The effects of a novel phosphodiesterase 7A and -4 dual inhibitor, YM-393059, on T-cell-related cytokine production in vitro and in vivo

YM-393059, (+/-)-N-(4,6-dimethylpyrimidin-2-yl)-4-[2-(4-methoxy-3-methylphenyl)-5-(4-methylpiperazin-1-yl)-4,5,6,7-tetrahydro-1H-indol-1-yl]benzenesulfonamide difumarate, is a novel phosphodiesterase (PDE) inhibitor that inhibited the PDE7A isoenzyme with a high potency (IC50=14 nM) and PDE4 with a moderate potency (IC50=630 nM). In a cell-based assay, YM-393059 was found to inhibit anti-CD3 antibody, Staphylococcal enterotoxin B, and phytohaemagglutinin-induced interleukin (IL)-2 production in mouse splenocytes with IC50 values ranging from 0.48 to 1.1 microM. It also inhibited anti-CD3 antibody-induced interferon (IFN)-gamma and IL-4 production in splenocytes with IC50 values of 1.8 and 2.8 microM, respectively. YM-393059's inhibition of anti-CD3 antibody-stimulated cytokine (IL-2, IFN-gamma, and IL-4) production was 20- to 31-fold weaker than that of YM976, a selective PDE4 inhibitor. However, orally administered YM-393059 and YM976 inhibited anti-CD3 antibody-induced IL-2 production equipotently in mice. In addition, YM-393059 inhibited lipopolysaccharide-induced tumor necrosis factor-alpha production in vivo more potently than IL-2 (ED50 values of 2.1 mg/kg and 74 mg/kg). In contrast to YM976, YM-393059 did not shorten the duration of alpha2-adrenoceptor agonist-induced sleep in mice, which is a model for the assessment of the typical side effects caused by PDE4 inhibitors, nausea and emesis. YM-393059 is a novel and attractive compound for the treatment of a wide variety of T-cell-mediated diseases.     

FR180204, a novel and selective inhibitor of extracellular signal-regulated kinase,ameliorates collagen-induced arthritis in mice

Extracellular signal-regulated kinase (ERK), a serine/threonine protein kinase of the mitogen-activated protein kinase superfamily, is activated by various stimuli in inflammatory cells. We recently described FR180204 (5-(2-phenylpyrazolo[1,5-a]pyridin-3-yl)-1H-pyrazolo[3,4-c]pyridazin-3-amine), a novel selective ERK inhibitor. In this paper, we investigated the effect of FR180204 on collagen-induced arthritis (CIA) in DBA/1 mice, an animal model of rheumatoid arthritis (RA) mediated by type II collagen (CII)-reactive T cells and anti-CII antibodies. Preventive administration of FR180204 (100 mg/kg, i.p., b.i.d.) significantly ameliorated the clinical arthritis and body weight loss occurring in the CIA mice. Further, FR180204-treated mice showed a significant decrease in plasma anti-CII antibody levels (62%). FR180204 also attenuated delayed-type hypersensitivity in CII-immunized DBA/1 mice, an inflammatory response elicited by CII-reactive T cells, in a dose-dependent manner (52 and 62% inhibition at 32 and 100 mg/kg, respectively). Moreover, FR180204 inhibited in vitro CII-induced proliferation of lymph node cells prepared from CII-immunized mice, in which CII-specific T cells are known to undergo specific proliferation. In conclusion, our results suggest that ERK regulates both the cell-mediated and humoral immune responses in the development of CIA. ERK inhibitors may be useful as therapeutic reagents for the treatment of RA.     

Anti-asthmatic effect of ASP3258, a novel phosphodiesterase 4 inhibitor

ASP3258 is a potent and selective PDE4 inhibitor and exerts a wide-range of anti-inflammatory effects with low emetic potential, a major adverse effect of PDE4 inhibitors. Here, we investigated the anti-asthmatic potency of ASP3258 as compared with those of two representative PDE4 inhibitors: roflumilast and cilomilast. Orally administered ASP3258, roflumilast, and cilomilast all inhibited ovalbumin (OVA)-induced eosinophil infiltration into the airway of sensitized Brown Norway rats with ED(50) values of 0.81, 0.46, and 4.4 mg/kg, respectively. Histological examination also revealed a decreasing trend in inflammatory cell infiltration into the lung following ASP3258 administration. In vitro investigation of bronchodilatory activities showed that these compounds (10(-8)-10(-6) M) concentration-dependently inhibited OVA-induced contraction of trachea isolated from sensitized guinea pigs but had no effect on spasmogen-precontracted tracheal tension prepared from non-sensitized guinea pigs up to 10(-6) M. In vivo experiments using sensitized guinea pigs showed that these orally administered compounds inhibited OVA-induced increases in airway resistance with ED(50) values of 2.2, 0.35, and 12 mg/kg, respectively. Further, orally administered ASP3258 (0.1 and 1 mg/kg), roflumilast (0.1 and 1 mg/kg), and cilomilast (10 mg/kg) significantly suppressed airway hyperresponsiveness caused by OVA exposure. ASP3258's potent inhibition of antigen-induced bronchoconstriction and airway hyperresponsiveness, two characteristic symptoms of bronchial asthma, suggests that this compound will be useful in treating asthma.     

Prevention of progressive joint destruction in collagen-induced arthritis in rats by a novel matrix metalloproteinase inhibitor, FR255031

FR255031 (2-[(7S)-7-[5-(4-ethylphenyl)-2-thienyl]-1,1-dioxido-4-(2-pyridinylcarbonyl)hexahydro-1,4-thiazepin-7-yl]-N-hydroxyacetamide) is a novel synthetic matrix metalloproteinase (MMP) inhibitor that inhibits human collagenases (MMP-1, MMP-8 and MMP-13), gelatinases (MMP-2 and MMP-9) and membrane type 1 MMP (MT1-MMP/MMP-14). FR255031 also inhibits rat collagenase and gelatinase. We studied the effect of FR255031 and Trocade, an inhibitor of collagenase and MMP-14, on a rat collagen-induced arthritis (CIA) model. Rat CIA was induced by intradermal injection of type II collagen (IIC) and oral administration of FR255031 or Trocade was performed for 28 days. Body weight loss, hind paw swelling, elevation of serum anti-IIC antibody, and histological and radiographic scores were evaluated. FR255031 markedly inhibited cartilage degradation in a dose-dependent manner in the CIA model, but Trocade failed to prevent the degradation. FR255031 at a dose of 100 mg kg(-1) also had statistically significant effects on bone destruction and pannus formation and on the recovery of body weight loss on day 28. These results indicate that FR255031 is effective for rat CIA, especially on joint cartilage destruction. These data suggest that as well as collagenases or MT-MMP, gelatinases are also involved in joint destruction in arthritis.     

新型磷酸二酯酶4抑制剂氯比普兰改善老年小鼠的认知功能障碍

目的探讨新型磷酸二酯酶4抑制剂氯比普兰(chlorbipram)对老年小鼠学习记忆功能障碍的影响。方法 20月龄和6月龄昆明雄性小鼠,分别随机分为溶剂对照组和氯比普兰给药组(0.5 mg·kg-1),连续给药21 d。旷场实验检测穿越格子数、直立次数和粪便粒数;新物体识别实验(NOR)检测识别指数(RI);水迷宫实验检测逃避潜伏期、穿越平台时间、目标象限停留时间及路程和游泳速度。ELISA法测定海马环磷酸腺苷(c AMP)的含量,Western蛋白印迹法检测磷酸化蛋白激酶A(p-PKA)和磷酸化c AMP反应元件结合蛋白(p-CREB)的水平;逆转录PCR(RT-PCR)检测脑源性神经营养因子(BDNF)mRNA的表达。结果旷场实验结果显示,20月龄正常组小鼠粪便粒数明显多于6月龄正常组小鼠(P<0.05),给予氯比普兰后粪便粒数明显减少。NOR实验结果表明,20月龄正常组小鼠RI明显低于6月龄正常组小鼠(P<0.01),给予氯比普兰后RI明显升高(P<0.05),达到6月龄正常组小鼠水平。水迷宫实验结果显示,与6月龄正常组小鼠相比,20月龄正常组小鼠穿越平台次数明显减少(P<0.01),第一次到达平台时间明显延长(P<0.05),目标象限的探索时间和路程显著性下降(P<0.01);给予氯比普兰明显增加穿越平台次数(P<0.01),缩短第一次到达平台时间(P<0.05),延长在目标象限探索的时间和路程(P<0.01)。ELISA分析结果显示,20月龄正常组小鼠海马c AMP水平明显低于6月龄正常组小鼠(P<0.01),氯比普兰能显著增加海马c AMP含量(P<0.01)。Western蛋白印迹结果显示,20月龄正常组小鼠海马内p-PKA和p-CREB的蛋白表达明显低于6月龄正常组小鼠(P<0.01),氯比普兰能够增强p-PKA和p-CREB表达(P<0.01)。RTPCR结果表明,20月龄正常组小鼠海马内BDNF mRNA水平明显低于6月龄正常组小鼠(P<0.01),给予氯比普兰能显著提高BDNF mRNA水平(P<0.01)。结论氯比普兰可以通过影响c AMP水平,上调p-PKA和p-CREB蛋白表达,促进BDNF的转录,从而改善老年小鼠的认知功能障碍。     

Anti-neutrophilic inflammatory activity of ASP3258, a novel phosphodiesterase type 4 inhibitor

Neutrophil-dominant pulmonary inflammation is an important feature of chronic obstructive pulmonary disease (COPD). Here, we evaluated the in vitro and in vivo anti-neutrophilic inflammatory activities of ASP3258, a novel, orally active, and selective phosphodiesterase (PDE) 4 inhibitor with anti-inflammatory potency comparable to that of second-generation compound roflumilast but with lower emetic activity in vivo. In in vitro experiments using human peripheral blood neutrophils, PDE4 inhibitors ASP3258, cilomilast, and roflumilast inhibited fMLP-induced superoxide production in a concentration-dependent manner with IC50 values of 5.0, 96, and 4.7 nM, respectively. ASP3258, cilomilast, and roflumilast also attenuated fMLP-induced neutrophil chemotaxis in a concentration-dependent manner with IC30 values of 18, 270, and 9.7 nM, respectively. In contrast, the glucocorticoid prednisolone inhibited neither superoxide production nor chemotaxis up to 1 μM. In a rat model of lipopolysaccharide (LPS)-induced lung inflammation, orally administered ASP3258, cilomilast, roflumilast, and prednisolone (at 10 or 30 mg/kg) dose-dependently attenuated pulmonary accumulation of neutrophils. The inhibitory effect of ASP3258 was more potent than cilomilast and almost the same as roflumilast and prednisolone. Treatment with ASP3258 inhibited the elevation of TNF-α in the bronchoalveolar lavage fluid following LPS instillation. Histological examination revealed significant inhibition of neutrophil and macrophage infiltration into alveoli by ASP3258. Overall, these findings suggest that ASP3258 has therapeutic potential for treating neutrophilic inflammation such as COPD, partly through direct inhibition of neutrophil activation as well as possibly through inhibition of the TNF-α-mediated pathway.     

Effect of a monoclonal antibody against interleukin-4 on collagen-induced arthritis in mice

1. The present study was undertaken to investigate the effect of a monoclonal antibody (11B11 mAb) against interleukin-4 (IL-4) on collagen-induced arthritis (CIA) in mice.
2. 11B11 mAb was daily injected intraperitoneally over a period of 10 days, commencing on the day of immunization with type II collagen (CII).
3. The results showed that the anti-IL-4 mAb markedly augmented both the incidence and the severity of CIA. The augmentation of the disease was associated with a significant increase in anti-CII IgG2a antibody production, proliferative responses of lymph node cells to CII and interferon-γ (IFN-γ) secretion from the lymphoid cells. The production of anti-CII IgG1 antibodies the secretion of IL-4 was markedly reduced in the mAb-treated mice.
4. Thus, the neutralization of IL-4 by 11B11 mAb appears to be effective in augmenting CIA.

     

YM-254890, a novel platelet aggregation inhibitor produced by Chromobacterium sp. QS3666

A novel platelet aggregation inhibitor, YM-254890, was isolated from the culture broth of strain QS3666. This strain was isolated from a soil sample collected at Okutama, Tokyo, Japan, and was identified as Chromobacterium sp. by morphological and physiological criteria. YM-254890 was purified from the culture supernatant by solvent extraction, ODS and silica gel flash chromatography, followed by preparative HPLC. YM-254890 inhibited ADP-induced platelet aggregation in human platelet-rich plasma with an IC50 value below 0.6 microM by blocking the P2Y1 receptor-signal transduction pathway.     

Antiplatelet and antithrombotic effects of a novel selective phosphodiesterase 3 inhibitor, NSP-513, in mice and rats

We investigated the effects of NSP-513, (R)-4,5-dihydro-5-methyl-6-[4-(2-propyl-3-oxo-1-cyclohexenyl)amino] phenyl-3(2H)-pyridazinone, on phosphodiesterase (PDE) isozyme activities, in vitro platelet aggregation and in vivo thrombus formation. NSP-513 selectively inhibited human platelet PDE 3 isozyme with an IC50 value of 0.039 microM. In an in vitro human platelet aggregation assay, the IC50 values (microM) of NSP-513 for platelet aggregation induced by collagen, U-46619, arachidonic acid, adenosine diphosphate (ADP), epinephrine and thrombin were 0.31, 0.25, 0.082, 0.66, 0.23 and 0.73, respectively. In a mouse pulmonary thromboembolism model, orally administered NSP-513 showed in vivo antithrombotic effects that were 320 to 470 times more potent than those of cilostazol. In a rat carotid arterial thrombosis model, intraduodenally administered NSP-513 (0.1 mg/kg), cilostazol (30 mg/kg) and aspirin (30 mg/kg) reduced thrombus formation by 75%, 66% and 48%, respectively. However, intravenously administered dipyridamole (10 mg/kg) did not significantly prevent thrombus formation. These results demonstrate that NSP-513 has the potential to prevent not only in vitro platelet aggregation but also in vivo thrombus formation and indicate that the highly selective PDE 3 inhibitory effect of NSP-513 may make this compound useful for assessing the physiological role of PDE 3.     

Beneficial effects of GW274150, a novel,potent and selective inhibitor of iNOS activity,in a rodent model of collagen-induced arthritis

The aim of this study was to investigate the role of inducible nitric oxide synthase (iNOS) on the modulation of the inflammatory response in mice subjected to collagen-induced arthritis. Collagen-induced arthritis was induced in wild-type mice (iNOS-WT) treated with GW274150, a novel, potent and selective inhibitor of iNOS activity, and in mice lacking the gene for iNOS (iNOS 'knock-out', iNOS-KO), by an intradermal injection of 100 microl of emulsion containing 100 microg of bovine type II collagen and complete Freund's adjuvant at the base of the tail. After 21 days, a second injection of type II collagen in complete Freund's adjuvant was administered. iNOS-WT mice developed erosive hind paw arthritis when immunised with type II collagen in complete Freund's adjuvant. Over a 35-day period, macroscopic clinical evidence of collagen-induced arthritis first appeared as periarticular erythema and oedema in the hind paws. By day 28, the incidence of collagen-induced arthritis was 100% in type II collagen-challenged iNOS-WT mice and the severity of collagen-induced arthritis progressed with radiographic evaluation revealing resorption of bone. Histopathology of collagen-induced arthritis mice demonstrated erosion of the cartilage at the joint margins. iNOS-WT mice treated with GW274150 (5 mg/kg, i.p. daily) starting at the onset of arthritis (day 23), and iNOS-KO mice showed a delay of the development of the clinical signs at days 24-35 and an improvement of the histological status in the knee and paw. Immunohistochemical analysis for nitrotyrosine and for poly(ADP-ribose) polymerase revealed positive staining in inflamed joints from type II collagen-treated iNOS-WT mice. The degree of staining for nitrotyrosine and poly(ADP-ribose) polymerase were markedly reduced in tissue sections obtained from type II collagen-treated iNOS-WT mice, who had received GW274150 and from iNOS-KO mice. Furthermore, radiographic signs of protection against bone resorption were present in the joints of iNOS-WT mice treated with GW274150 as well as in the joint from iNOS-KO mice. This study provides the first evidence that GW274150, a novel, potent and selective inhibitor of iNOS activity, attenuates the degree of chronic inflammation and tissue damage associated with collagen-induced arthritis in mice. Furthermore, these results suggest that the induction of iNOS and NO production are essential for the up-regulation of the inflammatory response during experimental collagen-induced arthritis.     

Effects of rolipram, a selective inhibitor of phosphodiesterase 4, on hyperlocomotion induced by several abused drugs in mice

The effects of rolipram, a selective inhibitor of phosphodiesterase 4, on the hyperlocomotion induced by several abused drugs (methamphetamine, morphine and phencyclidine) and a dopamine D1-receptor agonist (SKF81297; (+/-)-6-chloro-7,8-dihydroxy-1-phenyl-2,3 ,4,5-tetrahydro-1H-3-benzazepin hydrobromide) in mice were investigated. Methamphetamine (0.5-2.0 mg/kg), morphine (5.0-20 mg/kg), phencyclidine (1.25-5.0 mg/kg) and SKF81297 (2.5-10 mg/kg) each induced dose-dependent hyperlocomotion. A low dose (1.0 mg/kg) or moderate dose (3.2 mg/kg) of rolipram suppressed methamphetamine (2.0 mg/kg)- and morphine (20 mg/kg)-induced hyperlocomotion, but not phencyclidine (5.0 mg/kg)-induced hyperlocomotion. These results suggest that cAMP in the brain is involved in methamphetamine- and morphine-induced hyperlocomotion, while the underlying mechanism(s) of phencyclidine-induced hyperlocomotion may be different from those of methamphetamine- and morphine-induced hyperlocomotion. It is well known that methamphetamine- and morphine-induced hyperlocomotion are mediated by the dopaminergic system and that interaction between postsynaptic D1- and D2-receptors may play an important role in the expression of various dopamine-mediated behaviors. In the present study, SKF81297 (10 mg/kg)-induced hyperlocomotion was significantly but not completely suppressed by the highest dose of rolipram (10 mg/kg). Therefore it is unlikely that postsynaptic D1-receptor-mediated functions are involved in the suppressive effects of rolipram on methamphetamine- and morphine-induced hyperlocomotion. These results suggest that rolipram may inhibit methamphetamine- and morphine-induced hyperlocomotion via increase cAMP levels at D2-receptors.     

Amelioration by the natural polyamine spermine of cartilage and bone destruction in rats with collagen-induced arthritis

We investigated pharmacological properties of naturally occurring polyamines on cartilage and bone destruction seen in joints of rats with collagen-induced arthritis (CIA). Daily supplementation of spermine (SPM), but not spermidine, significantly inhibited increases in the hind paw volume and arthritis score in CIA rats, in addition to the increased mRNA expression of receptor activator of nuclear factor-κB ligand in both cartilage and synovial tissues. Histological analysis clearly revealed a drastic prevention by SPM of the cartilage and bone destruction in synovial joints of CIA rats. Particular natural polyamines would be beneficial for the prophylaxis of synovial joint destruction in rheumatoid arthritis.     

Anti-inflammatory and analgesic effects of the phosphodiesterase 4 inhibitor rolipram in a rat model of arthritis

There has been much interest in strategies which modulate tumour necrosis factor-alpha (TNF-alpha) levels and/or function in rheumatoid arthritis. The elevation of intracellular levels of cyclic AMP in leukocytes by phosphodiesterase 4 inhibitors is accompanied by significant inhibition of the production of TNF-alpha. Nevertheless, these drugs may enhance the hyperalgesia induced by a range of inflammatory mediators, including TNF-alpha. In the present study, we examined the effects of the phosphodiesterase 4 inhibitor rolipram on the local inflammatory infiltrate and hyperalgesia in a rat model of adjuvant-induced arthritis. Rolipram (3 mg/kg) was administered by oral gavage from day 10 to 14 after disease induction. Pretreatment with rolipram abrogated oedema formation and significantly inhibited hyperalgesia. Histopathological analysis revealed a marked inhibition of cellular influx as well as bone and cartilage destruction. Serum and local TNF-alpha levels were suppressed in treated animals whereas there were little changes in interleukin-1beta levels. Although cyclic AMP elevating agents may affect nociceptor threshold to increase the hyperalgesic responses acutely, they also possess significant anti-inflammatory activity, which may hinder local mediator release and/or action. The anti-inflammatory effects of rolipram predominate during this chronic arthritis model in the rat.     

Effect of YM-44781, YM-44778 and YM-49598, novel tachykinin antagonists, in a drug-induced bladder contraction model

The radioligand binding profiles and in vivo pharmacological characteristics of YM-44781, YM-44778 and YM-49598, novel non-peptide tachykinin receptor antagonists, were examined and compared to those of FK-888 and GR-159897. Since no functional NK(3) receptors were found in the rat bladder, the emphasis will be on the other two subtypes. YM-44781 and YM-49598 exhibited high binding affinities at NK(2) (pK(i) = 9.94 +/- 0.03) and NK(1) (pK(i) = 9.09 +/- 0.02) receptors, respectively, whereas YM-44778 exhibited high binding affinities at both NK(1) (pK(i) = 8.08 +/- 0.07) and NK(2) (pK(i) = 8.55 + 0.04) receptors stably transfected in CHO-K1 cells (Chinese hamster ovary cells). In an in vivo rat model, a drug-induced bladder contraction model, antagonism of the contractions produced by the selective NK(2) receptor agonist, [betaAla8]neurokinin A (4-10) (10 microg x kg(-1) i.v.) was observed after intravenous administration (dose range 0.001-1 mg x kg(-1)) of YM-44781 and YM-44778 (IC(50) = 27 +/- 8 and 100 +/- 44 microg x kg(-1), respectively). YM-44781 was more potent (about 3-fold) than YM-44778. YM-49598 was almost inactive but produced a potent inhibition (IC(50) = 11 +/- 7 microg x kg(-1)) of the contraction of the rat urinary bladder induced by challenge with the NK(1)-selective receptor agonist [Sar9,Met(O(2))11]substance P sulphone (0.3 microg x kg(-1)). YM-44781 and YM-44778 did not produce major inhibition of [Sar9,Met(O(2))11]substance P-induced bladder contraction. These findings indicate that YM-44781 and YM-49598 are potent NK(2) and NK(1) receptor antagonists, respectively, whereas YM-44778 is a nonselective NK(2)/NK(1) receptor antagonist in the drug-induced bladder contraction model.     

Suppression of murine collagen-induced arthritis by treatment with a novel thiazole derivative,SM-8849

The antiarthritic activity of a novel thiazole derivative, SM-8849, was compared with that of indomethacin and D-penicillamine, in mice with collagen-induced arthritis. SM-8849 reduced the incidence and severity of disease in collagen-immunized mice, as assessed by clinical observation. This efficacy was also confirmed by radiographic and histologic studies. Indomethacin produced an apparent reduction of the clinical score, but had only a marginal effect on bone destruction. D-penicillamine did not produce any improvement. Unlike indomethacin and D-penicillamine, SM-8849 reduced the serum levels of anti-type II collagen antibodies. Flow cytometric analysis of spleen cells from arthritic mice revealed an increase in T cells expressing activation antigens (class II antigens) in comparison with normal mice. Treatment with SM-8849, but not indomethacin or D-penicillamine, prevented the increase in Ia-bearing T cells. The results suggest that an effect of SM-8849 on immunocompetent cells may be responsible for the antiarthritic activity of the compound, and this would distinguish its action from that of traditional antirheumatic drugs.     

YM-53601, a novel squalene synthase inhibitor,suppresses lipogenic biosynthesis and lipid secretion in rodents

1. To better understand how it decreases plasma cholesterol and triglyceride levels, we evaluated the effect of (E)-2-[2-fluoro-2-(quinuclidin-3-ylidene)ethoxy]-9H-carbazole monohydrochloride(YM-53601) on lipogenic biosynthesis in the liver and lipid secretion from the liver in rats and hamsters. 2. Single administration of YM-53601 in cholestyramine-treated rats inhibited triglyceride and free fatty acid (FFA) biosynthesis at a similar dose range to that at which it inhibited cholesterol biosynthesis. YM-53601 inhibited both triglyceride and FFA biosynthesis in hamsters treated with cholestyramine. 3. YM-53601 by single oral administration decreased the enhanced plasma triglyceride levels in hamsters induced by an injection of protamine sulfate, which inhibits lipoprotein lipase (LPL) and consequently increases plasma very low-density lipoprotein (VLDL) triglyceride levels. YM-53601 also decreased the enhanced plasma triglyceride and cholesterol levels in hamsters treated with Triton WR1339, which also inhibits the degradation of VLDL. Plasma cholesterol was significantly decreased as soon as 1 h after single administration of YM-53601 in hamsters fed a normal diet. 4. This is the first report that a squalene synthase inhibitor suppresses lipogenic biosynthesis in the liver and cholesterol and triglyceride secretion from the liver in vivo. We therefore suggest that the mechanism by which YM-53601 decreases plasma triglyceride might include these effects. The finding that YM-53601 rapidly decreased plasma cholesterol suggests that this compound may be effective in decreasing plasma cholesterol levels early in the course of treatment of hypercholesterolemia in humans.     

The inhibition of antigen-induced eosinophilia and bronchoconstriction by CDP840, a novel stereo-selective inhibitor of phosphodiesterase type 4.

1. The novel tri-aryl ethane CDP840, is a potent and selective inhibitor of cyclic AMP phosphodiesterase type 4 (PDE 4) extracted from tissues or recombinant PDE 4 isoforms expressed in yeast (IC50S: 4-45 nM). CDP840 is stereo-selective since its S enantiomer (CT 1731) is 10-50 times less active against all forms of PDE 4 tested while both enantiomers are inactive (IC50S: > 100 microM) against PDE types 1, 2, 3 and 5. 2. Oral administration of CDP840 caused a dose-dependent reduction of interleukin-5 (IL-5)-induced pleural eosinophilia in rats (ED50 = 0.03 mg kg-1). The eosinophils in pleural exudates from CDP840-treated animals contained higher levels of eosinophil peroxidase (EPO) than cells from control animals, suggesting a stabilizing effect on eosinophil degranulation. CDP840 was approximately equi-active with the steroid dexamethasone in this model and was 10-100 times more potent than the known PDE 4-selective inhibitors rolipram and RP73401. The activity of CDP840 was not influenced by adrenalectomy, beta-sympathomimetics or beta-sympatholytics. 3. Antigen-induced pulmonary eosinophilia in sensitized guinea-pigs was reduced dose-dependently by CDP840 (0.01-1 mg kg-1, i.p.) and intracellular EPO levels were significantly higher. CDP840 was more potent in these activities than CT1731 or rolipram and comparable in potency to RP73401. 4. Rolipram or CDP840 were less active than dexamethasone in preventing neutrophil accumulation, or exudate formation in carrageenan-induced pleurisy in rats and thus do not exhibit general anti-inflammatory activity. 5. In sensitized guinea-pigs, aerosols of the antigen ovalbumin caused a dose-dependent bronchoconstriction demonstrated by an increase in pulmonary inflation pressure. Administration of CDP840 (0.001-1.0 mg kg-1, i.p.), 1 h before antigen challenge, resulted in dose-dependent reduction in response to antigen. This activity was not due to bronchodilatation since higher doses of CDP840 (3 mg kg-1) did not significantly change the bronchoconstrictor response to histamine. Rolipram was approximately 10 times less active than CDP840 in preventing antigen-induced bronchoconstriction. 6. These results confirm the observations that selective PDE 4 inhibitors reduce antigen-induced bronchoconstriction and pulmonary eosinophilic inflammation. CDP840 is more potent than rolipram in inhibiting native or recombinant PDE 4. Unlike the recently described potent PDE 4 inhibitor RP73401, CDP840 is more active than rolipram in the rat IL-5 model following oral administration. The novel series of tri-aryl ethanes, of which CDP840 is the lead compound, could be the basis of an orally active prophylactic treatment for human asthma.     

Inhibition of bronchospasm and ozone-induced airway hyperresponsiveness in the guinea-pig by CDP840, a novel phosphodiesterase type 4 inhibitor.

1. The activity of CDP840, a novel, potent and selective cyclic nucleotide phosphodiesterase type 4 (PDE 4) inhibitor, was evaluated in guinea-pig models (in vitro and in vivo) of bronchospasm, ozone-induced airway hyperresponsiveness (AHR) and non-cholinergic bronchoconstriction. Comparisons were made with (i) other PDE 4 inhibitors: CT1731 (S-enantiomer of CDP840), rolipram, RP73401 and (ii) the clinically used agents salbutamol and theophylline. 2. CDP840 relaxed isolated trachea, under basal tone (EC50 4.5 +/- 1.1 microM) being 17 fold less potent than rolipram (EC50 0.26 +/- 0.13 microM) but attaining the same Emax (83 +/- 6% of the response to 300 microM papaverine). 3. CDP840 relaxed tracheae pre-contracted with carbachol (IC25 39 +/- 9 microM) and histamine (IC25 4 +/- 1 microM) producing monophasic curves. Stereoselectivity was not observed with CT1731 against either carbachol (IC25 33 +/- 11 microM) or histamine (IC25 17 +/- 10 microM). Aminophylline was 1.6 fold (carbachol) and 11 fold (histamine) less potent than CDP840. Rolipram and RP73401 produced tri-phasic relaxation curves but were of similar potency (at the IC25 level) to CDP840 against carbachol (rolipram 18 +/- 5 microM, RP73401 39 +/- 1 microM) whereas against histamine they were approximately 20 fold more potent (rolipram 0.2 +/- 0.1 microM, RP73401 0.2 +/- 0.1 microM). In producing > 30% (carbachol) and > 60% (histamine) relaxation these inhibitors had similar potency and were poor compared to salbutamol. 4. Pre-incubation with CDP840 (10 microM) did not antagonize histamine-induced contraction of isolated trachea; however, it did cause a slight potentiation of the subsequent relaxation to salbutamol (IC50 23 +/- 1 to 15 +/- 2 nM). 5. Pretreatment (1 h) with either CDP840 (1 mg kg-1, i.p. or 3 mg kg-1, i.v.) or rolipram (1 mg kg-1, i.p.) did not bronchodilate or antagonize bronchospasm due to inhaled histamine in anaesthetized, ventilated guinea-pigs. Salbutamol (1 mg kg-1, i.p.) did not bronchodilate but caused a parallel 7 fold rightward shift in the histamine dose-response curve. 6. Stimulation of the vagus nerve in the presence of atropine resulted in a frequency-related bronchoconstriction. CDP840 and rolipram (i.v.) inhibited the response being approximately equipotent (EC50 approximately 10 micrograms kg-1). Neither drug inhibited bronchospasm to inhaled substance P. 7. CDP840 (1-10 micrograms kg-1 i.p.) dose relatedly inhibited ozone-induced bronchoconstriction. CT1731 (1 mg kg-1), rolipram (1 mg kg-1), RP73401 (10 micrograms kg-1) and aminophylline (10 mg kg-1) had no effect. Ozone-induced AHR to inhaled histamine was inhibited by CDP840 in a dose-related manner, 10 micrograms kg-1 abolishing the AHR. This effect was stereoselective as CT1731 was approximately 30 fold less potent than CDP840. Rolipram was approximately 100 fold less potent and RP73401 and aminophylline had no effect. CDP840 was orally active being approximately 10 fold less potent compared to i.p. administration. 8. CDP840 is a poor spasmolytic and anti-spasmogenic agent in response to exogenous mediators; however, it potently inhibits vagally mediated non-cholinergic bronchoconstriction and ozone-induced AHR to histamine. It is possible that regulation of cyclic AMP by PDE 4 contributes to neuronal sensitivity in the airways. Furthermore, CDP840 may suppress AHR without being an overt bronchodilator. Such a profile of activity may have therapeutic benefit in airways diseases such as asthma.     

SND-117, a sinomenine bivalent alleviates type II collagen-induced arthritis in mice

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder that affects about 1% of the population worldwide. RA is mainly manifested by persistent synovitis and progressive joint destruction. The aim of the present study was to examine the anti-arthritis effects of SND-117, a sinomenine bivalent that is obtained from the structure modification of a clinically available anti-RA drug, sinomenine. The arthritis model (CIA) was established by immunizing DBA/1 mice with type II collagen, and the arthritis scores including inflammation, joint destruction and bone erosion were assessed after booster immunization for 3 weeks. The levels of cytokines such as IL-1β, IL-6 and TNF-α were analyzed by quantitative PCR and ELISA. The TNF-α induced NF-κB activation in fibroblast-like synovial cells (FLSCs) was analyzed by Western blot. SND-117 significantly relieved the inflammatory symptoms of collagen-induced arthritis, reduced bone erosion and joint destruction in CIA mice. The serum levels of IL-1β, IL-6 and TNF-α of CIA mice were markedly decreased by SND-117. SND-117 also strongly inhibited the phosphorylation and nuclear translocation of NF-κB p65 in FLSCs upon TNF-α stimulation. These data demonstrated that SND-117 could effectively block the pathogenesis of collagen-induced arthritis in CIA mice via inhibition of NF-κB signaling, and might provide potential clinic benefits in rheumatoid arthritis management.