RESUMO
Studied the optimum extraction process of polysaccharide from Phaeoporus obliquus and the effect of Phaeoporus obliquus polysaccharide on carbon tetrachloride (CCl4)- or alcohol-induced acute liver injury in mice. The main factor in influencing the extraction rate of Phaeoporus obliquus polysaccharide were extraction power and time, which was a kind of pyran glucose by infrared spectroscopy. CCl4 and alcohol were employed respectively to establish CCl4 and alcohol-induced acute liver injury mouse models. Compared with model groups mice, Phaeoporus obliquus polysaccharide treatment at the doses of 100mg/kg and 200mg/kg exhibited an obvious reduction liver index, ALP, ALT, AST levels, MDA content and TNF-α level (p<0.01) and SOD activity was increased, which was in a dose-dependent manner. Compared with the model group, the necrosis degree of hepatocytes was obviously reduced and the small fat droplets were formed in some cytoplasm, especially in high dose group, which the liver cells recovered to the level of normal group. Rt-PCR results showed that the expression of CYP2E1 mRNA in liver tissues of Phaeoporus obliquus polysaccharide groups were significantly reduced, and the difference were statistically significant compared with the model group (p<0.05). These results demonstrated that Phaeoporus obliquus polysaccharide has significantly hepatoprotective effect on CCl4 and alcohol-induced acute liver injury in mice.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Polissacarídeos Fúngicos/farmacologia , Hepatócitos/efeitos dos fármacos , Inonotus , Hepatopatias Alcoólicas/metabolismo , Fígado/efeitos dos fármacos , Alanina Transaminase/efeitos dos fármacos , Alanina Transaminase/metabolismo , Fosfatase Alcalina/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/efeitos dos fármacos , Aspartato Aminotransferases/metabolismo , Tetracloreto de Carbono/toxicidade , Depressores do Sistema Nervoso Central/toxicidade , Citocromo P-450 CYP2E1/efeitos dos fármacos , Citocromo P-450 CYP2E1/genética , Etanol/toxicidade , Hepatócitos/metabolismo , Hepatócitos/patologia , Fígado/metabolismo , Fígado/patologia , Malondialdeído/metabolismo , Camundongos , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Superóxido Dismutase/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Protein tyrosine phosphatases (PTPs) are enzymes that catalyze protein tyrosine dephosphorylation of which Src homology phosphatase-1 (SHP-1) is one of the best-validated, a widely distributed intracellular tyrosine phosphatase that contains two SH2 domains. Down regulation of SHP-1 tyrosine phosphatases was significantly increased sensitivity to insulin in insulin signaling pathway. Through in vitro enzymatic reaction kinetics experiment, we found that the extract of Perilla stem was a potential inhibitor to δSHP-1, the catalytic domain of SHP-1 protein tyrosine phosphatase, and its IC(50) was 4ug/ml, and was more sensitive towards SHP-1than other PTPs, which indicated that SHP-1 might be a target of the extract of Perilla stem. It can strengthened the level of tyrosine phosphorylation of insulin receptor (IR) and extracellular signal-regulated protein kinase (ERK) in HepG2 cells, and then activated the insulin signaling pathway through inhibiting the protein phosphorylation of SHP-1. These results demonstrated that the extract of Perilla stem could play an important role for diabetes treatment through inhibiting the level of SHP-1 in insulin signaling pathway.
