Mogroside V Ameliorates Spinal Cord Injury by Inhibiting M1 Microglia Polarization

Spinal cord injury (SCI) constitutes a severe disorder of the central nervous system that is usually caused by external traumatic forces that damage the spinal cord's structure and disrupt its normal functions. SCI is characterized by a high disability rate and limited treatment options. The current treatments include surgery, medication, and rehabilitation. Additionally, some traditional Chinese medicines and their ingredients have shown potential effects in the treatment of SCI. Mogroside-V (Mog-V), derived from Siraitia grosvenorii, displays a range of biological functions, such as anti-inflammatory effects, antitumor actions, and antioxidant potential. However, the effect and fundamental mechanism of Mog-V on SCI remain unclear. In this study, we established a spinal cord contusion model in C57BL/6 mice to evaluate the effects of Mog-V. The results revealed that Mog-V effectively improved lower limb motor function after SCI in mice. Mog-V inhibited pro-inflammatory macrophage/microglia polarization in vivo and reduced the secretion levels of macrophage/microglia-associated pro-inflammatory cytokines, including interleukin (IL)-12, IL-6, IL-1β, and tumor necrosis factor-α (TNF-α). Mog-V effectively inhibited M1 microglial polarization and the release of their associated pro-inflammatory cytokines in vitro. Mog-V also inhibited the phosphorylation of P65, P38, JNK, and ERK proteins in vitro and P38, JNK, and ERK proteins in vivo. Overall, Mog-V may improve SCI by inhibiting M1 microglia/pro-inflammatory macrophage polarization and reducing the release of inflammatory cytokines via the mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways, highlighting the potential use of Mog-V for SCI treatment.