葛根素定量分析及对卵巢切除小鼠骨密度作用

Objective: Radix Puerariae (RP), the root of Puerariae labata (Willd) Ohwi, a wild creeper leguminous plant, is an important crude edible herb and one of the earliest traditional chinese medicine for various medicinal purposes. In previous paper, we have reported that the overall crude herb of RP inhibited bone loss by low dose and increased bone mass by high dose in OVX mice. RP contains high level of isoflavones. In this paper, we analysed the main isoflavones in RP by HPLC and examined the role of major isoflavone Puerarin on bone protective effects in ovariectomized mice. Methods: To quantfy the total isoflavones, 10mg RP powder was mixed with 25μl β-glucuronidase solution in 200μl sodium acetate buffer and incubated for 37℃ for 3h，then 800μl menthanol was added and mixed well. After the sample was centrifuged, the supernate was passed through the 0.22μm micorfilter, and 10μl of the extract was applayed to HPLC. On the other hand, to examined the role of puerarin on bone metabolism, female mice were ovariectomized (OVX), and administration with low, middle and high dose of puerarin or 17-beta-estradiol, 4 weeks after the femoral bone mineral density (BMD) were measured. Results:HPLC chromatogram showed that puerarin is the major peak and it amounted to 43.5mg/g of the RP in dry weight. Daidzein and Genistein were other two peaks, and were 8.03mg/g and 1.01mg/g separately. The whole femoral bone mineral density (BMD) was significantly reduced by OVX, and the decrease in BMD was inhibited by any of thd dose of RP, and low dose of RP is significantly. Treatment with 17-beta-estradiol not only completely inhibited the decrease in BMD,but also increased the BMD in OVX mice. Conclusions: The isoflavones containing in RP are mainly puerarin, and also contanin two of the major isoflavones Daidzein and Genistein existed in soybean. Puerarin has shown inhibited bone loss in ovariectomized mice, and should be one of the important components responsble for regulating bone matabolism by RP.