Thäle C, Kiderlen AF, Kolodziej H (2008): Anti-infective mode of action of EPs®7630 at the molecular level
Planta Med. 74: 675-681. eFirst original paper.  DOI:10.1055/s.2008.1034324.

Clinical trials have shown that EPs® 7630, an aqueous ethanolic extract from the roots of Pelargonium sidoides, is an efficacious treatment for respiratory tract infections. A large body of in vitro studies has provided evidence for an anti-infective principle associated with activation of the non-specific immune system. However, the mode of action at the cellular and molecular level is still insufficiently defined. This study, therefore, aimed to provide further insight into the underlying principles of the therapeutic benefit of EPs® 7630 under these conditions. Using murine bone marrow-derived macrophages (BMMΦ) experimentally infected with facultative intracellular bacteria, Listeria monocytogenes, incubation with EPs® 7630 (1 – 30 µg/mL) increased release of NO, production of membrane bound/intra- and extracellular IL-1, IL-12 and TNF-α, and changed the expression of the surface markers CD40 and CD119 at an early time point post infection (6h) in a concentration-dependent manner in most experiments. These effects of EPs® 7630 were more pronounced in infected compared with non-infected BMMΦ cultures. LPS + IFN-γ served as positive, untreated cells as negative controls. Analyses were carried out at single cell levels using flow-cytometry, while ELISA was additionally utilized for monitoring secreted cytokines. Although the current data provide additional valuable information for understanding the anti-infective effects of EPs® 7630, the triggered signalling pathways associated with the immune responses appear even more complex than anticipated and are evidently not shared by "classical" immunomodulators to this extent.