An Optimized and Sensitive Pharmacokinetic Quantitative Method of Investigating Gastrodin, Parishin, and Parishin B, C and E in Beagle Dog Plasma using LC-MS/MS after Intragastric Administration of Tall Gastrodia Capsules.

Junqiu Liu,Jun Zhang,Yuesheng Wang,An Liu,Jintang Cheng,Sha Chen

doi:10.3390/molecules22111938

Abstract

Gastrodia elata Blume, called Tianma in China, has been widely used to treat headaches, convulsions and epilepsy for thousands of years. In the present study, a series of optimizations were employed to develop a rapid, sensitive, and reliable high-performance liquid chromatography-triple quadrupole mass spectrometry method, which was then used for the simultaneous determination of gastrodin, parishin, parishin B, parishin C and parishin E in beagle dog plasma after intragastric administration of tall Gastrodia capsules (Tianma brand). The chromatographic separation was achieved on a C18 column with gradient elution by using a mixture of 0.4% formic acid aqueous solution and acetonitrile as the mobile phase at a flow rate of 0.15 mL/min. A tandem mass spectrometric detection was conducted using multiple-reaction monitoring (MRM) via electrospray ionization (ESI) source in negative ionization mode. Samples were pre-treated by a single-step protein precipitation with methanol, and bergenin was used as internal standard (IS). Under the optimized conditions, the lower limit of quantification (LLOQ) was 0.10 ng/mL for gastrodin, 0.40 ng/mL for parishin B, 0.02 ng/mL for parishin E and 0.20 ng/mL for parishin and parishin C, all of which previously were the highest levels of sensitivity. The methods were optimized for selectivity, calibration curves, accuracy and precision. Extraction recoveries, matrix effects and stability were within acceptable ranges. Pharmacokinetic parameters of the tested substances were also quantitatively determined. Finally, a possible metabolic pathway was induced based on correlations obtained from quantitative and qualitative data analysis in vivo.

Highlights

Pharmacokinetic studies on Gastrodia elata Blume (GE, tianma) have mainly focused on gastrodin and one or two parishin and hydroxybenzyl alcohol compounds in dogs and rats [1,2,3]
sample preparation (SP) 3 and SP 4 were based on the results from SP 1 and SP 2, which showed that the target compounds were obtained with good separation efficiency
Research has validated the use of fluorescence detection for quantification of parishin and its metabolites in rats at lower limit of quantification (LLOQ) of 2.5 ng/mL [27]

Summary

Introduction

Pharmacokinetic studies on Gastrodia elata Blume (GE, tianma) have mainly focused on gastrodin and one or two parishin and hydroxybenzyl alcohol compounds in dogs and rats [1,2,3]. Pharmacokinetic research on compounds like gastrodin, p-hydroxybenzyl alcohol and parishin compounds has typically been conducted in rodents. Some bottlenecks exist in studying the oral administration pharmacokinetics of these compounds in plasma, such as a lack of a highly sensitive method of integrated analysis of gastrodin and parishins, or a clear method for explaining the inner links among these bioactive compounds in vivo. Molecules 2017, 22, 1938 and transformation of compounds, suitable acidity of the mobile phase is key for bio-availability analysis in vivo for GE compounds analysis. The mobile phase acidity can change the charged condition of ions, influencing the sensitivity of quantitative methods. There is an urgent need to establish a systematic analysis protocol

Methods

Results

Conclusion