Effects of quercetin on glial scar formation and axonal regeneration after acute spinal cord injury in rats and its association with p38 mitogen activated protein kinase signal pathway

Abstract

Objective To investigate the effects of quercetin on glial scar formation and axonal regeneration after spinal cord injury (SCI) and its association with the p38 mitogen activated protein kinase (MAPK) signal pathway. Methods 128 female Sprague-Dawley (SD) rats were randomly divided into a control group (SCI + saline), an intervention group (SCI + quercetin + anisomycin), a treatment group (SCI + quercetin) and a sham-operation group (n=32). Basso Beattie Bresnahan (BBB) assessment and footprint analysis of the hind limb were performed on days 1, 3, 7, 14, 21 and 28 postoperation in each group. The expression levels of p38MAPK, phosphorylation p38MAPK, glial fibrillary acidic protein (GFAP) and neurofilament protein-200 (NF-200) were detected by Western blot. The numbers of GFAP and NF-200 positive staining cells in the injured spinal cord in each group were detected by immunohisto-chemistry. Results The BBB scores in the treatment group were significantly higher than in the inter-vention and control groups at each time point after SCI except on day 3 postoperation (P 0.05). The numbers of NF-200 and GFAP positive staining cells were significantly greater than in the sham-operation group at each time point postoperation (P< 0.05); the NF-200 positive staining cells in the treatment group were significantly increased in comparison with the control and intervention groups (P< 0.05); the GFAP positive staining cells in the treatment group were significantly fewer than in the control and intervention groups on days 7, 14 and 28 postoperation (P< 0.05). Conclusions Quercetin may have protective effects against acute SCI by decreasing glial scar formation, increasing axonal regeneration and promoting recovery of locomotor and nerve function in rats. The effects may be correlated with inhibition of the p38MAPK signal pathway. Key words: Spinal cord injury; Quercetin; Glial fibrillary acidic protein; neurofilament protein-200; p38 mitogen activated protein kinase