eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2026-09-30 19 3 2665 2674 10.13005/bpj/3523 73174 article Safa khaldoon 1 Emad Yousif 1 Khawla Kasar 1 Muna Bufaroosha 2 Department of Chemistry, College of Science, Al-Nahrain University, Baghdad, Iraq Department of Chemistry, College of Science, United Arab Emirates University, Al-Ain, United Arab Emirates Organotin (IV) complex have acquired significant interest because of their fascinating biological and anticancer properties. In the present study, a new dibutyltin (IV)-allopurinol complex (Bu₂SnL₂) was synthesized and characterized and its effect on lactate dehydrogenase (LDH) activity associated with breast cancer was investigated. The complex was prepared by reacting dibutyltin dichloride and allopurinol in a 1:2 metal to ligand molar ratio under reflux conditions. The melting point determination, FTIR, EDX, ¹HNMR, ¹³CNMR and ¹¹⁹ Sn-NMR techniques were used for structural analysis and confirmed the effective coordination of allopurinol to the tin center via the pyrazole nitrogen atom and the formation of a stable six-coordinated geometry. The biological activity of the synthesized complex in vitro was evaluated using serum samples obtained from 25 healthy controls and 75 Iraqi women with breast cancer. Serum LDH levels were determined by ELISA and statistical analysis was performed by one way ANOVA and Dunnett’s multiple comparisons test. LDH activity was significantly higher in patients with breast cancer than in healthy controls (p < 0.0001). Treatment with Bu₂SnL₂ modulated LDH activity in a concentration dependent manner with the largest decrease observed at 50 µg/mL. In the solvent control group, no significant changes were observed, showing that the effect was due to the organotin complex itself. The results indicate that the synthetic dibutyltin (IV)-allopurinol complex shows a promising LDH-modulating activity and may be a potential candidate for further investigation as an anticancer drug targeting breast cancer metabolism. https://biomedpharmajournal.org/vol19no3/evaluation-of-a-dibutyltiniv-allopurinol-complex-in-breast-cancer-patients-using-serum-lactate-dehydrogenase-as-a-biomarker/ Allopurinol Anticancer Activity Breast Cancer Dibutyltin(IV) Complex Lactate Dehydrogenase Inhibition