Neuroprotective effects of safranal in a rat model of traumatic injury to the spinal cord by anti-apoptotic, anti-inflammatory and edema-attenuating.

Abstract

Studies on the pathology of spinal cord injury (SCI) have focused on inflammation-associated neuronal apoptosis. The traditional Chinese medicine safranal has been studied extensively and found to have various beneficial health effects. However, study of its potential role in neuroprotection and the underlying mechanism of action in SCI models has been limited. We investigated the effect of safranal on neurologic functions and histopathologic changes after SCI and the mechanism underlying its neuroprotective effects. First, the most effective safranal dose for SCI was evaluated with the Basso, Beattie, and Bresnahan Locomotor Rating Scale and H&E staining: 100mg/kg was the most effective dose of safranal for SCI. Histopathologic changes were evaluated by performing Nissl staining, which indicated an increased number of neurons after safranal administration. In terms of the mechanism of action, anti-apoptotic effect, downregulation of inflammation, and edema-attenuating effects were detected. TUNEL staining and electron microscopy revealed that safranal treatment inhibited injury-induced apoptosis, and affected the expression of the apoptosis-related genes Bax and Bcl-2, which indicated an anti-apoptotic role after SCI. Safranal treatment suppressed immunoreactivity and expression of the inflammatory cytokines IL-1β, TNF-α, and p38 MAPK, and increased expression of IL-10 after SCI, suggesting an anti-inflammatory effect. Safranal treatment suppressed expression of AQP-4, which is related to spinal-cord edema, suggesting an edema-attenuating effect. These data suggest that safranal promotes the recovery of neuronal function after SCI in rats, and that this effect is related to its anti-apoptotic, anti-inflammatory, and edema-attenuating effects.