Chrysin is a naturally occurring flavone chemically extracted from the passion flowers Passiflora caerulea. Chrysin displays anti-inflammatory and antitumor properties. Chrysin inhibits HIF-1α (hypoxia-inducible factor-1α) and induces apoptosis. In vitro study shows that chrysin inhibits COX-2 expression and via IL-6 signaling, which may contribute to anti-inflammatory effects. Chrysin demonstrated cell toxicity and inhibition of DNA synthesis at very low concentrations in a normal trout liver cell line.