In recent years, literature shows that proteases have the potential to induce inflammation through activation of protease-activated receptors (PAR) [1]. Besides secondary plant constituents like phenols, di-, and polyterpenes, proteases are abundant in latices from plants of Euphorbiaceae Juss. [2,3]. It is known, that these latices induce strong skin inflammation. Therefore, we investigated the plant latex from Euphorbia mauritanica L. (Euphorbiaceae). Human skin is the first barrier of the body in defense from environmental influences and the inflammatory response is an important tool against pathogens. In our study, we are focused on the combination of diterpenes with proteases regarding its inflammatory potential on human skin. Therefore, Mauritanicain, a serine protease from E. mauritanica, was isolated by ion exchange and size exclusion chromatography and characterized by MALDI-TOF-MS/MS. We used HaCaT cell line and primary human dermal fibroblasts as monocultures, as well as human skin model. The skin model was composed by primary keratinocytes and fibroblasts. Mauritanicain and PMA were incubated in different concentrations, depending on the cell system. 48 hours after removing the stimulating substances, medium was removed and investigated regarding IL1-ß and IL-8 by FACS and ELISA. When the experiment was finished, HE-staining of the skin model was performed. The occurrence of PAR2 was visualized by immunofluorescence staining and PCR. The results showed that Mauritanicain and the combination with PMA is able to induce skin inflammatory response.
[1] Guenther F, Melzig MF. Protease-activated receptors and their biological role - focused on skin inflammation.; J Pharm Pharmacol 2015; 67: 1623-1633
[2] Sytwala S, Guenther F, Melzig MF. Lysozyme- and chitinase activity in latex bearing plants of genus Euphorbia – A contribution to plant defense mechanism. Plant Physiology and Biochemistry 2015; 95: 35-40
[3] Vasas A, Hohmann J. Euphorbia diterpenes: isolation, structure, biological activity, and synthesis (2008-2012). Chem Rev 2014; 114: 8579-8612