Efficacy of topotecan treatment on antioxidant enzymes and TBA-RS levels in submandibular glands of rabbits:: An experimental study

OBJECTIVE: The aim of this study was to investigate the effects of topotecan (Hycamtin), a topoisomerase I inhibiting anticancer agent, on antioxidant enzymes (SOD, CAT, and GSH-Px) and TBA-RS values of the submandibular glands of the rabbits. STUDY DESIGN AND SETTING: The study was conveyed in two groups (Group I, II) and control with a total of 24 rabbits. Eight rabbits in group I received intravenous (i.v.) topotecan (0.25 mg/kg once daily) for 3 days. Eight rabbits in group II received i.v. topotecan (0.5 mg/kg once daily) for 3 days. On the 15th day after administration of topotecan, submandibular glands were removed and levels of the SOD, CAT, and GSH-Px and the TBA-RS in the submandibular glands of the rabbits were examined. RESULTS: SOD, CAT, and GSH-Px values were significantly higher in high-dose topotecan group compared to control group (P < 0.05). SOD and TBA-RS values were significantly higher in high-dose topotecan group compared to low-dose topotecan group (P < 0.05). CONCLUSION: It was concluded that, to prevent the hazardous effects of oxygen free radicals due to topotecan, antioxidant enzymes SOD, CAT, and GSH-Px were increased. The higher levels of the TBA-RS values in group II showed that permanent damage was present because of high-dose topotecan administration in the submandibular glands of the rabbits.