番荔枝内酯抗肿瘤作用研究进展

番荔枝内酯是一类很有希望的新抗癌药物 ,被喻为“明日抗癌之星” ,它也是一类具有多种生物活性的物质 ,已经从多种番荔枝科植物的不同部位中分离提得。现就其抗癌作用、逆转肿瘤多药耐药作用、作用机制、构效关系等方面作简单的回顾     

番荔枝总内酯纳米混悬剂的制备及其体外抗肿瘤作用研究

目的制备番荔枝总内酯纳米混悬剂,并对其体外抗肿瘤作用进行研究。方法使用反溶剂沉淀法中的超声法制备番荔枝总内酯纳米混悬剂,考察其处方和制备工艺参数;动态光散射法测定其粒径和电位,透射电镜考察其粒径分布和形态;并对其人工胃肠液稳定性进行考察;采用MTT比色法比较番荔枝总内酯纳米混悬剂和溶液对HepG2细胞毒性差异。结果制备方法为将10 mg番荔枝总内酯与1 mg PGDA共溶于1 mL有机溶剂中,超声(250 W)快速注入到5 mL水中,减压旋转蒸发除去有机溶剂,调整总体积至5 mL。番荔枝总内酯纳米混悬剂平均粒径为(146.0±2.4)nm,多分散指数(PDI)为0.184±0.02,Zeta电位(26.0±2.0)mV,纳米混悬剂几乎呈类球型,粒径分布接近于正态分布,分布比较均匀;人工胃肠液内4 h稳定存在,粒径基本不发生变化;对HepG2细胞增殖均有一定的抑制作用,番荔枝总内酯纳米混悬剂组的细胞增殖抑制效果均优于溶液组。结论制备了以PGDA为载体的番荔枝总内酯纳米混悬剂,解决了药物的难溶和给药问题,为番荔枝总内酯的纳米剂型研究提供了参考。     

番荔枝总提取物防治肝癌的作用和机制研究

随着医药科技的进步,恶性肿瘤和心血管疾病已成为威胁人类生命的最主要影响因素。因此,对于肿瘤的研究正引起了临床医学学者们共同关注。第一部分是番荔枝科植物抗肿瘤作用的研究概况。第二部分为实验研究,研究了番荔枝总提取物对二乙基亚硝胺(DEN)诱发大鼠肝癌的防治作用、番荔枝内酯(AAs)对人肝癌细胞株Hep G2瘤体生长的抑制作用。     

番荔枝内酯克服肿瘤多药抗药性作用及机制

目的：探讨阿蒂莫耶番荔枝总内酯（ＡＡ）及其单体ｂｕｌｌａｔａｃｉｎ和ａｔｅｎｏｙａｃｉｎ－Ａ克服肿瘤多药抗药性（ＭＤＲ）的作用及其机制。方法：用两对ＭＤＲ细胞株及其相应的敏感株进行对比研究。结果：ＡＡ及其单体具有极强的细胞毒作用,且对ＭＤＲ细胞与其相应的敏感株的ＩＣ５０相近。加入ＡＡ,ｂｕｌｌａｔａｃｉｎ和ａｔｅｍｏｙａｃｉｎ－Ａ能使细胞内Ｆｕｒａ－２分别增加２．３９,３．１４和３．２４倍,但不能     

番荔枝总内酯平衡溶解度和油水分配系数的测定

目的:测定番荔枝总内酯的平衡溶解度以及表观油水分配系数,为体内吸收和设计其新剂型提供参考。方法:采用饱和法和超声振荡法分别测定番荔枝总内酯在不同溶剂中的平衡溶解度以及在正辛醇-水/缓冲溶液中的表观油水分配系数,采用比色法测定番荔枝总内酯的含量。结果:番荔枝总内酯在水和石油醚中的溶解度分别为0.06g·L-1和1.27g·L-1,其在乙醚中的溶解度最高,为482.28g·L-1;超声振荡80min后P值达到平衡,25℃下番荔枝总内酯的表观正辛醇/水分配系数P为54.91(logP=1.74),在pH 6.8的缓冲溶液中的表观分配系数最大为32.03(logP=1.51)。结论:番荔枝总内酯易溶于常用的有机溶剂,在中等极性溶剂的溶解度较大;平衡方法、平衡时间及pH对油水分配系数都有一定的影响。     

亚硫酸氢钠穿心莲内酯对小鼠和家兔的肾毒性作用

目的观察亚硫酸氢钠穿心莲内酯(ASB)的肾毒性作用。方法 30只ICR小鼠随机分为正常对照组、ASB150和1000mg.kg-1组,ASB组小鼠尾静脉iv给予ASB,每天1次,连续7d,正常对照组iv给予等体积生理盐水,检测体重、肾脏系数、血常规、血清尿素氮和肌酐浓度,观察肾脏组织病理变化等指标。18只新西兰家兔,随机分为对照组、ASB125和500mg.kg-1组,麻醉后单次经耳缘静脉iv给予ASB,导尿管法收集尿液并测定尿量及尿常规指标。结果与正常对照组比较,ASB1000mg.kg-1可使小鼠血清肌酐和尿素氮浓度分别从124±19和18±3升高至197±35和(35±10)mmol.L-1(P<0.05),并使外周血白细胞从(10.5±2.0)×109L-1升高至(13.7±3.4)×109L-1,血小板从(666±122)×109L-1降低至(451±207)×109L-1,淋巴细胞比例从(0.83±0.03)降低至(0.68±0.11)(P<0.05),7/10小鼠肾脏出现间质性肾炎,伴轻度纤维化,部分肾小管有蛋白,近曲小管浊肿;与正常对照组比较,ASB150mg.kg-1对小鼠上述指标无明显影响。ASB500mg.kg-1可引起家兔尿蛋白和酮体阳性检出率一过性增加,给药后120min总尿量明显增加(P<0.05);与正常对照组比较,ASB125mg.kg-1对家兔上述指标无明显影响。结论 ASB1000mg.kg-1和500mg.kg-1时分别对小鼠和家兔肾脏具有毒性作用。     

线粒体通透性转换在丁烯酸内酯细胞毒性中的作用

目的研究线粒体通透性转换在丁烯酸内酯(BUT)细胞毒性中的作用。方法HepG2细胞染毒BUT后,采用若丹明123荧光法测定线粒体膜电位(ΔΨm)的变化;线粒体膜通透性转换孔(MPTP)抑制剂环孢素A(CsA)预处理细胞后,采用MTT法测定线粒体膜通透性转换在BUT细胞毒性中的作用。结果BUT能够浓度依赖性地降低ΔΨm,而巯基化合物谷胱甘肽、N-乙酰半胱氨酸和二硫苏糖醇则能明显抑制该效应。CsA预处理能够明显减轻BUT的细胞毒性。结论BUT通过诱导HepG2细胞内氧化应激,导致MPTP的开放而最终引起细胞死亡。     

番荔枝内酯单体89-2实验治疗KBv200及KB细胞移植瘤的作用

目的番荔枝内酯单体89-2是自阿蒂莫耶番荔枝植物分离获得。本研究旨在探讨89-2对MDR肿瘤的实验治疗作用。方法以MTT法测定细胞毒;KBv200及KB细胞裸鼠移植瘤模型研究89-2对MDR肿瘤的实验治疗作用;以Fura-2-AM法测定P-糖蛋白(P-gp)功能。结果89-2对KBv200及KB细胞的IC₅₀分别为48.7和64.6 nmol·L^-1(P>0.05)。89-2对KB及KBv200细胞裸鼠移植瘤具有相似的剂量依赖性抑制作用,而毒性可以耐受。89-2剂量依赖性地增加KBv200细胞的Fura-2积累。结论89-2体内外均抑制KB和KBv200细胞生长,具有开发前景。     

番荔素纳米混悬剂的制备及其抗肿瘤作用研究

目的 制备高载药量番荔素纳米混悬剂（ACGs-NSPs）,并研究其对小鼠乳腺癌4T1移植肿瘤的生长抑制作用,为强效抗肿瘤药物ACGs的临床应用提供可用注射剂型。方法 番荔素、TPGS、SPC（质量比7:5:2）采用超声-沉淀法制备ACGs-NSPs,并用动态光散射法测定ACGs-NSPs的粒径,透射电镜观察其形态;稳定剂TPGS、SPC组成比例对ACGs-NSPs的溶血性考察;透析法考察其体外释放;采用MTT比色法评价ACGs-NSPs对4T1细胞细胞毒性;建立4T1乳腺癌皮下小鼠肿瘤模型,以紫杉醇注射液（PTX）为阳性对照,考察不同剂量ACGs-NSps静脉注射给药对4T1肿瘤的抗肿瘤药效。结果 ACGs-NSPs为表面光滑的球形,平均粒径为(129.03±1.03）nm,多分散指数PDI为0.134±0.03,zeta为（-17.7±0.16）mV,HPLC法测得番荔素线性回归方程为Y=0.157 2 X-0.363 2（R²=0.999）,在5~200 μg/mL范围内显性关系良好,载药量高达（45.03±0.72）%;体外释放较为缓慢;MTT试验中,ACGs-NSPs对4T1乳腺癌的细胞毒性显著强于游离药物（IC⁵⁰,3.221 μg/mL vs 4.464 μg/mL,P<0.05）;4T1荷瘤小鼠的药效学实验中,ACGs-NSPs表现出剂量相关性的抑瘤作用,高、中、低剂量组（0.4、0.2、0.1 mg/kg）抑瘤率分别为76.09%、74.34%、42.03%;但高剂量组小鼠有死亡（3/10）。结论 成功制备高载药量的ACGs-NSPs,且其对4T1乳腺癌有显著的抑制作用;从药效和小鼠存活率来看,0.2 mg/kg为合适的给药剂量。     

番荔素亚微乳的制备及其抗肿瘤作用研究

目的制备番荔素亚微乳,并进行体内外抗肿瘤作用研究,为番荔素的口服给药提供可行方案。方法以离心稳定常数(Ke)为指标,采用正交试验对注射用大豆油的用量、混合乳化剂总量和混合乳化剂的质量比进行考察,优化最佳处方配比。考察纳米乳匀机的运转压力和运转次数对番荔素亚微乳的粒径大小和分布的影响,优化工艺参数。透射电镜观察最佳工艺所得番荔素亚微乳,考察其在生物介质中的稳定性。采用噻唑蓝(MTT)比色法评价番荔素亚微乳对鼠乳腺癌4T1、人黑色素瘤A875细胞和人肝癌细胞Hep G2的细胞毒性。建立鼠源肝癌H22细胞实体瘤模型,小鼠ig番荔素亚微乳、番荔素油溶液,计算抑瘤率。结果番荔素亚微乳的最佳处方配比和制备工艺为:注射用大豆油用量为10%,乳化剂总量为3%,其中精制蛋黄卵磷脂与聚山梨酯80质量比为8∶2;均质压力为1 500 bar,均质次数为9次。番荔素亚微乳在人工胃肠液中稳定,呈球形,粒径较小,主要在100 nm左右。番荔素亚微乳对4T1、A875、Hep G2细胞IC50值分别为3.082、2.001、1.762μg/m L;ig给药1 mg/kg番荔素亚微乳与4 mg/kg油溶液对H22荷瘤鼠的抑瘤效果相当(65.0%vs 56.5%)。结论番荔素亚微乳可以解决番荔素难溶于水、难于给药的问题,能在不降低疗效的同时将用药剂量降低到传统油溶液的1/4,在一定程度上具有增效减毒作用。     

Methotrexate induced mitochondrial injury and cytochrome c release in rat liver hepatocytes

Methotrexate (MTX) is a folic acid antagonist that is widely used to treat a variety of diseases. One of the most serious side effects of MTX therapy is hepatotoxicity. The potential molecular cytotoxic mechanisms of MTX toward isolated rat hepatocytes were investigated using Accelerated Cytotoxicity Mechanism Screening (ACMS) techniques. A concentration and time dependent increase in cytotoxicity and reactive oxygen species (ROS) formation and a decrease in mitochondrial membrane potential (MMP) were observed with MTX. Furthermore, a significant increase in MTX (300?μM)-induced cytotoxicity and ROS formation were observed when glutathione (GSH)-depleted hepatocytes were used whereas addition of N-acetylcysteine (a GSH precursor) decreased cytotoxicity. Catalase inactivation also increased MTX-induced cytotoxicity, while the direct addition of catalase to the hepatocytes decreased cytotoxicity. MTX treatment in isolated rat mitochondria caused swelling and significantly decreased adenosine triphosphate (ATP) and GSH content, and cytochrome c release. Potent antioxidants such as mesna, resveratrol and Trolox decreased MTX-induced cytotoxicity and ROS formation and increased MMP. This study suggests that MTX-induced cytotoxicity caused by ROS formation and GSH oxidation leads to oxidative stress and mitochondrial injury in rat hepatocytes.     

Modulation of oxidative/nitrosative stress and mitochondrial protective effect of Semecarpus anacardium in diabetic rats

Objectives Oxidative and nitrosative stress play an important role in the complications of diabetes mellitus. Free radicals are produced when there is an electron leak in the mito‐chondria and a change in the mitochondrial membrane potential. The present study was undertaken to investigate the role of Semecarpus anacardium in protecting the mito‐chondria by modulating the production of reactive oxygen species and reactive nitrogen species in diabetic rats. Methods Diabetes was induced using streptozotocin at a dose of 50 mg/kg body weight and, starting 3 days after the induction, Semecarpus anacardium nut milk extract was administered for 21 days. The same duration of study was used for control, diabetes‐induced and drug control groups, together with a group treated with metformin. After the experimental period, the animals were sacrificed and the levels of superoxide, hydrogen peroxide, nitrate and nitrite were estimated. Changes in mitochondrial membrane potential, intracellular reactive oxygen species and intracellular calcium were also determined. Confocal laser microscopic images were taken for mitochondria isolated from the liver and kidneys. Key findings The results of the study revealed that Semecarpus anacardium was able to decrease the production of reactive oxygen and nitrogen species, and reverse the changes in mitochondrial membrane potential and the influx of calcium into the mitochondria. Conclusions The mitochondrial protective effect may be mediated by scavenging of free radicals and complexing of metal ions by virtue of the antioxidative effect of Semecarpus anacardium.     

Study on the biological mechanism of urolithin a on nasopharyngeal carcinoma in vitro

ContextUrolithin A (UroA) can inhibit the growth of many human cancer cells, but it has not be reported if UroA inhibits nasopharyngeal carcinoma (NPC) cells.ObjectiveTo explore the inhibitory effect of UroA on NPC and potential mechanism in vitro.Materials and methodsRNA-sequencing-based mechanistic prediction was conducted by comparing KEGG enrichment of 40 μM UroA-treated for 24 h with untreated CNE2 cells. The untreated cells were selected as control. After NPC cells were treated with 20–60 μM UroA, proliferation, migration and invasion of were measured by colony formation, wound healing and transwell experiments. Apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) were measured by flow cytometry, Hoechst 33342, Rhodamine 123, JC-1 staining and ROS assay methods, respectively. Gene and protein expression were measured by RT-qPCR and Western blotting assay.ResultsRNA-sequencing and KEGG enrichment revealed UroA mainly altered the ECM receptor interaction pathway. UroA inhibited cells proliferation, epithelial–mesenchymal-transition pathway, migration and invasion with IC₅₀ values of 34.72 μM and 44.91 μM, induced apoptosis, MMP depolarization and increase ROS content at a concentration of 40 μM. UroA up-regulated E-cadherin, Bax/Bcl-2, c-caspase-3 and PARP proteins, while inhibiting COL4A1, MMP2, MMP9, N-cadherin, Vimentin and Snail proteins at 20–60 μM. Moreover, co-treatment of UroA (40 μM) and NAC (5 mM) could reverse the effect of UroA on apoptosis-related proteins.Discussion and conclusionsRNA-sequencing technology based on bioinformatic analyses may be applicable for studiying the mechanism of drugs for tumour treatment.     

Hepatoprotective and neuroprotective activity of liposomal quercetin in combating chronic arsenic induced oxidative damage in liver and brain of rats

Context: Arsenic is a naturally occurring toxicant that causes acute and chronic adverse health effects, including cancer.

Objective: The study was performed to evaluate the therapeutic efficacy of liposome entrapped flavonoidal quercetin in combating arsenic toxicity mediated oxidative damage in hepatocytes and brain cells in rat model.

Materials and methods: Hepatic and neuronal cell damage in rats was made by daily arsenic (6mg/kg b wt, 9?mg/kg b wt and 12?mg/kg b wt) treatment via oral route for four consecutive months. Liposomal quercetin (2.71mg QC/kg b. wt) were injected s.c. on rats treated with 12?mg/kg b. wt. NaAsO₂ twice a week for four months.

Results and Discussion: Inorganic arsenic deposition was found to be most significant in hepatic (9.32?±?0.100 µg/g tissue) and neuronal (6.21?±?0.090 µg/g tissue) cells of rats treated with 12?mg/kg b wt of arsenite. Antioxidant levels in hepatic and neuronal cells were reduced significantly by the induction of arsenic. Liposomal quercetin was found most potent for a complete prevention of arsenite-induced reduction in antioxidant levels in the liver and brain of rats. Arsenic induced a substantial increase in hepatic hydroxyproline (HP) and Liposomal quercetin treatment resulted in complete replenishment of the HP level to normal. Liposomal quercetin completely prevented the arsenite-induced upregulation of cytochrome c expression in liver and brain significantly suggesting that the protective effect of Liposomal quercetin could be related to the reduction of arsenic deposition in both the organs. Conclusion: Thus, Liposomal quercetin might prove to be of therapeutic potential against arsenite-induced hepatic and neuronal cell damage in rats.     

Influence of intracellular Ca(2+), mitochondria membrane potential, reactive oxygen species, and intracellular ATP on the mechanism of microcystin-LR induced apoptosis in Carassius auratus lymphocytes in vitro

Microcystin-LR (MCLR), the most toxic microcystin up to date, could induce apoptosis in many kinds of fish and mammalian cells. For the fish immunotoxicity, it was found that MCLR could induce apoptosis in Carassius auratus lymphocytes in vitro. So this study focused on the role of intracellular Ca(2+), mitochondrial membrane potential, reactive oxygen species (ROS), and intracellular ATP in response to the mechanisms of MCLR-induced apoptosis in fish lymphocytes. MCLR (10 nM) administration resulted in a massive elevation in ROS, intracellular Ca(2+), decreased ATP, and rapid mitochondrial membrane potential (DeltaPsi(m)) disruption. When compared to controls, both a fourfold significant (P < 0.001) elevation in O(2) (-) in 1.5 h and an approximately twofold increase in Ca(2+) in 0.5 h were observed. After 6 h of treatment, an approximately 30% decrease for DeltaPsi(m) but about 75% decline for ATP were found. Together, the results demonstrated that MCLR-induced apoptosis was associated with a massive calcium influx, resulting in O(2) (-) elevation, DeltaPsi(m) disruption, and ATP depletion. This study provided a possible cytotoxic mechanism of fish lymphocytes caused by MCLR.     

Toxicity profiling of water contextual zinc oxide,silver, and titanium dioxide nanoparticles in human oral and gastrointestinal cell systems

Engineered nanoparticles (ENPs) are increasingly detected in water supply due to environmental release of ENPs as the by‐products contained within the effluent of domestic and industrial run‐off. The partial recycling of water laden with ENPs, albeit at ultra‐low concentrations, may pose an uncharacterized threat to human health. In this study, we investigated the toxicity of three prevalent ENPs: zinc oxide, silver, and titanium dioxide over a wide range of concentrations that encompasses drinking water‐relevant concentrations, to cellular systems representing oral and gastrointestinal tissues. Based on published in silico‐predicted water‐relevant ENPs concentration range from 100 pg/L to 100 µg/L, we detected no cytotoxicity to all the cellular systems. Significant cytotoxicity due to the NPs set in around 100 mg/L with decreasing extent of toxicity from zinc oxide to silver to titanium dioxide NPs. We also found that noncytotoxic zinc oxide NPs level of 10 mg/L could elevate the intracellular oxidative stress. The threshold concentrations of NPs that induced cytotoxic effect are at least two to five orders of magnitude higher than the permissible concentrations of the respective metals and metal oxides in drinking water. Based on these findings, the current estimated levels of NPs in potable water pose little cytotoxic threat to the human oral and gastrointestinal systems within our experimental boundaries. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1459–1469, 2015.     

Evidence for the regulation of L-type Ca2+ channels in the heart by reactive oxygen species: mechanism for mediating pathology

1. It is well recognized that reactive oxygen species (ROS) can activate transduction pathways to mediate pathophysiology. An increase in ROS has been implicated in a number of cardiovascular disorders. Reactive oxygen species regulate cell function through redox modification of target proteins. One of these target proteins is the L-type Ca(2+) channel. 2. There is good evidence that thiol reducing and oxidizing compounds, including hydrogen peroxide, can influence calcium channel function. The evidence for regulation of the channel protein and regulatory proteins by thiol-specific modifying agents and relevance to hypoxia and oxidative stress is presented. 3. Clinical studies suggest that calcium channel antagonists may be beneficial in reducing myocardial injury associated with oxidative stress. The identification of cysteines as possible targets for intervention during hypoxic trigger of arrhythmia or chronic pathological remodelling is discussed.