Our results have demonstrated that the combination of MO extract administration and hUCBSCs transplantation prevented cell loss and enhanced myelination. A possible explanation to this is that, the transplantation of hUCBSCs can increase the length of neurofilament-positive fibers and increase the numbers of growth cone-like structures at the lesion site. Grafted hUCBSCs can survive, move over short distances, and produce large amounts of glial cell line-derived neurotrophic factors and neurotrophin-3 (NT3) in the host spinal cord (Rodrigues et al., 2012). It has also been confirmed that the hUCBSCs can form morphologically myelin sheaths in the spinal cord. It has been revealed that oligodendrocytes derived from human umbilical cord blood secrete NT3 and brain-derived neurotrophic factor. Cord blood stem cells promote the synthesis of MBP and proteolipid protein in the injured areas, thereby facilitating the process of remyelination (Dasari et al., 2009). Conversely, a large number of experimental evidences support oxidative stress as important mediators of secondary cell death after SCI (Cuzzocrea and Genovese, 2008; Jia et al., 2012; Fatima et al., 2015). It has been shown that administration of MO extract has powerful antioxidant effects which are probably exerted through the rosmarinic acid and the benzodioxole present in the extract. Moreover, compounds such as linoleic acid, carnosic acid, and ursolic acid are also present in the extracts, all of which have antioxidant properties.