Synthesis of Novel Pentacyclic Triterpenoid Derivatives that Induce Apoptosis in Cancer Cells through a ROS-dependent, Mitochondrial-Mediated Pathway.

Betulinic acid (BA) and oleanolic acid (OA) are plant-derived conjugates found in various medicinal plants that have emerged as potential antitumor agents. Herein, a series of novel BA and OA derivatives were synthesized by conjugation with per-O-methylated-ß-cyclodextrin (PM-ß-CD), and their anticancer properties against a panel of three human cancer cell lines were evaluated. Two OA-PM-ß-CD conjugates (48 and 50) were observed to be the most potent conjugates against the three cell lines (MCF-7, BGC-823, and HL-60), with a 15- to 20-fold decrease in the IC50 values (IC50: 6.06-8.47 µM) compared with their parental conjugate (OA). Annexin V-FITC/propidium iodide staining and Western blot analysis revealed that both conjugates induced apoptosis in HL-60 cells. Additionally, in the representative conjugate 48-treated HL-60 cells, a decrease in mitochondrial membrane potential and subsequent release of cytochrome c into the cytosol were observed, indicating the activation of the intrinsic apoptosis pathway. Furthermore, 48 dramatically induced the generation of reactive oxygen species (ROS) in HL-60 cells, and the corresponding effect could be reversed using the ROS scavenger N-acetylcysteine. Collectively, these results suggest that the novel pentacyclic triterpenoid derivatives trigger the intrinsic apoptotic pathways via the ROS-mediated activation of caspase-3 signaling, inducing cell death in human cancer cells.

Trantinterol, a novel ß2-adrenoceptor agonist, noncompetitively inhibits P-glycoprotein function in vitro and in vivo.

P-glycoprotein (P-gp)-mediated drug-drug interactions are important factors causing adverse effects of drugs in clinical use. The aim of this study was to determine whether trantinterol (also known as SPFF), a novel ß2-adrenoceptor agonist, was a P-gp inhibitor or substrate. The results showed that trantinterol was not a substrate of P-gp but increased rhodamine 123 (Rho 123) uptake by MDCK-MDR1 cells and decreased the efflux transport of both Rho 123 and cyclosporine A (CsA) in bidirectional transport studies across MDCK-MDR1 cell monolayers. This suggested that trantinterol was a P-gp inhibitor but not a P-gp substrate. The mechanism of inhibition was investigated in the P-gp-Glo assay system, where it was found that trantinterol inhibited P-gp ATPase activity in a dose-dependent manner. A subsequent study using the antibody binding assay with the conformation-sensitive P-gp-specific antibody UIC2 confirmed that trantinterol decreased UIC2 binding at 10 µM in contrast to the competitive inhibitor, verapamil. This suggested that trantinterol was a noncompetitive inhibitor of P-gp. Finally, a pharmacokinetic study in rat showed that trantinterol significantly increased the area under the plasma concentration-time curve (AUC) and maximum plasma concentration (Cmax) of digoxin and paclitaxel (PAC), and the Cmax of cyclosporine A (CsA). In summary, trantinterol is a potent noncompetitive P-gp inhibitor which may increase the bioavailability of other P-gp substrate drugs coadministered with it.

[Sanhuangyinchi decoction pretreatment ameliorates acute hepatic failure in rats by suppressing antioxidant stress and caspase-3 expression].

OBJECTIVE: To observe the effects of Sanhuangyinchi decoction (SHYCD) pretreatment on acute hepatic failure (AHF) induced by D-galactosamine and lipopolysaccharide (LPS) in rats and explore the possible mechanisms involving antioxidant stress and cell apoptosis-related protein expression. METHODS: Forty-eight SD rats were randomized equally into control group, AHF model group, high-, medium- and low-dose SHYCD groups, and Bicyclol group. Five days after administration of the corresponding drugs, the rats were challenged with peritoneal D-galactosamine (700 mg/kg) plus LPS (10 ug/kg) injections to induce AHF acute hepatic failure except for those in the control group. At 48 h after the injections, blood samples were collected from the rats to detect the levels of ALT, AST, TBIL, PT, INR and FIB, and pathological changes and superoxide dismutase (SOD) and malondialdehyde (MDA) contents in the liver were examined; immunohistochemistry and western blotting were used to detect caspase-3 protein expression in the liver. RESULTS: The levels of ALT, AST, TBIL, TP and INR in the 3 SHYCD groups and Bicyclol group significantly decreased (P<0.05) while FIB significantly increased in comparison with those in the model group. SHYCD obviously ameliorated the pathological changes, enhanced SOD activity (P<0.05), and decreased MDA levels (P<0.05) and caspase-3 expression (P<0.05) in the liver tissue. SHYCD at the medium dose produced similar effects to Bicyclol (P>0.05) and showed better effects at the high dose than Bicyclol (P<0.05). CONCLUSION: SHYCD pretreatment can dose-dependently ameliorate AHF in rats possibly by suppressing antioxidant stress and caspase-3 expression to decrease hepatic cell apoptosis.

[Effects of Sanren decoction on Th1/Th2 cytokines in rats with spleen-stomach damp-heat syndrome].

OBJECTIVE: To investigate the effects of Sanren decoction on the immune function of rats with spleen-stomach damp-heat (DHSS) syndrome. METHODS: Fifty male SD rats were randomly allocated into normal control group, DHSS model group, and 3 Sanren decoction groups (high, medium and low doses). The effects of the decoction on the body mass, rectal temperature (RT), water and food intake, histopathological changes of the gastrointestinal mucosa and serum levels of interleukin (IL)-4 and interferon (IFN)-γ were evaluated. RESULTS: The serum levels of IFN-γ and IL-4 in the model group significantly increased compared with those in the control group (P<0.01), with a slightly increased IFN-γ/IL-4 ratio (P>0.05). Sanren decoction obviously reduced the rectal temperature and significantly decreased the production of both cytokines. High-dose Sanren decoction caused more markedly decreased IL-4 level (P<0.05) to result in a significantly increased IFN-γ/IL-4 ratio (P<0.05). CONCLUSIONS: A shift of Th1/Th2 balance toward Th1 immune response is demonstrated in rats with DHSS syndrome, and Sanren decoction produces a protective effect on the gastrointestinal mucosa by immunoregulation.