Immunostimulatory property of Goldenrod extracts to control intracelluar growth of Francisella tularensis during in vitro infection

Abstract

Francisella tularensis causes a disease called tularemia. Moreover, due to the highly infectious nature of F. tularensis, this organism can be used in bioterrorism. Therefore, to combat this threat, the necessity for novel treatments is highly desired.  F. tularensis replicates in macrophages (phagocytic cells of the immune system derived from monocytes) during infection. We identified that Nevada Goldenrod extract (Salidago spectabilis) inhibited the intracellular replication of F. tularensis, but did not alter bacterial growth in culture, suggesting that this plant had immuno-stimulatory properties. To see if a Goldenrod species indigenous to West Virginia (S. canadensis) recapitulated the previous results, extracts of various plant parts of S. Canadensis were obtained.  Current investigations involve utilizing these extracts were subsequently to treat THP-1 cells (a human monocyte line) infected with F. tularensis.