Effect fo ecdysone on incorporation of C-14-leucine into hepatic protein in vitro

Urinary Elimination of Ecdysterone and Its Metabolites Following a Single-Dose Administration in Humans

Ecdysterone is a phytosteroid widely discussed for its various pharmacological, growth-promoting, and anabolic effects, mediated by the activation of estrogen receptor beta (ERbeta). Performance-enhancement in sports was demonstrated recently, and ecdysterone was consequently included in the Monitoring Program, to detect potential patterns of misuse in sport. Only few studies on the pharmacokinetics of ecdysterone in humans have been reported so far. In this study, post-administration urine samples in twelve volunteers (single dose of 50 mg of ecdysterone) were analyzed using dilute-and-inject liquid-chromatography-tandem mass spectrometry. Identification and quantitation of ecdysterone and of two metabolites, 14-deoxy-ecdysterone and 14-deoxy-poststerone, was achieved. Ecdysterone was the most abundant analyte present in post-administration urine samples, detected for more than 2 days, with a maximum concentration (C_max) in the 2.8-8.5 h urine (C_max = 4.4-30.0 µg/mL). The metabolites 14-deoxy-ecdysterone and 14-deoxy-poststerone were detected later, reaching the maximum concentrations at 8.5-39.5 h (C_max = 0.1-6.0 µg/mL) and 23.3-41.3 h (C_max = 0.1-1.5 µg/mL), respectively. Sex-specific differences were not observed. Cumulative urinary excretion yielded average values of 18%, 2.3%, and 1.5% for ecdysterone, 14-deoxy-ecdysterone, and 14-deoxy-poststerone, respectively. Ecdysterone and 14-deoxy-ecdysterone were excreted following first-order kinetics with half-lives calculated with three hours, while pharmacokinetics of 14-deoxy-poststerone needs further evaluation.

Detection and quantitation of ecdysterone in human serum by liquid chromatography coupled to tandem mass spectrometry

The polyhydroxylated phytosteroid ecdysterone is present in various plants (e.g. spinach). It is widely marketed as the active component of dietary supplements, due to its reported health and performance promoting effects. For evaluation of its actual bioavailability, a fast and sensitive method was developed, optimized and validated for human serum. Instrumental analysis was performed utilizing liquid chromatography-tandem mass spectrometry with positive electrospray ionization and acquisition in multiple reaction mode. Solid phase extraction and dilute-and-inject (following protein precipitation) were tested to isolate ecdysterone from human serum. Both methods were compared in the light of the preset analytical target profile. The limit of detection (LOD) and quantitation (LOQ) for ecdysterone in human serum after SPE extraction corresponded to 0.06 ng/mL and 0.14 ng/mL, respectively, meeting the requested sensitivity of the method. The assay was linear over the range of 0.10 ng/mL to 20.83 ng/mL. As expected, the sensitivity of the SPE method was better than that of the dilute-and-inject procedure, which did not allow for quantitation of all post administration serum samples. Accuracy (relative error; %) and precision (coefficient of variation; %), were both within acceptance criteria (<15%). The developed method was successfully applied to a ten week intervention study conducted in young men performing regular resistance training. Different doses of supplements containing ecdysterone from spinach extract have been administered during the study and the quantitation of ecdysterone in serum samples has been successfully conducted. Ecdysterone could be quantified in all post-administration samples using solid phase extraction (SPE) for sample pretreatment.

Ecdysteroids as non-conventional anabolic agent: performance enhancement by ecdysterone supplementation in humans

Recent studies suggest that the anabolic effect of ecdysterone, a naturally occurring steroid hormone claimed to enhance physical performance, is mediated by estrogen receptor (ER) binding. In comparison with the prohibited anabolic agents (e.g., metandienone and others), ecdysterone revealed to be even more effective in a recent study performed in rats. However, scientific studies in humans are very rarely accessible. Thus, our project aimed at investigating the effects of ecdysterone-containing products on human sport exercise. A 10-week intervention study of strength training of young men (n = 46) was carried out. Different doses of ecdysterone-containing supplements have been administered during the study to evaluate the performance-enhancing effect. Analysis of blood and urine samples for ecdysterone and potential biomarkers of performance enhancement has been conducted. To ensure the specificity of the effects measured, a comprehensive screening for prohibited performance-enhancing substances was also carried out. Furthermore, the administered supplement has been tested for the absence of anabolic steroid contaminations prior to administration. Significantly higher increases in muscle mass were observed in those participants that were dosed with ecdysterone. The same hypertrophic effects were also detected in vitro in C2C12 myotubes. Even more relevant with respect to sports performance, significantly more pronounced increases in one-repetition bench press performance were observed. No increase in biomarkers for liver or kidney toxicity was noticed. These data underline the effectivity of an ecdysterone supplementation with respect to sports performance. Our results strongly suggest the inclusion of ecdysterone in the list of prohibited substances and methods in sports in class S1.2 "other anabolic agents".

Practical uses for ecdysteroids in mammals including humans: an update

Ecdysteroids are widely used as inducers for gene-switch systems based on insect ecdysteroid receptors and genes of interest placed under the control of ecdysteroid-response elements. We review here these systems, which are currently mainly used in vitro with cultured cells in order to analyse the role of a wide array of genes, but which are expected to represent the basis for future gene therapy strategies. Such developments raise several questions, which are addressed in detail. First, the metabolic fate of ecdysteroids in mammals, including humans, is only poorly known, and the rapid catabolism of ecdysteroids may impede their use as in vivo inducers. A second set of questions arose in fact much earlier with the pioneering "heterophylic" studies of Burdette in the early sixties on the pharmacological effects of ecdysteroids on mammals. These and subsequent studies showed a wide range of effects, most of them being beneficial for the organism (e.g. hypoglycaemic, hypocholesterolaemic, anabolic). These effects are reviewed and critically analysed, and some hypotheses are proposed to explain the putative mechanisms involved. All of these pharmacological effects have led to the development of a wide array of ecdysteroid-containing preparations, which are primarily used for their anabolic and/or "adaptogenic" properties on humans (or horses or dogs). In the same way, increasing numbers of patents have been deposited concerning various beneficial effects of ecdysteroids in many medical or cosmetic domains, which make ecdysteroids very attractive candidates for several practical uses. It may be questioned whether all these pharmacological actions are compatible with the development of ecdysteroid-inducible gene switches for gene therapy, and also if ecdysteroids should be classified among doping substances.

Ecdysone: Five Biologically Active Fractions from Bombyx

Five fractions of the growth and differentiation hormone, ecdysone, separated from extracts of Bombyx have been detected by bioassay. Three of these have not been described heretofore.