Examination of the Effects of Thiamine and Thiamine Pyrophosphate on Doxorubicin-Induced Experimental Cardiotoxicity

To investigate the effect of thiamine and thiamine pyrophosphate on doxorubicin-induced cardiotoxicity biochemically and histopathologically and to examine whether doxorubicin cardiotoxicity is related to the conversion of thiamine into thiamine pyrophosphate and inhibition of thiamine pyrophosphokinase (TPK) enzyme.A total of 48 Albino Wistar male rats were used. Rats were divided into groups as thiamine + doxorubicin (TIA + DOX), thiamine pyrophosphate + doxorubicin (TPP + DOX), DOX, and healthy (HEA) groups. One hour after the administration of thiamine and TPP in 25 mg/kg doses, 5 mg/kg doxorubicin were injected to all groups except HEA group during 7 days. Then, the samples were collected for biochemical (glutathione [GSH], malondialdehyde [MDA], DNA damage, creatine kinase (CK), CK-MB, and troponine I [TP-I]), molecular (TPK), and histopathological examinations.Oxidant parameters (MDA and DNA damage) decreased and antioxidant parameter (GSH) increased in TPP + DOX group. In addition, levels of CK, CK-MB, and TP-I were low in the TPP + DOX group and high in the TIA + DOX and DOX groups. Cardiac tissue was protected in TPP + DOX group, and no protective effect was observed in TIA + DOX and DOX groups. Messenger RNA expression of TPK was decreased in DOX and TIA + DOX groups.The cardiotoxic effect of doxorubicin originated from the inhibition of TPK enzyme resulting in insufficient production of thiamine pyrophosphate.