N-(2-羟丙基)甲基丙烯酰胺聚合物-5-氟尿嘧啶接合物的体外释药规律、体内分布及抗肿瘤活性研究

考察本实验室合成的N-(2-羟丙基)甲基丙烯酰胺［N-(2-hydroxypropyl) methacrylamide，HPMA］聚合物-5-氟尿嘧啶(5-flurouracil，5-FU)接合物(P-FU)的体外释药、体内分布及抗肿瘤活性。以小鼠血浆为介质，考察P-FU中5-FU的释放规律；以小鼠H22肝癌实体瘤模型(皮下型)为肿瘤模型，考察接合物在荷瘤小鼠体内的分布情况、药代动力学规律及抑瘤活性。结果表明，37 ℃时P-FU在小鼠血浆中具有一定的稳定性，半衰期(t_1/2)为32.4 h。与5-FU相比，P-FU在荷瘤小鼠体内的循环时间明显延长(血浆中t_1/2为原药的166倍)，在肿瘤中的沉积量(AUC为5-FU的3.3倍)及滞留时间(t_1/2为5-FU的2.3倍)均有明显增加。体内药效学研究表明，P-FU组对荷瘤小鼠的肿瘤生长抑制率(69.09%)显著高于5-FU组(56.49%，P<0.05)，瘤块组织病理学观察结果也显示P-FU组小鼠肿瘤组织中细胞凋亡程度大于5-FU组。HPMA聚合物可被用于为5-FU构建一种新型实体瘤高分子给药系统。     

N-(2-羟丙基)甲基丙烯酰胺聚合物-5-氟尿嘧啶接合物的体外释药规律、体内分布及抗肿瘤活性研究

考察本实验室合成的N-(2-羟丙基)甲基丙烯酰胺[N-(2-hydroxypropyl)methacrylamide,HPMA]聚合物-5-氟尿嘧啶(5-flurouracil,5-FU)接合物(P-FU)的体外释药、体内分布及抗肿瘤活性。以小鼠血浆为介质,考察P-FU中5-FU的释放规律;以小鼠H22肝癌实体瘤模型(皮下型)为肿瘤模型,考察接合物在荷瘤小鼠体内的分布情况、药代动力学规律及抑瘤活性。结果表明,37℃时P-FU在小鼠血浆中具有一定的稳定性,半衰期(t1/2)为32.4 h。与5-FU相比,P-FU在荷瘤小鼠体内的循环时间明显延长(血浆中t1/2为原药的166倍),在肿瘤中的沉积量(AUC为5-FU的3.3倍)及滞留时间(t1/2为5-FU的2.3倍)均有明显增加。体内药效学研究表明,P-FU组对荷瘤小鼠的肿瘤生长抑制率(69.09%)显著高于5-FU组(56.49%,P<0.05),瘤块组织病理学观察结果也显示P-FU组小鼠肿瘤组织中细胞凋亡程度大于5-FU组。HPMA聚合物可被用于为5-FU构建一种新型实体瘤高分子给药系统。     

四嗪二甲酰胺对肺癌细胞株A549的体内外作用

为了观察四嗪二甲酰胺(ZGDHu-1)体外抑制肺癌细胞株A549增殖、诱导细胞凋亡和体内抗肿瘤活性的作用及其机制，将不同浓度的ZGDHu-1与A549细胞在体外培养，用台盼蓝染色、SRB法、5′-溴-2′脱氧尿苷-ELISA法，观察ZGDHu-1对A549细胞增殖的作用；用细胞形态学、DNA凝胶电泳、DNA含量及细胞周期分析、Annexin V/PI双标记、Hoechst 33258荧光染色等技术检测细胞凋亡。腹腔注射ZGDHu-1后观察其对裸鼠移植瘤生长的抑制作用。用RT-PCR和流式细胞术观察A549细胞bcl-2，bax，p53基因和蛋白质的表达改变。结果表明，ZGDHu-1能抑制A549细胞的增殖和活力，呈现作用时间和剂量的依赖关系。A549细胞经ZGDHu-1作用后，大部分细胞阻滞于G₂-M期；出现DNA片段化，亚G₁峰显著增加，Annexin V+/PI-表达升高，Hoechst 33258荧光染色后出现凋亡细胞的特征性改变等。ZGDHu-1以10，20及40 mg·kg^-1剂量给裸鼠体内用药14 d后，移植瘤生长抑制率分别为43.7%，56.9%和60.0%。A549细胞经ZGDHu-1作用后，bcl-2基因和蛋白有所下调，但主要是上调bax基因和蛋白，导致bax/bcl-2比值明显增高，p53基因和蛋白表达也上调，均呈现剂量依赖性。ZGDHu-1在体内能明显抑制移植瘤的生长，体外通过诱导细胞凋亡抑制A549细胞增殖，其机制可能与上调bax和p53基因的表达有关。     

精氨酸水溶液复溶的多西他赛聚合物胶束的体外药效学及体内分布

目的：考察精氨酸复溶的多西他赛胶束的体外药效及体内分布情况。方法：用CCK-8法考察多西他赛胶束和多西他赛注射液对肿瘤细胞的增殖抑制作用。以荧光染料DIR标记多西他赛聚合物胶束,通过活体成像系统比较精氨酸水溶液复溶组,生理盐水复溶组和多西他赛注射液组的荧光分布。结果：多西他赛胶束组IC₅₀值明显比多西他赛注射液组高。精氨酸复溶的多西他赛胶束组肿瘤部位荧光强度比生理盐水复溶组和多西他赛注射液组都强。结论：精氨酸复溶的多西他赛胶束肿瘤靶向性更强且在肿瘤部位的停留时间更长,但其体外抗肿瘤活性有待提高。     

In vitro cytotoxicity,in vivo biodistribution and antitumor activity of HPMA copolymer–5-fluorouracil conjugates

5-Fluorouracil (5-FU) is an antimetabolite with a broad-spectrum activity against solid tumors. However, its very short half-life in plasma circulation greatly limited the in vivo antitumor efficacy and clinical application. The current work aimed to solve this problem as well as to increase 5-FU biodistribution to tumor by covalently conjugating 5-FU to a biocompatible, non-toxic and non-immunogenic drug carrier – N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer. The in vitro cytotoxicity, in vivo biodistribution and therapeutic efficacy of HPMA copolymer–5-FU conjugates (P-FU) were reported. Cytotoxicity was evaluated by using a serial of tumor cells (A549, CT-26, Hela, HepG₂ cells and 5-FU resistant HepG₂ cells). In vivo biodistribution and therapeutic efficacy were investigated in Kunming mice-bearing hepatoma 22 (H₂₂). Results indicated that P-FU could increase the cytotoxicity of 5-FU in Hela, HepG₂ and 5-FU resistant HepG₂ cells, while it decreases the cytotoxicity of 5-FU in A549 and CT-26. Both in vitro release profile in plasma and biodistribution study showed that P-FU significantly prolonged the drug plasma circulation time. P-FU also showed an over 3-fold larger area under the concentration–time curve (AUC) in tumor when compared with free drug. Therapeutic evaluation also demonstrated that the treatment with P-FU displayed stronger inhibition of the tumor growth when compared with that of control group (physiologic saline) or 5-FU group at the same dose. All the results suggested that P-FU could increase cytotoxicity of 5-FU in certain cancer cell lines, prolong 5-FU circulation time in vivo, enhance 5-FU distribution to tumor and improve therapeutic efficacy. Therefore, HPMA copolymer is a potential carrier for 5-FU for the effective treatment of cancer.     

RGD-modified PEG–PAMAM–DOX conjugates: In vitro and in vivo studies for glioma

This work was based on our recent studies that a promising conjugate, RGD-modified PEGylated polyamidoamine (PAMAM) dendrimer with doxorubicin (DOX) conjugated by acid-sensitive cis-aconityl linkage (RGD-PPCD), could increase tumor targeting by binding with the integrin receptors overexpressed on tumor cells and control release of free DOX in weakly acidic lysosomes. To explore the application of RGD-PPCD to glioma therapy, the effects of the conjugate were further evaluated in glioma model. For comparative studies, DOX was also conjugated to PEG–PAMAM by acid-insensitive succinic linkage to produce the PPSD conjugates, which was further modified by RGD to form RGD-PPSD. In vitro cytotoxicity of the acid-sensitive conjugates against C6 cells was higher than that of the acid-insensitive ones, and further the modification of RGD enhanced the cytotoxicity of the DOX-polymer conjugates as a result of the increased cellular uptake of the RGD-modified conjugates by C6 cells. In vivo pharmacokinetics, biodistribution and antitumor activity were investigated in an orthotopic murine model of C6 glioma by i.v. administration of DOX-polymer conjugates. In comparison with DOX solution, all the conjugates showed significantly prolonged half-life and increased AUC and exhibited higher accumulation in brain tumor than normal brain tissue. Although RGD-PPCD was more than 2-fold lower tumor accumulation than RGD-PPSD, it exhibited the longest survival times among all treatment groups, and therefore, RGD-PPCD conjugate provide a desirable candidate for targeted therapy of glioma.     

Synthesis and in vitro anti-tumor activity of novel HPMA copolymer-drug conjugates with potential cell surface targeting property for carcinoma cells

In several groups of malignant tumors including head and neck tumors, a protein named Hsp47/CBP2 leaked from the cell was expressed on the tumor cell surface. Several synthetic peptides have been identified as effective ligands for binding to Hsp47/CBP2. This study has focused on the synthesis and in vitro characterization of a targeting delivery system of 5-fluorouracil (5-FU) to human head and neck squamous cell carcinoma (HNSCC) in order to improve anti-cancer efficacy and reduce dose-limiting toxicity of 5-FU. An N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer, with Hsp47/CBP2 binding peptide sequence (namely WHYPWFQNWAMA) as a targeting ligand, was synthesized by a novel and simplified synthetic route. Under the controlled synthetic conditions, 1,3-dimethylol-5-FU, derived from 5-FU, was attached to the HPMA copolymer backbone via the lysosomally degradable GFLG linker, while the WHYPWFQNWAMA was conjugated via a non-degradable Gly-Gly (GG) linker. A control polymer without targeting moiety was also synthesized (P-FU). The in vitro cytotoxicity, internalization and apoptosis assays of the polymeric conjugates were evaluated. The characteristic apoptotic morphological changes were also assessed. Compared to 5-FU and P-FU, the HPMA copolymer containing the Hsp47/CBP2 binding peptide (P-FU-peptide) exhibited the highest cytotoxic efficacy to cell line of human head and neck squamous cell carcinoma (p < 0.05) and was internalized much faster than P-FU, especially after being incubated for 30 min. Both of the morphology and apoptosis analyses demonstrated that the treatment of P-FU-peptide resulted in more apoptotic and necrotic induction of tumor cells than P-FU. Meanwhile, the rate of apoptosis induced by P-FU-peptide was higher than that of necrosis. In summary, the HPMA copolymer-Hsp47/CBP2 binding peptide conjugates showed a promising future for the treatment of HNSCC with improved efficacy.     

HPMA copolymers: Origins, early developments, present, and future

The overview covers the discovery of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers, initial studies on their synthesis, evaluation of biological properties, and explorations of their potential as carriers of biologically active compounds in general and anticancer drugs in particular. The focus is on the research in the authors' laboratory — the development of macromolecular therapeutics for the treatment of cancer and musculoskeletal diseases. In addition, the evaluation of HPMA (co)polymers as building blocks of modified and new biomaterials is presented: the utilization of semitelechelic poly(HPMA) and HPMA copolymers for the modification of biomaterial and protein surfaces and the design of hybrid block and graft HPMA copolymers that self-assemble into smart hydrogels. Finally, suggestions for the design of second-generation macromolecular therapeutics are portrayed.     

In vitro and in vivo antioxidant properties of different fractions of Moringa oleifera leaves

The antioxidant potency of different fractions of Moringa oleifera leaves were investigated by employing various established in vitro systems, such as β-Carotene bleaching, reducing power, DPPH/superoxide/hydroxyl radical scavenging, ferrous ion chelation and lipid peroxidation. On the basis of in vitro antioxidant properties polyphenolic fraction of M. oleifera leaves (MOEF) was chosen as the potent fraction and used for the DNA nicking and in vivo antioxidant properties. MOEF shows concentration dependent protection of oxidative DNA damage induced by HO and also found to inhibit the toxicity produced by CCl₄ administration as seen from the decreased lipid peroxides (LPO) and increased glutathione (GSH) levels. Among the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) levels were restored to almost normal levels compared to CCl₄ intoxicated rats. The HPLC analysis indicated the presence of phenolic acids (gallic, chlorogenic, ellagic and ferulic acid) and flavonoids (kaempferol, quercetin and rutin). Thus, it may be concluded that the MOEF possess high phenolic content and potent antioxidant properties, which may be mediated through direct trapping of the free radicals and also through metal chelation.     

In vivo and in vitro anti-cancer activity of thermo-sensitive and photo-crosslinkable doxorubicin hydrogels composed of chitosan–doxorubicin conjugates

Doxorubicin was chemically conjugated to acrylated chitosan in order to obtain sustained-release profiles of doxorubicin from thermo-responsive and photo-crosslinkable hydrogels. Chitooligosaccharide was acrylated with glycidyl methacrylate and subsequently conjugated to doxorubicin via an amide linkage. A mixture of doxorubicin–chitosan conjugates, acrylated Pluronic, and doxorubicin formed physical gels at 37 °C. Photo-irradiation was subsequently performed to chemically crosslink the physical hydrogel at 37 °C. Chitooligosaccharide–doxorubicin conjugates in the doxorubicin hydrogels significantly reduced burst release of free doxorubicin from doxorubicin hydrogels compared hydrogels without the conjugates. Upon incubating doxorubicin hydrogels at 37 °C, chitosan–doxorubicin conjugates were confirmed to be degraded into more hydrophilic oligomers by reversed-phase chromatography. In vitro cytotoxicity assay using released media from doxorubicin hydrogels showed that degraded chitosan–doxorubicin had cytotoxicity comparable to free doxorubicin. Athymic nude mice bearing human lung adenocarcinoma were subjected to intra-tumoral injections of physical hydrogels. After photo-crosslinking injected hydrogels using surgical catheters, tumor sizes, body weights, and survivals were measured for 1 month. Released media from doxorubicin hydrogels exerted similar cytotoxicities to free doxorubicin, and the tumor volume was significantly reduced for 1 month compared to other samples. Thus, doxorubicin hydrogels containing doxorubicin conjugates can be employed as a novel injectable anti-cancer drug aiming to achieve sustained release of doxorubicin for several weeks against solid tumors.     

The effect of microneedles on the skin permeability and antitumor activity of topical 5-fluorouracil

Topical 5-fluorouracil (5-FU) is approved for the treatment of superficial basal cell carcinoma and actinic keratosis. However, 5-FU suffers from poor skin permeation. Microneedles have been successfully applied to improve the skin permeability of small and large molecules, and even nanoparticles, by creating micron-sized pores in the stratum corneum layer of the skin. In this report, the feasibility of using microneedles to increase the skin permeability of 5-FU was tested. Using full thickness mouse skin mounted on Franz diffusion apparatus, it was shown that the flux of 5-FU through the skin was increased by up to 4.5-fold when the skin was pretreated with microneedles (500 μm in length, 50 μm in base diameter). In a mouse model with B16-F10 mouse melanoma cells implanted in the subcutaneous space, the antitumor activity of a commercially available 5-FU topical cream (5%) was significantly enhanced when the cream was applied on a skin area that was pretreated with microneedles, as compared to when the cream was simply applied on a skin area, underneath which the tumor cells were implanted, and without pretreatment of the skin with microneedles. Fluorouracil is not approved for melanoma therapy, but the clinical efficacy of topical 5-FU against tumors such as basal cell carcinoma may be improved by integrating microneedle technology into the therapy.KEY WORDS: Microneedles, 5-Fluorouracil, Cytotoxicity, Melanoma, Immunohistochemistry, Flux, Transdermal, Antitumor activity, Skin permeability     

水飞蓟素磷脂复合物微孔渗透泵控释片比格犬体内药动学及体内外相关性研究

目的 评价水飞蓟素磷脂复合物微孔渗透泵(SM-PC MPOP)控释片的体外释药特性、比格犬体内药动学及其体内外相关性。方法 释放介质为pH7.5的磷酸盐缓冲液(添加0.5%十二烷基硫酸钠),以高效液相色谱法(HPLC)检测SM-PC MPOP的体外释放特征。用6只比格犬进行双周期交叉对照实验,按照30 mg/kg的剂量给药。HPLC法测定比格犬血浆内水飞蓟素的主要成分水飞蓟宾的质量浓度,应用药动学软件进行数据分析。结果 SM-PC MPOP在12 h累积释放度超过85%。药动学研究情况表明,受试制剂(SM-PC MPOP)和参比制剂(市售水飞蓟素胶囊)在比格犬体内的主要药动学参数：T_max分别为(3.2±0.4)、(0.9±0.1)h,C_max分别为(0.298 6±0.068 9)、(0.629 9±0.076 5)μg/ml,AUC_0→24分别为(2.996 8±0.583 3)、(2.268 9±0.432 8) h·μg/ml,SM-PC-MPOP对市售水飞蓟素胶囊的相对生物利用度为(162.21±30.82)%...     

Antrodia camphorata inhibits proliferation of human breast cancer cells in vitro and in vivo

Antrodia camphorata (A. camphorata) has been shown to induce apoptosis in cultured human breast cancer cells (MDA-MB-231). In this study, we report the effectiveness of the fermented culture broth of A. camphorata in terms of tumor regression as determined using both in vitro cell culture and in vivo athymic nude mice models of breast cancer. We found that the A. camphorata treatment decreased the proliferation of MDA-MB-231 cells by arresting progression through the G1 phase of the cell cycle. This cell cycle blockade was associated with reductions in cyclin D1, cyclin E, CDK4, cyclin A, and proliferating cell nuclear antigen (PCNA), and increased CDK inhibitor p27/KIP and p21/WAF1 in a dose and time-dependent manner. Furthermore, the A. camphorata treatment was effective in delaying tumor incidence in the nude mice inoculated with MDA-MB-231 cells as well as reducing the tumor burden when compared to controls. A. camphorata treatment also inhibited proliferation (cyclin D1 and PCNA) and induced apoptosis (Bcl-2 and TUNEL) when the tumor tissue sections were examined histologically and immunohistochemically. These results suggest that the A. camphorata treatment induced cell cycle arrest and apoptosis of human breast cancer cells both in vitro and in vivo.     

新型苯并噁唑酮衍生物W3D的含量测定及体内抗炎活性研究

目的 建立全新结构化合物4-（5''-二甲氨基）-萘磺酰氧基苯并噁唑酮（W3D）的含量测定方法,并对其进行体内抗炎活性评价。方法 采用Diamonsil C₁₈（250 mm×4.6 mm,5 μm）色谱柱,以甲醇-水（75∶25）为流动相,体积流量1.0 mL·min^-1,检测波长257 nm,柱温28℃,测定W3D的峰面积,建立其含量测定方法;采用二甲苯致小鼠耳肿胀模型评价化合物W3D（25.000、12.500、6.250、3.125 mg·kg^-1）体内抗炎活性。结果 供试品主峰专属性良好,在1～100 μg·mL^-1线性关系良好（R²＝0.999 9）,精密度、重复性、稳定性的RSD分别为0.61%、0.19%、0.84%,回收率为99.55%（RSD＝0.81%）;与对照组比较,W3D各剂量组耳肿胀率均显著下降（P＜0.05、0.01）,12.5 mg·kg^-1组抑制率可达53.88%,优于阳性药塞来昔布。结论 建立的HPLC法简便、准确,且专属性好,可用于W3D的含量检测;W3D具有较好的体内抗炎活性,作为新结构抗炎小分子化合物具有深入研究的价值。     

Study on dissolution and absorption of four dosage forms of isosorbide mononitrate: Level A in vitro–in vivo correlation

The objective of the present study was to develop a novel in vitro system to simulate the process of dissolution and permeation of oral solid dosage forms in vivo, and to establish a correlation between in vitro permeation and in vivo absorption that could predict the bioavailability (BA) and bioequivalence (BE) of congeneric products. The in vitro dissolution and absorption kinetics of four dosage forms of isosorbide mononitrate (ISMN) were evaluated by the USP basket/paddle system and drug dissolution/absorption simulating system (DDASS). The corresponding pharmacokinetic study was performed in beagle dogs. A comparative study was carried out between the classical and the novel method to estimate the effectiveness of the modified DDASS in simulating the course of dissolution and absorption in vivo. Indeed, the correlation coefficients of in vitro dissolution and in vivo absorption obtained from DDASS and dogs were higher. Moreover, a higher level A in vitro–in vivo correlation (IVIVC) between DDASS permeation and dog absorption was established, with correlation coefficients of 0.9968, 0.9872, 0.9921, and 0.9728. The DDASS method was more accurate at modeling the process of dissolution and absorption in vivo for both immediate-release (IR) and sustained-release (SR) dosage forms of ISMN.     

LC-MS/MS鉴定木兰花碱在大鼠体内外主要代谢产物

目的 研究木兰花碱在大鼠体内外的主要代谢产物及代谢途径。方法 SD大鼠ig木兰花碱（50 mg/kg）,收集0~24 h尿液和粪便,0~6 h胆汁以及1、2、4、6、8 h血浆;体外代谢采用肝微粒体温孵系统和肠菌培养液。利用LC-MS/MS对生物样品中的原型药及代谢产物进行鉴定。采用Agilent TC-C₁₈色谱柱（150 mm×4.6 mm,5 μm）,以乙腈-0.1%甲酸水溶液为流动相梯度洗脱,体积流量1.0 mL/min,柱温30℃。质谱采用电喷雾电离源（ESI）,正离子采集模式;扫描范围m/z100~1 000。根据药物体内代谢规则,结合木兰花碱的色谱保留时间和多级质谱碎片离子特征,推测其代谢产物的结构。结果 给药后生物样品中共鉴定出12个代谢产物,其中Ⅰ相代谢产物8个,Ⅱ相代谢产物4个。主要的代谢途径为羟基化、去甲基化、脱氢作用、酮基化、葡萄糖化、葡萄糖醛酸化及硫酸酯化。结论 木兰花碱在体内可发生Ⅰ相和Ⅱ相代谢,肠道菌群和肝药酶可催化木兰花碱发生Ⅰ相代谢转化,Ⅱ相代谢存在于肠道以外部位,最有可能的部位是肝脏。     

Noninvasive Visualization of Pharmacokinetics,Biodistribution and Tumor Targeting of Poly[<Emphasis Type="BoldItalic">N</Emphasis>-(2-hydroxypropyl)methacrylamide] in Mice Using Contrast Enhanced MRI

Purpose To study a non-invasive method of using contrast enhanced magnetic resonance imaging (MRI) to visualize the real-time pharmacokinetics, biodistribution and tumor accumulation of paramagnetically labeled poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) copolymer conjugates with different molecular weights and spacers in tumor-bearing mice. Materials and Methods Paramagnetically labeled HPMA copolymer conjugates were synthesized by free radical copolymerization of HPMA with monomers containing a chelating ligand, followed by complexation with Gd(OAc)₃. A stable paramagnetic chelate, Gd-DO3A, was conjugated to the copolymers via a degradable spacer GlyPheLeuGly and a non-degradable spacer GlyGly, respectively. The conjugates with molecular weights of 28, 60 and 121 kDa and narrow molecular weight distributions were prepared by fractionation with size exclusion chromatography. The conjugates were injected into athymic nude mice bearing MDA-MB-231 human breast carcinoma xenografts via a tail vein. MR images were acquired before and at various time points after the injection with a 3D FLASH sequence and a 2D spin-echo sequence at 3T. Pharmacokinetics, biodistribution and tumor accumulation of the conjugates were visualized based on the contrast enhancement in the blood, major organs and tumor tissue at various time points. The size effect of the conjugates was analyzed among the conjugates. Results Contrast enhanced MRI resulted in a real-time, three-dimensional visualization of blood circulation, pharmacokinetics, biodistribution and tumor accumulation of the conjugates, and the size effect on these pharmaceutical properties. HPMA copolymer conjugates with high molecular weight had a prolonged blood circulation time and high passive tumor targeting efficiency. Non-biodegradable HPMA copolymers with molecular weights higher than the threshold of renal filtration demonstrated higher efficiency for tumor drug delivery than biodegradable poly(L-glutamic acid). Conclusions Contrast enhanced MRI is an effective method for non-invasive visualization of in vivo properties of the paramagnetically labeled polymer conjugates in preclinical studies.     

姜黄素体内外逆转结肠癌的5-氟尿嘧啶耐药研究及机制探讨

目的 探究姜黄素在体内外对结肠癌5-氟尿嘧啶（5-fluorouracil,5-FU）耐药的逆转作用及其相关机制。方法 以SW480结肠癌细胞为亲代细胞,构建5-FU耐药细胞株SW480R,采用MTT法检测SW480R细胞的耐药指数以及不同浓度的姜黄素对SW480R细胞增殖能力的影响;流式细胞术检测姜黄素对SW480R细胞周期和凋亡的影响;Western blotting检测姜黄素对SW480R细胞上皮-间充质转化（epithelial-mesenchymal transition,EMT）相关蛋白以及Wnt信号通路相关蛋白的影响;采用裸鼠移植瘤模型检测肿瘤体积变化情况,计算姜黄素的体内抑瘤率,Western blotting检测肿瘤组织中相关蛋白变化。结果 SW480R的耐药指数为12.16,姜黄素能够剂量依赖性地抑制SW480R细胞的增殖,阻滞SW480R细胞周期于G₀/G₁期,以及诱导SW480R细胞凋亡;Western blotting结果表明姜黄素能够在体内外抑制EMT和Wnt信号通路的活性;体内试验表明姜黄素能够有效抑制裸鼠移植瘤的生长。结论 姜黄素能够在体内外逆转结肠癌的5-FU耐药,可能是通过调控Wnt信号通路从而抑制EMT的发生。     

6种黄槿倍半萜类成分的衍生化改造和体外抗肿瘤活性研究

目的 对黄槿中6种天然倍半萜类成分进行衍生化改造,并对所得衍生物进行体外抗肿瘤活性评价,分析其构效关系。方法 选取各种芳胺对黄槿中发现的6种倍半萜成分进行席夫碱修饰,采用噻唑蓝(MTT)法考察合成的目标化合物对HeLa、HepG2和MCG-803细胞的体外抗增殖活性。结果 衍生改造了19个不同的倍半萜类衍生物,结合¹H-NMR、¹³C-NMR、HR-MS确定其结构,其中17个衍生物首次得到。部分衍生物表现出良好的抗肿瘤活性,苄胺基团对此类骨架化合物的结构修饰能够较好地提高其抗肿瘤活性。结论 部分衍生物表现出良好的抗肿瘤活性,特别对HepG2细胞活性有较大的提高,化合物12、22、23具有进一步研究价值。