Current mass spectrometry approaches and challenges for the bioanalysis of traditional Chinese medicines

Discovery of effective combination from Renshen-Fuzi herbal pair against heart failure by spectrum-effect relationship analysis and zebrafish models

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional herbal pair Ginseng Radix et Rhizoma (roots and rhizomes of Panax ginseng C.A. Mey, Renshen in Chinese) and Aconiti Lateralis Radix Praeparata (lateral roots of Aconitum carmichaelii Debeaux, Fuzi in Chinese), composition of two traditional Chinese medicinal herbs, has been widely used in traditional Chinese medicine formula, in which Shenfu decoction has been used clinically in China for the treatment of heart failure at present.

AIM OF THE STUDY

Although the ginsenosides and aconite alkaloids have been proven as the essential bioactive components in Renshen-Fuzi herbal pair, the exact composition of effective components to combat heart failure are still unclear. Therefore, spectrum-effect relationship analysis was performed to reveal its effective combination for anti-heart failure effect.

MATERIALS AND METHODS

Firstly, the chemical constituents of Renshen-Fuzi herbal pair were identified using ultra high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). The 39 major compounds in Renshen-Fuzi with five different compatibility ratios were simultaneously quantified using ultra high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-QQQ MS/MS). Subsequently, zebrafish models induced by verapamil hydrochloride were constructed and four heart failure-related indexes were selected for pharmacodynamic evaluation of Renshen-Fuzi. To analyze the spectrum-effect relationships, partial least squares regression (PLSR) models were established among the contents of 39 compounds in Renshen-Fuzi with each pharmacodynamic index. According to the contribution of each compound to the whole efficacy, 12 compounds were finally screened out as the effective combination.

RESULTS

A total of 157 chemical compounds of Renshen-Fuzi herbal pair were identified, in which 39 components were simultaneously determined. The pharmacological effects indicated that Renshen-Fuzi with 1:2 ratio exhibited the best effect based on zebrafish model, which could improve cardiac output and blood flow velocity and inhibit pericardial enlargement and venous blood stasis significantly. A combination of 9 ginsenosides and 3 aconite alkaloids based on a component-efficacy modeling by PLSR was screened, and exerted approximately equivalent pharmacological effects compared with Renshen-Fuzi herbal pair.

CONCLUSIONS

Our findings elucidated the effective combination of Renshen-Fuzi herbal pair that has been used in clinic for the treatment of heart failure, which could also promote the pharmacological research and quality control of their formula such as Shenfu decoction.

Characterization of effective phytochemicals in traditional Chinese medicine by mass spectrometry

Traditional Chinese medicines (TCMs) have been widely used in clinical and healthcare applications around the world. The characterization of the phytochemical components in TCMs is very important for studying the therapeutic mechanism of TCMs. In the analysis process, sample preparation and instrument analysis are key steps to improve analysis performance and accuracy. In recent years, chromatography combined with mass spectrometry (MS) has been widely used for the separation and detection of trace components in complex TCM samples. This article reviews various sample preparation techniques and chromatography-MS techniques, including the application of gas chromatography-MS and liquid chromatography-MS and other MS techniques in the characterization of phytochemicals in TCM materials and Chinese medicine products. This article also describes a new ambient ionization MS method for rapid and high-throughput analysis of TCM components.

Limitation standard of toxic aconitines in Aconitum proprietary Chinese medicines using on-line extraction electrospray ionization mass spectrometry

Development of rapid analytical methods and establishment of toxic component limitation standards are of great importance in quality control of traditional Chinese medicine. Herein, an on-line extraction electrospray ionization mass spectrometry (oEESI-MS) coupled with a novel whole process integral quantification strategy was developed and applied to direct determination of nine key aconitine-type alkaloids in 20 Aconitum proprietary Chinese medicines (APCMs). Multi-type dosage forms (e.g., tablets, capsules, pills, granules, and liquid preparation) of APCM could be determined directly with excellent versatility. The strategy has the characteristics of high throughput, good tolerance of matrix interference, small amount of sample (∼0.5 mg) and reagent (∼240 μL) consumption, and short analysis time for single sample (<15 min). The results were proved to be credible by high performance liquid chromatography-mass spectrometry (LC-MS) and electrospray ionization mass spectrometry, respectively. Moreover, the limitation standard for the toxic aconitines in 20 APCMs was established based on the holistic weight toxicity (HWT) evaluation and the Chinese Pharmacopoeia severally, and turned out that HWT-based toxicity evaluation results were closer to the real clinical applications. Hence, a more accurate and reliable APCM toxicity limitation was established and expected to play an important guiding role in clinics. The current study extended the power of ambient MS as a method for the direct quantification of molecules in complex samples, which is commonly required in pharmaceutical analysis, food safety control, public security, and many other disciplines.

Employing fingerprinting of medicinal plants by means of LC-MS and machine learning for species identification task

A dataset of liquid chromatography-mass spectrometry measurements of medicinal plant extracts from 74 species was generated and used for training and validating plant species identification algorithms. Various strategies for data handling and feature space extraction were tested. Constrained Tucker decomposition, large-scale (more than 1500 variables) discrete Bayesian Networks and autoencoder based dimensionality reduction coupled with continuous Bayes classifier and logistic regression were optimized to achieve the best accuracy. Even with elimination of all retention time values accuracies of up to 96% and 92% were achieved on validation set for plant species and plant organ identification respectively. Benefits and drawbacks of used algortihms were discussed. Preliminary test showed that developed approaches exhibit tolerance to changes in data created by using different extraction methods and/or equipment. Dataset with more than 2200 chromatograms was published in an open repository.

Developing slow-off dickkopf-1 aptamers for early-diagnosis of hepatocellular carcinoma

In this work, we obtained fast-off and slow-off aptamer recognizing dickkopf-1(DKK1), a promising biomarker for detection of early-stage hepatocellular carcinoma (HCC), with high affinity in a single SELEX procedure. The two types of aptamer possessed distinct characteristics confirmed via different validation methods. In comparison to fast-off aptamers, slow-off aptamers were proven more suitable for aptamer-based ELISA assay. Using slow dissociation SELEX, slow-off aptamers were selectively retained. Meanwhile, a mutant (34del) of slow-off D10 was estimated with picomolar affinity (371.9 pM). The mutant was further truncated into 39nt before pairing with an antibody in the aptamer-based ELISA. The aptamer-target-antibody construction showed similar performance as conventional ELISA with a detection limit of 62.5 pg/ml. Quantification in 60 sera samples with the construction was also correlated with conventional ELISA. The results demonstrated novel DKK1 aptamer could replace capture antibody for potential early HCC diagnosis.

Recent development in mass spectrometry and its hyphenated techniques for the analysis of medicinal plants

INTRODUCTION

Medicinal plants are gaining increasing attention worldwide due to their empirical therapeutic efficacy and being a huge natural compound pool for new drug discovery and development. The efficacy, safety and quality of medicinal plants are the main concerns, which are highly dependent on the comprehensive analysis of chemical components in the medicinal plants. With the advances in mass spectrometry (MS) techniques, comprehensive analysis and fast identification of complex phytochemical components have become feasible, and may meet the needs, for the analysis of medicinal plants.

OBJECTIVE

Our aim is to provide an overview on the latest developments in MS and its hyphenated technique and their applications for the comprehensive analysis of medicinal plants.

METHODOLOGY

Application of various MS and its hyphenated techniques for the analysis of medicinal plants, including but not limited to one-dimensional chromatography, multiple-dimensional chromatography coupled to MS, ambient ionisation MS, and mass spectral database, have been reviewed and compared in this work.

RESULTS

Recent advancs in MS and its hyphenated techniques have made MS one of the most powerful tools for the analysis of complex extracts from medicinal plants due to its excellent separation and identification ability, high sensitivity and resolution, and wide detection dynamic range.

CONCLUSION

To achieve high-throughput or multi-dimensional analysis of medicinal plants, the state-of-the-art MS and its hyphenated techniques have played, and will continue to play a great role in being the major platform for their further research in order to obtain insight into both their empirical therapeutic efficacy and quality control.