Rehmannioside A is a neuroprotective agent that can be isolated from Rehmanniae radix. Rehmannioside A can inhibit the release of proinflammatory mediators from microglia and promote M2 polarization in vitro, thereby protecting co-cultured neurons from apoptosis by inhibiting NF-κB and MAPK signaling pathways. Rehmannioside A can be used in spinal cord injury research.