Neuroprotective effect of apigenin in rats after contusive spinal cord injury

Abstract

Apigenin, a common plant flavonoid, has been extensively studied and showed a wide variety of beneficial effects. The aim of this study was to determine the therapeutic efficacy of starting apigenin treatment 3day after spinal cord injury (SCI) in rat and to investigate the underlying mechanism. SCI was induced using the modified weight-drop method in Sprague-Dawley rats. The SCI animals were randomly assigned to five groups: sham control group, SCI model group, the methylprednisolone sodium succinate (MPSS) group, the 10mg/kg apigenin treatment group and the 20mg/kg apigenin treatment group. First, neuronal function after SCI was evaluated with Basso Beattie Bresnahan locomotor rating scale (BBB) and the result showed that injured animals treated with apigenin showed a significant increase in BBB scores. To explore the underlying mechanism, antioxidative effect of apigenin was assessed by measuring malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities after SCI. Apigenin treatment reversed the decrease of SOD and GSH-Px activity, and the increase of MDA level caused by SCI, suggesting its antioxidative role in response to the injury. In addition, apigenin treatment decreased serum interleukin-1β, tumor necrosis factor-α and intercellular adhesion molecule-1 release after SCI, suggesting an anti-inflammatory effect of apigenin. Finally, apigenin treatment affected the expression level of apoptosis-related gene Bax, Bcl-2 and caspase-3, which indicated its antiapoptosis role after SCI. Our data suggest that apigenin significantly promotes the recovery of rat neuronal function after SCI, which is associated with its antioxidative, anti-inflammatory and antiapoptotic properties.