Protective effect of polysaccharide of Prismatomeria tetrandra in activating Nrf2 against bleomycin-induced pulmonary fibrosis in mice
Objective To investigate whether polysaccharide of Prismatomeria tetrandra(PSPT)exerts an anti-pulmonary fibrosis(PF)effect by activating nuclear factor erythrocyte 2-related factor 2(Nrf2).Meth-ods A mouse lung fibrosis model was established by intratracheal instillation of bleomycin(BLM).The mice were randomly divided into a control group,a BLM model group,low(40 mg/kg),medium(100 mg/kg)and high(250 mg/kg)dose PSPT groups,and a pirfenidone(PFD)group(200 mg/kg)which were administered by gavage according to the body weights of the mice,or by an equal amount of physiological saline,respectively.Lung tissue specimens were collected after 28 days of drug administration,and H&E and Masson staining were used to detect the degree of lung fibrosis.hydroxyproline(HYP)level in lung tissue was determined by alka-line hydrolysis method,while RT-qPCR and immunofluorescence methods were employed to detect the mRNA and protein expression levels of Nrf2 in lung tissue,respectively.Results When compared with the control group,lung tissue damage and fibrosis were significant in the model group.In contrast,the inflammatory re-sponse and fibrosis were attenuated in all PSPT dose groups and the PFD group compared to the model group.Additionally,the HYP level was significantly decreased in each treatment group(P＜0.001).The mRNA levels of Nrf2 were significantly increased in the middle and high-dose PSPT groups(P＜0.01),while the protein level of the Nrf2 transcription factor was significantly elevated in the high-dose PSPT group(P＜0.001).Conclusion PSPT may protect cells from oxidative damage by activating Nrf2 expression,thus pro-moting the accumulation of Nrf2 in the nucleus and increasing antioxidant enzyme activity.Consequently,PSPT exerts an anti-PF effect by inhibiting oxidative stress through Nrf2 pathway.
pulmonary fibrosisbleomycinpolysaccharide of Prismatomeria tetrandra
万方数据
维普
