Effects of carnosic acid on interferon production. Effects of isolated compounds on interferon-β (A) and interferon-λ1 and -λ2 (B) production were analyzed by RT-qPCR using the same samples from Figure 3. Data represent means ± SD. ** p < 0.01 versus Mock-treated (Mock). A.U.: Arbitrary unit. (C) To determine the effect of isolated compounds themselves on interferon- β production, A549 cells were treated with carnosic acid without virus infection. Data represent means ± SD. A.U.: Arbitrary unit.