Abstract Body: Introduction: Multiple myeloma ranks as the second most prevalent hematologic cancer in the US. Survival rates have significantly improved owing to advances in chemotherapy treatment. Carfilzomib, an irreversible proteasome inhibitor, has been used globally for the treatment of multiple myeloma. Unfortunately, its clinical use has been linked to cardiovascular complications. Empagliflozin is a sodium glucose co-transporter-2 inhibitor with potential cardioprotective activities, for which it is approved for heart failure management.

Aims: The current study determined the beneficial effects of Empagliflozin against Carfilzomib-induced cardiotoxicity in C57BL/6 mice and the possible underlying mechanisms.

Methods: Thirty-two mice were randomly divided into four groups and treated for two days as follows: Control (vehicle), Empagliflozin (10 mg/kg, oral), Carfilzomib (8 mg/kg, i.p.), and Carfilzomib + Empagliflozin groups.

Results: The impact of Carfilzomib and Empagliflozin treatment on markers of cardiotoxicity and heart tissue architecture was assessed. Empagliflozin corrected histological alterations, CK-MB activity, and troponin I level induced by Carfilzomib. Additionally, Empagliflozin mitigated Carfilzomib-induced oxidative deficits via its effect on catalase activity, reduced glutathione level, and superoxide dismutase activity, restoring the balance of redox circuit. Moreover, Empagliflozin averted Carfilzomib-induced inflammatory response as evidenced by reducing nuclear factor-κB (p65), tumor necrosis factor-α, and interleukin-1β levels. Mechanistically, a substantial amelioration in the activating transcription factor 6-mediated endoplasmic reticulum stress was demonstrated with Empagliflozin treatment owing to its effect on glucose regulated protein-78, activating transcription factor-6, and C/EBP homologous protein. Intriguingly, the induction of autophagy by Carfilzomib was notably amplified following Empagliflozin administration as evidenced by higher mRNA expression of LC3B and beclin-1, and lower expression of p62. Accordingly, the apoptotic marker cleaved caspase-3 expression was markedly reduced following Empagliflozin treatment. Importantly, Empagliflozin did not alter the cytotoxic effect of Carfilzomib on human U266B1 myeloma cell line.

Conclusion: This research suggests Empagliflozin could offer cardioprotection against Carfilzomib-induced cardiotoxicity in multiple myeloma patients.