Protective effect of genistein on hypoxic injuries of osteoblasts cultivated in vitro / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effect of genistein on osteoblast proliferation, cellular cycle, apoptosis and differentiation of osteoblasts cultivated under hypoxia conditions.</p><p><b>METHOD</b>Rat osteoblasts were isolated from calvarias by enzyme digestion and a hypoxic model was established by in a triple-gas incubator. Rat osteoblasts were grouped into the normoxic control group, the hypoxia control group and the hypoxia administration group which was subdivided into Ge-6 group, Ge-5 group and Ge-4 group, to which genistein was administered at doses of 1 x 10(-6), 1 x 10(-5), 1 x 10(-4) mol x L(-1). The cell survival rate, lactic dehydrogenase leakage rate, apoptosis and differentiation of osteoblasts were observed for each group at 3 h after hypoxia, and the gene expression of HIF-1alpha, Bcl-2, Caspase-3 was detected by Real time RT-PCR. Forty-eight hours after hypoxia, osteogenic differentiation markers including alkaline phosphatase activity and nodules were detected.</p><p><b>RESULT</b>Compared with the hypoxia control group, the hypoxia administration group displays a significant increase in the survival rate and a decreased in LDH leakage rate, apoptosis rate and percentage of S + G2 phases. Besides, the mRNA level of HIF-1alpha and Bcl-2 were enhanced, the mRNA level of Caspase-3 was inhibited.</p><p><b>CONCLUSION</b>Genistein has an effect on protecting osteoblasts from hypoxia.</p>

Study on estrogenic effect of genistein and apigenin in vitro / 中国中药杂志

<p><b>OBJECTIVE</b>To detect the estrogenic activity of genistein and apigenin with ER-positive cell line MCF-7 human breast cancer cells.</p><p><b>METHOD</b>MTT method was adopted to study the impact of genistein and apigenin on MCF-7 proliferation in vitro. Real-time RT-PCR method was used to detect their impact on ERalpha, ERbeta, PR and PS2 mRNA expression levels.</p><p><b>RESULT</b>Genistein and apigenin promoted the proliferation of MCF-7. Genistein 1 x 10(-10) mol x L(-1) group showed a significant increase in the expression of ERa mRNA levels or a 17. 76 times more than the control group and a 1.75 times more than the E2 group. Apigenin notably promoted the PR mRNA expression or a 4. 57 times more than the control group and a 1.11 times more than the E2 group. Both of them had different effect in promoting ERalpha, ERbeta, PR or PS2 mRNA.</p><p><b>CONCLUSION</b>Both genistein and apigenin have a strong estrogen-like effect. Although they have different effect in promoting estrogenic response genes (such as ERa, ERbeta, PR and PS2 mRNA), genistein shows a stronger activity than apigenin. It also suggests that the signaling pathways of phytoestrogens showing estrogen-like effect are not completely identical with estrogen pathways. The B-cycle position of flavonoids is one of the key sites to estrogen-like activity, and isoflavones (cycle B on site 3) show stronger estrogen-like activity than flavones (B-cycle lies in site 2).</p>

Effect of osthol on apoptosis and bone resorption of osteoclasts cultured in vitro / 药学学报

This study is to investigate the effect of osthol on osteoclasts' activity, bone resorption as well as apoptosis in vitro, and explore the mechanism of osthol in preventing osteoporosis. Osteoclasts were separated from long-limb bones of new born rabbits, cultured in 24-well plate with glass slices and bone slices, and treated by 1 x 10(-5) mol x L(-1) osthol. Osteoclasts were identified by observing live cells with phase contrast microscope, HE staining, TRAP staining and toluidine blue staining of bone resorption pits. The numbers of bone resorption pits were counted as well as the surface area of bone resorption on bone slice. Osteoclasts were stained with acridine orange to detect the cell apoptosis. The ratio of apoptotic osteoclasts was observed under fluorescence microscope. The gene expression of RANKL, OPG, TRAP and p-JNK1/2 protein expression were examined using real time PCR and Western blotting, respectively. Comparing with the control group without osthol, the rates of apoptotic osteoclasts increased obviously and the number and area of bone resorption pits decreased evidently with 1 x 10(-5) mol x L(-1) osthol. There is significant difference between control group and experiment group treated by 1 x 10(-5) mol x L(-1) osthol. Therefore, the osthol through RANK+RANKL/TRAF6/Mkk/JNK signal pathway inhibits the osteoclasts activity, enhances osteoclasts apoptotic and inhibits the bone resorption.