Ecdysteroid

Ecdysteroids are arthropod steroid hormones that are mainly responsible for molting (ecdysis), development and, to a lesser extent, reproduction;^[1][2][3][4] examples of ecdysteroids include ecdysone, 20-hydroxyecdysone (ecdysterone), turkesterone and 2-deoxyecdysone.^[5] These compounds are synthesized in arthropods from dietary cholesterol via the Halloween family of cytochrome P450 enzymes.^[6]

Chemical structures of ecdysteroids, ecdysone (top) and 20-hydroxyecdysone

Compounds with ecdysteroid activity in arthropods are not only produced by these animals (zooecdysteroids). Phytoecdysteroids also appear in many plants mostly as a protection agents (toxins or antifeedants) against herbivore insects.^[7][8] Fungi also produce a handful of mycoecdysteroids.^[9] In addition, synthetic ecdysteroid pesticides such as methoxyfenozide have been produced.^[10]

Mammals

Ecdysterone has been tested on mammals due to the interest in its potential hypertrophic effect. It has been found to increase hypertrophy in rats at a similar level to some anabolic androgenic steroids and SARMs.^[11] This is proposed to be through increase of Calcium leading to activation of Akt and protein synthesis in skeletal muscles.^[12] A newer study points to estrogen receptor beta.^[13]

20-hydroxyecdysone is a human drug candidate.^[14]

See also

• Ecdysone receptor