Dear Albert Braeuning,
Many thanks for your comment. With great interest we have read the papers describing the inhibitory effects of resveratrol on firefly luciferase (FFluc). In these papers, resveratrol showed inhibition on FFluc only when cells were treated with resveratrol for short periods of time (up to 30 minutes). As you already mentioned and showed in your paper (Braeuning&Vetter, Biosci Rep 32:531-7,2012),the inhibition of firefly luciferase activity by resveratrol was weaker after 1 h and disappeared in all cell lines already at 24 h after addition of the compound to the cells. In our manuscript, NfKB luciferase assays were performed in live cells after 24 hours of incubation with resveratrol so we don’t expect that the inhibition of firefly luciferase is an artefact in the NF-kB luciferase assay.