Abstract:The plants of the Euphorbiaceae family, especially those of the genus Euphorbia, are frequently used by Brazilian folk communities to treat a wide variety of infectious, tumoral and infl ammatory illnesses. Among the species of this genus, Euphorbia tirucalli L. is widely used in some Brazilian regions, such as the Jequitinhonha River Valley. There is evidence that the latex produced by E. tirucalli has antiviral and antitumor activities, but little is known about the mechanisms involved in these effects. It is likely that the mechanism for such activities involves leukocyte activation and cytokine production. In this work, we aimed to evaluate the production of type 1 (TNF-α and IFN-γ) and type 2 (IL-4 and IL-10) cytokines by circulating leukocyte subsets submitted to brief stimulation with the crude latex of E. tirucalli. Peripheral blood leukocytes of twenty healthy subjects were submitted to 4 h incubation with crude E. tirucalli latex diluted in dimethylsulfoxide. After the incubation period, the cells were stained with FITC-conjugated monoclonal antibodies specifi c to the cell surface receptors CD4, CD8 and CD14, and to PE-conjugated monoclonal antibodies specifi c to the cytokines TNF-α, IFN-γ, IL-4 and IL-10. The acquisition and analysis of data were performed by fl ow cytometry. The results showed a signifi cant increase (p<0.05) in the percentage of CD4 + T lymphocytes positive for the type 1 cytokines TNF-α and IFN-γ. Neutrophils and CD8 + T lymphocytes showed a mixed profi le of cytokine production, characterized by an increase in the percentage of cells expressing IFN-γ, TNF-α, and IL-10. The data indicate a predominant type 1 cytokine response. The fi ndings presented suggest that the effect popularly attributed to E. tirucalli usage may be attributed to its effect on the production of TNF-α and IFN-γ. However, the relationship between the in vitro and in vivo effects of E. tirucalli needs to be investigated.

Background: The aim of the present study was to determine the action of crude latex from Euphorbia tirucalli dissolved in DMSO in animal models of DMBA-induced carcinogenesis. Methods: Three groups of hamsters received a topical application on edge of the tongue: 1) 0.5% DMBA+crude latex from E. tirucalli in 10% DMSO; 2) 0.5% DMBA+10% DMSO; and 3) 0.5% DMBA+saline solution. Macroscopic and histopathological analyses of the tumors were performed and antibodies were quantified using ELISA after 13 and 20 weeks of treatment. Results: No statistically significant association was found between the development of cancer of the tongue mucosa and the production of antibodies in the different groups. Conclusions: Although the data were non-significant, crude latex from E. tirucalli seems to reduce the aggressiveness and size of lesions, but further tests are required.