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in mammals development of arthropods and probably many other invertebrates. Phytoecdysteroids are analogues occurring in a wide range of plant species, where they contribute to the deterrence of phytophagous invertebrates. The purpose of this short review is to summarise findings on the occurrence, mammalian systems and to draw attention to their potential applications, particularly in gene-switch technology, where ecdysteroid analogues (steroidal and non-steroidal) can be used as effective and potent elicitors. they regulate moulting, metamorphosis, reproduction and diapause ( extensively investigated (Lafont 1997). Ecdysteroids are also present in 56% of plant species ( arthropods, where they are regarded as contributing to the deterrence of invertebrate predators ( range of structural analogues has been elucidated, especially from plant sources ( various classes of vertebrate steroid hormones, in spite of the fact that development in more than 90% of all animal species is dependent upon ecdysteroids. However, since the early reports of the occurrence of ecdysteroids in insects and plants, researchers have posed questions about the occurrence (from the diet), metabolism and possible effects of ecdysteroids in mammals. In the intervening period, a substantial body of evidence relevant to these questions has been obtained, pharmacological properties. This is consistent with the use of several ecdysteroid-containing plant species in traditional medicines. The ready availability of large amounts of 20E from certain plant sources has led to a boom in recent years in its inclusion in many commercial anabolic preparations for body-builders and sportsmen. Further, since ecdysteroids are not endogenous products of mammalian metabolism and are non-toxic to mammals, they are also finding application as elicitors of novel gene-switch systems. With the intention of bringing this area to a wider audience of endocrinologists, we shall summarise the most significant findings. Also, we shall focus on the developments in this area since our previous review ( literature and the concepts. metabolism. However, they can be detected in mammalian tissues and fluids as a consequence of dietary intake of ecdysteroid-containing plants (or insects in certain population groups) or infection by invertebrate parasites. Most crop plant species do not contain phytoecdysteroids, although both spinach (Spinacia oleracea) and quinoa (Chenopodium quinoa) do contain significant levels, especially in the seeds and |
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