Curcumin Promotes The Recovery Of Motor Function After Brachial Plexus Root Avulsion In Rats

[Objective]The aim of this study is to establish a rat model of brachial plexus root avulsion(Brachial Plexus Root Avulsion,BPRA)to study the effect of curcumin(CUR)on the recovery of motor function after BPRA.[Methods]1.Adult male SD rats(weight 200-220 g)suffered from the avulsionof brachial plexus nerve roots(neck 5-neck 7,C5-C7)combined with neck 6(C6)re-implantion surgery were randomly divided into 2groups: PBS group,Curcumin group(CUR group),with 7 rats in each group.2.Terzis grooming test(TGT)was performed to evaluate the recovery of the motor function of the affected limb in rats,muscle weighing was performedto observe muscle atrophy,Hematoxylin-eosin staining(hematoxylin-eosin staining,HE)was performed to observe the pathological changes of rat muscle tissues,Luxol Fast Blue(LFB)staining was performed to observe the morphology of nerve fibers,Quantitative Reverse Transcription PCR(q RT-PCR)was performed to detect the relative expression changes of myelination-related proteins(Hmgcr,and Pou3f1),Western Blot(WB)was performed to detect the changes of growth associated protein-43(GAP-43),neural cell adhesion molecule L1(L1CAM),phosphorylated protein kinase B(p-AKT1)and nuclear factor activated B cell κ-Increased light chain(NF-κB)and phosphorylated P65(p-P65)in the anterior horn of the spinal cord on the injured side of the rats.[Results]1.Compared with the PBS group,rats in the CUR group had significantly higher scores in the Terzis grooming test(TGT),indicating that curcumin can promote the recovery of motor function of the affected limb in BPRA rats.2.Compared with the PBS group,the biceps brachii muscle weight of the CUR group rats was increased significantly,the muscle fiber diameter was increased significantly,and the number of fibroblast nuclei was decreased,indicating that curcumin can improve the muscle atrophy of BPRA rats.3.Compared with the PBS group,the diameter of the musculocutaneous nerve and the number of LFB-labeled axons in musculocutaneous nerve of the affected limb of the CUR group were increased significantly,indicating that curcumin can improve the abnormal morphology of the musculocutaneous nerve in BPRA rats.4.Compared with the PBS group,the relative expression of myelinization-related gene Hmgcr in the musculocutaneous nerve of the affected limb in the CUR group increased,and the relative expression of differentiation-related gene Pou3f1 decreased,indicating that curcumin can promote the myelination of musculocutaneous nerve axons in BPRA rats.5.Compared with the PBS group,the relative m RNA levels of GAP-43,L1 CAM in the musculocutaneous nerve were increased,andthe relative protein levels of GAP-43,L1 CAM,and p-AKT1 in the anterior horn of the spinal cord of the CUR group were increased,indicating that curcumin can promote the survival of motor neurons in BPRA rats.6.Compared with the PBS group,thelevels of NF-κB and p-P65 in the anterior horn of the affected spinal cord of the CUR group were significantly reduced,indicating that curcumin can inhibit the inflammatory response in BPRA rats.[Conclusion]Curcumin can promote the recovery of motor function in BPRA rats,and it may be a potential drug for treatment of BPRA.