Objective To explore the effect and mechanism of hesperidin in treating the lung injury in the mouse model of respiratory syncytial virus (RSV)-induced bronchiolitis. Methods A mouse model of RSV-induced bronchiolitis was established,and 60 BALB/c mice were assigned into a control group,a model group,a low-dose hesperidin (18 mg/kg) group,a high-dose hesperidin (36 mg/kg) group,and a high-dose hesperidin (36 mg/kg)+Jagged1(1 mg/kg) group by random number table method,with 12 mice in each group. Corresponding doses of drugs were administrated for intervention,and the control group and model group were administrated with the same amount of saline.The bronchoalveolar lavage fluid (BALF) samples were collected and alveolar macrophages were isolated.ELISA was employed to detect the levels of interleukin (IL)-4,IL-6,tumor necrosis factor-α (TNF-α),and IL-10 in BALF,and flow cytometry to detect the M1/M2 polarization of macrophages.qRT-PCR and Western blotting were respectively conducted to detect the mRNA and protein levels of inducible nitric oxide synthase (iNOS),arginase 1 (Arg-1),Jagged1,and Notch1 in the lung tissue. Results Compared with the control group,the modeling of RSV-induced bronchiolitis elevated the IL-4,IL-6,and TNF-α levels,increased the proportion of M1-type macrophages and the lung inflammation and mucus secretion scores,and up-regulated the mRNA and protein levels of iNOS,Jagged1,and Notch1 in BALF (all P<0.001).Meanwhile,the modeling lowered the IL-10 level,decreased the proportion of M2-type macrophages,and down-regulated the mRNA and protein levels of Arg-1 (all P<0.001).Compared with the model group,low- and high-dose hesperidin lowered the IL-4,IL-6,TNF-α levels,decreased the proportion of M1-type macrophages and the lung inflammation and mucus secretion scores,and down-regulated the mRNA and protein levels of iNOS,Jagged1,and Notch1 in BALF (all P<0.05).Moreover,hesperidin elevated the IL-10 level,increased the proportion of M2-type macrophages,and up-regulated the mRNA and protein levels of Arg-1 (all P<0.001).Using recombinant Jagged1 protein to activate Notch1 signaling pathway can significantly attenuate the promotion of high-dose hesperidin on M2 macrophage polarization and amelioration of lung inflammation damage (all P<0.01). Conclusion Hesperidin may alleviate the lung inflammation damage in mice with RSV-induced bronchiolitis by inhibiting the Jagged1/Notch1 signaling pathway and promoting the M2-type polarization of macrophages.
Animals ; Mice ; Bronchiolitis/metabolism* ; Hesperidin/metabolism* ; Interleukin-10/pharmacology* ; Interleukin-4/pharmacology* ; Interleukin-6/metabolism* ; Jagged-1 Protein/pharmacology* ; Lung Injury/metabolism* ; Macrophages ; Mice, Inbred BALB C ; RNA, Messenger/metabolism* ; Tumor Necrosis Factor-alpha/metabolism*