Ecdysone
Ecdysone is a prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. It is of steroidal structure. Insect molting hormones (ecdysone and its homologues) 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 (sites of high expression) to form in polytene chromosomes. Recent findings in the laboratory of Chris Q. Doe have found a novel role of this hormone in regulating temporal gene transitions within neural stem cells of the fruit fly. Ecdysone and other ecdysteroids also appear in many plants mostly as a protection agent ( toxins or antifeedants) against herbivorous insects. These phytoecdysteroids have been reputed to have medicinal va ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ecdysone Receptor
The ecdysone receptor is a nuclear receptor found in arthropods, where it controls development and contributes to other processes such as reproduction. The receptor is a non-covalent heterodimer of two proteins, the EcR protein and ultraspiracle protein (USP). It binds to and is activated by ecdysteroids. Insect ecdysone receptors are currently better characterized than those from other arthropods, and mimics of ecdysteroids are used commercially as caterpillar-selective insecticides. Function Pulses of 20-hydroxyecdysone occur during insect development, whereupon this hormone binds to the ecdysone receptor, a ligand-activated transcription factor found in the nuclei of insect cells. This in turn leads to the activation of many other genes, as evidenced by puffing of polytene chromosomes at over a hundred sites. Ultimately the activation cascade causes physiological changes that result in ecdysis (moulting). The temporal expression of ecdysone receptor within neural stem ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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20-hydroxyecdysone
20-Hydroxyecdysone (ecdysterone or 20E) is a naturally occurring ecdysteroid hormone which controls the ecdysis (moulting) and metamorphosis of arthropods. It is therefore one of the most common moulting hormones in insects, crabs, etc. It is also a phytoecdysteroid produced by various plants, including ''Cyanotis vaga'', ''Ajuga turkestanica'' and ''Rhaponticum carthamoides'' where its purpose is presumably to disrupt the development and reproduction of insect pests. In arthropods, 20-hydroxyecdysone acts through the ecdysone receptor. Although mammals lack this receptor, 20-hydroxyecdysone may affect mammalian (including human) biological systems ''in vitro'', but there is uncertainty whether any ''in vivo'' or physiological effects occur. 20-Hydroxyecdysone is an ingredient of some supplements that aim to enhance physical performance. In humans, it is hypothesized to bind to the estrogen receptor beta (ERβ) protein-coding gene. Sources in arthropods The primary sources of 20-h ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Ecdysteroid
Ecdysteroids are arthropod steroid hormones that are mainly responsible for molting, development and, to a lesser extent, reproduction; examples of ecdysteroids include ecdysone, ecdysterone, turkesterone and 2-deoxyecdysone. These compounds are synthesized in arthropods from dietary cholesterol upon metabolism by the Halloween family of cytochrome P450s. Phytoecdysteroids also appear in many plants mostly as a protection agents (toxins or antifeedants) against herbivore insects. 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 SARM S 1. This is proposed to be through increase of Calcium leading to activation of Akt and protein synthesis in skeletal muscles. See also * Ecdysone receptor The ecdysone receptor is a nuclear receptor found in arthropods, where it controls development and contributes to other processes such ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Prohormone
A prohormone is a committed Precursor (chemistry), precursor of a hormone consisting of peptide hormones synthesized together that has a minimal hormonal effect by itself because of its expression-suppressing structure, often created by protein folding and binding additional peptide chains to certain ends, that makes hormone receptor binding sites located on its peptide hormone chain segments inaccessible. Prohormones can travel the blood stream as a hormone in an inactivated form, ready to be activated later in the cell by post-translational modification. The body naturally produces prohormones as a way to regulate hormone expression, making them an optimal storage and transportation unit for inactive hormones. Once prohormones are needed to be expressed, prohormone convertase, a protein, cleaves the prohormones and separates them into one or more active hormones. Often in nature, this cleaving process happens immediately, and a prohormone is quickly converted to a set of one or mo ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Phytoecdysteroid
Phytoecdysteroids are plant-derived ecdysteroids. Phytoecdysteroids are a class of chemicals that plants synthesize for defense against phytophagous (plant eating) insects. These compounds are mimics of hormones used by arthropods in the molting process known as ecdysis. When insects eat the plants with these chemicals they may prematurely molt, lose weight, or suffer other metabolic damage and die. Chemically, phytoecdysteroids are classed as triterpenoids, the group of compounds that includes triterpene saponins, phytosterols, and phytoecdysteroids. Plants, but not animals, synthesize phytoecdysteroids from mevalonic acid in the mevalonate pathway of the plant cell using acetyl-CoA as a precursor. Over 250 ecdysteroid analogs have been identified so far in plants, and it has been theorized that there are over 1,000 possible structures which might occur in nature. Many more plants have the ability to "turn on" the production of phytoecdysteroids when under stress, animal attack ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Steroids
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and as signaling molecules. Hundreds of steroids are found in plants, animals and fungi. All steroids are manufactured in cells from the sterols lanosterol (opisthokonts) or cycloartenol (plants). Lanosterol and cycloartenol are derived from the cyclization of the triterpene squalene. The steroid core structure is typically composed of seventeen carbon atoms, bonded in four " fused" rings: three six-member cyclohexane rings (rings A, B and C in the first illustration) and one five-member cyclopentane ring (the D ring). Steroids vary by the functional groups attached to this four-ring core and by the oxidation state of the rings. Sterols are forms of steroids with a hydroxy group at position three and a skeleton derived from cholestane. '' ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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PTTH
Prothoracicotropic hormone (PTTH) was the first insect hormone to be discovered.The chemical symbol for prothoracicotropic hormone is (C64H102N16O19S2). It was originally described simply as "brain hormone" by early workers such as Stefan Kopeć (1922) and Vincent Wigglesworth (1934), who realized that ligation of the head of immature insects could prevent molting or pupation of the body region excluded from the head if the ligation was performed before a critical age in the lifestage was reached. After a certain point the ligation had no effect and both sections of the insect would molt or pupate. However, implantation of a conspecific brain to a sessile ligated abdomen or an abdomen under diapause would induce molting or pupation. Thus, the brain was originally thought to be the source of the hormone that induces molting in insects. Later it was established that the insect brain produces a number of hormones, but the hormone which was the cause of the observations made by Kopeć ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Bayer
Bayer AG (, commonly pronounced ; ) is a German multinational corporation, multinational pharmaceutical and biotechnology company and one of the largest pharmaceutical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include pharmaceuticals; consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the Euro Stoxx 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer and dyer Friedrich Weskott. As was common in this era, the company was established as a dyestuffs producer. The versatility of aniline chemistry led Bayer to expand their business into other areas, and in 1899 Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. In 1904 Bayer received a trademark for the "Bayer Cross" logo, which was subsequently stamped onto each aspirin tablet, creating an iconic product that is still sold by Bayer. Ot ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tebufenozide
Tebufenozide is an insecticide that acts as a molting hormone. It is an agonist of the ecdysone receptor that causes premature molting in larvae. It is primarily used against caterpillar pests. Because it has high selectivity for the targeted pests and low toxicity otherwise, the company that discovered tebufenozide, Rohm and Haas, was given a Presidential Green Chemistry Award for its development. It has been characterised, along with RH-2485, as a bisacylhydrazine.Dhadialla TS, Carlson GR, Le DP: "New Insecticides with ecdysteroidal and juvenile hormone activity" in ''Annual Review of Entomology'' 43(1):545-69 · February 1998 Its environmental [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lipid Peroxidation
Lipid peroxidation is the chain of reactions of oxidative degradation of lipids. It is the process in which radical (chemistry), free radicals "steal" electrons from the lipids in cell membranes, resulting in cell damage. This process proceeds by a free radical chain reaction#Chemical chain reactions, chain reaction mechanism. It most often affects polyunsaturated fatty acids, because they contain multiple double bonds in between which lie methylene bridges (-CH2-) that possess especially reactive hydrogen atoms. As with any radical reaction, the reaction consists of three major steps: initiation, propagation, and termination. The chemical products of this oxidation are known as lipid peroxides or lipid oxidation products (LOPs). Initiation Initiation is the step in which a fatty acid radical (chemistry), radical is produced. The most notable initiators in living cells are reactive oxygen species (ROS), such as hydroxyl radical, OH· and hydroperoxyl, HOO·, which combines wi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants, to prevent oxidation, and to foods to prevent spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress. The only dietary antioxidants are vitamins A, C, and E, but the term ''antioxidant'' has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro, with little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans. History As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxi ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cytotoxic
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells with the cytotoxic compound can result in a variety of cell fates. The cells may undergo necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death (apoptosis). Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism, and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient time or energy to activate apoptotic machinery and will not express apoptotic markers. Apoptosis is characterized by well defined cytological and molecular events including a change i ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |