Flavonoids from the leaves ofRhododendron brachycarpum

The flavonoids isolated from the leaves ofRhododendron brachycarpum, were identified as quercetin, avicularin, quercitrin and hyperin.     

Quercitrin and Taxifolin stimulate osteoblast differentiation in MC3T3-E1 cells and inhibit osteoclastogenesis in RAW 264.7 cells

Flavonoids are natural antioxidants that positively influence bone metabolism. The present study screened among different flavonoids to identify biomolecules for potential use in bone regeneration. For this purpose, we used MC3T3-E1 and RAW264.7 cells to evaluate their effect on cell viability and cell differentiation. First, different doses of chrysin, diosmetin, galangin, quercitrin and taxifolin were analyzed to determine the optimum concentration to induce osteoblast differentiation. After 48 h of treatment, doses ≥100 μM of diosmetin and galangin and also 500 μM taxifolin revealed a toxic effect on cells. The same effect was observed in cells treated with doses ≥100 μM of chrysin after 14 days of treatment. However, the safe doses of quercitrin (200 and 500 μM) and taxifolin (100 and 200 μM) induced bone sialoprotein and osteocalcin mRNA expression. Also higher osteocalcin secreted levels were determined in 100 μM taxifolin osteoblast treated samples when compared with the control ones. On the other hand, quercitrin and taxifolin decreased Rankl gene expression in osteoblasts, suggesting an inhibition of osteoclast formation. Indeed, osteoclastogenesis suppression by quercitrin and taxifolin treatment was observed in RAW264.7 cells. Based on these findings, the present study demonstrates that quercitrin and taxifolin promote osteoblast differentiation in MC3T3-E1 cells and also inhibit osteoclastogenesis in RAW264.7 cells, showing a positive effect of these flavonoids on bone metabolism.     

Consumption of polyphenol concentrate with dietary fructo-oligosaccharides enhances cecal metabolism of quercetin glycosides in rats

Objective

We verified the hypothesis that the consumption of polyphenol concentrate (PC), rich in quercetin and its glycosides (36 g/100 g), in association with different dietary fiber matrices, that is, an easily fermentable fructo-oligosaccharides (FOS) or non-fermentable cellulose (CEL), causes a disparate adaptive response of the cecal microbial activity in rats. This in turn facilitates further utilization of biologically active polyphenolic compounds, which are not, as usual, digested in the foregut.

Methods

Four-week experimental feeding of male Wistar rats consisted of diets containing 5% FOS or CEL, as a source of dietary fiber, with or without 0.3% addition of PC.

Results

Positive changes in rat cecum were observed resulting from the ingestion of an FOS-containing diet, such as decreased pH and increased the production of short-chain fatty acids in the digesta, compared with a CEL-containing diet. The addition of PC to the FOS diet did not eliminate the positive effects of the latter, except for a slight increase in cecal pH and a decrease in microbial glycolytic activity. However, a simultaneous increase in the cecal butyrate pool was also observed. An adaptation process of the microflora enzymatic system to dieting with PC and FOS was proven in further enhanced susceptibility of rutin (quercetin 3-O-glucorhamnoside), hyperoside (quercetin 3-O-galactoside), and quercitrin (quercetin 3-O-rhamnoside) to hydrolysis by the cecal digesta solution.

Conclusion

Especially when consumed together, PC and FOS are important dietary factors affecting the susceptibility of quercetin glycosides to microbial metabolism in the cecum. The intensification of the hydrolysis of quercetin glycosides by dietary treatments leads also to the increased metabolism of quercetin itself.     

地锦草抗真菌有效部位中芦丁及槲皮苷含量的高效液相色谱法测定

目的 建立高效液相色谱(HPLC)法同时测定维吾尔医药地锦草抗真菌有效部位中芦丁及槲皮苷含量的方法.方法 色谱柱为waters symmetry C18(4.6 mm×150 mm,5μm);流动相为甲醇-0.4％磷酸水溶液(42:58,V/V),,检测波长为360nm;流速为1.0 ml· min-1;柱温25℃;进样量10μl.结果 芦丁和槲皮苷线性范围分别在0.42～2.52 μg,0.6～3.6μg内线性关系良好(r≥0.999 5),平均加样回收率分别为99.2％,101.1％,RSD≤3.3％.结论 该方法操作简便、准确、灵敏度高、重复性好,可用于地锦草抗真菌有效部位的质量控制.     

高效液相色谱法测定鱼腥草中金丝桃苷与槲皮苷的含量

目的用高效液相色谱法测定鱼腥草中金丝桃苷与槲皮苷的含量。方法采用ShimadzuC18柱(150mm×4.6mm,5μm),流动相为甲醇-0.2%H3PO4水溶液(45:55),流速1.0mL.min-1,检测波长350nm,柱温室温,用外标法定量,测定鱼腥草中金丝桃苷与槲皮苷的含量。结果金丝桃苷的线性范围0.50-2.50μg,r=0.9998,回收率102.47%,RSD1.04%;槲皮苷的线性范围0.40-2.00μg,r=0.9996,回收率97.92%,RSD2.13%。结论该方法简便,快速,线性关系良好。     

HPLC法测定不同产地黄蜀葵花中黄酮类成分含量

目的:研究建立同时测定黄蜀葵花中多个黄酮成分含量的方法,并比较江苏不同产地黄蜀葵花中黄酮成分的含量差异.方法:采用HPLC法,以金丝桃苷、杨梅素和槲皮素3种黄酮为对照品,以乙腈-0.4%磷酸溶液为流动相,梯度洗脱,在360nm波长下检测,柱温:30℃,流速:1.0mL·min-1.结果:对3种黄酮的方法学考察结果表明符合含量测定要求,三者在一定浓度范围内有良好的线性关系.结论:方法操作简便,结果可靠,重复性好,专属性强,可用于黄蜀葵花药材的质量控制.江苏境内黄蜀葵花中3种黄酮成分含量稍有差异.     

高效薄层扫描法测定166种杜鹃中6种黄酮类成分的含量

在高效硅胶薄层板上以石油醚(bp60～90℃)—乙醚—甲酸(62:31:7)的上层(展开剂Ⅰ)分离杜鹃素、山奈素和槲皮素;扫描测定后再次展开,以氯仿—甲醇—水(7:3:1)的下层—甲酸(7:0.5)(展开剂Ⅱ)分离蓼属甙、槲皮甙干口金丝桃甙。用瑞士Camag 76510型单波长薄层扫描仪进行直线扫描,测定波长366nm,用美国Hewlett Packard 3390 A型积分仪测出峰面积。测定了166种杜鹃叶中上述6种黄酮类成分的含量。     

HPLC法同时测定黄葵胶囊中5种成分的含量

目的:测定不同批次黄葵胶囊中金丝桃苷、异槲皮苷、棉皮苷、槲皮素-3′-葡萄糖苷和槲皮素的含量。方法:采用高效液相色谱法。色谱柱为Zorbax SB-C18柱,流动相为乙腈-0.2%磷酸(梯度洗脱),检测波长为360nm,柱温为30℃,流速为1.0mL·min-1,进样量为10μL。结果:3个批次黄葵胶囊中金丝桃苷的平均含量为1.64%,RSD=1.09%;异槲皮苷的平均含量为1.06%,RSD=1.13%;棉皮苷的平均含量为3.87%,RSD=1.15%;槲皮素-3′-葡萄糖苷的平均含量为1.50%,RSD=1.22%;槲皮素的平均含量为0.08%,RSD=1.45%。结论:黄葵胶囊3个批次中5种黄酮类成分的含量相似,其中棉皮苷、金丝桃苷、槲皮素-3′-葡萄糖苷、异槲皮苷含量较高。该方法简便、准确、重复性好,可为黄葵胶囊提供质量控制依据。     

槲皮苷对大鼠骨髓间充质干细胞（rBMSCs）成骨分化和成脂分化的分子调控机制研究

Objective:The study was designed to investigate the molecular mechanism of quercitrin on osteogenic differentiation and adipogenic differentiation of r BMSCs.Methods:r BMSCs were harvested from SD rats,and determination of alkaline phosphatase(ALP)activity,quantification of mineralization by Alizarin Red S staining,and the m RNA expression of osteogenic differentiation markers(Runx2,BMP-2,and OSX)by RT-PCR after r BMSCs stimulated by osteogenic induction with(0.1–10)μg/m L of quercitrin,quantification of Lipid droplet by Oil Red O staining and the m RNA expression of adipogenic differentiation marker(,and a P2)by RT-PCR after r BMSCs stimulated by adipogenic induction with(0.1-10)μg/m L of quercitrin.Results:Quercitrin can up-regulate the m RNA expression of osteogenic differentiation markers(Runx2,BMP-2,and OSX)and increase ALP activity and mineralization after osteogenic induction,on the other hand quercitrin can suppress the m RNA expression of adipogenic differentiation markers(,and a P2)and decrease lipid droplet after adipogenic induction.Conclusion:This study suggested that quercitrin not only stimulated osteogenic differentiation but also inhibited adipogenic differentiation of r BMSCs,which was associated with the up-regulation of Runx2,BMP-2,and OSX m RNA expression and the down-regulation of,and a P2 m RNA expression.