Antioxidant and Radical Scavenging Effects of Aged Garlic Extract and its Constituents

The antioxidant properties of three garlic preparations and organoslfur compounds in garlic have lreen determined. Aged garlic extract inhibited the emission of low level chemiluminescence and the early formation of thiobarbituric acid-reactive sulrstances (TBA-RS) in liver microsomal fraction initiated by t-butyl hydroperoxide. However, the water extracts of raw and heat-treated garlic enhanced the emission of low level chemiluminescence. Among the variety of organosulfur compounds, S-allylcysteine (SAC) and S-allylinercaptocysteine (SAMC), the major organosulfur compounds found in aged garlic extract, showed radical scavenging activity in lroth chemiluminescence and 1,1 -diphenyl2-picrylhydrazyl (DPPH) assays, indicating that these compounds may play an important role in the antioxidative activity of aged garlic extract