SAB And SGB Anti-cancer Acitivity And Mechanism In Inducing Cell Apoptosis

Betulin, as a pentacyclic triterpene with a variety of pharmacological activity and widely exist in nature. Today many of the drugs used to treat cancer side effects on the human body. Betulin and its derivatives is far superior to other chemical substances in terms of dose-liniting, its low tosicity, targeting strong. To betulin derivatives anticancer lineage, the improvement of the design and structure of the drug molecule has more accurate information available. In the present study, we analyzed mechanism of the Tert-butyl ester of3,28-di-o-succinyl-alanylamino-betulin(SAB) and tert-butyl ester of3,28-di-o-succinyl-glycylamino-betulin(SGB) two betulin decivatives induce tumor cell apoptosis. The results were as follows:1.Determinde by MTT assay SAB and SGB human tumor cell growth and impact were detected HepG-2(liver cells),MCF-7(breast cancer cells),A549(lung cancer cells),PC-3(pancreatic cancer cells),SMMC7721(liver cells)and SK(cervical cancer cells).The results showed that the drug has a certain growth inhibitory effect on a variety of cells,HepG-2(liver cells) the inhibitory effect is most obvious,and the IC5o values for the SAG:15.33±0.71μM,SBG:17.01±0.94μM.2. Morphological characteristics of HepG-2cells detected by laser scanning confocal microscope (LSCM). Treated with SAB and SGB after48h can be found in the cell size smaller, nucleus shrinkage and marginalized chromatin condensation and apoptotic bodies. Compared with the negative control, a significant difference tu the uniformity of the nuclear staining.3. Mitochondrial membrane potential (△ψm) using flow cytometry HepG-2cells, and the level of reactive oxygen species (ROS).The results showed: Rh123staining, flow cytometry as SAB and SGB concentration increased HepG-2cells induced mitochondrial membrane potential (△ψm).Fluorescent probe DCFH-DA notation, flow cytometry HepG-2cells reactive oxygen species (ROS) increased with the the SAB and SGB concentration increase, which elevated test results ROS.4. To adopt AnnexinV-FITC/PI double staining flow cytometry to detect the the SAB and SGB induction HepG-2cell apoptosis percentage change processing in different concentrations of SAB and SGB soon HepG-2cells48h cause of its occurrence withereddeath, and as the concentration increased apoptotic cell.5.The HepG-2cycle distribution and apoptosis were analyzed by flow cytometry the cell cycle distribuition did not change singnificantly.6. SAB and SGB can induce apoptosis, agarose gel electrophoresis obvious apoptosis most typical feature of stepped apoptotic DNA Ladder.7. Clear SAB and SGB HepG-2cells apoptosis induced by mitochondrial signaling pathway.Western blot analysis of Bax protein expression, SAB and SGB down the expression of Bcl-2protein, the activation of caspase-9and caspase-3, active-caspase-3Cut the PARP, and then induced HepG-2cell apoptosis.In summary, SAB and SGB had a significant cytotoxic effect and was able to inhibit proliferation and induce apoptosis in HepG-2cells. The mechanism of apoptosis induced by SAB and SGB may be related to the activation of mitochondrial apoptotic pathway and alteration of apoptotic protein expression. SAB and SGB newly synthesized betulin derivatives, and so provide a better value for the study of new special effects of anticancer drugs.