小檗碱抑制结肠癌细胞中COX-2表达作用的研究

目的:研究小檗碱(Ber)抑制肿瘤细胞中环氧合酶-2(COX-2)表达与时间及浓度的关系,探讨Ber作为抗肿瘤药物的可能.方法:以结肠癌细胞系HT-29为研究对象,培养后加入不同浓度的Ber,用荧光定量PCR法观察其对COX-2的抑制作用,MTT法检测Ber对癌细胞的杀伤作用.结果:在浓度大于0.25μmol·L-1时Ber对COX-2有抑制作用,与时间、浓度正相关.在浓度大于3.0μmol·L-1时对癌细胞有杀伤作用.结论:Ber可抑制COX-2及癌细胞生长,推测Ber有一定的抑癌作用,可望成为一种新型的抗癌药.     

The effect of ginkgo biloba extract on free radical production in hypoxic rats.

In the present study, we assayed the antioxidant properties of Ginkgo biloba (Gb) extract on rats submitted to 21 d of chronic hypoxia. Doses of 25 and 50 mg/kg were examined. Oxygenated free radical production measured by the chemiluminescence technique was significantly decreased in treated rats compared to control rats placed in similar experimental conditions, and this effect was more significant at the 50 mg/kg dose. On the other hand, no antioxidant enzyme activities of the drug were observed towards red blood cells. These results suggest that ginkgo biloba extract has a free radical scavenging action. These antioxidant properties could explain the beneficial hematological properties of Gb extract.     

The inhibitory effect of triterpenoid glycosides originating from Sanguisorba officinalis on tissue factor activity and the production of TNF-alpha

We examined the inhibitory effects of novel triterpene glycoside compounds [ziyu-glycoside II (ZY-II) and its methyl ester (ZYM-201)], which originated from the roots of sanguisorba officinalis L. (Rosaceae), on tissue factor (TF) activity and tumor necrosis factor (TNF)-alpha production. In in vitro TF activity tests, ZY-II but not ZYM-201 strongly blocked lung TF activity with an IC50 value of 0.46 microM. By contrast, only ZYM-201 dose-dependently inhibited in vivo TF activity with an ED50 value of 1.7 mg/kg, when orally administered. Furthermore, ZYM-201 diminished both in vitro and in vivo TNF-alpha production with IC50 or ED50 values of 69.4 microM and 87.4 mg/kg, respectively. Therefore, these results suggest either that ZYM-201 may be developed as a potent inhibitor of both TF- and TNF-alpha-mediated diseases such as atherosclerosis and septic shock, or it may be a lead compound to be derivatized for further improvement of its curative efficacy.     

Tachykinin receptor modulation of cyclooxygenase-2 expression in human polymorphonuclear leucocytes

Background and purpose:

We investigated the ability of natural and synthetic selective NK receptors agonists and antagonists to modulate cyclooxygenase-2 (COX-2) expression in human polymorphonuclear leucocytes (PMNs).

Experimental approach:

The presence of all three tachykinin in PMNs was assessed by Western blot and PCR techniques. Natural and synthetic ligands selective for the tachykinin receptors were used to modulate COX-2 protein (measured with Western blotting) and activity [as prostaglandin E₂ (PGE₂) output]. Effects of substance P (SP) on phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB) activation were studied to analyse the signalling pathway involved in COX-2 up-regulation mediated by SP.

Key results:

Stimulation of NK receptors with the natural ligands SP, neurokinin A (NKA) and neurokinin B, in the pmol·L⁻¹-µmol·L⁻¹ concentration range, modulated COX-2 expression and PGE₂ release in a concentration- and time-dependent manner. Experiments with synthetic selective agonists [Sar⁹, Met(O₂)¹¹]SP, [β-Ala⁸] NKA(4-10), senktide or selective antagonists L703,606, SR48,968 or SR142801, confirmed that COX-2 up-regulation was mediated by NK receptors. We found that mainly p38, p42 and p46 MAPKs were phosphorylated by SP and SB202190, PD98059 and SP600125, which are selective inhibitors of these kinases, blocked SP-induced COX-2 expression. SP also induced nuclear translocation of NF-κB concentration-dependently, with a maximum effect at 1 nmol·L⁻¹.

Conclusions and implications:

Human PMNs possess functional NK₁, NK₂ and NK₃ receptors, which mediate the induction of COX-2 expression and NF-κB activation by SP.     

自由基在平阳霉素硬化治疗血管瘤中的作用

目的 :探讨自由基在平阳霉素硬化治疗中的作用。方法 :将平阳霉素分别注入 6 2例口腔颌面部血管瘤腔内后抽出瘤腔血液 ,测定丙二醛 (MDA)含量。结果 :两次取材中自由基代谢产物MDA含量显著增高。结论 :自由基是平阳霉素在治疗血管瘤发挥硬化作用的重要机制     

Priming effect of substance Ponsuper oxideanionradical production inhumanneu trophils

神经肽Ｐ物质能激活多种参与炎症和免疫反应的细胞．然而Ｐ物质直接刺激人粒细胞产生超氧阴离子（Ｏ÷２）需要较高的浓度（＞１０μｍｏｌ·Ｌ－１）．本实验观察了低浓度Ｐ物质对人粒细胞超氧阴离子生成的活化作用．结果表明，Ｐ物质在低浓度时（３μｍｏｌ·Ｌ－１）能活化人粒细胞，使甲酰基－甲硫氨酰基－亮氨酰基苯丙氨酸（ｆＭＬＰ）刺激产生的超氧阴离子明显增多．Ｐ物质的这一活化作用呈剂量和时间依赖性．在无细胞外钙的情况下，Ｐ物质没有这种活化作用．Ｐ物质活化ｆＭＬＰ引起的Ｏ÷２生成增多作用可被神经激肽（ＮＫ）－１受体阻断剂ｓｐｅｎｔｉｄｅ（１μｍｏｌ·Ｌ－１），磷脂酶Ｃ抑制剂Ｕ－７３１２２（１０ｎｍｏｌ·Ｌ－１）以及Ｃａ２＋通道阻断剂尼卡地平（１μｍｏｌ·Ｌ－１）所抑制．这些发现提示，Ｐ物质活化人粒细胞可能是经ＮＫ－１受体偶联的磷脂酰肌醇代谢途径，并且是细胞外钙依赖性的     

物质对人中性粒细胞超氧阴离子生成的活化作用

神经肽P物质能激活多种参与炎症和免疫反应的细胞. 然而P物质直接刺激人粒细胞产生超氧阴离子(O^÷₂)需要较高的浓度(>10 μmol·L^-1). 本实验观察了低浓度P物质对人粒细胞超氧阴离子生成的活化作用. 结果表明, P物质在低浓度时(3 μmol·L^-1)能活化人粒细胞, 使?甲酰基-甲硫氨酰基-亮氨酰基苯丙氨酸(fMLP)刺激产生的超氧阴离子明显增多. P物质的这一活化作用呈剂量和时间依赖性. 在无细胞外钙的情况下，P物质没有这种活化作用. P物质活化fMLP引起的O^÷₂生成增多作用可被神经激肽(NK)-1受体阻断剂spentide (1 μmol·L^-1), 磷脂酶C抑制剂U-73122 (10 nmol·L^-1)以及Ca²⁺通道阻断剂尼卡地平 (1 μmol·L^-1)所抑制. 这些发现提示, P物质活化人粒细胞可能是经NK-1受体偶联的磷脂酰肌?醇代谢途径, 并且是细胞外钙依赖性的.     

The lipolytic effect of beta 1- and beta 2-adrenoceptor activation in healthy human volunteers.

1. We investigated the effect of activation beta 1- and beta 2-adrenoceptors on the process of lipolysis in human volunteers. Ten male subjects underwent a single-blind randomized cross-over trial using infusions of terbutaline (a specific beta 2-adrenoceptor agonist), xamoterol (a partial beta 1-agonist with beta 2-adrenoceptor blocking activity) and saline (placebo control). The effect of these infusions on plasma potassium, glucose, free fatty acids (FFA) (total and individual) and insulin levels was studied. 2. Terbutaline infusion induced a significant rise in plasma glucose and a fall in plasma potassium in keeping with its beta 2-adrenoceptor stimulant properties. Xamoterol infusion had no significant effect on these values. Terbutaline infusion caused a greater rise in total and individual FFA than xamoterol, but both effects were significantly different from placebo. 3. The possible reasons for these results and their implications on the beta-adrenergic control of lipolysis are discussed.     

Biotransformation of prim-O-glucosylcimifugin by human intestinal flora and its inhibition on NO production and DPPH free radical

prim-O-Glucosylcimifugin (PGCN), a highest content chromone in the roots of Saposhnikovia divaricata, was incubated with human intestinal flora (HIF), and two biotransformation products were obtained from the incubated solution by chromatographic methods. The chemical structures of the two biotransformation products were elucidated as cimifugin (CN) and 5-O-methylvisamminol (MVL), respectively, on the basis of NMR and MS data. The biotransformation product CN was formed through a deglucosylation of PGCN by β-glucosidase secreted from the HIF, and then the hydroxymethyl group of CN was reduced to lead to occurrence of MVL. All of these compounds were evaluated for their effect on the inhibition of nitric oxide production induced by lipopolysaccharide in macrophage cell line RAW 264.7 and for 1,1-diphenyl-2-picrylhydrazyl free-radical scavenging activity in cell-free bioassay system.     

应用中空纤维测定法评价藤甲酰苷对人癌细胞生长的抑制作用

目的应用中空纤维测定法评价藤甲酰苷（garcinia glycosides,GG）对8种人癌细胞的体内生长的抑制作用,通过裸鼠体内异位移植瘤实验,验证中空纤维测定法在抗肿瘤药效学研究中的可靠性。方法采用中空纤维测定法,将载有肿瘤细胞的中空纤维管植入NOD/SCID小鼠背部皮下,给药结束后取出中空纤维管,应用二苯基溴化四氮唑蓝（MTT）比色法检测GG对各种肿瘤细胞在体内的抑瘤率;选取HL-60及B16人癌细胞,异位移植于BALb/c裸鼠右下肢外侧皮下,以环磷酰胺（CTX）为阳性对照,各组连续给药10 d,于给药结束24 h后解剖小鼠,取出瘤块,计算CTX及GG的抑瘤率。结果应用中空纤维测定法及裸鼠体内异位移植瘤法测得GG高剂量组8 mg/（kg·d）、中剂量组4 mg/（kg·d）能明显抑制HL-60及B16人癌细胞在裸鼠体内的生长,实验测得结果与溶剂对照组比较,有显著性差异（P〈0.01）。结论应用中空纤维测定法测定样品GG对肿瘤细胞的生长抑制作用,实验结果与裸鼠体内异位移植瘤实验结果基本一致。该模型节约成本、效率提高、实验结果准确可靠,为GG的后续研究提供了指导和可靠证据。     

The antioxidant effect of rebamipide on oxygen free radical production by H. pylori-activated human neutrophils: in comparison with N-acetylcysteine, ascorbic acid and glutathione.

Helicobacter pylori(H. pylori)-activated neutrophils produce the oxygen-derived free radicals (OFRs) which play an important role in gastric mucosal cell damage. Rebamipide (2-(4-chlorobenzoylamino)-3-[2-(1H)-quinolinon-4-yl] propionic acid) is an antiulcer compound, which protects gastric mucosa against OFR-mediated injury. In order to investigate the effects of rebamipide on OFR production and to compare the antioxidant activity of rebamipide with those of three known antioxidants, N-acetylcysteine (AC), ascorbic acid (Vit C) and glutathione (GSH), the antioxidant activities were determined by luminol-dependent chemiluminescence (ChL) assay and pyrogallol autoxidation assay. The ChL value was markedly elevated immediately after the addition of H. pylori into the medium containing neutrophils. The antioxidant activity of 1.0 mM rebamipide was greater than that of 0.1 mM rebamipide in the luminol-dependent ChL assay, while in the pyrogallol autoxidation assay, the antioxidant activity of 1.0 mM rebamipide was similar to that of 0.1 mM rebamipide. Rebamipide inhibited OFR generation in the pyrogallol autoxidation assay, with the potency being in the order of GSH > Vit C > rebamipide > AC. In the luminol-dependent ChL assay, the antioxidant activity of rebamipide was the greatest among them. These results indicate that rebamipide is a potent antioxidant and scavenges OFRs produced by H. pylori effectively in luminol-dependent ChL assays.     

The effect of orthotopic transplantation on total, beta 1- and beta 2-adrenoceptors in the human heart.

1. [125I]-(-)pindolol binding was used to determine beta-adrenoceptor density in homogenate preparations of right ventricular endomyocardial biopsies from 43 non-rejecting patients over the first 13 months following cardiac transplantation. The selective beta 1 subtype antagonist ligand CGP 20712A was used to determine the subtype density in 32 of the patients. Biopsy specimens from 15 donor hearts were used as controls. 2. beta-adrenoceptor density (expressed in terms of fmol mg-1 protein) was increased in the group of transplanted hearts as a whole compared with the donor hearts with respect to total (35 +/- 2 vs 23 +/- 2) and the beta 1 subtype (25 +/- 2 vs 16 +/- 2) whereas the beta 2 subtype and radioligand dissociation constant did not differ. 3. Non-parametric analysis of variance of total receptor density over time revealed significant heterogeneity which appears to be due to a discrete increase in beta-adrenoceptor density during the 4th post operative month. 4. These results indicate that beta-adrenoceptor density is not constant following transplantation. Furthermore, the increase in receptor density following transplantation is due mainly to an increase in the beta 1 subtype without a significant change in the beta 2 subtype.     

Antifolate effect of triamterene on human leucocytes and on a human lymphoma cell line

Summary The inhibitory effect of triamterene and its metabolites on human leucocyte dihydrofolate reductase has been studied. Under test conditions with dihydrofolic acid 0.5×10^–5 M, triamterene 7×10^–5 M produced total enzyme inhibition, whereas the metabolites hydroxytriamterene and the sulphate ester of hydroxytriamterene were less effective inhibitors; at their maximum attainable concentration of 5×10^–5 M, dihydrofolate reductase was inhibited by 80% and 50%, respectively. Cultures of the BJAB-B95-8 human lymphoma cell line were incubated with various concentrations of triamterene. Because of their increased specific activity of dihydrofolate reductase, the cells were able to maintain normal DNA metabolism, as measured by the ratio of the incorporation rates of ³H-deoxyuridine and ³H-thymidine, as well as normal cell growth at 1×10^–6 M, and in some cases at 1 × 10^–5 M triamterene. At 8×10^–5 M triamterene, the strong inhibitory effect caused severe impairment of DNA metabolism and subsequently dissolution of the cell culture. The results are discussed in relation to the possible toxic side effects of long-term triamterene treatment in patients suffering from alcoholic cirrhosis, who may have impaired metabolism of triamterene and a concomitant severe folate deficiency.     

盐酸小檗碱抑制结肠癌细胞环氧化酶-2/钙离子途径

目的探讨盐酸小檗碱对结肠癌细胞系生长、增殖的作用及环氧化酶2/钙离子途径的影响,为阐明盐酸小檗碱作为一种新的结肠癌化学治疗药物进行理论上的准备。方法0.1、0.3、3.0、30.0μmol·L-1的盐酸小檗碱加入到HT29结肠癌细胞系培养液中。MTT法检测细胞的生长和增殖,RTPCR法检测环氧化酶2mRNA,免疫细胞化学法检测环氧化酶2蛋白质表达,ELISA法检测前列腺素E2的含量,免疫荧光分光光度法检测细胞内钙离子浓度([Ca2+]i)。结果盐酸小檗碱在浓度大于0.3μmol·L-1时则有明显的量效关系抑制细胞的生长、增殖;在浓度大于0.3μmol·L-1时对环氧化酶2mRNA水平和蛋白的表达有明显的抑制作用;对前列腺素E2的生成有抑制作用,可以降低细胞内钙离子浓度。结论盐酸小檗碱通过抑制细胞内钙离子浓度进而通过某些途径抑制COX2在mRNA水平和蛋白质水平的表达,同时也抑制COX2活性进而抑制前列腺素E2的生成,这可能是其抑制HT29细胞生长和增殖的机制之一。     

The in vitro inhibitory effect of psilocybin and related compounds on human cholinesterases

Summary The comparison of the anticholinesterase activity of psilocybin, bufotenin and 5-hydroxytryptamine in human plasma, red cells and gray matter homogenate indicates that like with LSD and its derivatives, there is no correlation between the in vitro anticholinesterase activity and the hallucinogenic effect of these compounds. This investigation was supported by U.S.P.H. Grant No. M-1425 (C3) and Grant No. E-59 1960 of the Health Research and Services Foundation of Pittsburgh, Pa.     

Inhibitory effect of nafamostat mesilate (FUT-175) on O2- production in rat polymorphonuclear leucocytes

Effect of nafamostat mesilate (FUT-175), a serine protease inhibitor, having anti-inflammatory effects was studied on superoxide (O2-) production in rat polymorphonuclear leucocytes (PMN) and compared with those of other serine protease inhibitors and typical anti-inflammatory agents. 1) O2- productions in rat PMN stimulated with concanavalin A (Con A) and cytochalasin B (Cyt B) were too weak to observe. With NADH, however, strong O2- production was induced by Con A and Cyt B. 2) FUT-175 at 10(-6) and 10(-5) M inhibited O2- production in rat PMN induced by Con A and Cyt B with NADH in a concentration-dependent manner. 3) The serine protease inhibitor L-tosylamido-2-phenylethyl-chloromethyl ketone (TPCK) and soybean trypsin inhibitor (SBTI) inhibited O2- production at 10(-5) M and 10(-4) M, respectively, while aprotinin, chymostatin and leupeptin did not. 4) Neither indomethacin nor dexamethasone, typical anti-inflammatory agents, inhibited O2- production. Mepacrine, a phospholipase A2 inhibitor, strongly inhibited it. 5) O2- production in PMN prepared from the rat administered FUT-175, 200 mg/kg, p.o., was significantly decreased in comparison with that of the control rat. 6) FUT-175 had no effect on O2- production by hypoxanthine-xanthine oxidase. These results showed FUT-175 had a strong inhibitory effect on O2- production in rat PMN which other typical anti-inflammatory agents did not have.