Decoding active compounds and molecular targets of herbal medicine by high-throughput metabolomics technology: A systematic review.

Clinical experiences of herbal medicine (HM) have been used to treat a variety of human intractable diseases. As the treatment of diseases using HM is characterized by multi-components and multi-targets, it is difficult to determine the bio-active components, explore the molecular targets and reveal the mechanisms of action. Metabolomics is frequently used to characterize the effect of external disturbances on organisms because of its unique advantages on detecting changes in endogenous small-molecule metabolites. Its systematicity and integrity are consistent with the effective characteristics of HM. After HM intervention, metabolomics can accurately capture and describe the behavior of endogenous metabolites under the disturbance of functional compounds, which will be used to decode the bioactive ingredients of HM and expound the molecular targets. Metabolomics can provide an approach for explaining HM, addressing unclear clinical efficacy and undefined mechanisms of action. In this review, the metabolomics strategy and its applications in HM are systematically introduced, which offers valuable insights for metabolomics methods to characterizing the pharmacological effects and molecular targets of HM.

Metabolomics for Clinical Biomarker Discovery and Therapeutic Target Identification.

As links between genotype and phenotype, small-molecule metabolites are attractive biomarkers for disease diagnosis, prognosis, classification, drug screening and treatment, insight into understanding disease pathology and identifying potential targets. Metabolomics technology is crucial for discovering targets of small-molecule metabolites involved in disease phenotype. Mass spectrometry-based metabolomics has implemented in applications in various fields including target discovery, explanation of disease mechanisms and compound screening. It is used to analyze the physiological or pathological states of the organism by investigating the changes in endogenous small-molecule metabolites and associated metabolism from complex metabolic pathways in biological samples. The present review provides a critical update of high-throughput functional metabolomics techniques and diverse applications, and recommends the use of mass spectrometry-based metabolomics for discovering small-molecule metabolite signatures that provide valuable insights into metabolic targets. We also recommend using mass spectrometry-based metabolomics as a powerful tool for identifying and understanding metabolic patterns, metabolic targets and for efficacy evaluation of herbal medicine.

Oxidative stress and mitochondrial injury-mediated cytotoxicity induced by silver nanoparticles in human A549 and HepG2 cells.

OBJECTIVES: Considering the increasing applications of silver nanoparticles (AgNPs) in food- and cosmetic-related products worldwide, the aim of this study was to investigate the potential adverse health effects induced by AgNPs exposure in terms of cytotoxicity, oxidative stress, and mitochondrial injury in human A549 and HepG2 cells. METHODS: After a 48 h AgNPs treatment, the cell viability was measured by MTT assay. Oxidative damage was determined by assays of malondialdehyde (MDA), 8-epi-PGF2α and 8-hydroxy-2'-deoxyguanosine (8-oxo-dG). The protein expression of HSPA1A and HO-1 was analyzed by western blot analysis. Mitochondrial membrane potential (MMP) was detected by using JC-1 as fluorescent probes. The uptake and intracellular localization of AgNPs was measured by transmission electron microscopy (TEM), and cellular AgNPs was determined by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: A dose-dependent decrease in cell viability after AgNPs treatment was observed, which was associated correspondingly with oxidative damage as indicated by increases in MDA amount, 8-epi-PGF2α and 8-oxo-dG levels, HSPA1A and HO-1 expression, as well as mitochondrial injury as indicated by decreased MMP. The cellular uptake of AgNPs measured by ICP-MS analysis was correlated correspondingly with the oxidative damage and mitochondrial injury. CONCLUSIONS: The dose-dependent cytotoxicity induced by AgNPs may result from an interaction of oxidative stress, DNA damage and mitochondrial injury in A549 and HepG2 cells. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1691-1699, 2016.

The development of GADD45α luciferase reporter assays in human cells for assessing the genotoxicity of environmental pollutants.

OBJECTIVES: In order to assess the potential carcinogenic and genotoxic responses induced by environmental pollutants, genotoxicity test systems based on a GADD45α promoter-driven luciferase reporter in human A549 and HepG2 cells were established. MATERIALS AND METHODS: Four different types of environmental toxicants including DNA alkylating agents, precarcinogenic agents, DNA cross-linking agents and non-carcinogenic agents, and three environmental samples collected from a coke oven plant were used to evaluate the test systems. After treated with the tested agents and environmental samples for 12 h, the cell viabilities and luciferase activities of the luciferase reporter cells were determined, respectively. RESULTS: Methyl methanesulfonate, benzo[a]pyrene, formaldehyde and the extractable organic matter (EOM) from coke oven emissions in ambient air generally produced significant induction of relative luciferase activity in a similar dose-dependent manner in A549- and HepG2-luciferase cells. No significant increases in relative luciferase activity were observed in pyrene-treated A549- or HepG2-luciferase cells. Significant increase in relative luciferase activity was already evident after 2.5 µM benzo[a]pyrene, 5 µM formaldehyde, 0.006 µg/L bottom-EOM, 0.10 µg/L side-EOM or 0.06 µg/L top-EOM, where no cytotoxic damage was observed. Compared with the A549-luciferase cells, the tested pollutants produced higher induction of relative luciferase activity in HepG2-luciferase cells. DISCUSSION AND CONCLUSION: Therefore, the new genotoxicity test systems can detect different types of genotoxic agents and low concentrations of environmental samples. The luciferase reporter cells, especially the HepG2-luciferase cells, could provide a valuable tool for rapid screening of the genotoxic damage of environmental pollutants and their complex mixtures.

The communication mechanism of the gut-brain axis and its effect on central nervous system diseases: A systematic review.

Gut microbiota is involved in intricate and active metabolic processes the host's brain function, especially its role in immune responses, secondary metabolism, and symbiotic connections with the host. Gut microbiota can promote the production of essential metabolites, neurotransmitters, and other neuroactive chemicals that affect the development and treatment of central nervous system diseases. This article introduces the relevant pathways and manners of the communication between the brain and gut, summarizes a comprehensive overview of the current research status of key gut microbiota metabolites that affect the functions of the nervous system, revealing those adverse factors that affect typical communication between the brain-gut axis, and outlining the efforts made by researchers to alleviate these neurological diseases through targeted microbial interventions. The relevant pathways and manners of communication between the brain and gut contribute to the experimental design of new treatment plans and drug development. The factors that may cause changes in gut microbiota and affect metabolites, as well as current intervention methods are summarized, which helps improve gut microbiota brain dialogue, prevent adverse triggering factors from interfering with the gut microbiota system, and minimize neuropathological changes.

Innovation in identifying metabolites from complex metabolome-Highlights of recent analytical platforms and protocols.

Metabolites are closely intertwined genotypes that can provide clear information about the final phenotype. The high-throughput analysis platform used to identify candidate metabolites and describe their contributions can help to quickly detect metabolic characteristics from large spectral data, which may lead to peak data preprocessing, statistical analysis and functional interpretation. Developing a comprehensive strategy for discovering and verifying bioactive metabolites can provide a large number of new functional biomarkers, and then more closely reveal their functional changes, which has relevant biological significance for disease diagnosis and prognosis treatment.

Mass spectrometry-based metabolomics for discovering active ingredients and exploring action mechanism of herbal medicine.

Natural products derived from herbal medicine are a fruitful source of lead compounds because of their structural diversity and potent bioactivities. However, despite the success of active compounds derived from herbal medicine in drug discovery, some approaches cannot effectively elucidate the overall effect and action mechanism due to their multi-component complexity. Fortunately, mass spectrometry-based metabolomics has been recognized as an effective strategy for revealing the effect and discovering active components, detailed molecular mechanisms, and multiple targets of natural products. Rapid identification of lead compounds and isolation of active components from natural products would facilitate new drug development. In this context, mass spectrometry-based metabolomics has established an integrated pharmacology framework for the discovery of bioactivity-correlated constituents, target identification, and the action mechanism of herbal medicine and natural products. High-throughput functional metabolomics techniques could be used to identify natural product structure, biological activity, efficacy mechanisms, and their mode of action on biological processes, assisting bioactive lead discovery, quality control, and accelerating discovery of novel drugs. These techniques are increasingly being developed in the era of big data and use scientific language to clarify the detailed action mechanism of herbal medicine. In this paper, the analytical characteristics and application fields of several commonly used mass spectrometers are introduced, and the application of mass spectrometry in the metabolomics of traditional Chinese medicines in recent years and its active components as well as mechanism of action are also discussed.

Detection, mechanisms, and therapeutic implications of oncometabolites.

Metabolic abnormalities are a hallmark of cancer cells and are essential to tumor progression. Oncometabolites have pleiotropic effects on cancer biology and affect a plethora of processes, from oncogenesis and metabolism to therapeutic resistance. Targeting oncometabolites, therefore, could offer promising therapeutic avenues against tumor growth and resistance to treatments. Recent advances in characterizing the metabolic profiles of cancer cells are shedding light on the underlying mechanisms and associated metabolic networks. This review summarizes the diverse detection methods, molecular mechanisms, and therapeutic targets of oncometabolites, which may lead to targeting oncometabolism for cancer therapy.

Metabolomics of various samples advancing biomarker discovery and pathogenesis elucidation for diabetic retinopathy.

Diabetic retinopathy (DR) is a universal microvascular complication of diabetes mellitus (DM), which is the main reason for global sight damage/loss in middle-aged and/or older people. Current clinical analyses, like hemoglobin A1c, possess some importance as prognostic indicators for DR severity, but no effective circulating biomarkers are used for DR in the clinic currently, and studies on the latent pathophysiology remain lacking. Recent developments in omics, especially metabolomics, continue to disclose novel potential biomarkers in several fields, including but not limited to DR. Therefore, based on the overview of metabolomics, we reviewed progress in analytical technology of metabolomics, the prominent roles and the current status of biomarkers in DR, and the update of potential biomarkers in various DR-related samples via metabolomics, including tear as well as vitreous humor, aqueous humor, retina, plasma, serum, cerebrospinal fluid, urine, and feces. In this review, we underscored the in-depth analysis and elucidation of the common biomarkers in different biological samples based on integrated results, namely, alanine, lactate, and glutamine. Alanine may participate in and regulate glucose metabolism through stimulating N-methyl-D-aspartate receptors and subsequently suppressing insulin secretion, which is the potential pathogenesis of DR. Abnormal lactate could cause extensive oxidative stress and neuroinflammation, eventually leading to retinal hypoxia and metabolic dysfunction; on the other hand, high-level lactate may damage the structure and function of the retinal endothelial cell barrier via the G protein-coupled receptor 81. Abnormal glutamine indicates a disturbance of glutamate recycling, which may affect the activation of Müller cells and proliferation via the PPP1CA-YAP-GS-Gln-mTORC1 pathway.

Efficient and stable catalysis of hollow Cu9S5 nanospheres in the Fenton-like degradation of organic dyes.

The development of new heterogeneous catalysts with stable catalytic activity in a wide pH range to prevent polluting precipitation plays a vital role in large-scale wastewater treatment. Here, a facile anion exchange strategy was designed to fabricate hollow Cu9S5 nanospheres by using Cu2O nanospheres as hard-templates. The structural and compositional transformation from Cu2O nanospheres to hollow Cu9S5 nanospheres were investigated via X-ray diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The Fenton-like degradation of organic dyes was used to evaluate the catalytic performance of the obtained Cu-containing catalysts. Results reveal that the hollow Cu9S5 nanospheres have the best catalytic activity among five kinds of Cu-containing catalysts. Hollow Cu9S5 nanospheres can effectively accelerate the decomposition of H2O2 into hydroxyl radicals and superoxide radical, which have been proven to be mainly oxidative species in the Fenton-like degradation of organic pollutants. Hollow Cu9S5 nanospheres have a wide pH application range of 5.0-9.0, and their extremely stable activity can be maintained in at least 15 catalytic cycles with a Cu2+ ion leaching rate of less than 1.0 %. The outstanding catalytic performance of the Cu9S5 catalyst is expected to enhance the practical applications of copper sulfide catalysts in Fenton-like wastewater treatment.

Prevalence of overweight and malnutrition among ethnic minority children and adolescents in China, 1991-2010.

This study aimed to determine the trends in prevalence of childhood overweight and malnutrition in a large Chinese ethnic minority population from 1991 to 2010. In the Chinese National Survey on Students' Constitution and Health from 1991 to 2010, multistage stratified sampling was conducted in the series of cross-sectional studies. Participants were 7-18-year-old students randomly selected by sex and region, and included Han and 26 ethnic minorities. During the survey period, the overall prevalence of overweight increased from 5.8% to 13.5%, and malnutrition trend increased from 3.6% to 4.1% in ethnic minority children and adolescents. Moreover, Korean and Mongol children were more likely than Han children to be obese (Korean: RR = 1.52; 95% CI: 1.48-1.56; Mongol: RR = 1.24; 95% CI: 1.20-1.28). Among these minorities, the Dongxiang and Li children were more likely to be malnourished (Li: RR = 1.47; 95% CI: 1.37-1.57; Dongxiang: RR = 1.45; 95% CI: 1.34-1.58). Shui, Khalkhas, Lisu, and Monguor children were less likely to be overweight and malnourished compared with the Hans. The prevalence of overweight among ethnicities increased yearly while that for malnutrition has fluctuated over the past few decades.

Activation of HSPA1A promoter by environmental pollutants: An early and rapid response to cellular damage.

We established the HepG2-luciferase cells containing a luciferase reporter gene regulated by human HSPA1A promoter. The screening of heat shock and three typical environmental toxicants revealed differences in their capacities to activate HSPA1A promoter in HepG2-luciferase cells. After heat shock, a progressive time-dependent increase in relative luciferase activity was detected peaking at 8h of recovery. Benzo[a]pyrene, formaldehyde and sodium bisulfite induced significant time-dependent elevation of relative luciferase activity, which were positively correlated with MDA concentration, Olive tail moment and micronuclei frequency. The significant increase in relative luciferase activity was already evident after 4h of benzo[a]pyrene, 1h of formaldehyde and sodium bisulfite exposure, when no increases in cellular damage were detected by other toxicity tests. Therefore, the HepG2-luciferase cells are useful model for examining the overall cellular responses to oxidative stress and genotoxic damage, and provide a reporter system for rapid and sensitive screening of environmental pollutants.

Organic extracts of coke oven emissions can induce genetic damage in metabolically competent HepG2 cells.

Coke oven emissions (COEs) containing various carcinogenic polycyclic aromatic hydrocarbons (PAHs) represent the coal-burning pollution in the air. Organic pollutants in the aerosol and particulate matter of COEs were collected from the bottom, side, and top of a coke oven. The Comet assay and cytokinesis-block micronucleus cytome assay were conducted to analyze the genetic damage of extractable organic matter (EOM) of COEs on HepG2 cells. All the three EOMs could induce significant dose-dependent increases in Olive tail moment, tail DNA, and tail length, micronuclei, nucleoplasmic bridges, and nuclear buds frequencies, which were mostly positively correlated with the total PAHs concentration in each EOM. In conclusion, EOMs of COEs in the three typical working places of coke oven can induce DNA strand breaks and genomic instability in the metabolically competent HepG2 cells. The PAHs in EOMs may be important causative agents for the genotoxic effects of COEs.