Schisandra Lignans Research Articles

Qualitative and quantitative determination of complicated herbal components by liquid chromatography hybrid ion trap time-of-flight mass spectrometry and a relative exposure approach to herbal pharmacokinetics independent of standards

To date, the pharmacokinetic research of herbal medicines (HMs) is still in its infancy and is facing critical technical challenges on the qualitative and quantitative analysis of complicated components from biological matrices. Additionally, the lack of authentic standards constitutes another bottleneck on assessing herbal pharmacokinetics. This present work contributes to the development of a powerful technical platform for both qualitative and quantitative pharmacokinetic analysis of herbal components, and a strategy of relative exposure that provides a practicable pharmacokinetic assessment independent of authentic standards, based on the use of liquid chromatography hybrid ion trap time-of-flight mass spectrometry (LC–IT-TOF/MS). Taking schisandra lignans extract (SLE) as an example, the LC–IT-TOF/MS assay was initially applied to the global qualitative analysis of components contained in SLE per se and in the rat plasma post SLE dosing. Afterwards, this study focused on validating the quantitative performance of LC–IT-TOF/MS assay by comparison with a well-established LC–Q/MS assay. For the absolute quantification of five lignans components with authentic standards, both assays showed very similar analytical figures of merit such as linearity, precision, accuracy, and pharmacokinetic parameters. Compared with LC–Q/MS, the prominent advantage of LC–IT-TOF/MS assay is its much higher sensitivity. Moreover, a ‘relative exposure approach’ (REA) that entails the use of sequentially diluted original herbal preparations to prepare the ‘mixed calibration curves’ was developed to assessing herbal pharmacokinetics independent of specific authentic compounds for each component. Such an approach was found capable of providing virtually identical pharmacokinetic parameters as that from the typical pharmacokinetic assay calibrated by authentic standards, except for the absolute plasma concentrations. The presently developed methodology and approach will find its wide use in, but not limited to, the qualitative and quantitative pharmacokinetic analysis of herbal medicines.

Simultaneous quantification of four active schisandra lignans from a traditional Chinese medicine Schisandra chinensis( Wuweizi) in rat plasma using liquid chromatography/mass spectrometry

A simple, rapid and sensitive method was developed for the simultaneous quantification of four active schisandra lignans (schisandrin, schisantherin A, deoxyshisandrin and γ-schisandrin) from a traditional Chinese medicine Schisandra chinensis( Wuweizi) in rat plasma using a high-performance liquid chromatography system coupled to a positive ion electrospray mass spectrometric analysis. The plasma sample preparation was a simple deproteinization by the addition of three volumes of methanol followed by centrifugation. The analytes and internal standard (IS) bicyclol were separated on a Zorbax SB-C18 column (3.5 μm, 2.1 mm × 100 mm) with mobile phase of methanol/water (70:30, v/v) containing 0.1% formic acid at a flow rate of 0.2 mL/min with an operating temperature of 25 °C. Detection was performed on a Trap XCT mass spectrometer equipped with an electrospray ionization (ESI) source operated in selected ion monitoring (SIM) mode. Positive ion ESI was used to form sodium adduct molecular ions at m/ z 455 for schisandrin, m/ z 559 for schisantherin A, m/ z 439 for deoxyshisandrin, m/ z 423 for γ-schisandrin, and m/ z 413 for the internal standard bicyclol. Linear detection responses were obtained for the four test compounds ranging from 0.010 to 2.0 μg/mL and the lower limits of quantitation (LLOQs) for four lignans were 0.010 μg/mL. The intra- and inter-day precisions (R.S.D.%) were within 12.5% for all analytes, while the deviation of assay accuracies was within ±13.0%. The average recoveries of analytes were greater than 80.0%. All analytes were proved to be stable during all sample storage, preparation and analytic procedures. The method was successfully applied to the pharmacokinetic study of the four lignans after oral administration of Schisandra chinensis extraction to rats.

Validation of a method for the simultaneous determination of four schisandra lignans in the raw herb and commercial dried aqueous extracts of Schisandra chinensis (Wu Wei Zi) by RP-LC with DAD

A rapid and specific reversed-phase high performance liquid chromatography (RP-LC) method with photodiode array detection (DAD) was developed and validated for the determination of four common schisandra lignans, schisandrin (1), schisandrol B (2), deoxyshisandrin (3) and γ-schisandrin (4), in raw herb materials and commercial dried aqueous extracts of Schisandra chinensis (Wu Wei Zi). The extraction solvent and extraction method were optimised where it was found that a 4h Soxhlet extraction using methanol was successful at extracting >99.5% of each of the schisandra lignans analysed from the raw herb material. The sample preparation process for the dried aqueous extract samples involved sonication using methanol for 2×30min. The herb and extract solutions were separated on a Varian Microsorb-MV 100-5 C18 column using a gradient mixture of 0.1% aqueous phosphoric acid and acetonitrile. Subsequent detection and quantitation of the schisandra lignans was performed at 210nm. The correlation coefficients of the linear regression analysis performed on these calibration curves were >0.9996 for all four schisandra lignans assayed. The detection limits and quantification limits ranged from 0.12 to 0.57 and 0.41 to 1.89mgg−1, respectively. The mean recoveries of the various analytes ranged from 92.20 to 107.01%. The method was used to investigate the levels of the four mentioned components in herb samples and dried aqueous extracts. The identities of the chromatographic peaks were confirmed by (+) electrospray ionisation LC–MS/MS.

Effects of Schisandra Lignans on P-Glycoprotein-Mediated Drug Efflux in Human Intestinal Caco-2 Cells

Schisandra fruits (Schisandraceae) are often used in traditional medicine and can be taken concomitantly with conventional medicine. In this study, the effects of dibenzocyclooctadiene lignans from Schizandra chinensis on P-gp-mediated efflux were examined to investigate a possible interaction with P-gp substrates. The cellular accumulation of rhodamine-123 in Caco-2 cells was measured with 12 Schisandra lignans. Most compounds resulted in slight or moderate increases of rhodamin-123 cellular uptake, indicating their P-gp inhibitory activity. Among them, deoxyschizandrin exhibited the most potent effect on the accumulation of rhodamine-123. Subsequently, bidirectional transports of digoxin and rhodamine-123 in Caco-2 cells were determined with deoxyschizandrin, the most active compound for the rhodamine-123 assay. In the bidirectional transport study, apical-to-basal (A-to-B) transports of digoxin and rhodamine-123 were increased, whereas basal-to-apical (B-to-A) transports were decreased by deoxyschizandrin in concentration- and time-dependent manners. At 50 microM of deoxyschizandrin, the transport ratios (B-A/A-B) for digoxin and rhodamine-123 were 2.2 and 2.1 compared with the control ratios of 15.2 and 12.2, respectively. These results demonstrated that deoxyschizandrin effectively inhibited the P-gp-mediated efflux in Caco-2 cells, suggesting they could potentially increase the absorption of drugs that can act as a P-gp substrate.

Evaluation of the protective effects of Schisandra chinensis on Phase I drug metabolism using a CCl 4 intoxication model

To evaluate the potential activity of Schisandra chinensis in restoring hepatic drug metabolism in CCl 4 damaged liver, antipyrine was employed as a probe for the possible effects of the herb on Phase I oxidative metabolism in rats. Schisandra lignan fraction (160 mg/kg) was given orally to male Sprague–Dawley rats (220–240 g) 30 min or 6 h before CCl 4 intoxication (4 ml/kg, s.c.). Following a single oral dose of antipyrine (80 mg/kg) to the rats with damaged liver, the pharmacokinetics of antipyrine in whole blood were determined and levels of liver enzymes, e.g. SGPT, SGOT, and cytochrome P 450 were measured. Pharmacokinetic parameters for antipyrine were estimated using noncompartmental analysis. Results indicated that CCl 4 significantly increased the elimination half-life ( t 1/2) of antipyrine from 2.59±1.04 to 11.25±3.91 h ( P<0.001) and decreased its clearance (CL) from 65.94 to 10.84 ml/h as compared to control. Pretreatment with the Schisandra lignan fraction 30 min or 6 h before intoxication significantly ( P<0.001) improved antipyrine elimination by reducing its t 1/2 to 3.30±0.52 and 3.58±1.05 h, respectively. The corresponding improvements observed for CL, i.e. 49.06±21.75 ml/h ( P<0.01); 21.10±10.42 ml/h ( P<0.05), were also substantial. Moreover, normalization of SGPT, SGOT and P 450 levels was observed with the two Schisandra pretreatment schedules. In conclusion, Schisandra lignans exhibited strong protective effect on Phase I oxidative metabolism in the liver damaged by CCl 4. Furthermore, pretreatment of Schisandra 30 min before intoxication showed a more pronounced effect than that of the 6 h pretreatment. The current pharmacokinetic approach allowed the protective effects of Schisandra on oxidative drug metabolism in damaged liver to be systemically examined and will certainly help in the evaluation of hepato-protectants obtained from natural sources.