[Study on the effect of vibsane-type diterpenoids of Viburnum odoratissimum on human HepG2 cell growth and its underlying mechanism].

OBJECTIVE: To study the antiproliferation effect on HepG2 cells and its underlying mechanism of the active chemical composition of the Viburnum Odoratissimum. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and trypan blue dye exclusion assay were used to assess the effect of vibsane-type diterpenoids on the proliferation of various tumor cells. Alterations in cell cycle and apoptosis were determined by flowcytometry. The enzymatic activity of caspase-3/7 was measured by Apo-ONE homogeneous Caspase-3/7 Assay kit. RESULTS: Compound 1 #, a vibsane-type diterpenoid, was found to significantly inhibit the growth of HepG2 cells by anticancer proliferation activity screening. It was demonstrated that the modified groups on side chain coupled to C11 site affected the cell growth-inhibition activity of compounds by structure-activity analysis. In addition, HepG2 cell line was most sensitive to compound 1 #, which induced growth arrest of HepG2 cells in a dose- and time-dependent manner. Study on the mechanisms underlying these effects indicated that compound 1 # induced significant G0/G1 phase arrest of HepG2 cells in a time- and concentration-dependent manner. Meanwhile, It was found that higher concentrations of compound (5-10 micromol/L) caused evident increase in the unmber of apoptotic cells and dose-dependent activation of caspase-3/7. CONCLUSION: Vibsane-type diterpenoids could significantly inhibit the growth of HCC HepG2 cells. Induction of cell cycle arrest and apoptosis may play important roles in their anticancer effects.

[Protective effects of WR2721 on early bone marrow hematopoietic function in mice exposed to 6.5 Gy of (60)Co γ-rays].

The aim of this study was to investigate the effect of WR2721(amifostine) against bone marrow hematopoietic damage of mice exposed to 6.5 Gy of (60)Co-γ ray. A total of 60 C57/BL6J mice was divided into 3 groups:normal group (mice were injected with physiological salt solution), irradiation group (mice were injected with physiologic salt solution before irradiation) and WR2721 group (mice were injected with WR2721 before irradiation). The WBC, neutrophil (Neut), Plt and RBC levels in peripheral blood of 3 group mice were counted within 60 days after irradiation; the bone marrow nuclear cells (BMNC) were counted at 2 and 24 hours after irradiation; the hematopoietic stem/progenitor cell (LK/LSK) level and colony formation capability were detected by flow cytometry at 2 and 24 hours after irradiation. The results indicated that the counts of WBC and neut at 4 and 18 days, Plt at 7-18 days and RBC at 10-30 day after irradiation in WR2721 group were higher than those in irradiation group (P < 0.05); the BMNC, LSK and LK levels obviously increased at 24 hours after irradiation (P < 0.05), the CFU-GEMM, CFU-GM, CFU-MK BFU-E and CFU-E all significantly increased at 2 and 24 hours after irradiation (P < 0.01), as compared with irradiation group. It is concluded that WR2721 can effectively alleviate early hematopoietic damage and promote the fast recovery of peripheral blood cells in mice exposed to γ-ray, suggesting that the WR2721 has significant radioprotective effect on hematopoietic system.