Dynamics of antioxidant defense system indicators in children with osteosarcoma during high-dose chemotherapy with methotrexate

One of the factors of Mtx toxicity during high-dose chemotherapy is its prooxidant action. For the compensation of arising oxidative stress such antioxidant drugs as ademetionin are used in clinical. The purpose of the study: investigation of the dynamics of antioxidant defense system indicators in children during high-dose chemotherapy. The object of study: 246 patients who received high-dose Mtx chemotherapy, aged 9–15 years.
Methods. Determination of GGT, GR, SOD and OAOS in blood on key hours from the start of Mtx administration – 4, 24, 42, 48; determination of their biokinetics parameters.
Results. For the first 4 courses the regularities are found: GGT activity and SOD have a maximum increase in the 4th hour, further reduced. SOD activity recovers slightly up to 48^th hour. Levels of GR and OAOS are the lowest for the 4^th hour, then increased to a level above the reference one.
Conclusion. Oxidative stress caused by the action of Mtx, can be compensated by coadministration of ademetionine, which has a positive effect on all measured indicators. After 4 courses of high-dose Mtx chemotherapy hepatotoxicity increases despite of treatment with ademetionine the degree of hepatotoxicity is growing, which founds the reflection in the dynamics of SOD and GGT.