多酚类物质对心脑血管保护作用的研究进展

多酚类是一类最重要也是最丰富的植物化学物,为植物体内的复杂酚类次生代谢物。因为多酚类具有多种生物活性,近年来已成为研究热点。除了抗肿瘤、调节免疫功能、抗衰老等,多酚类最重要的作用之一是对心脑血管系统的保护作用。本综述通过抗氧化机制和调节血脂、保护血管内皮机制两方面综合阐述了多酚类对心脑血管保护作用的机制及研究进展。     

植物化学物诱导肿瘤细胞自噬性死亡及对核受体调节作用研究进展

自噬性细胞死亡是一种非依赖性细胞程序性死亡。核受体可以调控下游基因的转录和翻译,影响自噬相关基因的表达,调节肿瘤细胞的自噬。目前研究发现,一些植物化学物,如异硫氰酸盐、黄酮类化合物、皂苷、植物雌激素、蒽醌类和生物碱等,可诱导特定的肿瘤细胞自噬性死亡。异硫氰酸盐、黄酮类化合物和植物雌激素等植物化学物与核受体结合可使核受体活化。除此之外,一些通过核受体发挥抗肿瘤作用的药物如他莫昔芬、15-脱氧Δ12,14-前列腺素J2、维生素D类似物EB1089、倍半萜烯紫杉醇类似物AGS 115和EFDAC也可以诱导肿瘤细胞发生自噬性死亡。上述研究为了解植物化学物、核受体和自噬三者之间的联系提供了线索。     

澳洲茄边碱抗肿瘤作用及其机制研究进展

从天然植物中提取并发展成药物已成为抗肿瘤药物研发的主要途径之一。澳洲茄边碱是从龙葵中分离获得的天然甾体生物碱糖苷化合物,具有较强的抗肿瘤作用和较低的细胞毒性,对肺癌、肝癌、胃癌、前列腺癌、鼻咽癌、脊索瘤和胰腺癌等多种常见肿瘤具有明显的抑制作用。澳洲茄边碱的抗肿瘤作用机制可能与抑制肿瘤细胞增殖、诱导肿瘤细胞凋亡、阻滞肿瘤细胞周期、抑制肿瘤迁移和侵袭、增强化疗药物的敏感性、调节信号通路和基因表达等有关。澳洲茄边碱不仅能单独抑制肿瘤细胞,而且可作为增敏剂与其他化疗药物合用增强疗效。该文基于澳洲茄边碱的抗肿瘤作用及其机制进行综述,以期为澳洲茄边碱的进一步研究和开发提供依据。     

鬼针草属植物抗肿瘤作用的研究概况

目的掌握鬼针草属植物抗肿瘤作用研究概况。方法查阅国内外近年来相关的文献资料并进行分析和综述。结果鬼针草属植物通过抑制肿瘤细胞增殖、诱导凋亡、调节免疫、抗氧化、清除自由基等发挥抗肿瘤的作用。结论鬼针草属植物具有一定的抗肿瘤活性,应加强抗肿瘤活性成分厦作用机制的研究。     

卫矛属植物化学成分及药理活性研究进展

国内外已研究的20种卫矛属植物中主要成分有倍半萜类、黄酮类、三萜类、甾体和强心苷类及其他类化合物。卫矛属植物的药理活性有抗肿瘤作用、昆虫拒食作用、杀虫作用、抗HIV作用以及对心血管系统的作用等。     

中药卷柏抗肿瘤作用及新型炔酚类化合物Selaginellin的研究进展

卷柏属植物资源丰富,药理作用广泛,近年来国内外在卷柏属药用植物的资源、活性成分、药理作用等方面有很多新发现和研究。特别是卷柏属植物的抗肿瘤作用引起了广大学者的关注,目前多认为卷柏属植物中的双黄酮类是其发挥抗肿瘤作用的主要物质。细胞毒作用,诱导细胞凋亡,阻滞肿瘤细胞的侵袭、转移,是双黄酮类发挥抗肿瘤作用的主要机制。卷柏属新型炔酚类化合物Selaginellin是近几年分离得到的新型碳骨架化合物,除了具有抗氧化作用外,最近发现其能通过发挥细胞毒作用,从而起到抗肿瘤的作用。本文针对近年来对卷柏属植物的抗肿瘤作用及其机制的研究概况以及对Selaginellin的研究历程、抗肿瘤作用等研究概况进行综述。     

健康教育在日间治疗室紫杉醇化疗患者中的重要性

紫杉醇作为一类植物类抗肿瘤药物，广泛应用于临床，已证实有一定的效果。对应用紫杉醇化疗的患者实施健康教育，起到了重要的作用，可根据患者的不同年龄．不同病种，不同层次采取灵活多样的健康教育方法。为语言教育，示范性教育，电化教育。文字教育等，使患者了解紫杉醇化疗药的作用机理和效果。     

植物来源的抗肿瘤药物研究进展

综述喜树碱、紫杉醇、鬼臼毒素和combretastatin A-4等4类植物来源的抗肿瘤药物的作用机制、构效关系及衍生物的研究进展。植物来源的抗肿瘤药物已逐步在临床肿瘤治疗领域占据主导地位,而充分利用我国丰富的药用植物资源,研发高效低毒的天然抗肿瘤药物也已成为广大药学工作者的热点课题。     

小资料

比较毒理学 (comparativetoxicology)它以比较解剖学、比较生理学和比较生物化学等为基础 ,研究外源化学物对不同种系动物 (有时包括植物 )的毒性、效应、中间代谢和作用机制 ,并进行比较分析 ,揭示有关规律 ,更深层次地了解外源化学物对生物体的有害作用小资料@顾祖维     

紫金牛属植物皂苷类化学成分及其抗肿瘤作用研究进展

目的综述紫金牛属植物皂苷类化学成分及其抗肿瘤作用研究进展,为该属植物的研究提供理论依据。方法查阅近年来公开发表的论文,对紫金牛属植物皂苷类化学成分及其抗肿瘤作用进行概述。结果大量的研究证明紫金牛属植物中皂苷类成分具有抗肿瘤作用。结论紫金牛属植物具有良好的开发应用前景。     

Effect of Seville orange juice and grapefruit juice on indinavir pharmacokinetics

Considerable interpatient variability in indinavir pharmacokinetics, possibly due in part to variable metabolism of the drug through intestinal cytochrome P450 (CYP) 3A4, may contribute to poor virologic response in certain individuals with HIV infection. The purpose of this study was to characterize the influence of intestinal CYP3A4 modulation with grapefruit juice and Seville orange juice on indinavir pharmacokinetics. In an open-label, three-period crossover study, 13 healthy volunteers received indinavir 800 mg every 8 hours for 1 day and a single 800 mg dose the next morning. The last two indinavir doses were taken with 8 ounces of Seville orange juice, single-strength grapefruit juice, or water (control). Plasma samples were collected at time 0 (predose) and at 0.5, 1, 2, 3, 4, and 5 hours after the last indinavir dose. Concentration-time data were analyzed using noncompartmental methods. Coadministration of Seville orange juice and indinavir resulted in a statistically significant increase in indinavir t(max) (1.87 [1.65-2.22] vs. 1.25 [1.03-1.60] h; p < 0.05) without altering other pharmacokinetic parameter values. Grapefruit juice administration did not result in any changes in indinavir pharmacokinetics. Modulation of intestinal CYP3A4 by grapefruit juice and Seville orange juice did not alter the systemic availability of indinavir. The contribution of presystemic metabolism to indinavir interpatient variability appears to be small.     

果汁中展青霉素的测定

目的:检测果汁中展青霉素。方法:采用NY/T1650-2008对果汁中的展青霉素进行了测定。结果:对196批次的果汁按上述方法进行了测定,约有30多批次检出,又经二极管阵列检测器确认,最终有10多批次为阳性。     

Grapefruit juice and orange juice effects on the bioavailability of nifedipine in the rat

Previous studies with rats indicate that nifedipine undergoes both hepatic and extrahepatic presystemic metabolism after peroral (po) administration, and that its bioavailability is increased and absorption delayed by concomitant administration of grapefruit juice concentrate (GJC). Hence, the effects of GJC could be to delay stomach emptying and inhibit nifedipine metabolism in the small-intestinal wall and liver or, alternatively, to impede nifedipine absorption until reaching the large intestine where gut wall presystemic metabolism is not a factor. The mechanism(s) of action of GJC might be partially resolved by comparison with orange juice concentrate (OJC), which has a similar consistency but lacks inhibitory effects on nifedipine presystemic metabolism, and also by giving regular-strength solutions of the two juices, both of which should not significantly affect stomach emptying. This study compared the po bioavailability on nifedipine (6 mg kg⁻¹) in male Sprague–Dawley rats coadministered GJC, OJC, grapefruit juice regular strength (GJRS), orange juice regular strength (OJRS), or (tap) water. Nifedipine plasma concentration–time profiles in the GJRS, OJRS, and (tap) water groups displayed a single peak. Both GJC and OJC groups have double-peak profiles (indicating delayed gastric emptying); however, the majority of the nifedipine dose in both cases was absorbed during the interval of the second peak, which occurred several hours postdosing. GJC significantly increased nifedipine bioavailability (relative bioavailability 2.02, compared with (tap) water), indicating that GJC may affect both extrahepatic and hepatic first-pass metabolism, although a reduction in systemic nifedipine clearance cannot be ruled out. Surprisingly, GJRS had no significant effect on nifedipine bioavailability. OJC did not increase nifedipine bioavailability, further suggesting that the delay in nifedipine absorption by GJC or OJC results from delayed gastric emptying. © 1998 John Wiley & Sons, Ltd.     

葡萄柚汁与药物的相互作用

目的：了解葡萄柚汁对其他药物代谢的影响及合用后的相互作用。方法：通过对近几年来的国内外文献报道进行收集，归纳，分析，加以综述。结果：葡萄柚汁可改变许多药物的药动学，使血药浓度升高，引起有临床意义的食物－药物相互作用。结论：临床上应尽量避免葡萄柚汁与易受影响的药物，如二氢吡啶类钙拮抗剂，免疫抑制剂，许多中枢神经系统药物，他汀类药物，促胃肠动力药沙必利，HIV蛋白酶抑制剂等合用，以确保用药安全。     

Stability of metallothionein in gastric juice

Metallothionein (MT), is presumably the major Cd-binding component of human food. It is not or only partially destroyed by cooking. To study whether MT is stable in gastric juice MT was incubated at various pH values with pepsin and human gastric juice in vitro. Above pH 3.5 nearly all Cd remained bound to the protein and Cd-MT was resistant towards proteolysis. At pH values of 2.5 and 1.7 the protein was digested to 80% and 100%, respectively. At pH 2.5 two Cd-containing peptides with 25-30 amino acids similar to the alpha-domain of the protein were detected. At pH 1.7 these fragments were further degraded to smaller peptides. The results indicate that the pH-dependent proteolytic degradation of Cd-MT depends on the metal content of the protein. Furthermore, the identical results obtained with pepsin and human gastric juice suggest that Cd-MT proteolysis occurs in vivo and will affect Cd resorption.