Free radical scavenging and inhibition of lipid peroxidation by magnesium lithospermate B

AIM: To study the effect of magnesium lithospermate B (MLB) on the lipid pe roxidation and on its free radical scavenging activity. METHODS: MLB was in cubated in rat tissue homogenate or in a free radical generating system. ML B induced inhibition of lipid peroxidation and its scavenging activity on s uperoxide anions and hydroxyl radicals was studied using colorimetric estim ation. RESULTS: MLB inhibited the lipid peroxidation induced by either an a uto-oxidant or Fe2+/VitC in vitro, in the liver homogenate, the inhibitory rate of MLB (10 mg/L) being 69.2 % and 57.7 %, respectively. MLB (25 and 50 mg/kg ) decreased the amount of thiobarbituric acid reactive substances(TE ARS) in rat serum, liver, kidney, and heart. However, it did not inhibit th e lipid peroxidation of brain homogenate ex vivo. MLB scavenged superoxide anions generated from xanthine/xanthine oxidase system and iron-dependent h ydroxyl radicals. CONCLUSION: MLE is an inhibitor of lipid peroxidation and scavenge superoxide anions and hydroxyl radicals both in vitro and ex vivo .