Aim: The aim of the study is to investigate the protective effect of thiamine pyrophosphate on methotrexate- induced gastrotoxicity biochemically in rats and to compare it with thiamine. Methods: Rats were divided into four groups as sham (SG), thiamine+ methotrexate (TAMTX), thiamine pyrophosphate+methotrexate (TPMTX) and Methotrexate (MTX) groups. 5 mg/kg methotrexate was administrated to 24 hrfasted rat groups by oral gastric tube except sham rats. 20 mg/kg thiamine was injected to TAMTX group and 20 mg/kg thiamine pyrophosphate was injected to TPMTX group i.p. 5 min before the methotrexate administration. Equal amount distilled water was injected i.p. to SG and MTX groups. 6 hr after the methotrexate administration, the rats were sacrificed with high dose thiopental anesthesia (50 mg/kg). The stomachs of the rats were extracted and MDA, MPO, GSH and SOD analyzes were performed. Results: Biochemical results were evaluated by comparing among groups. While tGSH and MDA levels and MPO and SOD activities were 4.2±0.6, 10.0±0.9, 7.4±0.8, 5.2±0.9 μmol/g in MTX group, these parameters were 11.0±1.0, 3.4±0.4, 3.3±0.5, 13.2±1.1 μmol/g in SG group in the gastric tissue. These parameters were measured as 4.8±0.8, 8.7±0.8, 5.9±0.5, 6.1±0.8 μmol/g in TAMTX group and 10.8±0.8, 4.0±0.5, 3.6±0.4, 10.5±0.9 μmol/g in TPMTX group. Conclusion: The results showed that thiamine pyrophosphate prevented methotrexate induced oxidative damage in the gastric tissue, but thiamine could not prevent.
Key words: Gastrotoxicity, Methotrexate, Thiamine, Thiamin pyrophosphate, Ulcer.