RESUMO
Dried aceton-chloroform extract of aerial parts of Euphorbia spinidens Bornm. ex Prokh. endemic to Iran, yielded two new triterpenoids, lup-20(29)-ene-33, 28 diol commonly known as betulin and (3ß,23E)-Cycloarta-23-ene-3,25-diol. The structures of the isolated compounds were elucidated by 13C- and 1H-NMR as well as 2D-NMR, IR and by the aid of mass fragmentation pattern. In phagocyte chemiluminescence assay, different concentrations of compounds were incubated with the human whole blood in triplicate and the chemiluminescence activity of phagocytic cells were measured by using serum opsonized zymosan and luminol. For lymphocyte proliferation assay, peripheral human blood lymphocytes were incubated with different concentrations of the test compound in supplemented Roswell Park Memorial Institute (RPMI) 1640 medium along with 5.0 µg/ml phytohemagglutinin (PHA) at 37°C in CO2 environment for 72 h and proliferation level was determined by Beta-scintillation counter. In phagocyte chemiluminescence assay, betulin showed moderate inhibitory effect on the oxidative burst in the neutrophils, while addition of betulin triterpene was able to stimulate the proliferation of the phytohemagglutinin (PHA) treated human peripheral blood lymphocytes (hPBLs).
RESUMO
The cytotoxic chloroform fraction of Euphorbia aellenii Rech. F. (Euphorbiaceae) afforded two new phorbol diterpenoids: 4-deoxy-4α-phorbol-12-(2,3-dimethyl) butyrate-13-isobutyrate and 17-hydroxy-4-deoxy-4α-phorbol-12-(2,3-dimethyl) butyrate-13-isobutyrate. Their structures were elucidated by NMR and other spectroscopic methods. The immunomodulating potentials of the isolated compounds were tested using standard proliferation and chemiluminescence assays. Compound 2 showed moderate inhibitory activity against both T-cell proliferation and reactive oxygen species (ROS) production in whole blood with IC50 of 14.0 ± 0.57 and 44.1 ± 3.8 µg/ml, respectively, while compound 1 was relatively inactive with IC50 >50 µg/mL for T-cell proliferation, and >100 µg/mL for ROS.
