RESUMO
OBJECTIVES: Heme oxygenase (HO)-1 expression via nuclear factor-erythroid 2-related factor 2 (Nrf2) activation has an ability to inhibit tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 production. Costunolide has been reported to inhibit IL-1 production, but whether other cytokines could be inhibited remains to be confirmed. We investigated the effects of costunolide and its components (alpha-methylene-gamma-butyrolactone; CH2-BL, alpha-methyl-gamma-butyrolactone; CH3-BL, and gamma-butyrolactone; BL) on HO-1 expression as well as TNF-alpha and IL-6 production in RAW264.7 macrophages. METHODS: HO-1 expression and Nrf2 nuclear accumulation were analyzed by Western blot analysis. The production of TNF-alpha and IL-6 in RAW264.7 macrophages stimulated with lipopolysaccharide (LPS) was assayed by ELISA. RESULTS: Costunolide and CH2-BL induced HO-1 expression and Nrf2 nuclear accumulation, whereas CH3-BL and BL did not. Pre-incubation with costunolide inhibited LPS-induced production of TNF-alpha and IL-6. The inhibitory effects of costunolide on TNF-alpha and IL-6 production were abrogated by tin protoporphyrin, an HO inhibitor. CONCLUSIONS: Costunolide is an effective HO-1 inducer capable of inhibiting macrophage-derived pro-inflammatory cytokines. CH2-BL moiety of costunolide is essential for Nrf2 activation leading to HO-1 expression.
Assuntos
Heme Oxigenase-1/biossíntese , Interleucina-6/antagonistas & inibidores , Macrófagos/efeitos dos fármacos , Sesquiterpenos/farmacologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , 4-Butirolactona/análogos & derivados , 4-Butirolactona/farmacologia , Transporte Ativo do Núcleo Celular , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Linhagem Celular , Núcleo Celular/metabolismo , Indução Enzimática , Interleucina-6/biossíntese , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , Extratos Vegetais/farmacologia , Protoporfirinas/farmacologia , Fator de Necrose Tumoral alfa/biossínteseRESUMO
In the present study we have investigated whether butein could induce apoptosis in human leukaemic HL-60 cells. The treatment of HL-60 cells with butein induced apoptotic cell death as determined by morphological and biochemical changes. Apoptotic DNA fragments in the butein-treated HL-60 cells were increased gradually as determined by flow cytometric analysis. The caspase-3 activity was increased during butein-induced apoptosis. However, caspase-3 inhibitor abrogated the butein-induced DNA fragmentation. Furthermore, the treatment of HL-60 cells with butein decreased the expression of Bcl-2 protein, but increased the expression of Bax protein. These results suggest that butein-induced apoptosis is mediated through the activation of caspase-3 and it is associated with changed expression of Bcl-2 and Bax proteins.