Chemiluminescence evaluation of oxidative damage to biomolecules induced by singlet oxygen and the protective effects of antioxidants

A chemiluminescence (CL) method was developed for the evaluation of oxidative damage to biomolecules induced by singlet oxygen (1O2) and for the evaluation of the protective effects of antioxidants. The 1O2 was generated from the reaction of H2O2 + OCl−. Results showed that the CL signal from the reaction of H2O2 + OCl− was weak, however, it was enhanced dose-dependently with the addition of DNA and unsaturated fatty acid, respectively. Spectra analysis indicated that the enhanced CL could be ascribed to the decay of triplet-excited carbonyl compounds, which were generated from the reaction of 1O2 plus the biomolecules. On the other hand, the enhanced CL produced in the above systems could be effectively inhibited by lycopene, β-carotene, VC, and VE, but could not be inhibited by mannitol, SOD, and NaN3. The mechanism therein was discussed.