三尖杉属植物化学成分与药理活性研究进展

三尖杉属植物主要含有生物碱和黄酮两大类化学成分。因其三尖杉酯类生物碱具有抗癌活性,所以生物碱类成分得到了广泛的研究和重视。我国已将三尖杉酯碱HT和高三尖杉酯碱HHT开发成药物,对急性非淋巴细胞性白血病和慢性粒细胞性白血病有较好疗效。综述了三尖杉属植物的化学成分与药理活性研究进展,包括各类化合物的结构、药理活性、活性成分及衍生物的构效关系、HT和HHT的药理机制研究等。     

Metabolite profiling of 14C-omacetaxine mepesuccinate in plasma and excreta of cancer patients

1. Omacetaxine mepesuccinate (hereafter referred to as omacetaxine) is a protein translation inhibitor approved by the US Food and Drug Administration for adult patients with chronic myeloid leukemia with resistance and/or intolerance to two or more tyrosine kinase inhibitors.

2. The objective was to investigate the metabolite profile of omacetaxine in plasma, urine and faeces samples collected up to 72?h after a single 1.25-mg/m² subcutaneous dose of ¹⁴C-omacetaxine in cancer patients.

3. High-performance liquid chromatography mass spectrometry (MS) (high resolution) in combination with off-line radioactivity detection was used for metabolite identification.

4. In total, six metabolites of omacetaxine were detected. The reactions represented were mepesuccinate ester hydrolysis, methyl ester hydrolysis, pyrocatechol conversion from the 1,3-dioxole ring. Unchanged omacetaxine was the most prominent omacetaxine-related compound in plasma. In urine, unchanged omacetaxine was also dominant, together with 4′-DMHHT. In feces very little unchanged omacetaxine was found and the pyrocatechol metabolite of omacetaxine, M534 and 4′-desmethyl homoharringtonine (4′-DMHHT) was the most abundant metabolites.

5. Omacetaxine was extensively metabolized, with subsequent renal and hepatic elimination of the metabolites. The low levels of the metabolites found in plasma indicate that the metabolites are unlikely to contribute materially to the efficacy and/or toxicity of omacetaxine.

     

Evaluation of homoharringtonine efficacy in the treatment of squamous cell carcinoma of the head and neck: A phase II Illinois Cancer Council study

Summary Eighteen patients entered this study of the efficacy of homoharringtonine (HHT) treatment in advanced squamous cell carcinoma of the head and neck (SCCHN). Seventeen eligible patients received at least one day of the first 5-day cycle of HHT (4.0 mg/m²/day) by continuous IV infusion. Cycles were scheduled to repeat every 28 days. The major severe toxicities encountered were hypotension and myelosuppression. There was one drug-related death. Fourteen patients were evaluable for response, and no patient exhibited an objective response to treatment with HHT.Abbreviations HHT homoharringtonine - SCCHN squamous cell carcinoma of the head and neck - BP blood pressure - HCT hematocrit - CBC complete blood count - WBC white blood cell count     

Homoharringtonine mediates myeloid cell apoptosis via upregulation of pro-apoptotic bax and inducing caspase-3-mediated cleavage of poly(ADP-ribose) polymerase (PARP)

Homoharringtonine (HHT) is a plant alkaloid with antileukemia activity that is currently being used for treatment of acute, chronic leukemias and MDS. In this study, we show that HHT can induce apoptosis in a variety of human myeloid leukemia cell lines (U937, HL-60, HEL, THP, and K562). U937 and HL60 cells undergo rapid apoptosis on treatment with HHT, as indicated by increased annexin V binding capacity, caspase-3 activation, and cleavage of poly(ADP-ribose) polymerase (PARP). In addition, the expression of bax is upregulated during HHT-induced cell death, whereas the expression of bcl-2 is only slightly decreased. Importantly, treatment of primary leukemic cells, obtained from acute myeloid leukemia patients, resulted in rapid apoptosis. Thus, our data provide the mechanism of HHT and justify the use of HHT in the treatment of human myeloid leukemia.     

高三尖杉酯碱对鼻咽癌CNE-2Z细胞的增殖抑制和凋亡诱导作用

目的　探讨高三尖杉酯碱 (homoharringtonine,HHT)对鼻咽癌细胞CNE 2Z的增殖抑制和凋亡诱导作用。方法　采用MTT法检测增殖抑制率和IC50 ,流式细胞术、琼脂糖凝胶电泳和Hoechst 3 3 2 5 8/PI荧光染色分析细胞凋亡。结果　不同浓度的HHT分别处理CNE 2Z细胞 2 4、48和 72h ,抑制率随浓度的增加和时间的延长而增高 ,其IC50 分别为(0 62 9± 0 0 3 9)、(0 483± 0 0 2 7)、(0 3 89± 0 0 2 7)mg·L-1,各IC50 间差异有统计学意义 (P <0 0 1)。 1、0 5mg·L-1HHT处理细胞 8h ,流式细胞术观察到凋亡峰 ,荧光染色可见凋亡形态学改变 ,流式细胞术和荧光染色检出的凋亡率均高于对照组 (P <0 0 1) ;1mg·L-1HHT处理细胞 8h ,琼脂糖凝胶电泳可见DNA梯带。结论　HHT对CNE 2Z细胞具有增殖抑制作用 ,此抑制作用具有剂量和时间依赖性 ;HHT可诱导CNE 2Z细胞凋亡     

含高三尖杉酯碱的预激方案诱导治疗高危MDS或MDS转化为AML的疗效及其与CAG、HA方案的比较

本研究旨在探讨高三尖杉酯碱（HHT）、阿糖胞苷（Ara—C）合并使用粒细胞集落刺激因子（G-CSF）的低强度化疗方案（CHG方案）对高危骨髓增生异常综合征（MDS）或MDS转化的急性髓细胞白血病（AML）的疗效。30例未接受过化疗的高危MDS或MDS转化的AML患者入选CHG方案组,HHT和Ara-C每天1mg和25mg分别静脉滴注,连续14天,G-CSF300μg每天1次皮下注射,于化疗前12小时开始,持续使用至化疗结束或外周血白细胞计数〉20×10^9／L。使用本方案1疗程后若取得完全缓解（CR）,则给予常规化疗方案巩固并强化。33例高危MDS患者和MDS转化的AML患者入选CAG方案组,阿克拉霉素（Acla）每天10mg,连续8天,Ara—C每天25mg,连续14天,分别静脉滴注,G—CSF用法用量,同CHG方案。33例高危MDS和MDS转化的AML患者入选HA方案组,HHT每天2—3mg,Ara—C每天100—150mg,分别静脉滴注,连续7天。外周血白细胞计数〈4×10^9／L时,给以G—CSF,白细胞计数〉4×10^9／L时停用。结果表明：（1）CHG方案组1疗程后14例患者达到CR（46．67％）,7例患者达到部分缓解（PR）（23．33％）,总有效率为70％。CAG方案组1疗程后14例CR（42．4％）,9例PR（27．3％）,总有效率69．7％。HA方案组1疗程后11例CR（33．3％）,3例PR（9．1％）,总有效率42．4％。经统计学检验,CHG与CAG方案组比较P〉0．05,CHG与HA方案组比较P〈0．05。（2）30例接受CHG诱导的患者在治疗期间发生粒细胞缺乏的比例为40％（12例）,平均持续时间8天,无治疗相关死亡发生。（3）14例经CHG方案1疗程取得CR病人,1人失访,其他9例复发。平均复发时间为8．2月;复发者再重复使用该方案未能取得再次缓解。（4）CHG方案组中14例CR患者中除1例失访外,6例仅接受HA／DA方案巩固及强化,已全部复发,平均CR持续时间6．1个月。另外7名患者除接受HA／DA方案外,还交替接受AA／TA／MA／IA等方案巩固及强化,平均CR时间已达10．6月,仍有4例处于持续缓解中。结论：CHG方案能取得较高的1疗程缓解率,与CAG方案相仿,高于HA方案。CHG方案骨髓抑制较轻,临床应用较安全。但取得CR后应加强巩固／强化治疗,避免早期复发。     

高三尖杉酯碱与5—氟尿嘧啶在青光眼滤过性手术应用中的对比研究

本文采用随机、双盲及前瞻性方法,将高三尖杉酯碱(Homoharringtonine,H.H)和5-氟尿嘧啶(5-Fluorouracil,5-FU)用于难治性青光眼滤过手术。比较了两者对滤过手术疗效的影响及其毒副作用。其中,H.H组24只眼,5-FU组23只眼。随诊10～20个月(平均18个月),研究结果显示:(1)H.H组功能性滤过泡累计百分率为84.9％,显著高于5-FU组(62.2％)(P<0.05);(2)H.H组的累计手术成功率为85.7％,显著高于5-FU组(61.1％)(P<0.05),(3)H.H组角膜上皮缺损的发生率为20.8％,低于5-FU组(52.2％)(P<0.05)。其他并发症两组间无差别。     

家蝇胚胎细胞抗菌蛋白对人髓样白血病细胞K 562选择性杀伤作用的研究

目的：利用脂多糖刺激家蝇胚胎细胞产生并提取抗菌蛋白,对比研究家蝇胚胎细胞抗菌蛋白和高三尖杉酯碱（HHT）对人髓样白血病细胞K562和正常人体细胞的抑制杀伤作用。方法采用含20mg/L脂多糖的无血清M3培养基作用于处于对数生长期的家蝇胚胎细胞16h,提取上清液中的抗菌蛋白,将抗菌蛋白配制为40、80、160、320和640μg/mL5个浓度组,采用MTT法测定各浓度抗菌蛋白对K562和人脐静脉血管内皮细胞的抑制作用。将处于对数生长期的K562细胞和人脐静脉血管内皮细胞配制成相同浓度的HHT组、家蝇胚胎细胞抗菌蛋白组,两种细胞均采用自身设置对照组。采用流式细胞术测定K562细胞和人脐静脉血管内皮细胞3组药物的有效杀伤率。结果MTT法检测显示,5种浓度抗菌蛋白对K562细胞均具有明显抑制作用,各浓度抗菌蛋白对人脐静脉血管内皮细胞均无抑制作用。对照组、HHT组及家蝇胚胎细胞抗菌蛋白组对K562细胞的有效杀伤率分别为（28．16±2．14）％、（81．41±1．95）％和（82．90±3．03）％;对人脐静脉血管内皮细胞的有效杀伤率分别为（41．13±2．51）％、（82．20±2．57）％和（36．68±1．86）％。结论家蝇胚胎细胞抗菌肽与常用的白血病化疗药物相比,优点在于能有效杀伤白血病细胞又不损伤正常人体细胞。