ecdysterone and Hyperglycemia

A series of phytoecodysteroids, including alpha-ecdysone, 2-deoxy-alpha-ecdysone, and 2-deoxyecdysterone isolated from Silene praemixta, integristerone A and ecdysterone isolated from Rhaponticum carthamoides and 22-acetylcyasterone and turkesterone isolated from Ajuga turkestanica, exhibit a pronounced hypoglycemic effect in experiments on intact male rats. The most active compounds--ecdysteron and turkesterone--also produce an expressed hypoglycemic effect in animals with model hyperglycemia induced by the administration of glucose, adrenalin and alloxan. Phytoecdysteroids are substances possessing protein-anabolic activity and are somewhat similar to steranobols in this aspect. Phytoecdysteroids exhibit unidirectional effect and are well comparable with steranabol actionon the carbohydrate metabolism.

Topics: Ajuga; Animals; Asteraceae; Blood Glucose; Caryophyllaceae; Ecdysteroids; Ecdysterone; Hyperglycemia; Hypoglycemic Agents; Male; Methandrostenolone; Phytosterols; Rats

The steroid hormone 20-hydroxyecdysone (20HE) is an essential signaling molecule that modulates molting response in insects and may function as a putative anabolic factor in vertebrate animals, although no mammalian 20HE receptor has been identified. Here we show that in H4IIE cell culture, 20HE treatment decreased expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), reduced glucose production, and induced Akt2 phosphorylation sensitive to the phosphoinositide-3 kinase pathway-specific inhibitor LY-294002. Daily oral administration of 20HE (10 mg/kg for 13 wk) ameliorated obesity and insulin resistance in C57BL/6J mice fed a high-fat diet and produced a significant decrease of body weight gain and body fat mass compared with nontreated animals as demonstrated by dual-energy X-ray absorptiometry analysis. In addition, plasma insulin levels and glucose tolerance were significantly lowered by 20HE treatment. These changes were accompanied by the reduced hepatic expression of PEPCK and G6Pase and increased adiponectin production by visceral fat tissue. These studies demonstrate the anti-obesity and anti-diabetic effects of 20HE and begin to elucidate its putative cellular targets both in vitro and in vivo.

Topics: Adiponectin; AMP-Activated Protein Kinases; Animals; Blood Glucose; Body Weight; Carcinoma, Hepatocellular; Cells, Cultured; Dietary Fats; Ecdysterone; Glucose Intolerance; Hyperglycemia; Insulin; Insulin Resistance; Liver Neoplasms; Male; Mice; Mice, Inbred C57BL; Obesity; Phosphatidylinositol 3-Kinases; Rats; STAT1 Transcription Factor

To design a homologous bioassay for the molt-inhibiting hormone and the crustacean hyperglycemic hormone of the shrimp Penaeus vannamei, the effect of sinus gland homogenate (SGh), in vitro, on ecdysteroid production by Y-organs (YOs), and the effect of the injection of SGh, in vivo, on the glycemia of shrimps have been investigated. Addition of SGh to incubation medium of shrimp YOs dose dependently reduced, within a few hours, ecdysteroid release into the medium. Moreover, inhibition by SGh decreases drastically in YOs from animals in late premolt stages, when there is maximal ecdysteroid production. Injection of SGh into shrimps evokes a hyperglycemic response maximal after 2 hr. Immunoadsorption of SGh with an anti-Homarus americanus cHHA antiserum inhibited both biological activities of the homogenate. After fractionation of acidic sinus gland extract by RP-HPLC, the maximal response in both bioassays was associated with the major UV absorbent peak, which was also the major immunoreactive peak when tested by ELISA with the anti-lobster cHHA. After a further purification step, the molecular mass of the bioactive and immunoreactive peptide was found to be 8627 +/- 0.3 Da by electrospray ionization mass spectrometry. The amino acid sequence of the first 38 residues of this peptide was established by gas-phase microsequencing. This sequence shows 55% homology with the first 38 residues of the lobster cHHA.

Topics: Amino Acid Sequence; Animals; Biological Assay; Chromatography, High Pressure Liquid; Ecdysone; Ecdysterone; Enzyme-Linked Immunosorbent Assay; Hyperglycemia; Invertebrate Hormones; Mass Spectrometry; Molecular Sequence Data; Nephropidae; Neurosecretory Systems; Penaeidae; Tissue Extracts