RESUMO
An unusually substituted coumarin, named poligalen, was isolated from a chloroform extract of the aerial parts of Polygala boliviensis. This coumarin was identified by one- and two-dimensional NMR techniques, and the structure of the compound was confirmed by X-ray diffraction. Poligalen exhibits immunomodulatory effects, reducing the levels of IL-6 and TNF after LPS stimulation in peritoneal macrophages. However, poligalen potentiates NF-kB activation.
Assuntos
Cumarínicos/química , Interleucina-6/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Polygala/química , Fator de Necrose Tumoral alfa/metabolismo , Animais , Cumarínicos/isolamento & purificação , Regulação para Baixo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , NF-kappa B/metabolismo , Componentes Aéreos da Planta/química , Cultura Primária de Células , Células RAW 264.7RESUMO
Lipopolysaccharide (LPS) is the major structural component of Gram-negative bacteria cell wall and a highly pro-inflammatory toxin. Naringenin is found in Citrus fruits and exhibits antioxidant and anti-inflammatory properties through inhibition of NF-κB activation but its effects in LPS-induced inflammatory pain and leukocyte recruitment were not investigated yet. We investigated the effects of naringenin in mechanical hyperalgesia, thermal hyperalgesia and leukocyte recruitment induced by intraplantar injection of LPS in mice. We found that naringenin reduced hyperalgesia to mechanical and thermal stimuli, myeloperoxidase (MPO, a neutrophil and macrophage marker) and N-acetyl-ß-D-glucosaminidase (NAG, a macrophage marker) activities, oxidative stress and cytokine (TNF-α, IL-1ß, IL-6, and IL-12) production in the paw skin. In the peritoneal cavity, naringenin reduced neutrophil and mononuclear cell recruitment, and abrogated MPO and NAG activity, cytokine and superoxide anion production, and lipid peroxidation. In vitro, pre-treatment with naringenin inhibited superoxide anion and cytokine (TNF-α, IL-1ß, IL-6, and IL-12) production by LPS-stimulated RAW 264.7 macrophages. Finally, we demonstrated that naringenin inhibited NF-κB activation in vitro and in vivo. Therefore, naringenin is a promising compound to treat LPS-induced inflammatory pain and leukocyte recruitment.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Suplementos Nutricionais , Flavanonas/uso terapêutico , Hiperalgesia/prevenção & controle , Leucócitos Mononucleares/imunologia , Neutrófilos/imunologia , Fator de Transcrição RelA/antagonistas & inibidores , Animais , Anti-Inflamatórios não Esteroides/metabolismo , Antioxidantes/uso terapêutico , Comportamento Animal , Biomarcadores/metabolismo , Flavanonas/metabolismo , Temperatura Alta/efeitos adversos , Hiperalgesia/imunologia , Hiperalgesia/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/toxicidade , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Células RAW 264.7 , Pele/efeitos dos fármacos , Pele/imunologia , Pele/metabolismo , Estresse Mecânico , Fator de Transcrição RelA/metabolismoRESUMO
Isobrucein B (1) is a quassinoid isolated from the Amazonian medicinal plant Picrolemma sprucei. Herein we investigate the anti-inflammatory and antihyperalgesic effects of this quassinoid. Isobrucein B (1) (0.5-5 mg/kg) inhibited carrageenan-induced inflammatory hyperalgesia in mice in a dose-dependent manner. Reduced hyperalgesia was associated with reduction in both neutrophil migration and pronociceptive cytokine production. Pretreatment with 1 inhibited in vitro production/release of cytokines TNF, IL-1ß, and KC/CXCL1 by lipopolysaccharide-stimulated macrophages. To investigate its molecular mechanism, RAW 264.7 macrophages with a luciferase reporter gene controlled by the NF-κB promoter were used (RAW 264.7-Luc). Quassinoid 1 reduced the luminescence emission by RAW 264.7-Luc stimulated by different compounds. Unexpectedly, NF-κB translocation to macrophage nuclei was not inhibited by 1 when evaluated by Western blotting and immunofluorescence. Furthermore, quassinoid 1 did not change the levels of TNF mRNA transcription in stimulated macrophages, suggesting post-transcriptional modulation. In addition, constitutive expression of luciferase in RAW 264.7 cells transiently transfected with a plasmid containing a universal promoter was inhibited by 1. Thus, isobrucein B (1) displays anti-inflammatory and antihyperalgesic activities by nonselective post-transcriptional modulation, resulting in decreased production/release of pro-inflammatory cytokines and neutrophil migration.