In Vitro Investigation of Anti-Diabetic Effect of Taxus cuspidate Extracts by Ultrasound Assisted Method

Extracting active components from Chinese medicinal herbs efficiently is a key step in the investigation of their pharmacological effects and modes of action. In this project, we compared the ultrasound-assisted method and the conventional solvent method for extracting the active compound of Taxus cuspidate (dong bei hong dou shan). Through the analysis of various extractions with a quadruple time-of-fight (Q-TOF) LC/MS, we demonstrated that the ultrasound-assisted method reduced solvent consumption and had shorter extraction time, while the extraction yields of the active compound (taxol) were equivalent to or even higher than those obtained with the conventional solvent extraction method. Through the comparison of Taxus cuspidate extracts (TCEs) with different concentrations of acetone and ethanol, we proved that 50% ethanol was an optimal solvent for extracting taxol from Taxus cuspidate. Based on traditional Chinese medicine (TCM) literature, we further determined whether TCEs possess antidiabetic effects by testing glucose uptake in 3T3-L1 adipocytes treated with TCEs from Taxus cuspidate bark and twigs under insulin stimulation (100 nM). The results showed that neither taxol (10 μg/ml) nor TCEs (1 and 0.1 mg/ml) changed glucose uptake significantly compared with insulin alone. This study demonstrated that the ultrasound-assisted method with 50% ethanol is a highly efficient approach for extracting Taxus cuspidate, which may be applicable for extraction of other Chinese medicinal herbs. Extracts of Taxus cuspidate bark and twigs had no effect on insulin stimulated-glucose uptake in vitro. This result conflicts with the description in TCM literature. Further in vivo study to clarify Taxus cuspidate's metabolic actions is necessary.

Simultaneous Determination of 10-Deacetylbaccatin，Cephalomannine and Taxol in Different Parts of Taxus Media with Different Growth Years by UPLC

Taxus media is the natural hybrid variety of Taxus cuspidate and Taxus baccata, and has been used as an anticancer plant with some medical components-taxanes. In this study, ultra performance liquid chromatography was used for quantification of three major bioactive taxanes in Taxus media, which were collected in Zhejiang province and Sichuan province (China). As a result of this study, a convenient, accurate, rapid and reproducible UPLC method has been developed to successfully quantify 10-Deacetylbaccatin Ⅲ (10-DABⅢ), Cephalomannine and Taxol in the needle and twig of Taxus media. The results indicate that the sequence of the contents of three active components in Taxus media with different parts was needle>twig; the sequence of the contents of three active components in Taxus media with different growth years was 5 year old >4 year old >3 year old; and there were great differences in the contents of three active components in Taxus media between Zhejiang province and Sichuan province. The results also provided a scientific basis for uses of Taxus media.