Figure 6

Curcumin mitigates heat-induced inflammation by upregulating CFTR in airway epithelial cells in vitro and in vivo.

(a,b) Western blotting for CFTR and COX-2 (a) and ELISA detection of PGE₂and IL-8 (b) in 16HBE14o- cells before (−) and after (+) heat-treatment in the presence (+) or absence (−) of curcumin (Cur, 10 μM)or DMSO as vehicle control. Curcumin was administrated either 4 hours before (Pre), 0.5 hour after (Post, 0.5 h), or 8 hours after (Post, 8 h) the heat treatment. Tubulin was used as loading control. *P < 0.05; **P < 0.01; ***P < 0.001. n = 3, One-way ANOVA. (c) Curcumin (Cur,10 mg/kg body weight) was nasally administrated in rats in addition to heat-inhalation. H&E images show airway morphology of rats with heat-inhalation alone (Heat), treated with Cur after heat-inhalation (Heat + Cur) or without heat-inhalation (Sham). (d) Immunohistochemistry staining for MPO in airway tissues from rats of the three groups. The number of MPO-positive cells in each group was counted and is shown as mean ± SEM. ***P < 0.001 as compared to rats with heat-inhalation alone. n = 3, One-way ANOVA. (e,f)Representative images and corresponding semi-quantification of immunohistochemistry staining for CFTR (e) and COX-2 (f) in airway tissues from rats of the three groups. The intensity of CFTR and COX-2 signal was calibrated with the epithelial cell counts. **P<0.01; ***P<0.001 as compared to rats with heat-inhalation alone. n = 3, One-way ANOVA. (g) Western blotting for CFTR and COX-2 in normal rat airway tissues (Normal) or tissues with (Heat) or without (Sham) heat-inhalation administrated with curcumin (Cur, 10 mg/kg body weight) or DMSO. (h) ELISA for rat PGE₂ and IL-8 using homogenates of rat airway tissues with (Heat) or without (Sham) heat-inhalation administrated with curcumin (Cur, 10 mg/kg body weight) or DMSO Bars = 100μm.