Investigation of the drug-drug interaction and incompatibility mechanism between Aconitum carmichaelii Debx and Pinellia ternata (Thunb.) Breit.

ETHNOPHARMACOLOGICAL RELEVANCE: The combination of Aconitum carmichaelii Debx (Chuanwu, CW) and Pinellia ternata (Thunb.) Breit (Banxia, BX) forms an herbal pair within the eighteen incompatible medicaments (EIM), indicating that BX and CW are incompatible. However, the scientific understanding of this incompatibility mechanism, especially the corresponding drug-drug interaction (DDI), remains complex and unclear. AIM OF THE STUDY: This study aims to explain the DDI and potential incompatibility mechanism between CW and BX based on pharmacokinetics and cocktail approach. MATERIALS AND METHODS: Ultraperformance liquid chromatography-tandem mass spectrometry methods were established for pharmacokinetics and cocktail studies. To explore the DDI between BX and CW, in the pharmacokinetics study, 10 compounds were determined in rat plasma after administering CW and BX-CW herbal pair extracts. In the cocktail assay, the pharmacokinetic parameters of five probe substrates were utilized to assess the influence of BX on cytochrome P450 (CYP) isoenzyme (dapsone for CYP3A4, phenacetin for CYP1A2, dextromethorphan for CYP2D6, tolbutamide for CYP2C9, and omeprazole for CYP2C19). Finally, the DDI and incompatibility mechanism of CW and BX were integrated to explain the rationality of EIM theory. RESULTS: BX not only enhances the absorption of aconitine and benzoylaconine but also accelerates the metabolism of mesaconitine, benzoylmesaconine, songorine, and fuziline. Moreover, BX affects the activity of CYP enzymes, which regulate the metabolism of toxic compounds. CONCLUSIONS: BX altered the activity of CYP enzymes, consequently affecting the metabolism of toxic compounds from CW. This incompatibility mechanism may be related to the increased absorption of these toxic compounds in vivo.

Quantification and discovery of quality markers from Toddalia asiatica by UHPLC-MS/MS coupled with chemometrics.

INTRODUCTION: Toddalia asiatica (TA) is a classical traditional Chinese medicine used to treat rheumatoid arthritis and contusions. However, research regarding TA quality control is currently limited. OBJECTIVE: We aimed to establish a strategy for identifying quality markers that can be used for the evaluation of the quality of TA. METHOD: A rapid and efficient ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantitative determination of 19 compounds in TA from different regions. Then, the extraction process of TA was successively optimized by single-factor optimization and response surface methodology. Moreover, chemometrics was employed to confirm the correlation between quality and target compounds. RESULTS: Utilizing the UHPLC-MS/MS method, separation of the 19 bioactive compounds was achieved within 14 min. The method was validated in terms of linearity (r2 > 0.9982), precision (0.08%-3.70%), repeatability (0.50%-2.54%), stability (2.26%-5.46%), and recovery (95.8%-113%). The optimal extraction process (extraction solvent, 65% ethanol aqueous solution; solid-liquid ratio, 1:20; extraction time, 25 min) was determined with the total content of 19 bioactive compounds as indicator. Significant disparities were observed in the contents of target compounds across different batches of TA. Besides, all samples could be categorized into two distinct groups, and magnoflorine, (-)-lyoniresinol, nitidine chloride, norbraylin, skimmianine, and decarine were identified as quality markers. CONCLUSION: In the present study, we developed a strategy to improve the quality control of TA. In consideration of the pharmacodynamic activity and statistical differences, six compounds are proposed as quality markers for TA.

Simultaneous Separation and Determination of Nine Active Ingredients in Sanyetangzhiqing by Cyclodextrin-Modified Micellar Electrokinetic Capillary Electrophoresis-Diode Array Detector.

A simple and sensitive strategy using cyclodextrin-modified micellar electrokinetic chromatography with diode array detector was developed and applied for the simultaneous separation and determination of nine components in Sanyetangzhiqing (SYTZQ), a hypoglycemic and hypolipidemic agent. Several important parameters affecting separation performance were evaluated and optimized using single variable methods. Under the optimal conditions, baseline separation of the nine components, including four flavonoids (hyperoside, isoquercitrin, quercetin-3-O-glucuronoside, and astragalin), four phenolic acids (chlorogenic acid, rosmarinic acid, salvianolic acid B, and lithospermic acid), and a monoterpenoids (paeoniflorin), were achieved in less than 16 min. The correlation coefficients of the calibration curves were over 0.9996 for all the analytes. Intraday and interday precisions ranged from 0.4% to 4.8% and 1.7% to 5.0%, respectively. Recoveries of analytes varied from 95.3% to 105%. Validation results as well as the application to analyse SYTZQ samples demonstrated the applicability of the proposed method and thus provided an effective tool for the quality control of SYTZQ. Moreover, with the advantages of short time consuming, low energy consumption, high efficiency, and low cost, this method has laid a foundation for the determination and quality evaluation of multicomponents in Chinese herbal compounds.

Simultaneous determination of multiple components in rat plasma by UHPLC-sMRM for pharmacokinetic studies after oral administration of Qingjin Yiqi Granules.

As a Traditional Chinese Medicine prescription, Qingjin Yiqi Granules (QJYQ) provides an effective treatment for patients recovering from COVID-19. However, the pharmacokinetics characteristics of the main components of QJYQ in vivo are still unknown. An efficacious ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed and validated for the simultaneous determination of 33 components in rat plasma after oral administration of QJYQ. The plasma samples were precipitated with 400 µL methanol/acetonitrile (1/1, v/v) and analyzed in scheduled multiple reaction monitoring mode. The linear relationship of the 33 components was good (r > 0.9928). The lower limit of quantification for 33 components ranged from 0.4-60.5 ng/mL. The average recoveries and matrix effects of the analytes ranged from 72.9% to 115.0% with RSD of 1.4%-15.0%. All inter-day and intra-day RSDs were within 15.0%. After oral administration (3.15 g/kg), the validated approach was effectively applied to the pharmacokinetics of main components of QJYQ. Finally, fifteen main constituents of QJYQ with large plasma exposure were obtained, including baicalin, wogonoside, wogonin, apigenin-7-O-glucuronide, verbenalin, isoferulic acid, hesperidin, liquiritin, harpagide, protocatechuic acid, p-Coumaric acid, ferulic acid, sinapic acid, liquiritin apioside and glycyrrhizic acid. The present research lays a foundation for clarifying the therapeutic material basis of QJYQ and provides a reference for further scientific research and clinical application of QJYQ.

A novel biological sources consistency evaluation method reveals high level of biodiversity within wild natural medicine: A case study of Amynthas earthworms as "Guang Dilong".

For wild natural medicine, unanticipated biodiversity as species or varieties with similar morphological characteristics and sympatric distribution may co-exist in a single batch of medical materials, which affects the efficacy and safety of clinical medication. DNA barcoding as an effective species identification tool is limited by its low sample throughput nature. In this study, combining DNA mini-barcode, DNA metabarcoding and species delimitation method, a novel biological sources consistency evaluation strategy was proposed, and high level of interspecific and intraspecific variations were observed and validated among 5376 Amynthas samples from 19 sampling points regarded as "Guang Dilong" and 25 batches of proprietary Chinese medicines. Besides Amynthas aspergillum as the authentic source, 8 other Molecular Operational Taxonomic Units (MOTUs) were elucidated. Significantly, even the subgroups within A. aspergillum revealed here differ significantly on chemical compositions and biological activity. Fortunately, this biodiversity could be controlled when the collection was limited to designated areas, as proved by 2796 "decoction pieces" samples. This batch biological identification method should be introduced as a novel concept regarding natural medicine quality control, and to offer guidelines for in-situ conservation and breeding bases construction of wild natural medicine.

An efficient method for qualitation and quantitation of multi-components of the herbal medicine Qingjin Yiqi Granules.

Qingjin Yiqi Granules (QJYQ) is a Traditional Chinese Medicines (TCMs) prescription for the patients with post-COVID-19 condition. It is essential to carry out the quality evaluation of QJYQ. A comprehensive investigation was conducted by establishing deep-learning assisted mass defect filter (deep-learning MDF) mode for qualitative analysis, ultra-high performance liquid chromatography and scheduled multiple reaction monitoring method (UHPLC-sMRM) for precise quantitation to evaluate the quality of QJYQ. Firstly, a deep-learning MDF was used to classify and characterize the whole phytochemical components of QJYQ based on the mass spectrum (MS) data of ultra-high performance liquid chromatography quadrupole time of flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Secondly, the highly sensitive UHPLC-sMRM data-acquisition method was established to quantify the multi-ingredients of QJYQ. Totally, nine major types of phytochemical compounds in QJYQ were intelligently classified and 163 phytochemicals were initially identified. Furthermore, fifty components were rapidly quantified. The comprehensive evaluation strategy established in this study would provide an effective tool for accurately evaluating the quality of QJYQ as a whole.

A comprehensive review of the botany, ethnopharmacology, phytochemistry, pharmacology, toxicity and quality control of Perillae Fructus.

ETHNOPHARMACOLOGICAL RELEVANCE: Perilla frutescens (Linnaeus) Britton, Mem. Torrey Bot. Club 5: 277. 1894., is famous as a worldwide plant with multiple medical parts, including leaves, stems, fruits, etc. Perillae Fructus, the desiccative ripe fruit of P. frutescens, is locally called Zisuzi in Chinese Pharmacopoeia. It is a popularly used herb for relieving cough and asthma, dissipating phlegm and treating constipation in some Asian countries, such as China, Japan, India, South Korea, etc. Various chemical compounds were isolated and identified from Perillae Fructus. THE AIM OF THE REVIEW: This review aims to summarize the botany, ethnopharmacological applications, phytochemistry, pharmacology, toxicity and quality control of Perillae Fructus to provide scientific evidence for development and utilization Perillae Fructus. MATERIALS AND METHODS: Relevant information about Perillae Fructus was collected from ScienceDirect, PubMed, Web of science, CNKI, WanFang data, ancient classics and clinical reports. Some electronic databases were also retrieved. RESULTS: Perillae Fructus was exerted to treat cough and asthma in traditional application. It also had the effect on moistening intestine to relieve constipation for tremendous lipid substances. Up to now, 193 compounds have been isolated and identified from Perillae Fructus, mainly including fatty acids, flavonoids, phenolic acids, phytosterols, triterpenoids and volatile oils. As for its pharmacological activities, prevalent traditional applications of Perillae Fructus have been supported by modern pharmacological experiments in vivo or in vitro, such as anti-inflammatory and anti-oxidant effects. Besides, Perillae Fructus also has hypolipidemic, anti-tumor, antibacterial effects, etc. This review will provide a scientific basis for further studies and rational applications of Perillae Fructus in the future. CONCLUSIONS: According to its traditional applications, phytochemicals and pharmacological activities, Perillae Fructus was regarded as a valuable herb for application in medicine and food fields. Although some ingredients have been confirmed to have multiple pharmacological activities, their mechanisms of action are still unclear. Further studies on the material basis and mechanism of action are clearly warranted.

A green ultrasonic-assisted micellar extraction coupled with ultra-high performance liquid chromatography with photodiode array method for quantitative analysis of active ingredients in Yangxinshi Tablet.

An efficient and green ultrasonic-assisted micellar extraction method coupled with ultra-high performance liquid chromatography with photodiode array detection (UHPLC-PDA) was developed for the multi-ingredients quantitative analysis of Yangxinshi Tablet (YXST). The active ingredients were extracted from YXST using trehalose lipid biosurfactant solution as an environmentally friendly extraction solution. The response surface methodology (RSM) based on Box-Behnken design (BBD) was utilized to seek for the optimum extraction conditions of target analytes. When the concentration of trehalose lipid solution was 7 mg/mL, the liquid to solid was 125:1 (mL:g) and the extraction time was 40 min, the total extraction yield of eleven compounds (including puerarin, daidzin, ferulic acid, calycosin-7-O-ß-D-glucoside, tetrahydropalmatine, coptisine, epiberberine, jatrorrhizine, berberine, palmatine chloride and icariin) obtained the maximum value. The relative standard deviations (RSD) of intra-day and inter-day precision were all less than 5.0%. The recoveries of all analytes were in the range of 95.1%-104% with the RSDs were all below 3.0%. Consequently, the ultrasonic-assisted micellar extraction coupled with UHPLC-PDA method could be successfully and efficiently applied to the extraction and quantitative analysis of target components in YXST.

An online stepwise background subtraction-based ultra-high pressure liquid chromatography quadrupole time of flight tandem mass spectrometry dynamic detection integrated with metabolic molecular network strategy for intelligent characterization of the absorbed chemical-fingerprint of QiangHuoShengShi decoction in vivo.

QiangHuoShengShi decoction (QHSS) was an ancient and classical traditional Chinese medicine (TCM) prescription. In the previous study, its phytochemical fingerprint had been comprehensively characterized. However, no reports were available on its absorbed prototypes and the related metabolites in rat plasma samples. In this study, an intelligent and innovate analysis strategy was built for characterizing metabolic chemical-fingerprint in rat plasma after oral administration of QHSS extract. Firstly, a very simple and highly efficient online stepwise background subtraction (BS)-based ultra-high pressure liquid chromatography quadrupole time of flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) dynamic detection method was established to analyze the plasma samples. Secondly, the intelligent metabolic molecular network (MMN) technology was developed and used for rapidly screening out the metabolites of interest, which was followed by prediction of chemical types using the modified deep-learning assisted mass defect filter (MDF) analysis. Thirdly, the screened metabolites with identification features (metabolic pathways and chemical classification) were deeply characterized based on the MS/MS datasets. Finally, 58 prototypes of QHSS were successfully acquired and subsequently identified, including coumarins, chromones, phthalides, phenolic acids, flavonoids, and saponins. A total of 111 metabolites of the coumarins, chromones, phthalides were filtered to be tentatively characterized. This developed qualitative strategy was very helpful to quickly target medicine-related metabolites in the complex bio-matrix and, importantly, it could further visualize medicine-metabolic pathways hidden in the messy mass spectrum datasets. In all, the innovate strategy would provide a powerful tool for effectively acquiring and decode complex metabolic fingerprint of natural products in vivo.

Lingguizhugan decoction dynamically regulates MAPKs and AKT signaling pathways to retrogress the pathological progression of cardiac hypertrophy to heart failure.

BACKGROUND: Heart failure (HF) is a grave health concern, with high morbidity and mortality, calling for the urgent need for new and alternative pharmacotherapies. Lingguizhugan decoction (LD) is a classic Chinese formula clinically used to treat HF. However, the underlying mechanisms involved are not fully elucidated. PURPOSE: Based on that, this study aims to investigate the effects and underlying mechanisms of LD on HF. METHODS: After confirming the therapeutic benefits of LD in transverse aortic constriction (TAC)-induced HF mice, network pharmacology and transcriptomic analyzes were utilized to predict the potential molecular targets and pathways of LD treatment in failing hearts, which were evaluated at 3 and 9 w after TAC. UHPLC-QE-MS analysis was utilized to detect bioactive ingredients from LD and plasma of LD-treated rats. RESULTS: Our results showed that LD markedly alleviated cardiac dysfunction via down-regulating CH-related genes and proteins expression in TAC mice. Significantly, cardiac hypertrophy signaling, including AKT and MAPKs signaling pathways, were identified, suggesting the pathways as likely regulatory targets for LD treatment. LD inhibited p38 and ERK phosphorylated expression levels, with the latter effect likely dependent on regulation of AMPK. Interestingly, LD exerted a dual modulatory role in the AKT-GSK3ß/mTOR/P70S6K signaling pathway's regulation, which was characterized by stimulatory activity at 3 w and inhibitory effects at 9 w. Finally, 15 bioactive compounds detected from plasma were predicted as the potential regulators of the AKT-GSK3ß/mTOR and MAPKs signaling pathways. CONCLUSION: Our study shows LD's therapeutic efficacy in failing hearts, signifies LD as HF medication that acts dynamically by balancing AKT-GSK3ß/mTOR/P70S6K and MAPKs pathways, and reveals possible bioactive compounds responsible for LD effects on HF.

An integration strategy combined progressive multivariate statistics with anticoagulant activity evaluation for screening anticoagulant quality markers in Chinese patent medicine.

ETHNOPHARMACOLOGICAL RELEVANCE: The cardiovascular and cerebrovascular diseases affect human health globally. Naoxintong capsules (NXTs), a famous Chinese Patent Medicine, has been especially applied to treat cerebral infarction and coronary heart disease in clinical practice. The anticoagulant activity of this prescription plays an important role in this course of treatment. AIM OF THE STUDY: Thrombin and factor Xa (FXa) are two key targets considering the anticoagulant activity. The purpose of this investigation is to screen the quanlity markers as key thrombin and FXa inhibitors for the anticoagulant activity oriented quality control of Chinese patent medicine. MATERIALS AND METHODS: Simple multi-polar solvent extraction processes using various proportions of solvents were conducted and their thrombin/FXa inhibitory activities were evaluated in vitro. Bivariate correlation analysis (BCA), grey correlation analysis (GCA), and orthogonal partial least squares discriminate analysis (OPLS-DA) were adopted for screening the potential active markers related to the anticoagulant activity. The chemical structures of these active compounds were identified by UHPLC-Q-TOF-MS/MS and their thrombin/FXa inhibitory activity was determined. The molecular docking technology was applied to explore the interaction between the compounds and targets. The contribution of these anticoagulant active ingredients in NXT was also investigated. Last but not the least, the contents of these markers in NXT were determined by liquid chromatography-electrospray ionization tandem triple quadrupole mass spectrometry (HPLC-ESI-MS/MS) method. RESULTS: The results showed that the NXT extract exhibited great activity against thrombin and FXa, especially extracted by 75% methanol (v/v). Six marker compounds with potential anticoagulant activity were screened out. Therein, four of the active compounds owing thrombin inhibitory activity (paeoniflorin, lithospermic acid, salvianolic acid B, Z-ligustilide) and five of the active compounds owing FXa inhibitory activity (3,5-dicaffeoylquinic acid, rosmarinic acid, lithospermic acid, salvianolic acid B and Z-ligustilide). In addition, these active compounds accounted for a large proportion of thrombin/FXa inhibitory activity of NXTs. The binding energy also showed the strong interaction formed by close connection of the compounds to the residues of targets. CONCLUSIONS: The proposed integrated stategy could be an efficient strategy to screen potential thrombin/FXa inhibitors for the bioactivity related quanlity control of Chinese patent medicine.

Discovery of Herbacetin as a Novel SGK1 Inhibitor to Alleviate Myocardial Hypertrophy.

Cardiac hypertrophy is a pivotal pathophysiological step of various cardiovascular diseases, which eventually leads to heart failure and death. Extracts of Rhodiola species (Ext.R), a class of commonly used medicinal herbs in Europe and East Asia, can attenuate cardiac hypertrophy both in vitro and in vivo. Serum/glucocorticoid regulated kinase 1 (SGK1) is identified as a potential target of Ext. R. By mass spectrometry-based kinase inhibitory assay, herbacetin (HBT) from Ext.R is identified as a novel SGK1 inhibitor with IC50 of 752 nmol. Thermal shift assay, KINOMEscan in vitro assay combined with molecular docking proves a direct binding between HBT and SGK1. Site-specific mutation of Asp177 in SGK1 completely ablates the inhibitory activity of HBT. The presence of OH groups at the C-3, C-8, C-4' positions of flavonoids is suggested to be favorable for the inhibition of SGK1 activity. Finally, HBT significantly suppresses cardiomyocyte hypertrophy in vitro and in vivo, reduces reactive oxygen species (ROS) synthesis and calcium accumulation. HBT decreases phosphorylation of SGK1 and regulates its downstream forkhead box protein O1 (FoxO1) signaling pathway. Taken together, the findings suggest that a panel of flavonoids structurally related to HBT may be novel leads for developing new therapeutics against cardiac hypertrophy.

Optimization of the Purifying Process for Columbianetin-ß-D-Glucopyranoside from Angelicae Pubescentis Radix and Evaluation of Its Analgesic Activity Using Hot Plate Test.

The objective of this work was to provide an economic and practical method for the purification of columbianetin-ß-D-glucopyranoside from Angelicae Pubescentis Radix extract. In the static adsorption and desorption, the effects of resin type (D101, HP-20, AB-8, GDX-201, and DA201), contact time (10-360 min), and temperature (298-318 K) were assessed on columbianetin-ß-D-glucopyranoside adsorption efficiency in laboratory. GDX-201 resin showed the best adsorption and desorption properties for columbianetin-ß-D-glucopyranoside. The kinetic data revealed that the equilibrium time for columbianetin-ß-D-glucopyranoside adsorption was achieved within 150 min. Moreover, the adsorption kinetic curve was well in accordance with the pseudo-second-order equation (R 2 > 0.99). The rate controlling step of the adsorption process was the intraparticle diffusion. The Langmuir isotherm models (R 2 > 0.99) could describe the whole adsorption process, which was exothermic and spontaneous according to the result of thermodynamics tests. In the dynamic adsorption and desorption process, the optimum loading flow (4, 5, and 6 BV/h), ethanol concentration (0-60%), and elution volume (10-230 mL) were optimized. Under optimal conditions of 4 BV/h loading flow, 6.7 BV loading volume, 25% ethanol, and 14 BV elution volume, the content of columbianetin-ß-D-glucopyranoside in the product was increased 29.61-fold from 0.45% to 13.32 ± 0.64% with yield of 88.03 ± 2.76% by an experiment of lab-scale enlargement. Then, columbianetin-ß-D-glucopyranoside was further purified by PHPLC and its purity was more than 98%. Additionally, the analgesic activity of the columbianetin-ß-D-glucopyranoside was assessed by hot plate test. The experimental results showed that columbianetin-ß-D-glucopyranoside significantly increased the latency of pain response in mice. This study demonstrated columbianetin-ß-D-glucopyranoside could be as a potentially natural analgesic component. It could be summed up that the established method was successfully applied to purifying columbianetin-ß-D-glucopyranoside from Angelicae Pubescentis Radix extract.

Chaihu Guizhi Ganjiang Decoction Ameliorates Pancreatic Fibrosis via JNK/mTOR Signaling Pathway.

Pancreatic fibrosis is a pathological characteristic of chronic pancreatitis (CP) and pancreatic cancer. Chaihu Guizhi Ganjiang Decoction (CGGD) is a traditional Chinese medicine, which is widely used in the clinical treatment of digestive diseases. However, the potential anti-fibrosis mechanism of CGGD in treating CP remains unclear. Here, we conducted a series of experiments to examine the effect of CGGD on the CP rat model and primary isolated pancreatic stellate cells (PSCs). The results revealed that CGGD attenuated pancreatic damage, decreased collagen deposition, and inhibited PSC activation in the pancreas of CP rats. However, compared with the CP group, CGGD had no effect on body weight and serum amylase and lipase. In addition, CGGD suppressed autophagy by downregulating Atg5, Beclin-1, and LC3B and facilitated phosphorylation of mTOR and JNK in pancreatic tissues and PSCs. Moreover, the CGGD-containing serum also decreased LC3B or collagen I expression after rapamycin (mTOR inhibitor) or SP600125 (JNK inhibitor) treatment in PSCs. In conclusion, CGGD attenuated pancreatic fibrosis and PSC activation, possibly by suppressing autophagy of PSCs through the JNK/mTOR signaling pathway.

A strategy for intelligent chemical profiling-guided precise quantitation of multi-components in traditional Chinese medicine formulae-QiangHuoShengShi decoction.

Due to the tremendous clinical value, more and more Traditional Chinese Medicines (TCMs) and their formulae are attracted by world's attention. QiangHuoShengShi (QHSS) decoction is one of classic TCM formulae, which is clinically used for treating various rheumatic diseases. However, the phytochemical constituents of QHSS have rarely been reported. A simple, intelligent, and comprehensive strategy was developed to characterize the phytochemical-fingerprint and quantify the chemical-markers for precise quality evaluation of QHSS. Firstly, a new deep-learning assisted mass defect filter (MDF) method was built for rapid and accurate classification of mass spectrum (MS) ions acquired by ultra-high performance liquid chromatography quadrupole time of flight tandem mass spectrometry (UHPLC-Q-TOF/MS). Subsequently, herb species-specific chemical-category and characteristic identification were used for further characterization of multi-components. As the result, seven major types of compounds in QHSS were intelligently differentiated and 183 phytochemical compounds were tentatively identified. Finally, a sensitive scheduled multiple reaction monitoring (sMRM) detection method was applied to precisely quantify 37 target analytes in QHSS decoction. This integrated strategy would provide an alternative method for chemical-material basis study of more herbal medicine or natural products.

A Delicate Balance between Bacterial Iron and Reactive Oxygen Species Supports Optimal C. elegans Development.

Iron is an essential micronutrient for all forms of life; low levels of iron cause human disease, while too much iron is toxic. Low iron levels induce reactive oxygen species (ROS) by disruption of the heme and iron-sulfur cluster-dependent electron transport chain (ETC). To identify bacterial metabolites that affect development, we screened the Keio Escherichia coli collection and uncovered 244 gene deletion mutants that slow Caenorhabditis elegans development. Several of these genes encode members of the ETC cytochrome bo oxidase complex, as well as iron importers. Surprisingly, either iron or anti-oxidant supplementation reversed the developmental delay. This suggests that low bacterial iron results in high bacterial ROS and vice versa, which causes oxidative stress in C. elegans that subsequently impairs mitochondrial function and delays development. Our data indicate that the bacterial diets of C. elegans provide precisely tailored amounts of iron to support proper development.