸(PA)后D-CDes和L-CDes活性显著提高,并高于WT;冬凌草甲素显著抑制4种株系根的生长,其中d-cdes和l-cdes对冬凌草甲素更加敏感,外施NaHS可以促进冬凌草甲素处理下4种株系根的生长及内源H₂S产生,外施PA只对冬凌草甲素处理下的WT、pldα1和l-cdes株系根的生长及内源H₂S产生有促进作用,而对d-cdes株系没有明显作用。说明PLDα1和H₂S在拟南芥响应冬凌草甲素过程中发挥作用,且PLDα1/PA位于D-CDes上游,参与调控拟南芥幼苗H₂S的产生及根生长的信号过程。     

冬凌草毛状根的优化培养及其提取物的肿瘤细胞增殖抑制活性检测

探究并建立冬凌草毛状根的优化培养方案并检测其提取物的抗肿瘤活性。用发根农杆菌ATCC11325及ATCC15834诱导冬凌草外植体生成毛状根,并探究培养基种类、蔗糖浓度等条件对冬凌草毛状根生长的影响,测定其生长曲线;超声法制备毛状根粗提物,大孔吸附树脂进一步纯化粗提物获得提取物,用高效液相色谱法检测冬凌草甲素含量;提取物配制成不同浓度试液作用于癌细胞株BEL-7402、A-549、SGC-7901和HGC,用CCK-8法测定细胞存活率。仅ATCC15834可诱导冬凌草从叶柄和茎部切口处长出不定根,叶片外植体未见不定根萌发,不定根遗传鉴定符合毛状根特征。毛状根在含3%蔗糖B5培养基中增殖率最高,其生长曲线近似"S"型,25 d达到对数中期,70 d达到平台期,其冬凌草甲素含量分别为0.0171%、0.0022%。当毛状根提取物含量为1 mg/mL时,对四种癌细胞生长的抑制率均达95%以上。以ATCC15834侵染冬凌草叶柄和茎部外植体诱导出的冬凌草毛状根提取物在含3%蔗糖的B5培养基中摇瓶培养25 d再继代培养70 d得率最高;冬凌草毛状根提取物中含有冬凌草甲素,且能有效抑制体外培养肿瘤细胞生长。     

冬凌草甲素对金黄色葡萄球菌生物膜的抑制机制

【背景】金黄色葡萄球菌是一种常见的食源性致病菌,易在食品及加工器具表面形成生物膜,引起食品腐败和疾病的传播,威胁食品安全。【目的】研究冬凌草甲素抑制金黄色葡萄球菌生物膜形成的作用机制。【方法】使用结晶紫染色法和扫描电镜观察冬凌草甲素对金黄色葡萄球菌生物膜形成的抑制作用,刚果红平板法定性检测冬凌草甲素对细胞间多糖黏附素(polysaccharideintercellular adhesion,PIA)合成的影响,分光光度法测定冬凌草甲素对供试菌株胞外DNA (eDNA)释放量的影响,RT-PCR技术检测冬凌草甲素对供试菌株ica A、cid A、agr A和sar A基因表达量的影响。【结果】冬凌草甲素对金黄色葡萄球菌生物膜形成有较强的抑制作用;冬凌草甲素能显著抑制PIA的合成,且呈浓度剂量依赖;冬凌草甲素能抑制供试菌株e DNA的释放量,其中1/4最小抑菌浓度(minimum inhibitory concentration,MIC)的冬凌草甲素作用金黄色葡萄球菌16 h后,与对照组相比,e DNA的释放量降低了48.62%;冬凌草甲素可显著抑制金黄色葡萄球菌生物膜形成相关基因的表达,其中1/2MIC的冬凌草甲素作用金黄色葡萄球菌16 h后,ica A、cid A、agr A和sar A基因的表达量分别比对照降低了91.6%、94.7%、77.6%和70.4%。【结论】冬凌草甲素通过抑制ica A和cid A基因的表达,影响PIA的合成和eDNA的释放,进而干预生物膜的形成。     

卢氏冬凌草素的结构

冬凌草〔Rabdosia rubescens(Hemsl.)Hara〕为唇形科香茶菜属植物,是近年来河南省从民间发掘出来的一种具有对多种动物移植性肿瘤有一定的抗肿瘤作用,对食管癌、肝癌以及扁挑体炎、咽喉炎、口腔炎等有一定疗效的植物药。对河南省济源县产的冬凌草,其化学成份已进行了研究,从中分离鉴定了四个对映—贝壳杉烯型(ent-kaurene type)二萜化合物,分别命名为冬凌草甲素(rubescensin A=     

冬凌草甲素缓解脂多糖诱导的Caco-2肠上皮细胞屏障损伤和SIRT1/eIF2α信号通路活性的抑制

目的 探索冬凌草甲素对脂多糖（lipopolysaccharide, LPS）诱导的肠上皮屏障障碍的影响及其生物学机制。方法将Caco-2细胞进行单层培养21 d使其分化后，分为对照组、LPS组（2μg/mL LPS处理24 h）、LPS+低剂量冬凌草甲素组（10μg/mL冬凌草甲素预处理30 min,2μg/mL LPS处理24 h）和LPS+高剂量冬凌草甲素组（40μg/mL冬凌草甲素预处理30 min,2μg/mL LPS处理24 h）。采用跨上皮电阻法和FITC-dextran 4通量法评估细胞单层屏障功能；CCK-8法检测细胞活力；乳酸脱氢酶（LDH）法检测LDH释放活性；DCFH-DA探针法检测细胞内活性氧水平；ELISA法检测炎症因子IL-1β和TNF-α分泌水平；免疫荧光法检测细胞的屏障功能相关蛋白闭合蛋白（occludin）和闭锁小带蛋白1(zonula occludens protein 1, ZO-1)的表达分布情况；Western blot法检测SIRT1和p-eIF2α的相对表达水平。结果 与LPS组比较，冬凌草甲素能改善LPS诱导的肠上皮细胞单层屏障障碍，增...     

Generation of tumor-specific cytotoxic T lymphocytesin vivo by combined treatment with inactivated tumor cells and recombinant interleukin-2

In order to search for a new therapy that would maximize the effect of interleukin-2 (IL-2) in evoking antitumor immunity in vivo, the therapeutic effect of a combination of mitomycin-C(MMC)-treated tumor cells and recombinant IL-2 was examined for its induction of antitumor activity against established melanoma metastasis. In C57BL/6 mice intravenously (i. v.) injected with B16 melanoma cells on day 0, the combined treatment with an intraperitoneal (i. p.) injection of MMC-treated melanoma cells on day 6 and 2500 U rIL-2 (twice daily) on days 7 and 8 markedly reduced the number of pulmonary metastases. This antitumor activity was more effective than that in untreated controls and mice that were injected with MMC-treated melanoma cells alone or rIL-2 alone. When the i. p. injection of MMC-treated tumor cells was replaced by other syngeneic tumor cells, antitumor activity against metastatic melanoma was not induced. The antitumor activity induced by this treatment increased in parallel with an increase in the dose of rIL-2 injected. In contrast, an i. p. injection of soluble tumor-specific antigens alone could induce only a marginal level of antitumor activity, and this activity was not augmented by subsequent i. p. injections of rIL-2. In vivo treatment with anti-CD8 monoclonal antibody (mAb), but not with anti-CD4 mAb or anti-asialo-GM1 antibody, abrogated the antitumor activity induced by this combined therapy. This suggests that the antitumor effect was dependent on CD8⁺ T cells. Lung-infiltrating lymphocytes from mice that had been i. v. injected with melanoma cells 11 days before and were treated with this combined therapy, showed melanoma-specific cytolytic activity. This combined therapy also showed significant antitumor activity against subcutaneously inoculated melanoma cells. These results demonstrate that the combined therapy of an i. p. injection of MMC-treated tumor cells and subsequent and consecutive i. p. administration of rIL-2 increases antitumor activity against established metastatic melanoma by generating tumor-specific CD8⁺ CTL in vivo.     

Synthesis and structure-activity relationships of 3-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridines as novel antitumor agents

In order to obtain clinically useful antitumor agent, we have designed and synthesized various 3-substituted 1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridines, and evaluated their cytotoxic activity. The series of novel 3-substituted derivatives synthesized in this study showed good antitumor activity against murine P388 leukemia. Particularly, the 3-formyl 1,8-naphthyridine displayed an antitumor activity equal to that of the 3-carboxy 1,8-naphthyridine against murine and human tumor cell lines as well as in vivo test for mouse leukemia. These results demonstrate that the carboxy group at the C-3 position of 1,8-naphthyridine ring is not essential for antitumor activity. In addition, the trend of cytotoxic activity for the 3-substituted 1,8-naphthyridines was different from that of antibacterial activity.     

Screening of antineoplastic antibiotics using a rapid method of evaluating their cytostatic effect on tumor cells

The study was aimed at development of a rapid method for estimating in vitro cytostatic action of antitumor antibiotics on the basis of intensity of inclusion of labeled precursors into nucleic acids of tumor cells which should be useful in primary screening of antibiotics with potential antitumor activity. The method was applied to substances isolated from 600 cultures of actinomycetes. 35 antibiotics showed antitumor activity; 8 of them were studied in detail. They proved to be novel antibiotics having antitumor activity in animals.     

Antitumor activity of Herceptin in combination with STEALTH liposomal cisplatin or nonliposomal cisplatin in a HER2 positive human breast cancer model

Single agent antitumor activity of Herceptin, a humanized monoclonal antibody directed against HER2, has been demonstrated in numerous preclinical and clinical studies. Additionally, combination therapy with Herceptin and chemotherapy (CRx) has demonstrated additive antitumor activity in both preclinical models and early clinical trials. STEALTH (pegylated) liposomal (PL) cisplatin, also known as SPI-077, is currently in clinical trials for a variety of solid tumors. The three studies reported here discuss the antitumor activity of the combination of Herceptin and nonliposomal cisplatin or PL-cisplatin in two xenograft tumor models, initiated from the cell lines, BT474 and MDA453, that overexpress the oncogene, HER2. Herceptin alone had significant antitumor activity in all three experiments (p < 0.0001). Nonliposomal cisplatin and PL-cisplatin were both effective antitumor agents but, at tolerable dose levels, PL-cisplatin was superior to nonliposomal cisplatin (p < 0.0003). The effect of combining Herceptin with the chemotherapeutic cisplatin or PL-cisplatin, was most significant at moderate doses of H (0.5 mg/kg, p < 0.0001), but tended to be greater than either agent alone in all experiments. The combination of PL-cisplatin with Herceptin had statistically similar antitumor activity to that of nonliposomal cisplatin with Herceptin in all experiments. We conclude that combination therapy with PL-cisplatin and Herceptin results in significant antitumor activity with the potential for reducing toxicity in metastatic breast cancer patients.     

Micronucleus and antitumor activities of two newly synthesized pyrimidine derivatives

Micronucleus and antitumor activities of two newly synthesized iodides of pyrazolo[1,5a]pyrimidines were studied on mice. Both compounds were slightly toxic and had no antitumor activity in mice with Ehrlich ascites carcinoma; only one of them had low micronucleus activity. Both compounds substantially increase the micronucleus as well as the antitumor activities of cyclophosphamide.     

Synthesis and antitumor activity of 4-hydroxycoumarin derivatives

A series of 4-hydroxycoumarin derivatives was prepared and evaluated for antitumor activity. The key fragments were 2a-c, 5c, 12b, 13b, 17, and 18 which were prepared via dianion ring cyclization, Friedel-Crafts acylation, and Reformatsky reaction. Compound 20b showed the most potent antitumor activity among the total 12 derivatives and compounds 19a and 19b exhibited efficacy comparable to etoposide in vitro antitumor activity.     

Synthesis and antitumor activity of novel 10-substituted camptothecin analogues

In an attempt to improve the antitumor activity and decrease the cytotoxicity of camptothecin, 18 new 10-substituted camptothecin derivatives were prepared. The cytotoxicity in vitro on cancer cell lines and antitumor activity in vivo, and inhibitory properties of topoisomerase I of these derivatives were evaluated. Most of these derivatives possessed lower cytotoxicities than CPT, and the compounds 13, 21, 22, 23, and 24 showed similar topoisomerase I inhibitory activity to CPT. Analogues 13 exhibited the best antitumor activity in vivo among all derivatives we prepared.     

Synthesis and antitumor activity of CBI-bearing ester and carbamate prodrugs of CC-1065 analogue

Prodrugs of a CBI-bearing CC-1065 analogue were synthesized. Antitumor activity of the compounds was evaluated against tumor cells in vitro and in mouse tumor models. Compounds 1 and 7, bearing methylpiperazine and DHA moieties, respectively, showed significant antitumor activity in both the L1210 leukemia and Lewis lung carcinoma mouse tumor models. For the carbamate prodrugs 1-4 and 6, there is a good correlation between the drug's potency both in vitro and in animal tumor models; however, there is no correlation between the prodrug's antitumor activity and the type of bonds linking the free drug. There are no significant differences between the antitumor activities of those that can or cannot be protonated at physiological pH. Compounds 6 and 7, each bearing a DHA moiety, did not show significantly improved antitumor activity compared to other prodrugs bearing DHA moieties, suggesting that DHA may not be used universally to significantly improve a drug's antitumor efficacy.     

The preparation of 2,6-disubstituted pyridinyl phosphine oxides as novel anti-cancer agents

A series of 2,6-dimethoxylpyridinyl phosphine oxides have been synthesized and examined for their antitumor activity. 2,6-Dimethoxy-3-phenyl-4-diphenylphosphinoylpyridine 2 has been employed as the lead compound for this study. We found out that the presence of phosphine oxide on the 2,6-dimethoxylpyridine ring is important for the antitumor activity; the presence of bromine on this core leads to a further enhancement of its antitumor activity. This is the first reported work on the antitumor activity of the 2,6-dimethoxy-3,5-dibromopyridinyl phosphine oxide 5b towards MDAMB-231 breast cancer and SKHep-1 hepatoma cell lines.     

抗肿瘤海绵放线菌的分离及菌株HA01184的鉴定

目的：对采自海南、湛江等海域的海绵样品进行放线菌选择性分离,采用其发酵液进行抗肿瘤活性筛选,并对活性较好的菌株进行鉴定。方法：用含50μg／mL重铬酸钾为抑制剂的海水高氏一号合成培养基分离培养海绵放线菌;以MTT法进行菌株的抗肿瘤活性筛选;通过培养特征、形态特征、生理生化特征、16S rDNA序列测定及系统发育分析,对菌株HA01184进行鉴定。结果与结论：海水高氏一号合成培养基用于海绵放线菌分离培养具有很好的选择性,从海绵样品中共分离得到放线菌165株,细胞毒活性达80％以上的阳性菌株有10株,其中菌株HA01184的发酵液细胞毒活性为90％。结合形态观察、生理生化特征和16S rDNA序列比对分析,将HA01184归于链霉菌属,可能是来自海洋环境的一个潜在新种。