Figure 1.
Chemical structure of icariin.
(molecular formula: C33H40O15; molecular weight: 676.67).
Figure 2.
Effects of icariin on pulmonary function in CS-exposed mice.
(A) Peak expiratory flow (PEF); (B) Peak inspiratory flow (PIF); (C) Minute ventilation (MV), were measured in unrestrained mice using a whole-body plethysmograph (WBP) system. Data are mean ± SEM (n = 10). * P<0.05 vs. CS-exposed mice. DEX = dexamethasone.
Figure 3.
Effects of icariin on lung histopathology.
Mice were exposed to CS for 3 months and treated with icariin (25, 50 and 100 mg/kg) or dexamethasone (1 mg/kg). Lung tissue was stained by H&E before being examined. (A) The inflammatory cells of lungs measured by bright microscopy (original magnification,×400). (B) The severity of inflammation was calculated on a 0–3 scale defined as described in Materials and methods. Values of MLI (C) and DI (D) were scored also as described in Materials and methods. Data are mean ± SEM (n = 6). *P<0.05 vs. CS-exposed mice. DEX = dexamethasone; MLI = mean linear intercepts; DI = destructive index.
Figure 4.
Icariin suppresses CS-induced TNF-α, IL-8 and MMP-9 levels in vivo and in vitro.
TNF-α, IL-8 and MMP-9 levels in serum (A), BALF (B) and culture supernatant (C) were measured by ELISA. Data are mean ± SEM (n = 4–5). * P<0.05 vs. CS-exposed mice or CSE-exposed A549 cells. CS = cigarette smoke; CSE = cigarette smoke extract; DEX = dexamethasone; BALF = bronchoalveolar lavage.
Figure 5.
Icariin inhibits NF-κB activation in CS-induced inflammation.
Mice were exposed to CS for 3 months and dosed with icariin (25, 50 and 100 mg/kg) or dexamethasone (1 mg/kg). (A) Nuclear proteins were extracted from lung tissue and p65, p-p65 and IκB-α protein expression was measured by Western blot. The phosphorylation of p65 (B) and the degradation of IκB-α (C) were calculated using gray value ratio of p65/p-p65 and IκB-α/GAPDH, respectively. Data are mean ± SEM (n = 3). * P<0.05 vs. CS-exposed mice.
Figure 6.
Icariin restores CS-mediated reduction in expression of GR protein and mRNA in vivo and in vitro.
Nuclear proteins were extracted from lung tissue and GR protein expression was measured both by Immunohistochemistry and Western blot. (A) Micrographs of GR immunostaining in mice. (B) Immunohistochemical index of GR. Quantitative immunohistochemical evaluation values of GR were calculated as described in Materials and methods. Data are mean ± SEM (n = 6). (C, D) Protein expression of GR in lung tissue of mice treated with different ways using Western blot. Data are mean ± SEM (n = 3). (E) Icariin restores CSE-reduced expression of GR mRNA in vitro. Real-Time PCR were performed to assess the levels of mRNA expression of GR. Data are mean ± SEM (n = 3). * P<0.05 vs. CS-exposed mice or CSE-exposed cells. CS = Cigarette smoke; CSE = Cigarette smoke extract; DEX = dexamethasone.