MedChemExpress Hypericin is a naturally occurring substance found in Hypericum. Hypericin is an inhibitor of PKC (protein kinase C), MAO (monoaminoxidase), dopamine-beta-hydroxylase, reverse transcriptase, telomerase and CYP (cytochrome P450). Hypericin shows antitumor, antiviral, antidepressive activities, and can induce apoptosis.