1,2-Di-O-α-linolenoyl-3-O-β-galactosyl-sn-glycerol as a superoxide generation inhibitor from Perilla frutescens var. crispa.

Using a superoxide (O(2)(-)) generation assay system with differentiated HL-60 cells, 1,2-di-O-α-linolenoyl-3-O-β-galactosyl-sn-glycerol (DLGG) was identified as an O(2)(-) generation inhibitor from Perilla frutescens var. crispa (a local variety, kida-chirimen shiso). DLGG suppressed the O(2)(-) level in a dose-dependent manner with an IC(50) value of 21 µM, comparable to those of rosmarinic acid (RoA, IC(50) = 29 µM) and caffeic acid (CA, IC(50) = 30 µM). While RoA and CA also dose-dependently inhibited O(2)(-) generation in a xanthine-xanthine oxidase system, DLGG had no effect in the same system. Thus DLGG appeared to decrease the O(2)(-) level in the HL-60 assay system by mechanisms different from those of RoA and CA, which appeared to act as O(2)(-) scavengers.