New Functions of 20-Hydroxyecdysone in Lipid Peroxidation

Abstract

The antioxidizing action of 20-hydroxyecdysone was investigated in several systems in vitro. Changes in the parameters of chemiluminescence in the presence of 20-hydroxyecdysone were found in rat liver mitochondrial fractions. The effect of 20-hydroxyecdysone on methyl linoleate micelles free radical oxidation was studied. The rate of oxygen uptake in methyl linoleate micelles was found to be smaller when 20-hydroxyecdysone was present than at its absence. The action of 20-hydroxyecdysone in the liposomal membranes oxidation was investigated by means of α-tocopherol consumption. A lower rate of α-tocopherol consumption in the oxidation of liposomal membranes was found when 20-hydroxyecdysone was present. The effect of cholesterol on free radical formation in liposomal membranes was investigated. The rate of free-radical formation was smaller when cholesterol was present in the membrane than in membranes free of cholesterol. The α-tocopherol antioxidant effect in the membrane was also lower when cholesterol was present. We show here for the first time that 20-hydroxyecdysone has an antioxidant action in combination with α-tocopherol in membranes with cholesterol overload. Kinetic measurements were revealed the 20-hydroxyecdysone antioxidant effect on free radical reactions in membranes. © 2001, Japan Oil Chemists' Society. All rights reserved.