Amelioration of experimental autoimmune encephalomyelitis by β-elemene treatment is associated with Th17 and Treg cell balance.

Experimental autoimmune encephalomyelitis (EAE), an animal mode of multiple sclerosis (MS), was previously considered that is mediated by Th1 cells. However, a number of recent studies provided strong evidence that T helper cells that produce interleukin (IL)-17 (Th17) and anti-inflammatory CD4+ Foxp3+ regulatory T cells (Tregs) play a dominant role in the pathogenesis of EAE. β-elemene is a natural antitumor plant drug with the role of multiple target, and it has been found to pass through the blood-brain barrier easily. It also has been strongly implicated as an immune modulatory agent, but the precise mechanisms of its action are largely unknown. In the present study, we mainly investigated the efficacy and mechanism of β-elemene against EAE in vivo and vitro. The treatment of C57 mice with β-elemene significantly delayed the onset of EAE, markedly suppressed MOG-specific T cell proliferation in a dose-dependent manner, dramatically reduced the IL-17, IL-6, IL-23, and RORγt production and induced the Foxp3 expression in both the periphery and the inflamed spinal cord. These findings indicated that β-elemene amelioration EAE was, to a large extent, due to inhibit differentiation and development of Th17 cells depends on down-regulating expression of IL-6, IL-23, RORγt signaling, and promoting expansion in Treg cells. Suggesting it is useful in the control of MS and other Th17 cell-mediated inflammatory diseases.