[The Hematopoietic Protective Effect of PDGF-BB on Radiation-Induced Myelosuppression Model Mice].

OBJECTIVE: To investigate the hematopoietic protective effect of platelet-derived growth factor (PDGF)-BB on radiation-induced myelosuppression model mice and effect of anti-apoptosis of megakaryocyte line Meg-01 cells, and its possible mechanism. METHODS: Mice were radiated with 4 Gy of 137Csγ ray to establish the model of myelosuppression. Mice were weighed and peripheral blood cell were counted before radiation (day 0) and day 7, 14 and 21 after radiation. On the 21 st day, the mice were killed. The sternal tissues of the mice were taken for morphological observation, and the femoral bone marrow cells were cultured for the assay of colony cell forming units (CFU). Meg-01 cells were cultured without FBS for 24 h to induce apoptosis, and then treated with PDGF-BB for 48 h. The effects of PDGF-BB on the proliferation were investigated by cell counting. Flow cytometry was used to detect early apoptosis (Annexin V), mitochondrial membrane potential (JC-1) and the expression of caspase-3. RESULTS: Peripheral blood cell counts of mice showed that PDGF-BB stimulated the recovery of white blood cells, red blood cells and platelets after radiation (P<0.05), especially for white blood cells. Morphological examination showed bone marrow hyperplasia in PDGF-BB group, the numbers of megakaryocytes and their progenitor cells were higher than those in the control group. PDGF-BB significantly stimulated the formation of CFU-MK, CFU-GM, BFU-E and CFU-F. PDGF-BB showed a strong proliferation effect in the concentration range of 5-50 ng/ml (P<0.001). PDGF-BB (50 ng/ml) significantly reduced the positive expression of Annexin V (P<0.01). The mitochondrial membrane potential in the control group was decreased when compared with PDGF-BB group, which indicated that the number of apoptotic cells was increased (P<0.01). Besides, the expression of caspase-3 in PDGF-BB group was significantly lower than that in control group (P<0.05). CONCLUSION: PDGF-BB has a protective effect on the hematopoietic system of myelosuppression model mice, especially megakaryocytes and their progenitor cells. PDGF-BB has pro-proliferative and anti-apoptotic effects on Meg-01 cells, and the mechanism may be mediated through JC-1 and caspase-3 pathway.

Tabernaesines A-I, Cytotoxic Aspidosperma-Aspidosperma-Type Bisindole Alkaloids from Tabernaemontana pachysiphon.

Twenty-one aspidosperma-aspidosperma alkaloids, including the new tabernaesines A-J (1-9), were obtained from Tabernaemontana pachysiphon. The structures and absolute configurations were elucidated using HRMS and NMR experiments. Compounds 1-9 possessed a rare spiro heterocycle moiety between the monomeric units, while compounds 4 and 5 were characterized by an indole ring fused with an (N,N-diethyl)methyl amino group. Compounds 1, 5-7, 15, and 16 exhibited moderate cytotoxic potency against various human cancer cell lines at IC50 2.5-9.8 µM.

Two New C21 Steroidal Glycosides from the Roots of Cynanchum paniculatum.

Two new C21 steroidal glycosides, paniculatumosides H and I, together with four known ones were isolated from the roots of Cynanchum paniculatum (Bge.) Kitag. Their structures were identified by spectroscopic methods including extensive 1D and 2D NMR techniques. All compounds were subjected to detect the anti-tobacco mosaic virus (TMV) activities and their cytotoxities against three human tumor cell lines (SMMC-7721, MDA-MB-231 and A549). The results showed that compounds 1 and 5 exhibited potent protective activities against TMV, while 2, 4 and 6 had moderate effects on the SMMC-7721 cancer cells viability.

Cytotoxic indole alkaloids from Melodinus khasianus and Melodinus tenuicaudatus.

Four new indole alkaloids, melodinusines A-D (1, 2, 6, and 7), along with 26 known indole alkaloids, were isolated from Melodinus tenuicaudatus and Melodinus khasianus (Melodinus genus). Among them, 1 and 2 are aspidospermine-aspidospermine-type bisindole alkaloids while 7 is a novel melodinus-type alkaloid. Their structures were established on the basis of comprehensive spectroscopic data analysis and the structure of 7 was further confirmed by single-crystal X-ray diffraction analysis. Their cytotoxic activities against five human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW480 were also evaluated.