Society of Diabetic Nephropathy Prevention Journal of Nephropharmacology 2345-4202 16 1 2027 01 01 Therapeutic effect of semapimod on renal ischemia/reperfusion injury via necroptosis pathway inhibition in male rats; an experimental animal study e12792 e12792 10.34172/npj.12792 EN Ali F. Jaber https://orcid.org/0009-0007-2789-6029 Ali M. Janabi https://orcid.org/0000-0002-8569-7964 Journal Article 10.34172/npj.12792 2025 05 04 2026 06 26 Introduction: Renal ischemia-reperfusion (I/R) injury is a critical contributor to acute kidney injury (AKI) and chronic kidney disease (CKD), driven by oxidative stress, inflammation, and regulated cell death pathways such as necroptosis. Objectives: This study investigates the therapeutic potential of semapimod, a macrophage inhibitor and cholinergic anti-inflammatory agent, in mitigating renal I/R injury by targeting necroptosis in male rats. Materials and Methods: In this experimental animal study at the university of Kufa, Iraq, 24 male Sprague Dawley rats (about 8 weeks old, ~200 g) were housed under controlled conditions and randomly assigned to sham, I/R, vehicle+I/R (veh + I/R), and semapimod hydrochloride HCl + I/R (SPD + I/R) groups. In this study, I/R, veh+I/R, and SPD + I/R groups underwent a model of I/R consisting of 30 minutes of ischemia and 24 hours of reperfusion. The SPD+I/R group receives 10 mg/kg of semapimod HCl, and the veh+I/R group receives the solvent of semapimod HCl by intraperitoneal route, one hour before the induction of ischemia. The sham group underwent laparotomy I/R and received nothing. After anesthesia rates were sacrificed and kidneys were collected for histopathology, immunohistochemistry (mixed lineage kinase domain-like pseudokinase [MLKL]), and molecular analyses for kidney injury molecule-1 (KIM-1), tumor necrosis factor-α (TNF-α), caspase-3, and receptor-interacting protein kinase 1 (RIPK1), with all assessments were conducted to evaluate renal injury, inflammation, and necroptosis/apoptosis markers. Data were collected and compared between four groups. Results: The results demonstrated that semapimod pretreatment attenuates renal I/R injury through multimodal modulation of inflammatory, necroptotic, and apoptotic pathways. Inflammatory markers KIM-1 and TNF-α were markedly elevated in I/R and vehicle-treated groups, with semapimod significantly reducing both biomarkers. Necroptotic markers RIPK1 and MLKL exhibited robust upregulation in I/R injury, which persisted in vehicle-treated rats but were substantially normalized by semapimod. Similarly, caspase-3 activity and histopathological damage scores, reflective of apoptotic and structural injury, peaked in I/R and vehicle groups, while semapimod restored caspase-3 to near-sham levels and mitigated tubular necrosis, though residual histological damage persisted. Conclusion: These results collectively position semapimod as a promising therapeutic agent that concurrently dampens necroptosis, apoptosis, and inflammation, with normalization of injury biomarkers, emphasizing its efficacy in preserving renal architecture and function post-I/R insult.