Separation and purification of flavonoid from Taxus remainder extracts free of taxoids using polystyrene and polyamide resin.

An efficient separation process of flavonoid from Taxus wallichiana var. mairei remainder extracts free of taxoids was developed in this study. AB-8 macroporous resin and polyamide resin offered the fine adsorption capacity, and its adsorption rate at 30°C fitted well to the Langmuir and Freundich isotherms. Resin dynamic adsorption and desorption experiments were conducted to optimize the separation process of total flavonoids from T. wallichiana var. mairei remainder extracts free of taxoids. The optimum parameters for adsorption by AB-8 resin were as follows: (1) the concentration of flavonoids in a sample solution of 5.61 mg/mL with a processing volume of 2 bed volume (BV) (60 mL); (2) for desorption, ethanol-water (80:20, v/v), with 6 BV as an eluent at a flow rate of 2 BV/h. After a one-run treatment with AB-8 resin, the content of flavonoids was increased 5.10-fold from 4.05 to 20.65%. The optimum parameters for adsorption by polyamide resin were as follows: processing volume of 2 BV (30 mL); for desorption, ethanol-water (70:30, v/v), with 8 BV as an eluent at a flow rate of 2 BV/h. After one-run treatment with polyamide resin, the content of total flavonoids increased from 20.65 to 65.21%. The method will provide a potential approach for large-scale separation and purification of flavonoid for its wide pharmaceutical use.

Preliminary experimental research on the mechanism of liver bile secretion stimulated by peppermint oil.

OBJECTIVE: To investigate the choleretic effect and molecular mechanisms of action of peppermint oil (PO), the main component of Danshu capsules (Sichuan Jishengtang Pharmaceutical Co., Ltd., Pengzhou, Sichuan Province, China). METHODS: Bile secretion was measured by biliary drainage in rats. Total bile acids, total cholesterol and bilirubin in bile were determined. Cholesterol 7α-hydroxylase (CYP7A1), and farnesoid X receptor (FXR) messenger ribonucleic acid (mRNA) levels were assessed in HepG2 cells (a human hepatocellular carcinoma cell line) by reverse transcription polymerase chain reaction (RT-PCR). RESULTS: PO significantly promoted bile and bile acid secretion in rats. It also increased bile acid efflux and decreased cholesterol levels (P < 0.01) in bile. In HepG2 cells the mRNA levels of CYP7A1 and FXR were significantly upregulated after treatment with PO. CONCLUSIONS: PO stimulates bile fluid secretion and thus has a choleretic effect. PO might play a role in upregulating CYP7A1 and FXR mRNA levels, suggesting that the molecular mechanisms are related to gene expression involved in bile acid synthesis.