ANTIOXIDATIVE AND SUPEROXIDE SCAVENGING ACTIVITIES OF RETROCHALCONES IN GLYCYRRHIZA-INFLATA

Licochalcone A, B, C, D and echinatin, retrochalcones isolated from th e roots of Glycyrrhiza inflata (licorice), along with an ordinary chal cone isoliquiritigenin, were assessed for their inhibitory activities on lipid peroxidation in various systems and radical scavenging activi ty. Among those tested, licochalcones B and D strongly inhibited super oxide anion production in the xanthine/xanthine oxidase system. These two compounds also showed potent scavenging activity on DPPH radical. Microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH was inhibit ed almost completely by 3 mu g/ml of licochalcones B and D. Mitochondr ial lipid peroxidation induced by Fe(III)-ADP/NADH was more sensitive to these retrochalcones; almost complete inhibition was observed at 10 mu g/ml of all retorchalcones tested. Licochalcones B and D scavenged superoxide anion in microsome. Furthermore, these retrochalcones prot ected red cells against oxidative hemolysis. These phenolic compounds were shown to be effective to protect biological systems against vario us oxidative stresses. (C) 1998 Elsevier Science Ltd. All rights reser ved.