NMR-based Metabolomic Techniques Identify the Toxicity of Emodin in HepG2 Cells

A new phenolic compound from Persicaria capitata

Persicaria capitata was a frequently used Hmong medicinal flora in China. In this study, one new phenolic compound, capitaone A (1) together with 20 known ones, were isolated from the whole herb of P. capitata. Among them, 7 components (4, 9-11, 15-16, 20-21) were discovered from P. capitata for the first time. Their chemical structures were elucidated on the basis of extensive NMR and MS spectrum. Furthermore, three compounds (15, 20, 21) displayed remarkable cytotoxic activities against two human cancer cell lines (A549 and HepG2).

Combined cytotoxicity of phthalate esters on HepG2 cells: A comprehensive analysis of transcriptomics and metabolomics

Phthalate esters (PAEs), widely used as plasticizers, may pose a potential environmental and human hazard. The aim of this study was to compare the cytotoxicity of di(2-ethylhexyl) phthalates (DEHP) and dibutyl phthalate (DBP)) after their exposure to HepG2 cells alone or in combination. HepG2 cells treated with individual/combined DEHP and DBP at a dose of 10-2 M for 24 h were selected for metabolome and transcriptome analysis. The results demonstrated that exposure to the mixtures of DEHP and DBP caused enhanced or reduced toxic effects regarding 8 pathways with 1065 downregulated genes and 643 upregulated genes, in comparison with those of single chemicals. The combined toxicity of mixture revealed both synergistic and antagonistic interactions between DEHP and DBP. Besides, combined exposure to DEHP and DBP promoted TCA cycle, pyrimidine, and purine metabolism, while an antagonistic effect on fatty acid derangement should require further investigation. To summarize, our results suggest that DEHP exposed alone or combined with DBP caused a variety of metabolic disorders, and the type of combination effects varied among metabolic pathways.

The Expectation and Reality of the HepG2 Core Metabolic Profile

To represent the composition of small molecules circulating in HepG2 cells and the formation of the "core" of characteristic metabolites that often attract researchers' attention, we conducted a meta-analysis of 56 datasets obtained through metabolomic profiling via mass spectrometry and NMR. We highlighted the 288 most commonly studied compounds of diverse chemical nature and analyzed metabolic processes involving these small molecules. Building a complete map of the metabolome of a cell, which encompasses the diversity of possible impacts on it, is a severe challenge for the scientific community, which is faced not only with natural limitations of experimental technologies, but also with the absence of transparent and widely accepted standards for processing and presenting the obtained metabolomic data. Formulating our research design, we aimed to reveal metabolites crucial to the Hepg2 cell line, regardless of all chemical and/or physical impact factors. Unfortunately, the existing paradigm of data policy leads to a streetlight effect. When analyzing and reporting only target metabolites of interest, the community ignores the changes in the metabolomic landscape that hide many molecular secrets.

Emodin, an Emerging Mycotoxin, Induces Endoplasmic Reticulum Stress-Related Hepatotoxicity through IRE1α-XBP1 Axis in HepG2 Cells

Emodin, an emerging mycotoxin, is known to be hepatotoxic, but its mechanism remains unclear. We hypothesized that emodin could induce endoplasmic reticulum (ER) stress through the inositol-requiring enzyme 1 alpha (IRE1α)-X-box-binding protein 1 (XBP1) pathway and apoptosis, which are closely correlated and contribute to hepatotoxicity. To test this hypothesis, a novel IRE1α inhibitor, STF-083010, was used. An MTT assay was used to evaluate metabolic activity, and quantitative PCR and western blotting were used to investigate the gene and protein expression of ER stress or apoptosis-related markers. Apoptosis was evaluated with flow cytometry. Results showed that emodin induced cytotoxicity in a dose-dependent manner in HepG2 cells and upregulated the expression of binding immunoglobulin protein (BiP), C/EBP homologous protein (CHOP), IRE1α, spliced XBP1, the B-cell lymphoma 2 (Bcl-2)-associated X protein (Bax)/Bcl-2 ratio, and cleaved caspase-3. Cotreatment with emodin and STF-083010 led to the downregulation of BiP and upregulation of CHOP, the Bax/Bcl-2 ratio, and cleaved caspase-3 compared with single treatment with emodin. Furthermore, the apoptosis rate was increased in a dose-dependent manner with emodin treatment. Thus, emodin induced ER stress in HepG2 cells by activating the IRE1α-XBP1 axis and induced apoptosis, indicating that emodin can cause hepatotoxicity.

Application of vibrational spectroscopy and nuclear magnetic resonance methods for drugs pharmacokinetics research

OBJECTIVES

The development of new methods for determining the concentration of drugs is an actual topic today. The article contains a detailed review on vibrational spectroscopy and nuclear magnetic resonance methods using for pharmacokinetic research. This study is devoted to the possibility of using vibrational spectroscopy and 1H nuclear magnetic resonance spectroscopy to determine the concentration of drugs and the use of these groups of techniques for therapeutic drug monitoring.

CONTENT

The study was conducted by using scientific libraries (Scopus, Web of Science Core Collection, Medline, GoogleScholar, eLIBRARY, PubMed) and reference literature. A search was conducted for the period from 2011 to 2021 in Russian and English, by combinations of words: 1H nuclear magnetic resonance (¹H NMR), vibrational spectroscopy, Surface-Enhanced Raman spectroscopy, drug concentration, therapeutic drug monitoring. These methods have a number of advantages and are devoid of some of the disadvantages of classical therapeutic drug monitoring (TDM) methods - high performance liquid chromatography and mass spectrometry. This review considers the possibility of using the methods of surface-enhanced Raman scattering (SERS) and ¹H NMR-spectroscopy to assess the concentration of drugs in various biological media (blood, urine), as well as to study intracellular metabolism and the metabolism of ophthalmic drugs. ¹Н NMR-spectroscopy can be chosen as a TDM method, since it allows analyzing the structure and identifying metabolites of various drugs. ¹Н NMR-based metabolomics can provide information on the side effects of drugs, predict response to treatment, and provide key information on the mechanisms of action of known and new drug compounds.

SUMMARY AND OUTLOOK

SERS and ¹Н NMR-spectroscopy have great potential for further study and the possibility of introducing them into clinical practice, including for evaluating the efficacy and safety of drugs.

Innovative Application of Metabolomics on Bioactive Ingredients of Foods

Metabolomics, as a new omics technology, has been widely accepted by researchers and has shown great potential in the field of nutrition and health in recent years. This review briefly introduces the process of metabolomics analysis, including sample preparation and extraction, derivatization, separation and detection, and data processing. This paper focuses on the application of metabolomics in food-derived bioactive ingredients. For example, metabolomics techniques are used to analyze metabolites in food to find bioactive substances or new metabolites in food materials. Moreover, bioactive substances have been tested in vitro and in vivo, as well as in humans, to investigate the changes of metabolites and the underlying metabolic pathways, among which metabolomics is used to find potential biomarkers and targets. Metabolomics provides a new approach for the prevention and regulation of chronic diseases and the study of the underlying mechanisms. It also provides strong support for the development of functional food or drugs. Although metabolomics has some limitations such as low sensitivity, poor repeatability, and limited detection range, it is developing rapidly in general, and also in the field of nutrition and health. At the end of this paper, we put forward our own insights on the development prospects of metabolomics in the application of bioactive ingredients in food.

Combination Anticancer Therapies Using Selected Phytochemicals

Cancer is still one of the most widespread diseases globally, it is considered a vital health challenge worldwide and one of the main barriers to long life expectancy. Due to the potential toxicity and lack of selectivity of conventional chemotherapeutic agents, discovering alternative treatments is a top priority. Plant-derived natural products have high potential in cancer treatment due to their multiple mechanisms of action, diversity in structure, availability in nature, and relatively low toxicity. In this review, the anticancer mechanisms of the most common phytochemicals were analyzed. Furthermore, a detailed discussion of the anticancer effect of combinations consisting of natural product or natural products with chemotherapeutic drugs was provided. This review should provide a strong platform for researchers and clinicians to improve basic and clinical research in the development of alternative anticancer medicines.

Methodological Developments for Metabolic NMR Spectroscopy from Cultured Cells to Tissue Extracts: Achievements, Progress and Pitfalls

This is a broad overview and critical review of a particular group of closely related ex vivo and in vitro metabolic NMR spectroscopic methods. The scope of interest comprises studies of cultured cells and excised tissue, either intact or after physicochemical extraction of metabolites. Our detailed discussion includes pitfalls that have led to erroneous statements in the published literature, some of which may cause serious problems in metabolic and biological interpretation of results. To cover a wide range of work from relevant research areas, we consider not only the most recent achievements in the field, but also techniques that proved to be valid and successful in the past, although they may not have generated a very significant number of papers more recently. Thus, this comparative review also aims at providing background information useful for judiciously choosing between the metabolic ex vivo/in vitro NMR methods presented. Finally, the methods of interest are discussed in the context of, and in relation to, other metabolic analysis protocols such as HR-MAS and cell perfusion NMR, as well as the mass spectrometry approach.

Advances in the study of emodin: an update on pharmacological properties and mechanistic basis

Rhei Radix et Rhizoma, also known as rhubarb or Da Huang, has been widely used as a spice and as traditional herbal medicine for centuries, and is currently marketed in China as the principal herbs in various prescriptions, such as Da-Huang-Zhe-Chong pills and Da-Huang-Qing-Wei pills. Emodin, a major bioactive anthraquinone derivative extracted from rhubarb, represents multiple health benefits in the treatment of a host of diseases, such as immune-inflammatory abnormality, tumor progression, bacterial or viral infections, and metabolic syndrome. Emerging evidence has made great strides in clarifying the multi-targeting therapeutic mechanisms underlying the efficacious therapeutic potential of emodin, including anti-inflammatory, immunomodulatory, anti-fibrosis, anti-tumor, anti-viral, anti-bacterial, and anti-diabetic properties. This comprehensive review aims to provide an updated summary of recent developments on these pharmacological efficacies and molecular mechanisms of emodin, with a focus on the underlying molecular targets and signaling networks. We also reviewed recent attempts to improve the pharmacokinetic properties and biological activities of emodin by structural modification and novel material-based targeted delivery. In conclusion, emodin still has great potential to become promising therapeutic options to immune and inflammation abnormality, organ fibrosis, common malignancy, pathogenic bacteria or virus infections, and endocrine disease or disorder. Scientifically addressing concerns regarding the poor bioavailability and vague molecular targets would significantly contribute to the widespread acceptance of rhubarb not only as a dietary supplement in food flavorings and colorings but also as a health-promoting TCM in the coming years.

Molecular and Metabolomic Investigation of Celecoxib Antiproliferative Activity in Mono-and Combination Therapy Against Breast Cancer Cell Models

BACKGROUND

Chronic inflammation plays a crucial role in the initiation, promotion, and invasion of tumors, and thus the antiproliferative effects of numerous anti-inflammatory drugs have been frequently reported in the literature. Upregulation of the pro-inflammatory enzyme cyclooxygenase-2 (COX-2) has been linked to various human cancers, including breast cancer.

OBJECTIVES

This research aims to investigate the antiproliferative activity of different Non-steroidal anti-inflammatory drugs (NSAIDs), including COX-2 selective and non-selective agents, against various breast cancer cell lines and to elucidate possible molecular pathways involved in their activity.

METHODS

The antiproliferative and combined effects of NSAIDs with raloxifene were evaluated by MTT assay. Cell migration was assessed using a wound-healing assay. The mechanism of cell death was determined using the Annexin V-FITC/ propidium iodide staining flow cytometry method. A mass spectrometry-based targeted metabolomics approach was used to profile the metabolomic changes induced in the T47d cells upon drug treatment.

RESULTS

Our results have demonstrated that celecoxib, a potent and selective COX-2 inhibitor, resulted in significant antiproliferative activity against all examined breast cancer cell lines with IC50 values of 95.44, 49.50. and 97.70 μM against MDA-MB-231, T47d, and MCF-7, respectively. Additionally, celecoxib exhibited a synergistic effect against T47d cells combined with raloxifene, a selective estrogen receptor modulator. Interestingly, celecoxib treatment increased cell apoptosis and resulted in substantial inhibition of cancer cell migration. In addition, the metabolomic analysis suggests that celecoxib may have affected metabolites (n = 43) that are involved in several pathways, including the tricarboxylic acid cycle, amino acids metabolism pathways, and energy production pathways in cancer cells.

CONCLUSION

Celecoxib may possess potential therapeutic utility for breast cancer treatment as monotherapy or in combination therapy. The reported metabolic changes taking place upon celecoxib treatment may shed light on possible molecular targets mediating the antiproliferative activity of celecoxib in an independent manner of its COX-2 inhibition.

NMR-based Metabolomic Techniques Identify the Anticancer Effects of Three Polyphyllins in HepG2 Cells

Background:

Rhizoma Paridis (RP) is a traditional Chinese herb used for the treatment of tumors, detoxification and hemostasia. Studies show the main components of RP are Polyphyllin I (PPI), polyphyllin VI (PPVI), and polyphyllin VII (PPVII). However, the pharmaco-mechanisms of these compounds are not clear.

Objective:

By used 1 H nuclear magnetic resonance (1 H-NMR) based metabolomics approach to identify the Anticancer effects of PPI, PPVI and PPVII in HepG2 cells. Methods 1 H nuclear magnetic resonance (1 H-NMR) based metabolomics approach was applied to investigate the toxicological effect of PPI, PPVI, PPVII on HepG2 cells. Multivariate statistical analysis was employed to examine the metabolic changes and abnormal metabolic pathways, including Principal Component Analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA), and orthogonal PLS-DA (OPLS-DA).

Results:

The results showed that the effects of metabolic phenotypes were affected separately by PPI, PPVI, and PPVII. The metabolic phenotypes were also changed over time. The characteristic metabolites were varied by affecting different polyphylins, which were identified by the reconstructed OPLSDA loading plots. According to the characteristic metabolites, the mainly disturbed metabolic pathways were found, such as alanine, aspartate and glutamate metabolism, pyruvate metabolism, glycine, serine, and threonine metabolism.

Conclusion:

The current work could allow us to understand the therapeutic effect of RP in metabolism. It also indicated that RP would be a promising candidate for liver cancer treatment.

Is Emodin with Anticancer Effects Completely Innocent? Two Sides of the Coin

Many anticancer active compounds are known to have the capacity to destroy pathologically proliferating cancer cells in the body, as well as to destroy rapidly proliferating normal cells. Despite remarkable advances in cancer research over the past few decades, the inclusion of natural compounds in researches as potential drug candidates is becoming increasingly important. However, the perception that the natural is reliable is an issue that needs to be clarified. Among the various chemical classes of natural products, anthraquinones have many biological activities and have also been proven to exhibit a unique anticancer activity. Emodin, an anthraquinone derivative, is a natural compound found in the roots and rhizomes of many plants. The anticancer property of emodin, a broad-spectrum inhibitory agent of cancer cells, has been detailed in many biological pathways. In cancer cells, these molecular mechanisms consist of suppressing cell growth and proliferation through the attenuation of oncogenic growth signaling, such as protein kinase B (AKT), mitogen-activated protein kinase (MAPK), HER-2 tyrosine kinase, Wnt/-catenin, and phosphatidylinositol 3-kinase (PI3K). However, it is known that emodin, which shows toxicity to cancer cells, may cause kidney toxicity, hepatotoxicity, and reproductive toxicity especially at high doses and long-term use. At the same time, studies of emodin, which has poor oral bioavailability, to transform this disadvantage into an advantage with nano-carrier systems reveal that natural compounds are not always directly usable compounds. Consequently, this review aimed to shed light on the anti-proliferative and anti-carcinogenic properties of emodin, as well as its potential toxicities and the advantages of drug delivery systems on bioavailability.

Marine Anthraquinones: Pharmacological and Toxicological Issues

The marine ecosystem, populated by a myriad of animals, plants, and microorganisms, is an inexhaustible reservoir of pharmacologically active molecules. Among the multiple secondary metabolites produced by marine sources, there are anthraquinones and their derivatives. Besides being mainly known to be produced by terrestrial species, even marine organisms and the uncountable kingdom of marine microorganisms biosynthesize anthraquinones. Anthraquinones possess many different biological activities, including a remarkable antitumor activity. However, due to their peculiar chemical structures, anthraquinones are often associated with toxicological issues, even relevant, such as genotoxicity and mutagenicity. The aim of this review is to critically describe the anticancer potential of anthraquinones derived from marine sources and their genotoxic and mutagenic potential. Marine-derived anthraquinones show a promising anticancer potential, although clinical studies are missing. Additionally, an in-depth investigation of their toxicological profile is needed before advocating anthraquinones as a therapeutic armamentarium in the oncological area.

Emodin-Induced Oxidative Inhibition of Mitochondrial Function Assists BiP/IRE1α/CHOP Signaling-Mediated ER-Related Apoptosis

Cassiae Semen is a widely used herbal medicine and a popular edible variety in many dietary or health beverage. Emerging evidence disclosed that improper administration of Cassiae Semen could induce obvious liver injury, which is possibly attributed to emodin, one of the bioactive anthraquinone compounds in Cassiae Semen, which caused hepatotoxicity, but the underlying mechanisms are not completely understood. Hence, the present study firstly explored the possible role of oxidative stress-mediated mitochondrial dysfunction and ER stress in emodin-cause apoptosis of L02 cells, aiming to elaborate possible toxic mechanisms involved in emodin-induced hepatotoxicity. Our results showed that emodin-induced ROS activated ER stress and the UPR via the BiP/IRE1α/CHOP signaling pathway, followed by ER Ca²⁺ release and cytoplasmic Ca²⁺ overloading. At the same time, emodin-caused redox imbalance increased mtROS while decreased MMP and mitochondrial function, resulting in the leaks of mitochondrial-related proapoptotic factors. Interestingly, blocking Ca²⁺ release from ER by 2-APB could inhibit emodin-induced apoptosis of L02, but the restored mitochondrial function did not reduce the apoptosis rates of emodin-treated cells. Besides, tunicamycin (TM) and doxorubicin (DOX) were used to activate ER stress and mitochondrial injury at a dosage where obvious apoptosis was not observed, respectively. We found that cotreatment with TM and DOX significantly induced apoptosis of L02 cells. Thus, all the results indicated that emodin-induced excessive ROS generation and redox imbalance promoted apoptosis, which was mainly associated with BiP/IRE1α/CHOP signaling-mediated ER stress and would be enhanced by oxidative stress-mediated mitochondrial dysfunction. Altogether, this finding has implicated that redox imbalance-mediated ER stress could be an alternative target for the treatment of Cassiae Semen or other medicine-food homologous varieties containing emodin-induced liver injury.

Metabolic Changes of Cholangiocarcinoma Cells in Response to Coniferyl Alcohol Treatment

Cholangiocarcinoma (CCA) is a major cause of mortality in Northeast Thailand with about 14,000 deaths each year. There is an urgent necessity for novel drug discovery to increase effective treatment possibilities. A recent study reported that lignin derived from Scoparia dulcis can cause CCA cell inhibition. However, there is no evidence on the inhibitory effect of coniferyl alcohol (CA), which is recognized as a major monolignol-monomer forming a very complex structure of lignin. Therefore, we aimed to investigate the effect of CA on CCA cell apoptosis. We demonstrated that a half-inhibitory concentration of CA on KKU-100 cells at 48 h and 72 h was 361.87 ± 30.58 and 268.27 ± 18.61 μg/mL, respectively, and on KKU-213 cells 184.37 ± 11.15 and 151.03 ± 24.99 μg/mL, respectively. Furthermore, CA induced CCA cell apoptosis as demonstrated by annexin V/PI staining in correspondence with an increase in the BAX/Bcl-2 ratio. A metabonomic study indicated that CA significantly decreased the intracellular concentrations of glutathione and succinate in KKU-213 cells and increased dihydrogen acetone phosphate levels in KKU-100 cells treated with 200 µg/mL of CA compared to the control group. In conclusion, CA induced cellular metabolic changes which are involved in the antioxidant defense mechanism, glycerophospholipid metabolism and the tricarboxylic acid cycle. CA may serve as a potent anticancer agent for CCA treatment by inducing CCA cellular apoptosis.

UPLC-Q-TOF/MS-Based Metabolomics Approach to Reveal the Hepatotoxicity of Emodin and Detoxification of Dihydromyricetin

Dihydromyricetin (DMY), an important flavanone found in Ampelopsis grossedentata, plays a protective role in liver injury. Our previous research found that DMY protected L02 cells against hepatotoxicity caused by emodin. In this study, serum, urine, and liver samples from rats were systematically used for biochemical analysis, pathological observation, and nontargeted metabolomics to evaluate the toxicity of emodin and DMY intervention. After oral administration of DMY, DMY may alleviate liver injury by improving liver metabolism. Approximately, 8 of 15 metabolites in rat urine and serum were significantly regulated by DMY. Metabolic pathway analysis showed that glutathione metabolism, pyrimidine metabolism, and tryptophan metabolism were the most affected pathways, and 18 proteins were predicted to be potential targets of DMY during the alleviation of liver injury induced by emodin. This research is of great significance in confirming the liver-protective effect of DMY, especially during acute liver injury caused by traditional Chinese medicine.

1H-NMR metabolomics reveals a multitarget action of Crithmum maritimum ethyl acetate extract in inhibiting hepatocellular carcinoma cell growth

Hepatocellular carcinoma (HCC) is nowadays the sixth cause of tumour-related deceases worldwide, estimated to become the third in Western countries by 2030. New drugs for HCC treatment still have many adverse effects. Several lines of evidence indicate that plant metabolites offer concrete opportunities for developing new therapeutic strategies for many diseases, including cancer. We previously reported that ethyl acetate extract of a spontaneous edible plant harvested in Apulia, Crithmum maritimum, significantly inhibited cell growth in HCC cells. By ¹H-NMR spectroscopy, here we show that Crithmum maritimum ethyl acetate extract counteracts the Warburg effect, by reducing intracellular lactate, inhibits protein anabolism, by decreasing amino acid level, and affects membrane biosynthesis by lowering choline and phosphocholine. Also, we observed an effect on lipid homeostasis, with a reduction in triglycerides, cholesterol, monounsaturated fatty acids (MUFA), and diunsaturated fatty acids (DUFA), and an increase in polyunsaturated fatty acids (PUFA). Taken together, these data demonstrate that Crithmum maritimum-induced cytostasis is exerted through a multi-effect action, targeting key metabolic processes in HCC cells. Overall, our findings highlight the role of Crithmum maritimum as a promising tool for the prevention and the improvement of the therapeutic options for HCC and other types of tumours.

In Vitro and In Vivo Models for Evaluating the Oral Toxicity of Nanomedicines

Toxicity studies for conventional oral drug formulations are standardized and well documented, as required by the guidelines of administrative agencies such as the US Food & Drug Administration (FDA), the European Medicines Agency (EMA) or European Medicines Evaluation Agency (EMEA), and the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). Researchers tend to extrapolate these standardized protocols to evaluate nanoformulations (NFs) because standard nanotoxicity protocols are still lacking in nonclinical studies for testing orally delivered NFs. However, such strategies have generated many inconsistent results because they do not account for the specific physicochemical properties of nanomedicines. Due to their tiny size, accumulated surface charge and tension, sizeable surface-area-to-volume ratio, and high chemical/structural complexity, orally delivered NFs may generate severe topical toxicities to the gastrointestinal tract and metabolic organs, including the liver and kidney. Such toxicities involve immune responses that reflect different mechanisms than those triggered by conventional formulations. Herein, we briefly analyze the potential oral toxicity mechanisms of NFs and describe recently reported in vitro and in vivo models that attempt to address the specific oral toxicity of nanomedicines. We also discuss approaches that may be used to develop nontoxic NFs for oral drug delivery.

NMR as a "Gold Standard" Method in Drug Design and Discovery

Studying disease models at the molecular level is vital for drug development in order to improve treatment and prevent a wide range of human pathologies. Microbial infections are still a major challenge because pathogens rapidly and continually evolve developing drug resistance. Cancer cells also change genetically, and current therapeutic techniques may be (or may become) ineffective in many cases. The pathology of many neurological diseases remains an enigma, and the exact etiology and underlying mechanisms are still largely unknown. Viral infections spread and develop much more quickly than does the corresponding research needed to prevent and combat these infections; the present and most relevant outbreak of SARS-CoV-2, which originated in Wuhan, China, illustrates the critical and immediate need to improve drug design and development techniques. Modern day drug discovery is a time-consuming, expensive process. Each new drug takes in excess of 10 years to develop and costs on average more than a billion US dollars. This demonstrates the need of a complete redesign or novel strategies. Nuclear Magnetic Resonance (NMR) has played a critical role in drug discovery ever since its introduction several decades ago. In just three decades, NMR has become a "gold standard" platform technology in medical and pharmacology studies. In this review, we present the major applications of NMR spectroscopy in medical drug discovery and development. The basic concepts, theories, and applications of the most commonly used NMR techniques are presented. We also summarize the advantages and limitations of the primary NMR methods in drug development.

Molecular Mechanisms of Action of Emodin: As an Anti-Cardiovascular Disease Drug

Emodin is a natural occurring anthraquinone derivative isolated from roots and barks of numerous plants, molds, and lichens. It is found to be an active ingredient in different Chinese herbs including Rheum palmatum and Polygonam multiflorum, and it is a pleiotropic molecule with diuretic, vasorelaxant, anti-bacterial, anti-viral, anti-ulcerogenic, anti-inflammatory, and anti-cancer effects. Moreover, emodin has also been shown to have a wide activity of anti-cardiovascular diseases. It is mainly involved in multiple molecular targets such as inflammatory, anti-apoptosis, anti-hypertrophy, anti-fibrosis, anti-oxidative damage, abnormal, and excessive proliferation of smooth muscle cells in cardiovascular diseases. As a new type of cardiovascular disease treatment drug, emodin has broad application prospects. However, a large amount of evidences detailing the effect of emodin on many signaling pathways and cellular functions in cardiovascular disease, the overall understanding of its mechanisms of action remains elusive. In addition, by describing the evidence of the effects of emodin in detail, the toxicity and poor oral bioavailability of mice have been continuously discovered. This review aims to describe a timely overview of emodin related to the treatment of cardiovascular disease. The emphasis is to summarize the pharmacological effects of emodin as an anti-cardiovascular drug, as well as the targets and its potential mechanisms. Furthermore, the treatment of emodin compared with conventional cardiovascular drugs or target inhibitors, the toxicity, pharmacokinetics and derivatives of emodin were discussed.

Hepatoxicity mechanism of cantharidin-induced liver LO2 cells by LC-MS metabolomics combined traditional approaches

Hepatotoxicity induced by Mylabris has been reported in both clinical and animal experiments. Cantharidin (CTD), the main active compound of Mylabris was responsible for the hepatotoxicity, which aroused widespread concern. However, the mechanism of CTD hepatotoxicity remained unclear. In this study, LO2 cells were exposed to two doses of CTD (6.25 and 25 μM) for 12 h, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured. The metabolites in LO2 cells were profiled by LC-MS. Partial least squares discriminant analysis and orthogonal partial least squares discriminant analysis were used for screening potential biomarkers. The MetPA software was used for clustering and pathway analysis. Network pharmacology was used to predict the genes acted with potential biomarkers. Compared with the control group, the levels of ALT, AST, and LDH was significantly increased after CTD treatment. A total of 46 potential biomarkers for hepatotoxicity induced by CTD were identified. And downregulated potential biomarkers reflected the inhibitory effects of CTD toxicity on metabolism of LO2. Moreover, CTD-induced liver toxicity of LO2 cells is mainly related to three pathways: cysteine and methionine metabolism; glutathione metabolism; and glycine, serine, and threonine metabolism. Furtherly, the mRNA expression of CES2, DNMT1, NOS1, NOS3, S1PR2, and CES1 screened by network pharmacology were regulated by CTD. These studies provide valuable mechanistic insights into CTD-associated hepatotoxicity that will aid in the development of therapeutic prevention and treatment options for this liver disease.

Examining Safety of Biocolourants from Fungal and Plant Sources-Examples from Cortinarius and Tapinella, Salix and Tanacetum spp. and Dyed Woollen Fabrics

Biocolourants have been investigated as alternatives to synthetic dyes. However, natural origin per se is not a label of harmlessness and research is needed to obtain safe dyes. We studied the cytotoxicity of the extracts from fungal (Cortinarius semisanguineus, Tapinella atrotomentosa) and plant (Tanacetum vulgare, Salix phylicifolia) sources and the woollen fabrics dyed with the extracts. Cytotoxicity in vitro using hepa-1 mouse hepatoma cells for 24 h and 72 h exposure was observed as the highest tolerated dose. All biocolourants produced intensive colour on fabrics with fastness properties from moderate to good. The Salix and Cortinarius samples did not show any cytotoxic effects, whereas the Tanacetum and Tapinella samples had slightly higher test values but were not interpreted as being significantly toxic. Higher than zero values of the undyed fabrics showed the importance of examining their toxicity as well. It was found that the cytotoxicity of the samples dyed with the biocolourants did not differ significantly from the undyed wool fabric. The concentrations of dyes used in the assays were very low, imitating the dose of the user. In addition to colouring properties, natural dyes may have pharmaceutical and antibacterial properties which would enhance the interest in using them in products for added value.

Metabolomic modulations of HepG2 cells exposed to bisphenol analogues

Bisphenol analogues including bisphenol A (BPA), bisphenol AF (BPAF), bisphenol F (BPF), and bisphenol S (BPS) share similar chemical structures and endocrine disrupting effects. Their effects on metabolisms, however, are so far only marginally understood. In this study, NMR-based metabonomic profiles of HepG2 cell culture media and PCR array were used to assess the metabolomics disturbances and gene expression levels of HepG2 in response to four BPs (BPA, BPAF, BPF, and BPS). The results indicated that BP analogues resulted in disturbances in 7-15 metabolites that were classified as amino acid (alanine, glutamine, glutamate), intermediates and end-products in the glycolysis (pyruvate) and the tricarboxylic acid cycle (acetate, lactate). Their rank in order according to the number of metabolites and pathways was BPF > BPA > BPAF > BPS. The common disrupted pathways (pyruvate metabolism; alanine, aspartate, and glutamate metabolism) indicated enhanced glycolysis. The following glucometabolic PCR array analysis suggested that although four BPs shared the capability of disrupting glucose metabolism, they may act through different mechanisms: BPAF has increased the pyruvate kinase (PKLR) expression level, which implied enhanced glycolysis that was agreed with NMR results. The other three BP analogues, however, decreased the expression level of glucokinase (GCK) that indicated glucose sensing impairment. Our results demonstrated the potential for using metabolomic and PCR array to understand the underlying action of mechanisms and identify the potential targets for future targeted risk assessment.

Analysis of metabolome changes in the HepG2 cells of apatinib treatment by using the NMR-based metabolomics

Neovascularization is required for the growth of tumors, vascular endothelial growth factor (VEGF) and related signal pathways are important in tumor angiogenesis. Apatinib is a highly selective and potent antiangiogenesis drug targeting the receptor of VEGFR2, blocking downstream signal transduction and inhibiting angiogenesis of tumor tissue. Apatinib has a wide range of antitumor activities in vitro and in vivo, but its effect on metabolic changes has not deeply research at present. Nowadays, our research first systematically studied the metabolic changes affected by apatinib in the HepG2 cells at the half-maximal inhibitory concentration value. We used the metabolomics by using ¹ H nuclear magnetic resonance (¹ H-NMR) to analyze the HepG2 cell culture media. Multivariable Statistics was applied to analyze the ¹ H-NMR spectra of the cell media, including principal component analysis, partial least squares discriminant analysis (PLS-DA) and orthogonal PLS-DA (OPLS-DA). Compared with the uncultured and cultured media (negative/positive control), the metabolic phenotypes were changed in the apatinib treatment with a continuous effect over time. The metabolic pathway analysis is shown that the mainly disturbed metabolic pathways pyruvate metabolism, alanine, aspartate, and glutamate metabolism and amino acid metabolism associated with them in the apatinib treatment. The differential metabolites which were identified from the reconstructed OPLS-DA loading plots also reflected in these disturbed metabolic pathways. Our works could allow us to well understand the therapeutic effect of apatinib, especially in metabolism.