Antihyperglycaemic, haemorheological and antioxidant activities of Lychnis chalcedonica L. extract in a streptozotocin-induced rat model of diabetes mellitus.

Background New therapeutic strategies, such as the use of agents to correct rheological disorders, are needed for the prevention and treatment of angiopathy in diabetic patients. The aim of this work was to study the antihyperglycaemic, haemorheologic and antioxidant activities of an extract from the flowering plant Lychnis chalcedonica L. (ELC) and 20-hydroxyecdysone using the streptozotocin-induced model of diabetic rats. Methods The streptozotocin-induced model of diabetes was produced using streptozotocin at a dose of 50 mg/kg (ip). Animals from the experimental groups were treated with ELC (150 mg/kg) or 20-hydroxyecdysone (1.1 mg/kg) intragastrically in 1% aqueous starch mucilage daily, for 14 days; rats of control groups received an equal volume of starch mucilage. The following parameters were measured: glucose concentration (GC) in blood, whole blood viscosity (WBV), conjugated dienes in RBC membranes. Macro- and microrheological indicators (viz. plasma viscosity, haematocrit, RBC aggregation (T1/2) and the RBC elongation index (EI)) were additionally measured in rats that received ELC, and in the control group. Results After treatment with ELC, the GC in rats was 19% lower than that in the control group (14.7 ± 0.9 mM compared to 18.2 ± 1.1 mM). Rats with streptozotocin-induced diabetes have hyperviscosity syndrome, which is characterized by increased WBV, increased RBC aggregation and decreased deformability. ELC treatment reduced WBV at shear rates of 10-90 s-1 by 5-8%, and T1/2 and EI in the experimental group were 31% and 5-10% higher compared to the control group. 20-Hydroxyecdysone decreased WBV at shear rates of 10-90 s-1 by 3-11%. Finally, ELC and 20-hydroxyecdysone lowered the content of conjugated dienes by 27% and by 26% compared to the control groups. Conclusion In the streptozotocin-induced diabetic rat model, ELC showed measurable antihyperglycaemic activity; ELC and 20-hydroxyecdysone demonstrated similar haemorheological, and antioxidant activities.

The phytoecdysteroid profiles of 7 species of Silene (Caryophyllaceae).

The phytoecdysteroid profiles of extracts of aerial parts of flowering plants of 7 ecdysteroid-containing species in the genus Silene (Caryophyllaceae; S. fridvaldszkyana Hampe, S. gigantea L., S. graminifolia Otth, S. mellifera Boiss. & Reuter, S. repens Patr., S. schmuckeri Wettst., and S. sendtneri Boiss.) have been examined and identified by HPLC and, in the case of two new compounds, by mass spectrometry and NMR. S. frivaldszkyana was found to contain predominantly 20-hydroxyecdysone (20E), with smaller amounts of 2-deoxyecdysone (2dE), 2-deoxy-20-hydroxyecdysone (2d20E), polypodine B (polB), integristerone A (IntA), 26-hydroxypolypodine B (26polB), and 20,26-dihydroxyecdysone (20,26E). Additionally, a new minor ecdysteroid, 26-hydroxyintegristerone A, has been identified from this species. S. gigantea contains 3 major ecdysteroids (2dE, 2d20E, and 20E) and much smaller amounts of intA and 2-deoxy-20-hydroxyecdysone 25-beta-D-glucoside, which is a new ecdysteroid. Ecdysteroids in the other 5 species have been identified by co-chromatography with reference compounds on RP- and NP-HPLC systems. There is considerable variability with regard to ecdysteroid profiles within the genus Silene. The chemotaxonomic value of ecdysteroid profiles within the genus Silene is discussed.

Distribution of phytoecdysteroids in the Caryophyllaceae.

Certain genera within the Caryophyllaceae (especially Silene and Lychnis) have received a significant amount of attention with regard to the isolation and identification of ecdysteroids. However, the taxonomy of this family is difficult. Hence, the occurrence of phytoecdysteroids in members of the Caryophyllaceae is presented, and combined with new data on ecdysteroid agonist (phytoecdysteroid) and antagonist activities, in order to survey the distribution of phytoecdysteroid-containing species within this large family, and to assess the utility of phytoecdysteroids as chemotaxonomic markers. The new data presented (representing ca. 110 species) have been obtained by the application of sensitive biological/biochemical methods for the detection of ecdysteroid agonists and antagonists, using Drosophila melanogaster B(II) bioassay and ecdysteroid-specific immunoassays. In the antagonist version of the B(II) bioassay, only weak ecdysteroid antagonist activities were detected in a few of the extracts. From both new and previously available data, it was found that phytoecdysteroids were present predominantly in the Genera Lychnis, Petrocoptis, Sagina and Silene. Comparison of ecdysteroid occurrence with a molecular phylogeny for the tribe Sileneae [Taxon 44 (1995) 525] revealed close association of ecdysteroid occurrence with certain groups of this tribe. In 14 species of Silene examined, there is a reasonable, but not absolute, relationship between the presence of ecdysteroids in the seeds and in other plant parts. Where ecdysteroids are present in the plant, highest concentrations are generally present in the roots.