RESUMO
The purpose of the present study was to elucidate the cytoprotective effects of polysaccharides isolated from Inonotus obliquus. The polysaccharides were extracted from the fruiting body of I. obliquus (PFIO) and the liquid culture broth of I. obliquus (PLIO). The effects of PFIO and PLIO on hydrogen peroxide (H2O2)induced oxidative damage of RINm5F pancreatic ßcells were comparatively investigated using an MTT assay, immunofluorescent staining, flow cytometry, and western blot analyses in vitro. The results of the present study demonstrated that treatment with PFIO and PLIO decreased DNA fragmentation and the rate of apoptosis. In addition, pretreatment of cells with PFIO and PLIO prior to H2O2 exposure resulted in increased insulin secretion and scavenging activity for intracellular reactive oxygen species, as compared with treatment with H2O2 alone. The results of the present study suggested that PFIO and PLIO may exert protective effects against H2O2induced oxidative stress via the regulation of mitogenactivated protein kinases, nuclear factorκB and apoptotic proteins. Therefore, PFIO and PLIO may have potential merit as a medicinal food for the prevention of diabetes.
Assuntos
Diabetes Mellitus/tratamento farmacológico , Células Secretoras de Insulina/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polissacarídeos/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Basidiomycota/química , Fragmentação do DNA/efeitos dos fármacos , Diabetes Mellitus/patologia , Carpóforos/química , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/toxicidade , Células Secretoras de Insulina/patologia , Proteínas Quinases Ativadas por Mitógeno/genética , NF-kappa B/genética , Estresse Oxidativo/genética , Polissacarídeos/química , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
A number of polysaccharides exhibit pharmacological activities. Polysaccharides derived from Inonotus obliquus (PLIO) appear to have various potential pharmacological properties, including antitumor activity. However, the molecular mechanisms underlying these properties remain to be elucidated. The present study investigated the antimetastatic potential of PLIO and the underlying signaling pathways in B16F10 murine melanoma cells using the MTT colorimetric assay, in vitro migration and invasion assays, and flow cytometric and western blot analyses. PLIO inhibited the invasion of B16F10 cells and suppressed the expression of matrix metalloproteinases. PLIO treatment inhibited nuclear factorκB (NFκB) nuclear translocation in B16F10 cells. In addition, PLIO treatment inhibited the phosphorylation of c-Jun Nterminal kinases and AKT. These results suggest that PLIO may suppress the invasion of highly metastatic melanoma cells via inhibition of the AKT/NF-κB signaling pathways.
Assuntos
Proteínas Quinases JNK Ativadas por Mitógeno/genética , Melanoma Experimental/tratamento farmacológico , Proteína Oncogênica v-akt/genética , Polissacarídeos/administração & dosagem , Animais , Basidiomycota/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno/biossíntese , Melanoma Experimental/genética , Melanoma Experimental/patologia , Camundongos , NF-kappa B/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Metástase Neoplásica , Proteína Oncogênica v-akt/biossíntese , Fosforilação , Polissacarídeos/química , Transdução de Sinais/efeitos dos fármacosRESUMO
It is well known that Phellinus linteus, which produces hispidin and its derivatives, possesses antioxidant activities. In this study, we investigated whether hispidin has protective effects on palmitate-induced oxidative stress in C2C12 skeletal muscle cells. Our results showed that palmitate treatment in C2C12 myotubes increased ROS generation and cell death as compared with the control. However, pretreatment of hispidin for 8 h improved the survival of C2C12 myotubes against palmitate-induced oxidative stress via inhibition of intracellular ROS production. Hispidin also inhibited palmitate-induced apoptotic nuclear condensation in C2C12 myotubes. In addition, we found that hispidin can suppress cleavage of caspase-3, expression of Bax, and NF-κB translocation. Therefore, these results suggest that hispidin is capable of protecting C2C12 myotubes against palmitate-induced oxidative stress.
