Hyperoside alleviates macrophages and microglia-mediated neuroinflammation and oxidative stress through activating PI3K/AKT and Nrf2/HO-1 signaling pathway post spinal cord injury

Spinal cord injury (SCI) is a debilitating and destructive disorder of the central nervous system (CNS), resulting in severe sensory and motor deficits. Secondary injury mechanisms, including neuroinflammation and oxidative stress, play critical roles in disease progression. Pharmacological interventions with anti-inflammatory and antioxidant agents have shown promise as therapeutic strategies for SCI. Hyperoside (HYP), a bioactive flavonoid derived from traditional Chinese medicinal herbs, exhibits potent anti-inflammatory and antioxidant properties. This study aimed to investigate whether HYP mitigates secondary injury and promote functional recovery after SCI. We evaluated neuroinflammation and oxidative stress using western blot (WB), immunofluorescence staining, and quantitative real-time PCR in both in vitro and in vivo models. SCI mice were treated with HYP (10 mg/kg or 50 mg/kg) via intraperitoneal injection. Functional recovery was assessed using the Basso Mouse Scale score and swimming tests. Histopathological changes were examined through Hematoxylin and Eosin, Nissl, and Luxol Fast Blue staining. HYP treatment significantly reduced the expression of pro-inflammatory mediators (IL-1β, IL-6, TNF-α, iNOS, and COX-2) and oxidative stress-related markers (NOX1, NOX2, and NOX4). Furthermore, HYP enhanced the activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway and upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in LPS-insulted macrophages. Administration of HYP attenuated tissue damage, reduced demyelination, preserved neuronal structure, and promoted functional recovery following SCI. In vitro, these protective effects were mediated through the suppression of macrophage-driven neuroinflammation and oxidative stress via activation of the PI3K/ AKT and Nrf2/HO-1 signaling pathways. In conclusion, our findings demonstrate that HYP confers neuroprotection by alleviating neural tissue damage and facilitating locomotor recovery after SCI, highlighting its potential as a therapeutic agent for SCI treatment.