超声提取葛根总黄酮成分的研究

以乙醇为溶剂,研究了预浸时间、超声功率、超声作用时间以及占空比对葛根总黄酮提取率的影响,结果表明,预浸时间为10min,超声功率为300W,超声作用时间为20min,占空比为1时,所得到总黄酮的提取率最大。  

一阶导数极谱法测定红树秋茄色素中总黄酮含量

在pH9.18硼砂底液中,以芦丁作对照品,在峰电位Ep-1.610V(vs·SCE)处产生一灵敏的一阶导数极谱波,该极谱波的峰电流(ip)与芦丁浓度在0.06～1.2mg/L范围内呈良好的直线关系,检出限为0.023mg/L。用本方法测得红树秋茄色素中总黄酮含量为1.98%,操作简便,干扰少,结果可靠。  

Assessment of intestinal absorption of total flavones of Hippophae rhamnoides L. in rat using in situ absorption models

Purpose: The objective of this study was to investigate the absorption behavior of total flavones of Hippophae rhamnoides L. (TFH) (the sum of isorhamnetin and quercetin as the index component) in the rat intestine using in situ circulation method. Methods: The accumulated TFH absorption and related absorption parameters were calculated. Furthermore, the influences of Cremophor ELP and the P-glycoprotein inhibitor, verapamil, on the intestinal absorption of TFH were studied using the in situ circulation model. Results and Discussion: The results showed that the absorption of TFH increased linearly with its concentration, indicating that a passive diffusion process was dominated. There were no significant differences in the absorption of TFH in three small intestine segments of duodenum, jejunum, and ileum and at different concentrations of Cremophor ELP ranging from 0.25% to 1% (P > 0.05). With the presence of P-gp inhibitor, verapamil, in the circulation fluid, the accumulated absorption of TFH did not increase significantly (P > 0.05). Further studies on the solubility and permeability enhancement of TFH should be investigated to develop new TFH products with high bioavailability.  

Effects of solid dispersion and self-emulsifying formulations on the solubility,dissolution, permeability and pharmacokinetics of isorhamnetin,quercetin and kaempferol in total flavones of Hippophae rhamnoides L.

The aim of this study was to investigate the effects of solid dispersions (SD) and self-emulsifying (SE) formulations on the solubility and absorption properties of active components in total flavones of Hippophae rhamnoides L. (TFH). The solubility, dissolution rate, permeability and pharmacokinetics of isorhamnetin, quercetin and kaempferol in TFH SD/SE formulations and TFH were compared. The results showed that the solubility and dissolution rate of isorhamnetin, quercetin and kaempferol in SD/SE formulations were significantly enhanced compared to those in TFH, however, their intestinal permeability was comparable. The bioavailability of isorhamnetin, quercetin and kaempferol in rats remarkably increased after oral administration of TFH SD formulations compared to TFH, but there was no significant increase after oral administration of TFH SE formulations. The results of this study indicated the SD formulations on the improvement of pharmacokinetic properties of isorhamnetin, quercetin and kaempferol in TFH were much better than those of SE formulations. The improvement of pharmacokinetic properties of isorhamnetin, quercetin and kaempferol in TFH by SD formulations was probably ascribed to the enhancement of the solubility and dissolution of the three components, but was not relevant to the intestinal permeability. Therefore, as for herb extracts containing multiple components, especially for their major components with poor water solubility, solid dispersion formulations might have the better potential to enhance their bioavailability.