Mitigation of Cisplatin-Induced Cardiotoxicity by Isorhamnetin: Mechanistic Insights into Oxidative Stress, Inflammation, and Apoptosis Modulation

The flavonoid compound Isorhamnetin (IRMN) is known for its considerable pharmacological properties, which include antioxidant and anti-inflammatory effects, as well as significant protective actions on heart health. However, the potential of IRMN to guard against heart damage caused by cisplatin (CP), a common chemotherapeutic agent, and the specific mechanisms involved, remain unexplored areas. This research was designed to investigate how IRMN counters CP-induced heart toxicity. In our study, mice were orally given IRMN at 50 or 150 mg/kg/day for a week, followed by CP injections (5 mg/kg/day) on the third and sixth days. The animals were euthanized under sodium pentobarbital anesthesia (50 mg/kg, intraperitoneally) on the eighth day to collect blood and heart tissues for further examination. Our findings reveal that IRMN administration significantly reduced the heart damage and the elevation of heart injury markers such as cardiac troponin I, creatine kinase, and lactate dehydrogenase induced by CP. IRMN also effectively lowered oxidative stress markers, including reactive oxygen species and malondialdehyde, while boosting ATP production and antioxidants like superoxide dismutase, catalase, and glutathione. The compound's capability to diminish the levels of pro-inflammatory cytokines like tumor necrosis factor-alpha and interleukin-6, alongside modulating apoptosis-regulating proteins (enhancing Bcl-2 while suppressing Bax and Caspase-3 expression), further underscores its cardioprotective effect. Notably, IRMN modulated the p62-Keap1-Nrf2 signaling pathway, suggesting a mechanism through which it exerts its protective effects against CP-induced cardiac injury. These insights underscore the potential of IRMN as an effective adjunct in cancer therapy, offering a strategy to mitigate the cardiotoxic side effects of cisplatin.