Ecdysone (EDS)

Ecdysone is a steroidal prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. Insect molting hormones are generally called ecdysteroids. Ecdysteroids act as moulting hormones of arthropods but also occur in other related phyla where they can play different roles. In Drosophila melanogaster, an increase in ecdysone concentration induces the expression of genes coding for proteins that the larva requires, and it causes chromosome puffs to form in polytene chromosomes. Ecdysteroids also appear in many plants mostly as a protection agent against herbivorous insects. These phytoecdysteroids have been reputed to have medicinal value and are part of herbal adaptogenic remedies like Cordyceps, yet an ecdysteroid precursor in plants has been shown to have cytotoxic properties.