Figure 4.

Repair of DNA–DMPO adduct. (A) The DNA–DMPO adduct resulting from treatment of the RAW 264.7 cells with CuCl₂ and H₂O₂ in the presence of DMPO forms within 30 min of treatment, then slowly increases before reaching a maximum at 12 h with a subsequent drop in the adduct level. (B) The DMPO–DNA nitrone adduct was repaired in a few hours upon the addition of the cell lysate to the reaction mixture. (C) The repair of the preformed DMPO–DNA nitrone adduct was significantly inhibited upon the addition of the cell lysate containing methoxyamine even after 20 h.