Recent advances in the compound-oriented and pattern-oriented approaches to the quality control of herbal medicines

Spectrum-Effect Relationship in Chinese Herbal Medicine: Current Status and Future Perspectives

The quality of Chinese herbal medicine (CHM) directly impacts clinical efficacy and safety. Fingerprint technology is an internationally recognized method for evaluating the quality of CHM. However, the existing quality evaluation models based on fingerprint technology have blocked the ability to assess the internal quality of CHM and cannot comprehensively reflect the correlation between pharmacodynamic information and active constituents. Through mathematical methods, a connection between the "Spectrum" (fingerprint) and the "Effect" (pharmacodynamic data) was established to conduct a spectrum-effect relationship (SER) of CHM to unravel the active component information associated with the pharmacodynamic activity. Consequently, SER can efficiently address the limitations of the segmentation of chemical components and pharmacodynamic effect in CHM and further improve the quality evaluation of CHM. This review focuses on the recent research progress of SER in the field of CHM, including the establishment of fingerprint, the selection of data analysis methods, and their recent applications in the field of CHM. Various advanced fingerprint techniques are introduced, followed by the data analysis methods used in recent years are summarized. Finally, the applications of SER based on different research subjects are described in detail. In addition, the advantages of combining SER with other data are discussed through practical applications, and the research on SER is summarized and prospected. This review proves the validity and development potential of the SER and provides a reference for the development and application of quality evaluation methods for CHM.

Analytical Challenges and Metrological Approaches to Ensuring Dietary Supplement Quality: International Perspectives

The increased utilization of metrology resources and expanded application of its' approaches in the development of internationally agreed upon measurements can lay the basis for regulatory harmonization, support reproducible research, and advance scientific understanding, especially of dietary supplements and herbal medicines. Yet, metrology is often underappreciated and underutilized in dealing with the many challenges presented by these chemically complex preparations. This article discusses the utility of applying rigorous analytical techniques and adopting metrological principles more widely in studying dietary supplement products and ingredients, particularly medicinal plants and other botanicals. An assessment of current and emerging dietary supplement characterization methods is provided, including targeted and non-targeted techniques, as well as data analysis and evaluation approaches, with a focus on chemometrics, toxicity, dosage form performance, and data management. Quality assessment, statistical methods, and optimized methods for data management are also discussed. Case studies provide examples of applying metrological principles in thorough analytical characterization of supplement composition to clarify their health effects. A new frontier for metrology in dietary supplement science is described, including opportunities to improve methods for analysis and data management, development of relevant standards and good practices, and communication of these developments to researchers and analysts, as well as to regulatory and policy decision makers in the public and private sectors. The promotion of closer interactions between analytical, clinical, and pharmaceutical scientists who are involved in research and product development with metrologists who develop standards and methodological guidelines is critical to advance research on dietary supplement characterization and health effects.

Development of an HPTLC-based dynamic reference standard for the analysis of complex natural products using Jarrah honey as test sample

In this paper, we describe a novel approach to the development of a reference standard for the quality control of complex natural products, which will assist in the assessment of their authenticity and purity. The proposed method provides a template for the selection of samples, which can be pooled to obtain a reference standard. A shortfall of such an approach is, however, that the pooled sample is static in nature and therefore unable to capture difference in processing conditions or natural variations triggered by geographical or climatic impacts over time. To address this, the paper also outlines the development of a dynamic reference standard, which allows for ongoing adjustments to future variations. The method employs High-Performance Thin Layer Chromatography (HPTLC) derived extract profiles processed by multivariate analysis. The development of the dynamic reference standard is illustrated using honey, a complex natural matrix, as an example.

Integrated assessment of medicinal rhubarb by combination of delayed luminescence and HPLC fingerprint with emphasized on bioactivities based quality control

Background

To promote herbal medicine depends largely on its quality. Chromatographic fingerprint is a frequent approach for quality assessment of herbs however with challenges on robust and reproducibility. To develop rapid, cheap and comprehensive measurements as complementary tools for herbal quality control are still urgently needed. Moreover, biological activities are essential for herbal quality, and should be taken into consideration with emphasized in quality control.

Methods

In this research, HPLC fingerprint and delayed luminescence (DL, a rapid and systematic tool) were used to measure the rhubarb samples of multiple species. Statistics were explored to classify these rhubarb samples using data obtained from two analytic methods. In addition, DL properties were linked to specific chemical components which may reflect bioactivities of rhubarb using Spearman's rank correlation. Moreover, mice model was used to evaluate the cathartic effect between rhubarb samples stratifying by two analytic methods.

Results

We found that there was no significant difference of chemical fingerprints and DL signals among the different species of medicinal rhubarb. However, our results show a high similarity between HPLC fingerprint analysis and DL measurements in classification of these rhubarb samples into two sub-groups. In addition, the two sub-groups of rhubarb samples that may have different cathartic activities.

Conclusion

This approach provides new leads for development of herbal quality assessment based on bioactivity. In conclusion, integrated assessment by measuring HPLC fingerprint and DL with emphasized on bioactivity may provide novel strategy for herbal quality control.

Quantitation of Select Terpenes/Terpenoids and Nicotine Using Gas Chromatography-Mass Spectrometry with High-Temperature Headspace Sampling

Plants are the main sources of many high-value bioactive terpenoids used in the medical, fragrance, and food industries. Increasing demand for these bioactive plants and their derivative products (e.g., cannabis and extracts thereof) requires robust approaches to verify feedstock, identify product adulteration, and ensure product safety. Reported here are single-laboratory validation details for a robust testing method to quantitate select terpenes and terpenoids in dry plant materials and terpenoid-containing vaping liquids (e.g., a derivative product) using high-temperature headspace gas chromatography-mass spectrometry, with glycerol used as a headspace solvent. Validated method recoveries were 75-103%, with excellent repeatability (relative standard deviation (RSD) < 5%) and intermediate precision (RSD < 12%). The use of high-temperature headspace (180 °C) permitted terpene and terpenoid profiles to be monitored at temperatures consistent with vaping conditions.

From Plant Compounds to Botanicals and Back: A Current Snapshot

This work aims at giving an updated picture of the strict interaction between main plant biologically active compounds and botanicals. The main features of the emerging class of dietary supplements, the botanicals, are highlighted. Focus is also on the definition of actual possibilities of study approach and research strategies. Examples of innovative directions are given: assessment of interaction of bioactive compounds, chemometrics and the new goal of biorefineries. Current models of existing databases, such as plant metabolic pathways, food composition, bioactive compounds, dietary supplements, and dietary markers, are described as usable tools for health research. The need for categorization of botanicals as well as for the implementation of specific and dedicated databases emerged, based on both analytical data and collected data taken from literature throughout a harmonized and standardized approach for the evaluation of an adequate dietary intake.

Integration of botanicals in contemporary medicine: road blocks, checkpoints and go-ahead signals

The use of botanicals for maintaining good health and preventing diseases is undisputed. The claimed health benefits of natural health products and herbal medicines are based on traditional claims, positive results obtained in preclinical studies and early phase clinical trials that are not backed by safety and efficacy evidences approved by regulatory agencies. Although, the popularity of botanicals is growing, health care practitioners of modern medicine seldom recommend their use because of ill equipped database of their safety and potency. This review discusses problems that preclude botanicals from integrating into the mainstream contemporary therapeutics and cues that provide impetus for their realisation.

Pro-inflammatory and toxicological evaluation of Hepacare® in mice

Objectives

Hepacare^® is a widely marketed herbal formulation in Nigeria for treating chronic liver ailments. This study evaluated the safety, as well as pro-inflammatory and genotoxicity effects, of Hepacare^® in mice.

Methods

The effect of the formulation was estimated in a 28-day study where 25 mice were divided into five groups, and Hepacare^® was orally administered at 250, 500, 750 and 2500 mg/kg body weight. The biochemical and haematological parameters were determined, organ weights were estimated and histopathology was also conducted. mRNA expression of the pro-inflammatory cytokines, TNF-α and IL-6 was estimated by RT-PCR in acute toxicity experiments.

Results

The LD₅₀ was calculated at 3807.89 mg/kg body weight in mice. There was a significant increase (p < 0.05) in the ALP activity in the 750 mg/kg treated group, while the 2500 mg/kg group exhibited significant increases in their AST, ALT, ALP, total bilirubin and total protein levels compared with the control group. However, there was a significant dose related increase in monocytes counts in the groups treated with 750 and 2500 mg/kg. There was no significant difference (p > 0.05) in TNF-α and IL-6 mRNA expression in the genotoxicity studies in all of the treatment groups compared with the control. However, several hepatic and nephro-pathological derangements were observed in the groups treated with higher doses of the formulation.

Conclusions

The study established that the herbal formulation may not induce significant pro-inflammatory toxic responses and genotoxic effects, but prolonged intake of higher doses may cause severe biochemical and clinical abnormalities.

A Lack of Bioactive Predictability for Marker Compounds Commonly Used for Herbal Medicine Standardization

The use of botanical medicine by practitioners and the general public has dramatically increased in recent years. Most of these botanical therapeutics are obtained through commercial manufacturers or nutraceutical companies. The current standard of practice that manufacturers typically use to standardize botanicals is done based on the level of a well-known, abundant marker compound present in the botanical. This study evaluated the putative correlation between the level of a marker compound and the biological activity of eight common botanicals. Overall, the standardization of a botanical based on a marker compound was found not to be a reliable method when compared to in vitro bioactivity. A marker compound is often not the biologically active component of a plant and therefore the level of such a marker compound does not necessarily correlate with biological activity or therapeutic efficacy.

Quality assessment of medicinal herbs and their extracts: Criteria and prerequisites for consistent safety and efficacy of herbal medicines

Ingredients of commercial herbal medicines are assessed for quality primarily to ensure their safety. However, as complex mixtures of different groups of plant secondary metabolites, retention of overall phytochemical consistency of herbal medicines is pivotal to their efficacy. Authenticity and homogeneity of the herbs and strict regimes of physical processing and extract manufacturing are critical factors to maintain phytochemical consistency in commercial products. To ensure both safety and efficacy of herbal medicines, implementation of and adherence to good agricultural and collection practice (GACP), good plant authentication and identification practice (GPAIP), good manufacturing practice (GMP) before and during the manufacturing process, and good laboratory practice (GLP) in analysis are necessary. Establishment and application of harmonized multilaboratory-validated analytical methods and transparency in the supply (value) chain through vendor audits are additional requirements in quality assurance. In this article, we outline steps of a comprehensive quality assurance paradigm aimed at achieving and maintaining safety, consistent phytochemical composition, and clinical efficacy of ingredients of herbal medicines. This article is part of a Special Issue entitled Botanicals for Epilepsy.

The relevance of pharmacognosy in pharmacological research on herbal medicinal products

As all medicines, herbal medicinal products are expected to be safe, effective, and of appropriate quality. However, regulations on herbal medicinal products vary from country to country, and herbal preparations do occur not only in the form of medicinal products but also as less strictly regulated product groups like dietary supplements. Therefore, it is not always easy for the consumers to discriminate high-quality products from low-quality products. On the other hand, herbal medicines have many special features that distinguish them from conventional medicinal products. Plants are complex multicomponent mixtures; in addition, their phytochemical composition is not constant because of inherent variability and a plethora of external influences. Therefore, the production process of an herbal medicinal product needs to be strictly monitored. First of all, the starting materials need to be correctly authenticated and free of adulterants and contaminants. During plant growth, many factors like harvest season and time, developmental stage, temperature, and humidity have a strong impact on plant metabolite production. Also, postharvest processing steps like drying and storage can significantly alter the phytochemical composition of herbal material. As the production of many phytopharmaceuticals includes an extraction step, the extraction solvent and conditions need to be optimized in order to enrich the bioactive constituents in the extract. The quality of finished preparations needs to be determined either on the basis of marker constituents or on the basis of analytical fingerprints. Thus, all production stages should be accompanied by appropriate quality assessment measures. Depending on the particular task, different methods need to be applied, ranging from macroscopic, microscopic, and DNA-based authentication methods to spectroscopic methods like vibrational spectroscopy and chromatographic and hyphenated methods like HPLC, GC-MS and LC-MS. Also, when performing pharmacological and toxicological studies, many features inherent in herbal medicinal products need to be considered in order to guarantee valid results: concerning in vitro studies, difficulties are often related to lacking knowledge of ADME characteristics of the bioactive constituents, nuisance compounds producing false positive and false negative results, and solubility problems. In in vivo animal studies, the route of administration is a very important issue. Clinical trials on herbal medicinal products in humans very often suffer from a poor reporting quality. This often hampers or precludes the pooling of clinical data for systematic reviews. In order to overcome this problem, appropriate documentation standards for clinical trials on herbal medicinal products have been defined in an extension of the CONSORT checklist. This article is part of a Special Issue entitled "Botanicals for Epilepsy".

Flavonoids of Herba Epimedii stimulate osteogenic differentiation and suppress adipogenic differentiation of primary mesenchymal stem cells via estrogen receptor pathway

CONTEXT

Accumulating evidence indicates that Herba Epimedii [Epimedii folium (Berberidaceae)] has anti-osteoporotic effect by stimulating osteoblastic bone formation and reducing osteoclastic bone resorption. However, the effect of Herba Epimedii in regulating the cross-talk between osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs) remains unclear.

OBJECTIVE

The present study investigates the effect of total flavonoids of Herba Epimedii (HETF) on the osteogenesis and adipogenesis of primary MSCs.

MATERIALS AND METHODS

HETF were prepared and identified by HPLC-fingerprinting, primary mouse MSCs in the presence of 0.006-6 μg/mL HETF for 2-10 d were subject to morphological, biochemical, and quantitative real-time PCR analysis.

RESULTS

Sixteen chemical components were identified in HETF by HPLC-fingerprinting and account for over 95% of the total area of HPLC peaks. During osteogenesis of MSCs, 0.006-6 μg/mL HETF promoted the proliferation of MSCs from 17% to 22%, increased alkaline phosphatase activity up to 3.7-fold (0.6 μg/mL), and extracellular calcium deposits from 1.2- to 1.4-folds by up-regulating the expression of runt-related transcription factor-2 (Runx-2) and bone morphogenetic protein-2 (BMP-2). Meanwhile, HETF suppressed the adipogenesis of MSCs by reducing the formation of adipocyte-like cells and accumulation of fat droplets by down-regulating the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ). The above biological activities of HETF were mainly through estrogen receptor-mediated pathway, which were blocked by estrogen receptor antagonist, ICI 182,780.

CONCLUSION

HETF could regulate Runx-2-mediated osteogenesis and PPAR-γ-mediated adipogenesis in MSCs and thus exhibit beneficial effects to bone health, which suggests a new strategy for treating patients with osteoporosis and obesity.

The Saccharomyces cerevisiae transcriptome as a mirror of phytochemical variation in complex extracts of Equisetum arvense from America, China, Europe and India

BACKGROUND

Pattern-oriented chemical profiling is increasingly being used to characterize the phytochemical composition of herbal medicines for quality control purposes. Ideally, a fingerprint of the biological effects should complement the chemical fingerprint. For ethical and practical reasons it is not possible to test each herbal extract in laboratory animals or humans. What is needed is a test system consisting of an organism with relevant biology and complexity that can serve as a surrogate in vitro system. The purpose of this study was to test the hypothesis that the Saccharomyces cerevisiae transcriptome might be used as an indicator of phytochemical variation of closely-related yet distinctly different extracts prepared from a single species of a phytogeographically widely distributed medicinal plant. We combined phytochemical profiling using chromatographic methods (HPTLC, HPLC-PDA-MS/MS) and gene expression studies using Affymetrix Yeast 2.0 gene chip with principal component analysis and k-nearest neighbor clustering analysis to test this hypothesis using extracts prepared from the phytogeographically widely distributed medicinal plant Equisetum arvense as a test case.

RESULTS

We found that the Equisetum arvense extracts exhibited qualitative and quantitative differences in their phytochemical composition grouped along their phytogeographical origin. Exposure of yeast to the extracts led to changes in gene expression that reflected both the similarities and differences in the phytochemical composition of the extracts. The Equisetum arvense extracts elicited changes in the expression of genes involved in mRNA translation, drug transport, metabolism of energy reserves, phospholipid metabolism, and the cellular stress response.

CONCLUSIONS

Our data show that functional genomics in S. cerevisiae may be developed as a sensitive bioassay for the scientific investigation of the interplay between phytochemical composition and transcriptional effects of complex mixtures of chemical compounds. S. cerevisiae transcriptomics may also be developed for testing of mixtures of conventional drugs ("polypills") to discover novel antagonistic or synergistic effects of those drug combinations.

Quantitative analysis of catechins in Saraca asoca and correlation with antimicrobial activity

Herbal medicines are highly complex and have unknown mechanisms in diseases treatment. Saraca asoca (Roxb.), De. Wild has been recommended to treat gynecological disorders and used in several commercial polyherbal formulations. In present study, efforts have been made to explore antimicrobial activity and its co-relation with the distributions of catechins in the organs of S. asoca using targeted MS/MS. Eight extracts (cold and hot water) from four different organs of S. asoca and two drugs were prepared and antimicrobial activity was assessed by microbroth dilution assay. Quantitative and qualitative analysis of catechins in crude extracts was done by using targeted and auto-MS/MS and correlated with antimicrobial activity. (+)-Catechin and (+)-epicatechin and their biosynthesis related compound were found to be up-regulated in regenerated bark and leaves extracts. (−)-Epigallocatechin was found to be significantly higher in bark water extract as compared to others but showed low antimicrobial activity. Result showed down-regulation of (−)-epigallocatechin and up-regulation of (+)-catechin and (+)-epicatechin in the regenerated bark and leaves of S. asoca. It might be the contributing factor in the antimicrobial activity of regenerated bark and leaves of the plant. The concentration of (+)-epicatechin in processed drugs (Ashokarishta) from Baidyanath was found to be seven times higher than that of Dabur Pvt. Ltd., but no antimicrobial activity was observed, indicating the variations among the plant based drugs. This will be helpful in rational use of S. asoca parts. Furthermore, the analytical method developed is sensitive, repeatable and reliable; therefore, it is suitable for quality control of herbal drugs.

From classical taxonomy to genome and metabolome: towards comprehensive quality standards for medicinal herb raw materials and extracts

Fundamental to herbal medicine quality is the use of 'authentic' medicinal herb species. Species, however, 'represent more or less arbitrary and subjective man-made units'. Against this background, we discuss, with illustrative examples, the importance of defining species boundaries by accommodating both the fixed (shared) diagnostic and varying (within-species) traits in medicinal herb populations. We emphasize the role of taxonomy, floristic information and genomic profiling in authenticating medicinal herb species, in addition to the need to include within species phytochemical profile variations while developing herbal extract identification protocols. We outline the application of species-specific genomic and phytochemical markers, chemoprofiling and chemometrics as additional tools to develop qualifying herbal extract references. We list the diagnostic traits available subsequent to each step during the medicinal herb extract manufacturing process and delineate limits to qualification of extract references.

Natural products and traditional medicine: turning on a paradigm

Paradigm shifts in the strategies and the sciences that would enhance the quality, safety, and efficacy of traditional medicines and dietary supplements in global health care are discussed. Some of the challenges facing traditional medicine in health care are described, and the importance of defining clear goals and directions for the information systems, botany, chemistry, and biology related to plants and health care, including for drug discovery and quality control, is indicated.

Recent analytical approaches in quality control of traditional Chinese medicines--a review

Traditional Chinese medicines (TCMs) are gaining more and more attention all over the world, due to their specific theory and long historical clinical practice. But the uncontrollable quality is a bottleneck for its modernization and globalization. This paper reviewed the recent analytical methods in the quality control of TCMs, including screening strategies of bioactive markers from TCMs through biochromatographic methods, the traditional chromatographic methods, DNA methods, as well as the spectroscopic methods, including FT-IR, NIR and NMR. The comprehensive methods, such as fingerprint and multi-component quantification are emphasized; hyphenated techniques, like HPLC-MS, GC-MS, CE-MS, LC-NMR, chemometric methods, and combination of chemical and biological methods, such as biofingerprint, metabolic fingerprint are now more and more widely used in TCMs. In a few word, the analysis and quality control of TCMs are moving towards an integrative and comprehensive direction, in order to better address the inherent holistic nature of TCMs.