A simple luminescence method for detecting lipid peroxidation and antioxidant activity in vitro

The excited carbonyl species formed during lipid peroxidation may transfer their energy to dye molecules containing heavy atoms such as rose bengal to produce excited singlet state dye molecules. The excited dye then emits photons to return to its ground state. The aim of the present study was to investigate the relationship between methemoglobin (metHb)-induced lipid peroxidation, rose bengal luminescence, and O2 consumption in a system containing 0-850 mu M phospholipid and 1 mu M metHb and 1 mu M rose bengal in Tris-HCl buffer, pH 7.4. The rapid rise in rose bengal luminescence was accompanied by a rapid rise in O2 consumption. Further, the luminescence of rose bengal could be quenched by alpha -tocopherol or probucol present in the phospholipid liposomes, with the latter being strikingly more effective than the former. This simple luminescence method is a useful practical approach to detect lipid peroxidation and determined antioxidant effects of water insoluble compounds in vitro.