Comparative analysis of volatile oils in the stems and roots of Ephedra sinica via GC-MS-based plant metabolomics

With a great difference in therapeutic effects of Mahuang(MH, the stems of Ephedra sinica) and Mahuanggen(MHG, the roots of Ephedra sinica), chemical differences between MH and MHG should be investigated. In the present study, gas chromatography-mass spectrometry(GC-MS)-based plant metabolomics was employed to compare volatile oil profiles of MH and MHG. The antioxidant activities of volatile oils from MH and MHG were also compared. 32 differential chemical markers were identified according to the variable importance in the projection(VIP) value of orthogonal partial least squares discriminant analysis(OPLS-DA) and P value of Mann-Whitney test. Among them, chemical markers of tetramethylpyrazine(TMP) and α-terpineol were quantified. Their contents were much higher in most MH samples compared with MHG. The antioxidant assay demonstrated that MH had significantly higher free radical-scavenging activity than MHG. Although MH and MHG derived from the same medicinal plant, there was much difference in their volatile oil profiles. MH samples had significantly higher content of two reported pharmacologically important chemical markers of TMP and α-terpineol, which may account for their different antioxidant activities.

Plant metabolomics for studying the effect of two insecticides on comprehensive constituents of Lonicerae Japonicae Flos

Pesticides'overuse and misuse have been reported to induce ingredient variations in herbal medicine,which is now gaining attention in the medicinal field as a form of alternative medicine.To date,available studies on pesticide-induced ingredient variations of herbal medicine are limited only on a few compounds and remain most others unexamined.In this study,a plant metabolomics-based strategy was performed to systematically explore the effects of two frequently used insecticides on the comprehensive constituents of Lonicerae Japonicae Flos(LJF),the flower buds of Lonicera japonica Thunb..Field trials were designed on a cultivating plot of L.japonica with controls and treatments of imidacloprid(IMI)and compound flonicamid and acetamiprid(CFA).Unbiased metabolite profiling was conducted by ultra-high performance liquid chromatography/quadrupole-Orbitrap mass spectrometer.After data pretreatment by automatic extraction and screening,a data matrix of metabolite features was submitted for statistical analyses.Consequently,29 metabolic markers,including chlorogenic acids,iridoids and organic acid-glucosides were obtained and characterized.The relative quantitative assay was subsequently performed to monitor their variations across flowering developments.This is the first study that systematically explored the insecticide-induced metabolite variations of LJF while taking into account the inherent variability of flowering development.The results were beneficial for holistic quality assessment of LJF and significant for guiding scientific use of pesticides in the large-scale cultivation.

Metabolomics-based comparative analysis of the effects of host and environment on Viscum coloratum metabolites and antioxidative activities

Viscum coloratum(Kom.)Nakai is a well-known medicinal hemiparasite widely distributed in Asia.The synthesis and accumulation of its metabolites are affected by both environmental factors and the host plants,while the latter of which is usually overlooked.The purpose of this study was to comprehensively evaluate the effects of host and habitat on the metabolites in V.coloratum through multiple chemical and biological approaches.The metabolite profile of V.coloratum harvested from three different host plants in two habitats were determined by multiple chemical methods including high-performance liquid chromatography-ultraviolet(HPLC-UV),gas chromatography-flame ionization detector(GC-FID)and ultra-performance liquid chromatography quadrupole time of flight mass spectrometry(UPLC-QTOF/MS).The differences in antioxidant efficacy of V.coloratum were determined based on multiple in vitro models.The multivariate statistical analysis and data fusion strategy were applied to analyze the differences in metabolite profile and antioxidant activity of V.coloratum.Results indicated that the metabolite profile obtained by various chemical approaches was simultaneously affected by host and environment factors,and the environment plays a key role.Meanwhile,three main differential metabolites between two environment groups were identified.The results of antioxidant assay indicated that the environment has greater effects on the biological activity of V.coloratum than the host.Therefore,we conclude that the integration of various chemical and biological approaches combined with multivariate statistical and data fusion analysis,which can determine the influences of host plant and habitat on the metabolites,is a powerful strategy to control the quality of semi-parasitic herbal medicine.

Study on the dynamic variation of the secondary metabolites in Viscum coloratum using targeted metabolomics

Viscum coloratum(Kom.)Nakai is a well-known medicinal plant.However,the optimal harvest time for V.coloratum is unknown.Few studies were performed to analyze compound variation during storage and to improve post-harvest quality control.Our study aimed to comprehensively evaluate the quality of V.coloratum in different growth stages,and determine the dynamic variation of metabolites.Ultra-performance liquid chromatography tandem mass spectrometry was used to quantify 29 compounds in V.coloratum harvested in six growth periods,and the associated biosynthetic pathways were explored.The accumulation of different types of compounds were analyzed based on their synthesis pathways.Grey relational analysis was used to evaluate the quality of v.coloratum across different months.The compound variation during storage was analyzed by a high-temperature high-humidity accelerated test.The results showed that the quality of V.coloratum was the hightest in March,followed by November,and became the lowest in July.During storage,compounds in downstream steps of the biosynthesis pathway were first degraded to produce the upstream compounds and some low-molecular-weight organic acids,leading to an increase followed by a decrease in the content of some compounds,and resulted in a large gap during the degradation time course among different compounds.Due to the rapid rate and large degree of degradation,five compounds were tentatively designated as“early warning components”for quality control.This report provides reference for better understanding the biosynthesis and degradation of metabolites in V.coloratum and lays a theoretical foundation for rational application of V.coloratum and better quality control of V.coloratum during storage.

Mining plant metabolomes:Methods,applications,and perspectives

Plants produce a variety of metabolites that are essential for plant growth and human health.To fully understand the diversity of metabolites in certain plants,lots of methods have been developed for metabolites detection and data processing.In the data-processing procedure,how to effectively reduce false-positive peaks,analyze large-scale metabolic data,and annotate plant metabolites remains challenging.In this review,we introduce and discuss some prominent methods that could be exploited to solve these problems,including a five-step filtering method for reducing false-positive signals in LC-MS analysis,QPMASS for analyzing ultra-large GC-MS data,and MetDNA for annotating metabolites.The main applications of plant metabolomics in species discrimination,metabolic pathway dissection,population genetic studies,and some other aspects are also highlighted.To further promote the development of plant metabolomics,more effective and integrated methods/platforms for metabolite detection and comprehensive databases for metabolite identification are highly needed.With the improvement of these technologies and the development of genomics and transcriptomics,plant metabolomics will be widely used in many fields.

Evidence Based Validation of Indian Traditional Medicine–Way Forward

Evidence based validation of the ethno-pharmacological claims on traditional medicine(TM) is the need of the day for its globalization and reinforcement. Combining the unique features of identifying biomarkers that are highly conserved across species, this can offer an innovative approach to biomarker-driven drug discovery and development. TMs are an integral component of alternative health care systems. India has a rich wealth of TMs and the potential to accept the challenge to meet the global demand for them. Ayurveda, Yoga, Unani, Siddha and Homeopathy(AYUSH) medicine are the major healthcare systems in Indian Traditional Medicine. The plant species mentioned in the ancient texts of these systems may be explored with the modern scientific approaches for better leads in the healthcare. TM is the best sources of chemical diversity for finding new drugs and leads. Authentication and scientific validation of medicinal plant is a fundamental requirement of industry and other organizations dealing with herbal drugs. Quality control(QC) of botanicals, validated processes of manufacturing, customer awareness and post marketing surveillance are the key points, which could ensure the quality, safety and efficacy of TM. For globalization of TM, there is a need for harmonization with respect to its chemical and metabolite profiling, standardization, QC, scientific validation,documentation and regulatory aspects of TM. Therefore, the utmost attention is necessary for the promotion and development of TM through global collaboration and co-ordination by national and international programme.

Rhynchophorus ferrugineus attack affects a group of compounds rather than rearranging Phoenix canariensis metabolic pathways

The red palm weevil（RPW; Rhynchophorus ferrugineus） is spreading worldwide and severely harming many palm species. However, most studies on RPW focused on insect biology, and little information is available about the plant response to the attack. In the present experiment, we used metabolomics to study the alteration of the leaf metabolome of Phoenix canariensis at initial（1^（st） stage） or advanced（2^（nd） stage）attack by RPW compared with healthy（unattacked） plants.The leaf metabolome significantly varied among treatments. At the 1^（st） stage of attack, plants showed a reprogramming of carbohydrate and organic acid metabolism; in contrast, peptides and lipid metabolic pathways underwent more changes during the 2^（nd） than 1^（st） stage of attack. Enrichment metabolomics analysis indicated that RPW attack mostly affected a particular group of compounds rather than rearranging plant metabolic pathways. Some compounds selectively affected during the 1^（st） rather than 2^（nd） stage（e.g. phenylalanine; tryptophan; cellobiose;xylose; quinate; xylonite; idonate; and iso-threonate; cellobiotol and arbutine） are upstream events in the phenylpropanoid,terpenoid and alkaloid biosynthesis. These compounds could be designated as potential markers of initial RPW attack. However,further investigation is needed to determine efficient early screening methods of RPW attack based on the concentrations of these molecules.