Antiviral, anti-parasitic, and cytotoxic effects of 5,6-dihydroxyindole (DHI), a reactive compound generated by phenoloxidase during insect immune response

► DHI (5,6-dihydroxyindole) kills baculovirus and λ phage, besides bacteria and fungi. ► DHI causes embryonic death of the parasitic wasp, M. demolitor. ► Death of DHI-treated Sf9 cells shows that uncontrolled PO could damage host tissues. ► DHI and related compounds crosslink nucleic acids and proteins to exert toxicity.