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>

The changes of iNOS and NO in the osteogenic differentiation process of rat bone marrow stromal cells promoted by icariside II / 药学学报

This study is to investigate the effects on the expression of iNOS and production of NO in the osteogenic differentiation process of rat bone marrow stromal cells (rBMSCs) by icariside II. rBMSCs were cultured by adherence screening method. When the culture dishes were covered with 80% cells, the osteogenic induced cultures were adopted. Icariside II was supplemented into the culture at 1 x 10(-5) mol x L(-1). The activity of iNOS, content of NO and osteogenic differentiation markers including alkaline phosphatase (ALP) activity, CFU-FALP and mineralized bone nodules were compared among the icariside II-supplemented group, L-NMAE group, icariside II + L-NAME group and the control. Total RNA was isolated and the gene expression of iNOS, Osterix and Runx-2 was investigated by real-time PCR. Total protein was also isolated and the secretion of iNOS and collagen I was examined by Western blotting. Icariside II can significantly improved ALP activity, CFU-FALP amount and mineralized nodules. Besides, the mRNA level of factors related to the osteogenic differentiation includes Osterix and Runx-2 also enhanced. The secretion of collagen I also promoted significantly. But all of these effects can be inhibited by L-NAME which can specifically inhibit the activity of iNOS. Icariside II enhances the osteogenic differentiation of rBMSCs significantly, but if the activity of iNOS was blocked by L-NAME, the osteogenic differentiation markers decrease accompanied with iNOS and NO decrease, suggesting that icariside II stimulates the osteogenic differentiation via enhancing the activity of iNOS and promoting the generation of NO.

Enhancement of osteoblastic differentiation of bone marrow mesenchymal stem cells in rats by sinusoidal electromagnetic fields / 生物医学工程学杂志

The present research was aimed to investigate the effects of sinusoidal electromagnetic fields (SEMFs) on the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells in rats (rBMSCs) and to find out the intensity with the best therapeutic efficacy. Primary rat bone marrow mesenchymal stem cells were obtained from Wistar rats and screened by the adhesive method. The rBMSCs were exposed to sinusoidal electromagnetic fields with 50Hz frequency and intensities of 0 mT, 1.4 mT, 1.6 mT, 1.8 mT, 2.0 mT, and 2.2 mT respectively, 30 min per day. The proliferation of the rBMSCs was analyzed by MTT reduction assay. The osteogenic differentiation markers including ALP activity, calcium deposition, mineralized bone modulus and collagen I expression were compared between the rats in the exposed groups and those in the control group. The total cellular RNA was extracted after 6, 12, 24 and 48 hours, respectively. The gene expression of Osterix and IGF-1 was examined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The absorbance of exposed groups was suppressed significantly in comparison with that in the control group. The exposure to the rBMSCs with intensity of 1.8 mT strongly enhances the osteogenic differentiation of rBMSCs, indicated by remarkably improved ALP activity, calcium deposition, collagen I expression and the number of mineralized bone nodules compared to that in the control group and other groups. Osterix and IGF-1 were also significantly improved (P < 0.05). The SEMFs with frequency and 50Hz and 1.4-2.2 mT intensities enhanced the osteogenic differentiation of rBMSCs, but inhibited their proliferation in the presence of 0.1% serum culture. Among the rBMSCs used in the tests, the one with 1.8 mT had the strongest activity, indicating that it could be the optimal intensity for the clinical application.

Time effect of sinusoidal electromagnetic field on enhancing the maturation and mineralization of osteoblasts in vitro / 生物医学工程学杂志

The present research was to investigate the time effect of sinusoidal electromagnetic fields (SEMFs) at different exposure time on the proliferation and differentiation of osteoblasts (OB) in vitro. The newborn rat calvarial OB were isolated by enzyme digestion and divided randomly into 7 groups after one passage. The exposure times of the SEMFs were 0.5 h, 1.0 h, 1.5 h, 2.0 h, 2.5 h and 3.0 h, respectively, and the frequency was 50 Hz. The cells were exposed in the SEMFs of 1.8 mT. Those without SEMFs exposure were used as the control group. They were observed under the contrast phase microscope each day. After 48 h, cell proliferation was assayed by MTT method. The alkaline phosphatase (Alkaline Phosphatase, ALP) activities were measured after the exposure of SEMFs for 3 d, 6 d, 9 d and 12 d, respectively. The calcified nodules were stained by Alizarin Bordeaux after 10 d. The cells exposed in the SEMFs were arranged in Spiral appearance after 8 d. The SEMFs exposure time at 2.0 h, 2.5 h and 3.0 h significantly inhibited cell proliferation (P < 0.01) and 0.5 h, 1.0 h, 1.5 h groups more significantly than control groups (P < 0.05). When the 3 d, 6 d and 12 d the ALP activities of the 0.5 h, 1.0 h, 1.5 h and 2.0 h, times group were significantly higher than those in the control group (P < 0.05), and after 9 d the 1.0 h, 1.5 h and 2.0 h activity of ALP higher significantly than control and other groups (P < 0.01). Other groups had no effect on the ALP activity. Alizarin Bordeaux staining result showed the amounts of calcified nodules 1.0 h, 1.5 h and 2.0 h higher than control groups. The SEMFs at 50 Hz, 1.8 mT different time exposure groups inhibits the proliferation of OB, but they enhances the maturation and mineralization of the OB and SEMFs at 1.8 mT of the 1.5 h has the strongest activity.

An intensity window in the effects of pulsed electromagnetic fields on bone metabolism in ovariectomized rats / 中华物理医学与康复杂志

Objective To investigate the effects of pulsed electromagnetic fields (PEMFs) of different intensities on bone metabolism in ovariectomized rata. Methods Sixty 10-month-old female Sprague-Dawley rats were randomly divided into a normal group, an ovariectomized control group, a 0. 14 mT group, a 0. 16 mT group, a 0.18 mT group and an estrogen group. All rats except those in the normal group were subjected to bilateral ovariectomy. Beginning one week after the operation, the rats in the 0. 14 mT, 0. 16 mT and 0.18 mT groups were treated with PEMFs at 50 Hz, 60 min daily for 90 days, while those in the estrogen group received estrogen instead. During the experiment, the bone mineral density (BMD) of the whole body was observed dynamically, and local BMDs and biochemical indexes were measured after 3 months of treatment. Results Alkaline phosphatase (ALP) activity in the normal group was significantly lower than in the other groups. Tartrate-resistant acidic phosphatase 5b (TRAP5b)activity was elevated significantly, in the control and 0.14 mT groups compared with the normal group. After 2 months of treatment, whole body BMD was reduced significantly in the 0.14 mT group compared to the normal group. After 3 months of treatment, whole body BMD in the ovariectomized controls and the 0.14 mT group was reduced significantly compared to the normal group, but significantly elevated in the 0. 16 mT, 0.18 mT and estrogen groups when compared to the ovariectomized control group. At the end of 3 months of treatment, the trends in lumbar vertebral BMD were similar to those of the whole body BMD, with the femoral BMD in the ovariectomized group and the 0.14 mT group significantly lower than in the normal group, though the differences among the other groups were not statistically significant. Conclusions PEMF treatment at 50 Hz and 0.16 mT or 0.18 mT can promote bone formation. PEMFs at 50 Hz and 0.14 mT might stimulate bone resorption. An intensity-window effect exists in the action of PEMFs on bone metabolism in ovariectomized rats.

Icariin promotes osteogenic differentiation of rat bone marrow stromal cells in vitro / 中国中药杂志

<p><b>OBJECTIVE</b>To investigate the effects of icariin on the osteogenic differentiation of rat bone marrow stromal cells (rBMSCs).</p><p><b>METHOD</b>rBMSCs were cultured by adherence screening method. Icariin was supplemented into the culture at 1 x 10(-5) mol x L(-1). The osteogenic differentiation markers including alkaline phosphatase (ALP) activity, CFU-F(ALP) and mineralized bone modulus were compared between the icariin-supplemented group and the control group. Total RNA was isolated and the gene expression of bFGF, IGF-1, Osterix(OSX) and Runx-2 was investigated by RT Real-time PCR.</p><p><b>RESULT</b>Icariin significantly improved ALP activity, CFU-F(ALP) amounts and mineralized modulus. It also can enhance the mRNA level of bFGF, IGF-1, Osterix and Runx-2.</p><p><b>CONCLUSION</b>Icariin enhances the osteogenic differentiation of rBMSCs significantly, which suggested that icariin has the potentiality to be a new drug of anti-osteoporosis or fracture healing.</p>