Hesperidin improves motor and sensory recovery and modulates the balance of pro- and anti-inflammatory cytokine profiles after contusive spinal cord injury in mice

Abstract: Background: Hesperidin (HES) has anti-inflammatory and antioxidant properties, but coordinated in vivo evidence linking HES to functional recovery, cytokine rebalancing, microglial activation and MAPK signaling after contusive spinal cord injury (SCI) remains limited. Objectives: To evaluate whether HES improves motor and sensory function after SCI and to characterize associated changes in the spinal inflammatory microenvironment, oxidative stress and ERK/JNK-MAPK signaling. Methods: SCI was induced by a modified Allen weight-drop contusion at T10 in 100 C57BL/6 mice randomly assigned to sham, SCI, or HES low-, medium- and high-dose groups (25, 50 and 100 mg/kg; n = 20 each). HES was administered by gavage once daily for 21 days beginning 2 h after injury. Motor and sensory outcomes were assessed by BMS scoring and mechanical and thermal tests; spinal cord cytokines, redox indices and neurorepair-related factors were measured by ELISA/biochemical assays, microglial activation by Iba1 immunohistochemistry and MAPK phosphorylation by western blotting. Results: On day 21, significant functional improvement was observed in the 100 mg/kg group (p < 0.05), whereas lower doses showed non-significant trends. In day-7 spinal cord tissue, HES reduced pro-inflammatory cytokines and increased anti-inflammatory cytokines; TNF-α decreased from 218.17 ± 28.11 to 54.39 ± 11.37 pg/mg in the high-dose group (p < 0.05). MDA levels were lower, whereas SOD, GSH-Px and CAT activities and T-AOC were higher than in the SCI group (p <0.05). HES also reduced Iba1-positive microglia and ERK1/2 and JNK phosphorylation without altering total ERK1/2 or JNK levels. Conclusion: HES was associated with improved motor and sensory recovery, a less inflammatory cytokine profile, attenuated oxidative stress and microglial activation and reduced ERK/JNK phosphorylation after contusive SCI; pathway-specific experiments remain necessary to establish causality.