Fig. 6
Reversing the anti-inflammatory effects of arctiin in H9N2-avian influenza virus (AIV)-infected A549 cells by HO-1 inhibition. A549 cells were pretreated with Znpp (20 μM) for 2 h followed by H9N2 AIVs (MOI = 0.1) infection. Two hours after inoculation, the cells were treated with arctiin (300 μg/mL) or in combination with Znpp (20 μM) treatment for 24 h. A-B mRNA (A) and protein (B) levels of proinflammatory cytokines were analyzed by qPCR and ELISA, respectively. C-D mRNA (C) and protein (D) levels of COX-2 were analyzed by qPCR and western blot analysis, respectively. E Band intensities of COX-2 in (D) were normalized to GAPDH by densitometric analysis using ImageJ software. F The concentration of PGE2 in the culture supernatants was measured by ELISA. The results are expressed as means ± SD. ##p < 0.01; ###p < 0.001 compared with the control group; *p < 0.05; **p < 0.01 compared with H9N2 virus infection alone; ξp < 0.05 compared with H9N2 virus + arctiin (300 μg/mL) group