Abstract Formulations containing chitosan incorporated with methanolic fraction of Euphorbia umbellata (Pax) Bruyns, Euphorbiaceae, were studied aiming future applications of this new material as medicine. In order to investigate potential interactions between chitosan and the methanolic fraction (10, 50 and 100% in relation to the amount of chitosan) physicochemical characterization was performed by scanning electron microscopy, density, differential scanning calorimetry, thermogravimetry, X-ray diffraction, Fourier-transform infrared spectroscopy and colorimetry techniques. The phenolic compounds released from the chitosan membranes were evaluated using the Folin-Ciocalteau quantification method; antioxidant and antimicrobial activity were also studied. Increasing amounts of the methanolic fraction added to polymeric matrix produced different numbers of pores on the surface of the membranes, changes in the calorimetric, spectroscopic and crystalline properties as well as color changes, when compared to the inert membrane. These changes can be attributed to chemical interactions that occurred between the structure of the chitosan and the phenolic compounds present in the studied fraction. The matrix samples incorporated with 50 and 100% of the methanolic fraction presented different release profiles of phenolic compounds from the membranes (controlled manner) and promoted antioxidant and antimicrobial activity.

Synadenium grantii Hook f., Euphorbiaceae, is popularly known as leitosinha or janaúba. The diluted latex (18 drops/L of water) is commonly used in the south of Brazil to treat gastric disturbances. This study evaluated phytochemical screening and toxicity using Artemia salina Leach of crude bark extract and also latex. The toxicity and the anti-ulcer activity of S. grantii latex were also tested in rats. Phytochemical results showed presence of tannins, terpenes, unsaponificable substances, coumarins and anthraquinones in the crude bark extract and terpenes in the latex. Gas chromatography-mass spectrometry (GC-MS) analysis demonstrated the presence of diterpene tigliane esters in the latex, identified as 12-deoxyphorbol-13-(2-metilpropionate) and phorbol 12,13,20-triacetate. The toxicity results using A. salina presented CL50 26.58μg/mL and CL50 778.66μg/mL, for the latex and the crude bark extract respectively. The toxicological hepatic parameters of the diluted latex were not different to the control group (p<0.05). The eosinophils cells showed an increase in both the diluted and pure latex groups. The pure latex showed gastric protection of 90% (p<0.05) and the diluted latex showed 6% compared to the negative control. Therefore, our data indicate that S. grantii latex, under research conditions presented gastric protection. Pure latex showed more toxicity than the diluted latex.