The glucocorticoid ciclesonide is the 2'R-epimer of 2'-cyclohexyl-11beta-hydroxy-21-isobutyryloxy-16bH-dioxolo[5',4':16,17]pregna-1,4-diene-3,20-dione. The active metabolite desisobutyryl-ciclesonide (des-CIC) is derived from ciclesonide by esterase cleavage of isobutyrate at the C21 position. The relative binding affinities at the rat glucocorticoid receptor were dexamethasone, 100; ciclesonide, 12; des-CIC, 1212; and budesonide, 905. Des-CIC potently inhibited the activation of murine and human lymphocytes in a series of different in vitro systems. With the exception of concanavalin A-stimulated rat spleen cells, des-CIC was more potent than the parent compound. Des-CIC compared well with budesonide in all in vitro systems. Furthermore, the respective 2'S-epimers were always significantly less potent than the 2'R-epimers. In vivo, ciclesonide (intratracheal administration), des-CIC, and budesonide inhibited antigen-induced accumulation of eosinophils, protein, and tumor necrosis factor-alpha into the bronchoalveolar lavage fluid of ovalbumin-sensitized and -challenged Brown Norway rats with an ED(50) value ranging from 0.4 to 1.3 mg/kg, indicating similar potency, which suggests in vivo activation of the parent compound. Ciclesonide and budesonide inhibited the bradykinin-induced protein leakage into the rat trachea. In the rat cotton pellet model, ciclesonide inhibited granuloma formation (ED(50):= of 2 microg/pellet), whereas budesonide and des-CIC were 15- and 20-fold less active; thymus involution was induced with an ED(50) of 303, 279, and 154 microg/pellet, respectively. When applied orally to rats for 28 days, ciclesonide showed low potency in reducing weight of thymus and adrenals, suggesting low oral bioavailability. The in vivo data on ciclesonide highlight its effective local action and a reduced potential for side effects.
Objective The specific inhibition of phosphodiesterase (PDE)4 and dual inhibition of PDE3 and PDE4 has been shown to decrease inflammation by suppression of pro-inflammatory cytokine synthesis. We examined the effect of roflumilast, a selective PDE4 inhibitor marketed for severe COPD, and the investigational compound pumafentrine, a dual PDE3/PDE4 inhibitor, in the preventive dextran sodium sulfate (DSS)-induced colitis model. Methods The clinical score, colon length, histologic score and colon cytokine production from mice with DSS-induced colitis (3.5% DSS in drinking water for 11 days) receiving either roflumilast (1 or 5 mg/kg body weight/d p.o.) or pumafentrine (1.5 or 5 mg/kg/d p.o.) were determined and compared to vehicle treated control mice. In the pumafentrine-treated animals, splenocytes were analyzed for interferon-γ (IFNγ) production and CD69 expression. Results Roflumilast treatment resulted in dose-dependent improvements of clinical score (weight loss, stool consistency and bleeding), colon length, and local tumor necrosis factor-α (TNFα) production in the colonic tissue. These findings, however, were not associated with an improvement of the histologic score. Administration of pumafentrine at 5 mg/kg/d alleviated the clinical score, the colon length shortening, and local TNFα production. In vitro stimulated splenocytes after in vivo treatment with pumafentrine showed a significantly lower state of activation and production of IFNγ compared to no treatment in vivo. Conclusions These series of experiments document the ameliorating effect of roflumilast and pumafentrine on the clinical score and TNF expression of experimental colitis in mice.
ABSTRACT The lungs are the remote organ most commonly affected in human peritonitis. The major goals of this study were to define the dose- and time-dependent relationship between graded septic peritonitis and systemic and pulmonary inflammatory responses in mice. BALB/c mice were treated with intraperitoneal polymicrobial inoculi and sacrificed at 3, 12, and 24 h. The treatment protocol resulted in distinct groups of animals with respect to mortality rate, kinetics, and concentrations of a broad spectrum of pro- and anti-inflammatory endogenous mediators, intrapulmonary bacterial accumulation, and static lung compliance. In sublethally infected mice, pulmonary bacterial proliferation was controlled. Levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-10, interleukin-6, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor (TNF) in plasma were elevated 3 h after infection exclusively. At 3 h, MCP-1, gamma interferon, and TNF were detected in extracts of pulmonary tissue or in bronchoalveolar lavage (BAL) fluid. Static lung compliance ( C st ) was transiently decreased at 12 h. In contrast, in lethally infected mice pulmonary bacterial proliferation was not contained. Concentrations of MCP-1, G-CSF, and TNF in plasma were maximal at 24 h, as were pulmonary MCP-1 levels. Lung myeloperoxidase activity was increased at 3, 12, and 24 h. C st was reduced after 3 h and did not reach control values at 24 h. Pulmonary cyclooxygenase-2 mRNA and eicosanoids in BAL fluid and plasma were elevated at 3 and 24 h. This study shows that polymicrobial peritonitis in mice leads to dose-dependent systemic and pulmonary inflammation accompanied by a decrease in lung compliance.
We have investigated the bronchodilator and anti-inflammatory properties of roflumilast (3-cyclopropylmethoxy-4-difluoromethoxy-N-[3,5-dichloropyrid-4-yl]-benzamide), a novel, highly potent, and selective phosphodiesterase 4 (PDE4) inhibitor. Additionally, we compared the effects of roflumilast and its N-oxide, the primary metabolite in vivo, with those of the PDE4 inhibitors piclamilast, rolipram, and cilomilast. Roflumilast inhibited the ovalbumin-evoked contractions of tracheal chains prepared from sensitized guinea pigs (EC(50) = 2 x 10(-7) M) but showed no relaxant effect on tissues contracted spontaneously. In spasmogen-challenged rats and guinea pigs, intravenously administered roflumilast displayed bronchodilatory activity (ED(50) = 4.4 and 7.1 micromol/kg, respectively). Furthermore, roflumilast dose dependently attenuated allergen-induced bronchoconstriction in guinea pigs (ED(50) = 0.1 micromol/kg i.v.). Roflumilast given orally (ED(50) = 1.5 micromol/kg) showed equal potency to its N-oxide (ED(50) = 1.0 micromol/kg) but was superior to piclamilast (ED(50) = 8.3 micromol/kg), rolipram (ED(50) = 32.5 micromol/kg), and cilomilast (ED(50) = 52.2 micromol/kg) in suppressing allergen-induced early airway reactions. To assess the anti-inflammatory potential of orally administered roflumilast, antigen-induced cell infiltration, total protein, and TNFalpha concentration in bronchoalveolar lavage fluid of Brown Norway rats were determined. Roflumilast and its N-oxide equally inhibited eosinophilia (ED(50) = 2.7 and 2.5 micromol/kg, respectively), whereas the reference inhibitors displayed lower potency (ED(50) = 17-106 micromol/kg). Besides, orally administered roflumilast abrogated LPS-induced circulating TNFalpha in the rat (ED(50) = 0.3 micromol/kg), an effect shared by its N-oxide, with both molecules exhibiting 8-, 25-, and 310-fold superiority to piclamilast, rolipram, and cilomilast, respectively. These results, coupled with the in vitro effects of roflumilast on inflammatory cells, suggest that roflumilast represents a potential new drug for the treatment of asthma and chronic obstructive pulmonary disease.