In vitro immunomodulatory properties of a sesquiterpene lactone-bearing fraction from Artemisia khorassanica.

Artemisia species are important medicinal plants throughout the world. The present in vitro study, using a sesquiterpene lactone-bearing fraction prepared from Artemisia khorassanica (SLAK), sought to investigate immunomodulatory/anti-inflammatory properties of this plant and elucidate potential underlying mechanisms for the actions. Effects of the SLAK on mitogen-induced murine splenocyte proliferation and interleukin (IL)-4 and interferon (IFN)-γ secretion were evaluated. To assess anti-inflammatory activities, levels of inducible of nitric oxide (NO) and prostaglandin E2 (PGE2), as well as expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in peritoneal macrophages was examined. The results showed that SLAK noticeably was capable of suppressing PHA/LPS-stimulated splenocyte proliferation and of up-regulating production of the T-helper (TH)-2 cell cytokine IL-4 while down-regulating formation of TH1 IFNγ. In addition, while SLAK caused negligible proliferation inhibition, peritoneal macrophages displayed considerable decrease in NO and PGE2 production along with iNOS and COX-2 expression. The current experiment shows Artemisia khorasanica - a traditionally used herb - may have immunomodulatory and anti-inflammatory effects. It is anticipated that the ingredients may be employed as therapeutic candidates in the regulation of some immune responses implicated in various conditions and ailments.