Oral Administration of α-Asarone Promotes Functional Recovery in Rats With Spinal Cord Injury

• Main Authors: Min-Jae Jo, Hemant Kumar, Hari P. Joshi, Hyemin Choi, Wan-Kyu Ko, J. M. Kim, Sean S. S. Hwang, Song Y. Park, Seil Sohn, Alvin B. Bello, Kyoung-Tae Kim, Soo-Hong Lee, Xiang Zeng, Inbo Han
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2018-05-01
• Series: Frontiers in Pharmacology
• Subjects: spinal cord injury; α-asarone; neuroprotection; anti-inflammation; M2 polarization
• Online Access: https://www.frontiersin.org/article/10.3389/fphar.2018.00445/full

α-asarone, a bioactive compound found in Acorus plant species, has been shown to exhibit neuroprotective, anti-oxidative, anti-inflammatory, and cognitive-enhancing effects. However, the effects of α-asarone on spinal cord injury (SCI) have not yet been elucidated. The present study investigated the effects of α-asarone on the mRNA of pro-inflammatory cytokines, macrophage polarization toward an anti-inflammatory M2 phenotype, and angiogenesis in rats with compressive SCI. α-Asarone was orally administered (10 mg/kg) once per day for 14 days following moderate static compression SCI. Compared to controls, α-asarone treatment significantly improved locomotor score, prevented neuroinflammation, and facilitated angiogenesis in the spinal cord at 14 days after SCI. Furthermore, α-asarone significantly reduced the TNF-α, IL-1β, IL-6, monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 2 (MIP-2), and inducible nitric oxide synthase (iNOS) levels but increased the IL-4, IL-10, and arginase 1 levels at 24 h after SCI. At 7 and 14 days after SCI, immunohistochemistry showed reduced reactive gliosis and neuroinflammation and an increased expression of M2 macrophage markers and angiogenesis. The results suggest that the inhibition of pro-inflammatory cytokines, macrophage polarization toward an anti-inflammatory M2 phenotype, and angiogenesis by α-asarone may be some of the mechanisms underlying the α-asarone-mediated neuroprotective effects on an injured spinal cord.