Targeting RIPK1-mediated necroptosis, oxidative stress, and ferroptosis: A novel multitarget therapy for ischemic stroke.

Ischemic stroke is characterized by high mortality and disability rates, and involves complex pathological processes mediated by multiple damage cascade mechanisms. While current clinical investigational drugs predominantly target antioxidant stress pathways, there remains an urgent need for multi-target therapeutic agents with enhanced therapeutic potential. Notably, RIPK1-mediated necroptosis and neuroinflammation have emerged as critical drivers of secondary brain injury, impacting stroke severity and clinical prognosis. Guided by these mechanistic insights, we rationally designed and synthesized a structurally diverse series of novel 4,5-dihydro-1H-pyrazole derivatives, followed by comprehensive biological evaluations. Compound 23a demonstrated potent RIPK1 kinase inhibitory activity (IC50 = 0.115 μM), and exhibited superior antioxidant efficacy (IC50 = 9.72 μM) compared to the clinically approved drug edaravone (IC50 = 22.79 μM). Furthermore, 23a demonstrated remarkable anti-ferroptosis activity by suppressing PTGS2 mRNA expression (IC50 = 0.156 μM). In vivo studies showed that 23a markedly reduced cerebral infarction volume and improved neurological function scores in transient middle cerebral artery occlusion (tMCAO) model, outperforming edaravone, and demonstrated multi-target effects against oxidative stress, necroptosis, and ferroptosis in the ischemic penumbra tissue. These findings collectively highlight 23a as a promising triple-target lead compound for ischemic stroke therapy, warranting further optimization and development.