Augmentation of lymphocytes activation and T cell modulation by the extracts from some Euphorbia species

Abstract

Context: Euphorbia is an important Euphorbiaceae genus that is traditionally being used for various infections, inflammation, and cancer. Objective: The present study investigated the possible in vitro immunomodulatory effect of three species of Euphorbia genus including Euphorbia microciadia Boiss, Euphorbia osyridea Boiss, and Euphorbia heteradenia Jaub. & Sp. on lymphocyte activation and cytokine secretion. Materials and methods: Human lymphocytes were cultured in the presence of various concentrations (0.1-200g/ml) of the butanol/hexane extracts of the plants in the presence or absence of phytohemmagglutinin (PHA). The activation of lymphocytes after 48h was determined by a proliferation assay. The release of T cell cytokines was studied to determine the dominant T cell subsets involved in the immune response. Results: All three plant extracts increased the proliferation of PHA-treated lymphocytes (maximum; 132% of control). Extract treatment of lymphocytes in the absence of PHA resulted in an increased proliferation of the cells indicating their lymphocyte mitogenic activity (maximum at 10g/ml E. microciadia extract; 494.5±42.2% of control, p<0.01). The extracts of E. microciadia and E. osyridea could increase IL-4 and IL-10 secretion but not IFN-γ production showing their capacity to deviate immune response toward a Th2 pattern. Euphorbia heteradenia did not change the release of IL-4 and IFN-γ cytokines but increased IL-10 production. The three extracts stimulated lymphocytes to produce IL-17 which showed their possible effects on Th17 cells activation. Conclusion: The studied extracts had the ability to modulate T cell responses suggesting their possible beneficial effects on immune host defense.