Downregulation of IL-17 and IFN-gamma in the optic nerve by beta-elemene in experimental autoimmune encephalomyelitis.

BACKGROUND

beta-elemene is a natural antitumor plant drug. Beneficial effects of beta-elemene therapy have been demonstrated in some kinds of tumor clinically. Especially, it has been found to pass through the blood brain barrier easily. Other reports have indicated that immune disorder that appeared in some tumors usually can be seen in demyelinating diseases including multiple sclerosis and experimental autoimmune encephalomyelitis. However, no information regarding the effects of beta-elemene therapy on the T helper cell subsets, Th1 or Th17 cells in experimental autoimmune encephalomyelitis has been found.

RESULTS

We first determined morphologically that beta-elemene therapy markedly suppressed the inflammation in experimental autoimmune encephalomyelitis optic nerve. We then determined the effect in vivo of beta-elemene on Treg cells and Th17 and Th1 cells. We found that beta-elemene treatment modulated immune balance in both the periphery and the inflamed optic nerve by promoting less downregulation in Treg cells, inhibiting Th17 and Th1 polarization.

CONCLUSIONS

Taken together, our finding reveals an important new locus where beta-elemene induces substantial protection in experimental autoimmune encephalomyelitis optic nerve through signaling to several critical subsets of immune cells that reside in the peripheral and central nervous system.