Cerebrolysin Inhibits Lipid Peroxidation Induced by Insulin Hypoglycemia in the Brain and Heart of Mice

Summary As a consequence of enhanced production of oxygen free radicals, lipid peroxidation leads to the degradation of membrane lipids and disturbances of membrane permeability. Lipid peroxidation increases under stress conditions such as hypoxia, ischemia or acidosis as well as in metabolic diseases, e.g. diabetes mellitus. We have shown that subcomatous doses of insulin (6.0 IU/kg) significantly increase thiobarbituric acid reactive substances (TBARs), especially malondialdehyde (MDA) -the endproduct of lipid peroxidation, in the brain and heart of mice. In our model of insulin-induced hypoglycemia, mice were treated with the neuroprotective, peptide-containing drug Cerebrolysin (100 mg/kg b.w.). Animals were sacrificed by decapitation two or three hours after the injection of tested substance and samples were taken to determine several serum parameters (glucose, total protein, triglycerides and lactic acid) and TBARs in the brain and heart. Although Cerebrolysin was not able to affect serum parameters after subcomatous insulin injection, the drug significantly influenced lipid peroxidation. A single injection of Cerebrolysin already decreased TBARs levels in the brain and heart tissue. Presuming that an increase of TBARs reflects disturbances of the cell membrane, we have documented a promising effect of Cerebrolysin on cell integrity

Preservation of Mouse Sperm by Convective Drying and Storing in 3-O-Methyl-D-Glucose

With the fast advancement in the genetics and bio-medical fields, the vast number of valuable transgenic and rare genetic mouse models need to be preserved. Preservation of mouse sperm by convective drying and subsequent storing at above freezing temperatures could dramatically reduce the cost and facilitate shipping. Mouse sperm were convectively dried under nitrogen gas in the Na-EGTA solution containing 100 mmol/L 3-O-methyl-D-glucose and stored in LiCl sorption jars (Relative Humidity, RH, 12%) at 4°C and 22°C for up to one year. The functionality of these sperm samples after storage was tested by intracytoplasmic injection into mouse oocytes. The percentages of blastocysts produced from sperm stored at 4°C for 1, 2, 3, 6, and 12 months were 62.6%, 53.4%, 39.6%, 33.3%, and 30.4%, respectively, while those stored at 22°C for 1, 2, and 3 months were 28.8%, 26.6%, and 12.2%, respectively. Transfer of 38 two- to four-cell embryos from sperm stored at 4°C for 1 year produced two live pups while 59 two- to four-cell embryos from sperm stored at 22°C for 3 months also produced two live pups. Although all the pups looked healthy at 3 weeks of age, normality of offspring produced using convectively dried sperm needs further investigation. The percentages of blastocyst from sperm stored in the higher relative humidity conditions of NaBr and MgCl2 jars and driest condition of P2O5 jars at 4°C and 22°C were all lower. A simple method of mouse sperm preservation is demonstrated. Three-O-methyl-D-glucose, a metabolically inactive derivative of glucose, offers significant protection for dried mouse sperm at above freezing temperatures without the need for poration of cell membrane

Cis-trans isomerization of silybins A and B

Methods were developed and optimized for the preparation of the 2,3-cis- and the 10,11-cis-isomers of silybin by the Lewis acid catalyzed (BF 3-OEt2) isomerization of silybins A (1a) and B (1b) (trans-isomers). The absolute configuration of all optically pure compounds was determined by using NMR and comparing their electronic circular dichroism data with model compounds of known absolute configurations. Mechanisms for cis - trans-isomerization of silybin are proposed and supported by quantum mechanical calculations. © 2014 Novotná et al; licensee Beilstein-Institut.Funding Agencies|P207/10/0288, GACR, Czech Science Foundation</p

Preparation of silybin and isosilybin sulfates by sulfotransferase from Desulfitobacterium hafniense

Flavonolignans silybin and isosilybin are major components of silymarin complex isolated from seeds of the milk thistle (Silybum marianum) featuring strong antioxidant and hepatoprotective effects, and also anticancer, chemoprotective, dermatoprotective and hypocholesterolemic activities. Natural silybin and isosilybin are mixtures of diastereoisomers: silybin/isosilybin A (1a, 1b) and silybin/isosilybin B (2a, 2b). The metabolism of these compounds is supposed to be strongly linked to Phase II of biotransformation and the respective conjugates are rapidly excreted in bile and urine. The aim of this study was to obtain optically pure sulfated metabolites of both silybins and isosilybins. Aryl-sulfate sulfotransferase (EC 2.8.2.22) from Desulfitobacterium hafniense was found to be a highly effective tool for the regiospecific enzymatic synthesis of silybin A-20-O-sulfate, silybin B-20-O-sulfate, isosilybin A-20-O-sulfate and isosilybin B-20-O-sulfate providing nearly quantitative yields and employing cheap p-nitrophenyl sulfate as sulfate donor. The isolated sulfated products will be used as authentic standards in metabolic studies of both silybins and isosilybins. (C) 2012 Elsevier B.V. All rights reserved