Discrimination of Citrus reticulata Blanco and Citrus reticulata 'Chachi' by gas chromatograph-mass spectrometry based metabolomics approach

Identification and quantification of adulteration in collagen powder by terahertz spectroscopy - the effect of spectral characteristics on performance is considered

Terahertz spectroscopy is an emerging rapid detection method that can be used to detect and analyze food quality issues. However, models developed based on various spectral characteristics of terahertz have shown different performances in food identification. Therefore, we preliminarily analyzed the effect of terahertz spectral characteristics on the identification and quantification of collagen powder adulterated with food powders (plant protein powder, corn starch, wheat flour) with the use of random forest (RF), linear discriminant analysis (LDA), and partial least squares regression (PLSR), and determined the spectral characteristics suitable for identification and quantitative analysis. Then, the selected spectral characteristics data were preprocessed using baseline correction (BC), gaussian filter (GF), moving average (MA), and savitzky-golay (SG). Feature variables were extracted from preprocessed spectral characteristics data using genetic algorithm (GA), random forest (RF), and least angle regression (LAR). The study indicated that the BC-GA-LDA classification model based on the absorption coefficient spectra achieved an accuracy of 96.96% in identifying adulterated collagen powder. Additionally, the GA-PLSR model developed based on the power spectra demonstrated excellent performance in predicting adulteration levels, with the coefficient of determination (Rp2) values ranging from 0.93 to 0.99. The results showed that the rational selection of terahertz spectral characteristics is highly feasible for the accurate detection of collagen powder adulteration.

Geographical origin discrimination of Chenpi using machine learning and enhanced mid-level data fusion

Chenpi, or dried tangerine peel, is a traditional Chinese ingredient valued in medicine and edible for its digestive and respiratory benefits. The geographical origin of Chenpi is important, as it can impact its quality, active compounds and market value. This study develops a strategy to distinguish Chenpi samples on its origin. Thirty-nine samples from eight regions in Xinhui district (Guangdong, China) are analyzed by gas chromatography (GC) and mid-infrared (MIR) technique. Four machine learning methods are employed to establish discrimination models based on GC and MIR data, with two mid-level data fusion strategies to combine the data. The results show that data fusion significantly improves Chenpi origin discrimination. The K-nearest neighbors and artificial neural network models, using modified mid-level data fusion, provide the best performance, misclassified only one sample. Machine learning in combination with modified mid-level data fusion strategy provides effective classification of Chenpi samples from different geographical origins.

Therapeutic Potential of Chinese Herbal Medicine and Underlying Mechanism for the Treatment of Myocardial Infarction

Myocardial infarction (MI) is a prevalent disease with high mortality rates worldwide. The course of MI is intricate and variable, necessitating personalized treatment strategies based on different mechanisms. However, variety of postoperative complications and rejections, such as heart failure, arrhythmias, cardiac rupture, and left ventricular thrombus, contribute to a poor prognosis. Despite the inclusion of antiplatelet agents and statins in the conventional treatment regimen, their clinical applicability is constrained by potential adverse effects and limited efficacy. Additionally, the mechanisms leading to MI are complex and diverse. Therefore, the development of novel compounds for MI treatment. The use of traditional Chinese medicine (TCM) in the prevention and treatment of cardiovascular diseases, including MI, is grounded in its profound historical background, comprehensive theoretical system, and accumulated knowledge. An increasing number of contemporary evidence-based medical studies have demonstrated that TCM plays a significant role in alleviating symptoms and improving the quality of life for MI patients. Chinese herbal formulations and active ingredients can intervene in the pathological process of MI through key factors such as inflammation, oxidative stress, apoptosis, ferroptosis, pyroptosis, myocardial fibrosis, angiogenesis, and autophagy. This article critically reviews existing herbal formulations from an evidence-based medicine perspective, evaluating their research status and potential clinical applications. Additionally, it explores recent advancements in the use of herbal medicines and their components for the prevention and treatment of MI, offering detailed insights into their mechanisms of action.

Characterization and comparative analysis of volatile organic compounds in four aromatic wild strawberry species using HS-SPME-GC-MS

Strawberries are valued for their aroma, which is mainly determined by volatile organic compounds (VOCs). Wild strawberries, with broader and more intense VOC profiles, are especially important in breeding programs. Using HS-SPME-GC-MS, 126 VOCs were identified in the ripe fruit of 22 cultivars from four wild strawberry species. Significant interspecies differences were found, with Fragaria mandshurica and F. nilgerrensis showing several times higher VOC levels than F. vesca and F. viridis, primarily due to high lactone content (up to 79.71 % of total VOCs). Phylogenetic analysis revealed conserved VOC profiles within species and genotype-aroma correlations. PCA and PLS-DA identified 60 biomarkers explaining 37.07 % of the variance, with 10 biomarkers validated for species identification, achieving 100 % accuracy. Key biomarkers for F. mandshurica included furaneol and perillyl acetate, while butanoic acid butyl ester was characteristic of F. vesca. This study emphasizes the role of VOCs as biomarkers for species differentiation and their potential in strawberry breeding.

Targeted/untargeted metabolomics and antioxidant properties distinguish Citrus reticulata 'Chachi' from Citrus reticulata Blanco

Dried citrus peel (DCP), also called "Chen Pi", has edible and medicinal value. However, the specific differences among various sources remain unknown. Herein, we collected six DCP species, namely, one Citrus reticulata 'Chachi' (CZG) and five Citrus reticulata Blanco (CRB). Targeted high-performance liquid chromatography and untargeted ultra-high-performance liquid chromatography-tandem mass spectrometry were employed to comprehensively compare the phenolic compounds and metabolites in DCP. Interestingly, 13 different phenolic compounds were noted in DCP. The total phenolic compound content in all CRB samples (58.86-127.65 mg/g) was higher than that of CZG (39.47 mg/g). Untargeted metabolomic revealed 1495 compounds, with 115 differentially expressed metabolites for CRBs and CZG, particularly flavonoids (38), terpenoids (15), and phenolic acids and derivatives (9). Lastly, antioxidant assays revealed that all CRB samples exhibited higher antioxidant activities compared with CZG. Therefore, our study results provide a theoretical basis for the high-value utilization of citrus peels and their metabolites.

FT-NIR combined with machine learning was used to rapidly detect the adulteration of pericarpium citri reticulatae (chenpi) and predict the adulteration concentration

Pericarpium citri reticulatae (PCR) has been used as a food and spice for many years and is known for its rich nutritional content and unique aroma. However, price increases are often accompanied by adulteration. In this study, two kinds of adulterants (Orange peel-OP and Mandarin Rind-MR) were identified by chromaticity analysis, FT-NIR and machine learning algorithm, and the doping concentration was predicted quantitatively. The results show that colorimetric analysis cannot completely differentiate between PCR and adulterants. Using spectral preprocessing combined with machine learning algorithms, PCR and two adulterants were successfully distinguished, with classification accuracy reaching 99.30 % and 98.64 % respectively. After selecting characteristic wavelengths, the R2 P of the adulterated quantitative model is greater than 0.99. Generally, this study proposes to use FT-NIR to study the adulteration of PCR for the first time, which fills the technical gap in the adulteration research of PCR, and provides an important method to solve the increasingly serious adulteration problem of PCR.

Quality Change of Citri Reticulatae Pericarpium (Pericarps of Citrus reticulata 'Chachi') During Storage and Its Sex-Based In Vitro Digestive Performance

Citri Reticulatae Pericarpium (CRP), particularly including the pericarp of Citrus reticulata 'Chachi' (GCP), has been widely used as a food, a dietary supplement, and traditional Chinese medicine. Despite the widespread use of traditional foods, there is limited evidence regarding the precise relationships between storage conditions, aging duration, and the digestive performance of CRP. In this study, the aim was to investigate the impact of the storage conditions on the quality of aged GCP during shelf life and to evaluate the subsequent digestive performance of corresponding GCP decoctions. Respiration in GCP was monitored by measuring oxygen (O2), carbon dioxide (CO2), and methane (CH4) gases throughout the storage simulation, with O2 and CO2 validated as prospective safety measures. Five flavonoids (hesperidin, didymin, nobiletin, tangeretin, and 3,5,6,7,8,3',4'-heptamethoxyflavone) were determined as quality indicators, and their contents were significantly affected by the duration of the storage simulation and the aging periods of GCP. Our study also found that temperature and humidity significantly affected the volatile organic compounds (VOCs) emission from GCP. Eighteen compounds were proposed to show potential as descriptive measures of aging periods while eight compounds were proposed as potential indicators to discriminate among the spoilage level. Furthermore, the bioaccessibility of hesperidin ranged from ~30% to ~50% and was not significantly affected by the GCP's aging time nor the consumer's sex (p < 0.05). This study presents evidence for the future control of the quality of GCP and its digestive performance in males and females.

Evaluation of chemical components and quality in Xinhui Chenpi (Citrus reticulata 'Chachi') with two different storage times by GC-MS and UPLC

Xinhui Chenpi (XHCP) is a well-known type of Chenpi (CP) widely used as both a Chinese herb and a food ingredient. While previous studies have explored how the quality of CP changes over time, there has been limited research specifically on XHCP. This study aims to assess the chemical components and quality of XHCP based on total flavonoid content (TF), antioxidant activity (AA), and color value (CV) at two stages: freshly harvested (XHCP-0Y) and after 3 years of storage (XHCP-3Y). Thirty-eight common volatile compounds were identified, and the content of 17 compounds among them, nine nonvolatile compounds, which included one alkaloid (synephrine), three phenolic acids (PA, protocatechuic acid, vanillic acid, and ferulic acid), and five flavonoids (narirutin, hesperidin, sinensetin, nobiletin, and tangeretin), were firstly detected by the newly developed gas chromatograph-mass spectrometer (GC-MS) and ultra-performance liquid chromatography (UPLC) methods. Compared to XHCP-0Y, the content of 17 volatile compounds and synephrine decreased in XHCP-3Y to varying degrees, while the content of PA, five flavonoids, TF, AA, and CV increased. The reduction of dryness caused by volatile compounds and the enhancement of efficacy related to PA, flavonoids, and AA suggested improved quality of XHCP after 3 years of storage. The methods developed in this study show promise for evaluating the quality of XHCP during the aging process.

Recent Advances in the Health Benefits and Application of Tangerine Peel (Citri Reticulatae Pericarpium): A Review

Citrus fruits, renowned for their abundant of phytochemicals and bioactive compounds, hold a prominent position as commercially grown fruits with health-promoting properties. In this context, tangerine peel (Citri Reticulatae Pericarpium, CRP) is garnering attention as a byproduct of citrus fruits. Within the framework of the circular economy, CRP has emerged as a focal point due to its potential health benefits. CRP, extracted from Citrus reticulata cv. and aged for over three years, has attracted increasing attention for its diverse health-promoting effects, including its anticancer, cardiovascular-protecting, gastrointestinal-modulating, antioxidant, anti-inflammatory, and neuroprotective properties. Moreover, CRP positively impacts skeletal health and various physiological functions. This review delves into the therapeutic effects and molecular mechanisms of CRP. The substantial therapeutic potential of CRP highlights the need for further research into its applications in both food and medicine. As a value-added functional ingredient, CRP and its constituents are extensively utilized in the development of food and health supplements, such as teas, porridges, and traditional medicinal formulations.

Flavor characterization of Citri Reticulatae Pericarpium (Citrus reticulata 'Chachiensis') with different aging years via sensory and metabolomic approaches

Guangchenpi (GCP), which is the peel of Citrus reticulata 'Chachiensis', is widely used as an herbal medicine, tea and food ingredient in southeast Asia. Prolonging its aging process results in a more pleasant flavor and increases its profitability. Through the integration of sensory evaluation with flavoromic analysis approaches, we evaluated the correlation between the flavor attributes and the profiles of the volatiles and flavonoids of GCP with various aging years. Notably, d-limonene, γ-terpinene, dimethyl anthranilate and α-phellandrene were the characteristic aroma compounds of GCP. Besides, α-phellandrene and nonanal were decisive for consumers' perception of GCP aging time due to changes of their odor activity values (OAVs). The flavor attributes of GCP tea liquid enhanced with the extension of aging time, and limonene-1,2-diol was identified as an important flavor enhancer. Combined with machine learning models, key flavor-related metabolites could be developed as efficient biomarkers for aging years to prevent GCP adulteration.

Recent advances in the authentication (geographical origins, varieties and aging time) of tangerine peel (Citri reticulatae pericarpium): A review

The consumption of tangerine peel (Citri reticulatae pericarpium, CRP) has been steadily increasing worldwide due to its proven health benefits and sensory characteristics. However, the price of CRP varies widely based on its origin, variety, and aging time, which has led many manufacturers to offer inferior products by exploiting the sensory similarity of CRP, seriously undermining consumers' interests. Therefore, it is essential to identify the authenticity of the CRP. In this study, the research progress on the authenticity of CRP from different origins, years and varieties over the past 10 years and the application and prospects of the main technologies and techniques were reviewed. The advantages and disadvantages of the commonly used methods were also summarized and compared. Mass spectrometry-based and spectroscopy-based techniques are the most commonly used methods for analyzing CRP authenticity. However, designing fast, non-destructive and green methods for identifying CRP authenticity would be the future trend.

Effects of Natural Products through Inhibiting Endoplasmic Reticulum Stress on Attenuation of Idiopathic Pulmonary Fibrosis

With ever-increasing intensive studies of idiopathic pulmonary fibrosis (IPF), significant progresses have been made. Endoplasmic reticulum stress (ERS)/unfolded protein reaction (UPR) is associated with the development and progression of IPF, and targeting ERS/UPR may be beneficial in the treatment of IPF. Natural product is a tremendous source of new drug discovery, and accumulating studies have reported that many natural products show potential therapeutic effects for IPF via modulating one or more branches of the ERS signaling pathway. Therefore, this review focuses on critical roles of ERS in IPF development, and summarizes herbal preparations and bioactive compounds which protect against IPF through regulating ERS.

Exploration of optimal preparation strategy of Chenpi (pericarps of Citrus reticulata Blanco) flavouring essence with great application potential in sugar and salt-reduced foods

To obtain flavouring essence with application potential in sugar and salt-reduced foods, the optimal strategy for extraction and microencapsulation of essential oil (EO) from Chenpi was investigated. UPLC-QTOF-MS/MS and liquid-liquid-extraction-GC-MS confirmed the selectivity for volatiles ranked in hydrodistillation > supercritical fluid extraction > solvent extraction. The aroma characteristic of Chenpi EO was distinguished by 33 key volatiles (screened out via headspace-SPME-GC-MS) and quantitative descriptive analysis. EO extracted by supercritical fluid extraction was preferred for preserving the original aroma of Chenpi and displaying more fruity, honey and floral. Chenpi flavouring essence with superior encapsulation efficiency, particle size, water dispersibility, and thermostability was obtained through optimally microencapsulating EO with gum arabic and maltodextrin (1:1) by high-pressure homogenization coupled with spray drying. Chenpi flavouring essence was able to reduce the usage of sugar and salt by 20 % via enhancing flavour perception of sweetness and saltiness. This study first developed a flavouring essence promisingly effective in both sugar and salt-reduced foods.

Electrohydrodynamic drying of citrus (Citrus sinensis L.) peel: Comparative evaluation on the physiochemical quality and volatile profiles

Based on the concept of circular economy, citrus peel was considered a valuable source of bioactive compounds for high-value foods. Electrohydrodynamic (EHD) drying is a novel technology appropriated for the dehydration of heat-sensitive products such as citrus peel. In current work, EHD drying of citrus peel was performed based on alternating current (AC) or direct current (DC) sources at various voltage levels (9, 18, 27, 36, and 45 kV). The effect of EHD on drying characteristics, water retention capacity, enzyme inactivation, phytochemical contents (phenolic compounds and carotenoids), and volatile compounds of citrus peel were evaluated and compared. Results showed that the drying time in the AC electric field was shorter compared to DC electric field at the same applied voltages due to the polarization layer formed by unipolar charges. The applied voltage determined electric field strength as well as the degree of tissue collapse and cell membrane rupture. EHD elucidated the transformation and degradation of phytochemicals including phenolic compounds, carotenoids, and volatile composition in proportion to the applied voltage. The findings indicate that EHD drying with AC improves drying behaviors, inactivates enzymes, and retains the phytochemical properties of citrus peel.

Analysis of Flavonoid Metabolites in Citrus reticulata 'Chachi' at Different Collection Stages Using UPLC-ESI-MS/MS

Flavonoids are essential substances with antioxidant properties and high medicinal value. Citrus reticulata 'Chachi' peel (CRCP) is rich in flavonoids and has numerous health benefits. The different maturity periods of CRCP can affect the flavonoid contents and pharmacological effects. In this study, we successfully performed UPLC-ESI-MS/MS-based metabolic analysis to compare the metabolites of CRCP at different harvesting periods (Jul, Aug, Sep, Oct, Nov, and Dec) using a systematic approach. The results revealed the identification of a total of 168 flavonoid metabolites, including 61 flavones, 54 flavonols, 14 flavone C-glycosides, 14 dihydroflavones, 9 flavanones, 8 isoflavones, 3 flavanols, 3 dihydroflavonols, and 2 chalcones. Clustering analysis and PCA were used to separate the CRCP samples collected at different stages. Furthermore, from July to December, the relative contents of isoflavones, dihydroflavones, and dihydroflavonols gradually increased and flavanols gradually decreased over time. The relative content of flavonoid C-glycosides showed an increasing and then decreasing trend, reaching the highest value in August. This study contributes to a better understanding of flavonoid metabolites in CRCP at different harvesting stages and informs their potential future utilization.

Urinary Tract Infections Caused by Uropathogenic Escherichia coli: Mechanisms of Infection and Treatment Options

Urinary tract infections (UTIs) are common bacterial infections that represent a severe public health problem. They are often caused by Escherichia coli (E. coli), Klebsiella pneumoniae (K. pneumonia), Proteus mirabilis (P. mirabilis), Enterococcus faecalis (E. faecalis), and Staphylococcus saprophyticus (S. saprophyticus). Among these, uropathogenic E. coli (UPEC) are the most common causative agent in both uncomplicated and complicated UTIs. The adaptive evolution of UPEC has been observed in several ways, including changes in colonization, attachment, invasion, and intracellular replication to invade the urothelium and survive intracellularly. While antibiotic therapy has historically been very successful in controlling UTIs, high recurrence rates and increasing antimicrobial resistance among uropathogens threaten to greatly reduce the efficacy of these treatments. Furthermore, the gradual global emergence of multidrug-resistant UPEC has highlighted the need to further explore its pathogenesis and seek alternative therapeutic and preventative strategies. Therefore, a thorough understanding of the clinical status and pathogenesis of UTIs and the advantages and disadvantages of antibiotics as a conventional treatment option could spark a surge in the search for alternative treatment options, especially vaccines and medicinal plants. Such options targeting multiple pathogenic mechanisms of UPEC are expected to be a focus of UTI management in the future to help combat antibiotic resistance.

Review of recent advances on health benefits, microbial transformations, and authenticity identification of Citri reticulatae Pericarpium bioactive compounds

The extensive health-promoting effects of Citri Reticulatae Pericarpium (CRP) have attracted researchers' interest. The difference in storage time, varieties and origin of CRP are closely related to the content of bioactive compounds they contain. The consitituent transformation mediated by environmental microorganisms (bacteria and fungi) and the production of new bioactive components during the storage process may be the main reason for 'the older, the better' of CRP. In addition, the gap in price between different varieties can be as large as 8 times, while the difference due to age can even reach 20 times, making the 'marketing young-CRP as old-CRP and counterfeiting origin' flood the entire market, seriously harming consumers' interests. However, so far, the research on CRP is relatively decentralized. In particular, a summary of the microbial transformation and authenticity identification of CRP has not been reported. Therefore, this review systematically summarized the recent advances on the main bioactive compounds, the major biological activities, the microbial transformation process, the structure, and content changes of the active substances during the transformation process, and authenticity identification of CRP. Furthermore, challenges and perspectives concerning the future research on CRP were proposed.

Comparison of the volatile organic compounds in Citrus reticulata 'Chachi' peel with different drying methods using E-nose, GC-IMS and HS-SPME-GC-MS

Introduction

Citrus reticulata 'Chachi' peel (CRCP), which is named "Guangchenpi" in China, is a geographical indication product with unique flavor properties. CRCP has been used for centuries as a traditional genuine herb because of its excellent therapeutic effects. In addition, owing to its unique odor and high nutrition, it is widely used in various food preparations. Volatile organic compounds (VOCs) are regarded as an important quality marker for CRCP and are highly susceptible to effects in the drying process due to their thermal instability.

Methods

In the current study, the main VOCs in CRCP were processed using different drying methods, including sun-drying, hot air drying, and vacuum-freeze drying. The VOCs were identified by the electronic nose (E-nose), gas chromatography-ion mobility spectrometry (GC-IMS), and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS).

Results

The results showed that the CRCP dried by vacuum-freeze exhibited the highest VOCs contents and retained the richest compounds compared to those dried by other methods, which indicated that vacuum-freeze drying is the most suitable for CRCP production. Furthermore, the chemometrics analysis revealed that the primary differential metabolites of the samples generated using different drying methods were terpenes and esters.

Discussion

Overall, our study would help better understand the VOCs present in CRCP with different drying methods. The outcomes of the current study would guide the drying and processing of CRCP, which is beneficial for large-scale storage and industrial production of CRCP.

Screening for Neuroprotective and Rapid Antidepressant-like Effects of 20 Essential Oils

Depression is a serious psychiatric disorder with high prevalence, and the delayed onset of antidepressant effects remains a limitation in the treatment of depression. This study aimed to screen essential oils that have the potential for rapid-acting antidepressant development. PC12 and BV2 cells were used to identify essential oils with neuroprotective effects at doses of 0.1 and 1 µg/mL. The resulting candidates were treated intranasally (25 mg/kg) to ICR mice, followed by a tail suspension test (TST) and an elevated plus maze (EPM) after 30 min. In each effective essential oil, five main compounds were computationally analyzed, targeting glutamate receptor subunits. As a result, 19 essential oils significantly abolished corticosterone (CORT)-induced cell death and lactate dehydrogenase (LDH) leakage, and 13 reduced lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). From in vivo experiments, six essential oils decreased the immobility time of mice in the TST, in which Chrysanthemum morifolium Ramat. and Myristica fragrans Houtt. also increased time and entries into the open arms of the EPM. Four compounds including atractylon, α-curcumene, α-farnesene, and selina-4(14),7(11)-dien-8-one had an affinity toward GluN1, GluN2B, and Glu2A receptor subunits surpassed that of the reference compound ketamine. Overall, Atractylodes lancea (Thunb.) DC and Chrysanthemum morifolium Ramat essential oils are worthy of further research for fast-acting antidepressants through interactions with glutamate receptors, and their main compounds (atractylon, α-curcumene, α-farnesene, and selina-4(14),7(11)-dien-8-one) are predicted to underlie the fast-acting effect.

Soil conditions and the plant microbiome boost the accumulation of monoterpenes in the fruit of Citrus reticulata 'Chachi'

BACKGROUND

The medicinal material quality of Citrus reticulata 'Chachi' differs depending on the bioactive components influenced by the planting area. Environmental factors, such as soil nutrients, the plant-associated microbiome and climatic conditions, play important roles in the accumulation of bioactive components in citrus. However, how these environmental factors mediate the production of bioactive components of medicinal plants remains understudied.

RESULTS

Here, a multi-omics approach was used to clarify the role of environmental factors such as soil nutrients and the root-associated microbiome on the accumulation of monoterpenes in the peel of C. reticulata 'Chachi' procured from core (geo-authentic product region) and non-core (non-geo-authentic product region) geographical regions. The soil environment (high salinity, Mg, Mn and K) enhanced the monoterpene content by promoting the expression of salt stress-responsive genes and terpene backbone synthase in the host plants from the core region. The microbial effects on the monoterpene accumulation of citrus from the core region were further verified by synthetic community (SynCom) experiments. Rhizosphere microorganisms activated terpene synthesis and promoted monoterpene accumulation through interactions with the host immune system. Endophyte microorganisms derived from soil with the potential for terpene synthesis might enhance monoterpene accumulation in citrus by providing precursors of monoterpenes.

CONCLUSIONS

Overall, this study demonstrated that both soil properties and the soil microbiome impacted monoterpene production in citrus peel, thus providing an essential basis for increasing fruit quality via reasonable fertilization and precision microbiota management. Video Abstract.

The Chemical Variability, Nutraceutical Value, and Food-Industry and Cosmetic Applications of Citrus Plants: A Critical Review

Citrus fruits occupy an important position in the context of the fruit trade, considering that both fresh fruits and processed products are produced on a large scale. Citrus fruits are recognized as an essential component of the human diet, thanks to their high content of beneficial nutrients such as vitamins, minerals, terpenes, flavonoids, coumarins and dietary fibers. Among these, a wide range of positive biological activities are attributed to terpenes and flavonoids derivatives. In this review, a list of bibliographic reports (from 2015 onwards) on the phytochemical composition, beneficial effects and potential applications of citrus fruits and their by-products is systematically summarized. In detail, information regarding the nutraceutical and medicinal value closely linked to the presence of numerous bioactive metabolites and their growing use in the food industry and food packaging, also considering any technological strategies such as encapsulation to guarantee their stability over time, were evaluated. In addition, since citrus fruit, as well as its by-products, are interesting alternatives for the reformulation of natural cosmetic products, the sector of the cosmetic industry is also explored. More in-depth knowledge of the latest information in this field will contribute to future conscious use of citrus fruits.

Discrimination of Pericarpium Citri Reticulatae in different years using Terahertz Time-Domain spectroscopy combined with convolutional neural network

Pericarpium Citri Reticulatae (PCR) in longer storage years possess higher medicinal values, but their differentiation is difficult due to similar morphological characteristics. Therefore, this study investigated the feasibility of using terahertz time-domain spectroscopy (THz-TDS) combined with a convolutional neural network (CNN) to identify PCR samples stored from 1 to 20 years. The absorption coefficient and refractive index spectra in the range of 0.2-1.5 THz were acquired. Partial least squares discriminant analysis, random forest, least squares support vector machines, and CNN were used to establish discriminant models, showing better performance of the CNN model than the others. In addition, the output data points of the CNN intermediate layer were visualized, illustrating gradual changes in these points from overlapping to clear separation. Overall, THz-TDS combined with CNN models could realize rapid identification of different year PCRs, thus providing an efficient alternative method for PCR quality inspection.

Quality control strategies of medicine food homology materials based on fingerprint profiling and chemometrics: Citri Reticulata Pericarpium as an example

The study aimed to provide a reliable and feasible strategy for the comprehensive quality control of medicine food homology materials (MFHM). The high performance liquid chromatography (HPLC) fingerprints and Fourier transform mid-infrared (FT-MIR) quantized fingerprints were successfully developed to comprehensively evaluate overall quality of Citri Reticulata Pericarpium (CRP) by applying comprehensive quantified fingerprint method (CQFM). All samples were well distinguished and divided into 5 grades. In addition, through principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA), the identification ability of HPLC fingerprints and FT-MIR fingerprints on CRP with different storage years was discussed. The results showed that HPLC fingerprints combined with PCA had good discrimination ability, and the PLS-DA model established by the preprocessed FT-MIR fingerprint data could accurately distinguish and predict the storage period of CRP. Finally, based on 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging assay, combined with bivariate correlation analysis, the fingerprint-activity relationship of offline antioxidant activity of CRP samples with the fingerprints peak were studied. In general, the comprehensive strategies provide a reliable and scientific reference scheme for the quality control of MFHM in the future.

Citri Reticulatae Pericarpium (Chenpi): A multi-efficacy pericarp in treating cardiovascular diseases

Citri Reticulatae Pericarpium (CRP) has been utilized as a versatile medicinal herb with wide cardiovascular benefits in Asian nations for centuries. Accumulating evidence suggests that CRP and its components are effective in preventing cardiovascular diseases (CVDs) such as atherosclerosis, myocardial infarction, myocardial ischemia, arrhythmia, cardiac hypertrophy, heart failure, and hypertension. Studies show that the two most bioactive components of CRP are flavonoids and volatile oils. The cardiovascular protective effects of CRP have attracted considerable research interest due to its hypolipidemic, antiplatelet activity, antioxidant and anti-inflammatory effects. Hereby, we provide a rigorous and up-to-date overview of the cardiovascular protective properties and the potential molecular targets of CRP, and finally highlight the pharmacokinetics and the therapeutic potential of the main pharmacologically active components of CRP to treat CVDs.

Exploring the Molecular Mechanism of Tong Xie Yao Fang in Treating Ulcerative Colitis Using Network Pharmacology and Molecular Docking

Objective. The purpose of this study was to investigate the mechanisms of action of Tong Xie Yao Fang (TXYF) against ulcerative colitis (UC) by employing a network pharmacology approach. Methods. The network pharmacology approach, including screening of the active ingredients and targets, construction of the active ingredient-drug target network, the active ingredient-diseasetarget network, the protein–protein interaction (PPI) network, enrichment analyses, molecular docking, and targets validation, was used to explore the mechanisms of TXYF against UC. Results. 34 active ingredients and 129 and 772 targets of TXYF and UC, respectively, were identified. The intersection of the active ingredient-drug target network, the active ingredient-disease target network, and the PPI network suggested that kaempferol, beta-sitosterol, wogonin, and naringenin were the core ingredients and prostaglandin-endoperoxide synthase 2 (PTGS2) was the core target. Enrichment analyses showed that regulation of exogenous protein binding and other functions were of great significance. Nuclear factor-kappa B (NF-κB) signaling pathway, interleukin-17 (IL-17) signaling pathway, and tumor necrosis factor (TNF) signaling pathway were important pathways. Results of molecular docking indicated that the core ingredients and the target molecule had strong binding affinities. We have validated the high levels of expression of PTGS2 in UC by analyzing three additional datasets from the Gene Expression Omnibus (GEO) database. Conclusions. There are multiple ingredients, targets, and pathways involved in TXYF’s effectiveness against UC, and these findings will promote further research and clinical applications.

Effect of Drying Methods on Volatile Compounds of Citrus reticulata Ponkan and Chachi Peels as Characterized by GC-MS and GC-IMS

To reflect the volatile differences of dried citrus peel as affected by cultivars and drying methods, the volatile compounds of dried citrus peel of two cultivars (Citrus reticulata "Chachi" and Citrus reticulata "Ponkan"), prepared under three drying methods (sun-drying (SD), hot-air-drying (AD), and freeze-drying (FD)), were analyzed by GC-MS, odor activity values (OAVs), and GC-IMS. GC-MS data indicated that SD was favorable to preserve terpenic alcohols (linalool, α-terpineol and terpinene-4-ol), β-cymene, methyl methanthranilate, and monoterpenes; while AD was favorable to preserve aliphatic aldehydes and sesquiterpenes; and SD was more similar with AD in GC-MS analysis of volatile profile (of higher MW) for both cultivars from the PCA outcome. Furthermore, significant difference in volatile isomeric composition of different samples was also clearly demonstrated through extracted ion chromatogram (EIC) by GC-MS analysis. GC-IMS analysis showed the favorability of FD to preserve ketones, phenols, esters, and aromatic aldehydes; and SD was more similar with FD in GC-IMS analysis of volatile profile (of smaller MW) for both cultivars from the PCA outcome. Moreover, the OAVs indicate that 2-methoxy-4-vinylphenol contributed much to the flavor of dried Ponkan peel, while 2-methoxy-4-vinylphenol, methyl methanthranilate, and methyl anthranilate played an important role in the flavor of dried Chachi peel; and the highest OAVs for monoterpenes were observed at SD for both cultivars. Thus, the combination of GC-MS and GC-IMS analyses with PCA in this paper suggested the superiority of SD to preserve volatiles and characteristic aroma in dried citrus peel, and that SD contributed much to the quality of dried Chachi peel.

Simultaneous qualitative and quantitative analysis of 10 bioactive flavonoids in Aurantii Fructus Immaturus (Zhishi) by ultrahigh-performance liquid chromatography and high-resolution tandem mass spectrometry combined with chemometric methods

INTRODUCTION

Aurantii Fructus Immaturus (Zhishi in Chinese) is the dried young fruit of Citrus aurantium L. (CA) and its cultivated varieties or Citrus sinensis Osbeck (CS). The content of flavonoids in different varieties of Zhishi may be significantly different. However, there is confusion about the botanical origin of Zhishi, and there is no reliable and systematic method to control Zhishi quality.

OBJECTIVES

We aimed to establish an ultrahigh-performance liquid chromatography method coupled with diode-array detection and high-resolution tandem mass spectrometry (UPLC-DAD-HRMS/MS) for the quantitative analysis of 10 flavonoids in Zhishi that could be used for quality control and botanical origin identification.

METHODOLOGY

A UPLC-DAD-HRMS/MS method was established for simultaneous identification and quantification of 10 flavonoids. Separation was performed on a Waters Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 μm) with 0.1% formic acid and acetonitrile as mobile phase under gradient elution. MS was performed in positive and negative ionisation modes. The flavonoids in 41 batches were isolated and quantified. Zhishi of different botanical origins were identified by chemometrics.

RESULTS

The results showed that the established method for the determination of 10 components was reliable and accurate. Chemometrics could be used to distinguish Zhishi of different botanical origins. There were significant differences in the contents of 10 flavonoids in samples of different botanical origins.

CONCLUSIONS

The quantitative analysis method in this study can be used to accurately determine the content of 10 flavonoids and provide a chemical basis for quality control and botanical origin identification of Zhishi.

Development and validation of ultra-high performance supercritical fluid chromatography method for quantitative determination of four target flavonoids components in citrus samples

A new method for the analysis of four target flavonoids in two kinds of citrus samples by ultra-high performance supercritical fluid chromatography (UHPSFC) method was developed. Main variables affecting the UHPSFC separation were optimized, and under the optimized conditions the four target compounds (tangeretin, nobiletin, hesperetin and naringenin) can be separated within 10 min. The UHPSFC method allowed the determination of the four target compounds in the diluted stock solutions with limit of detection (LOD) ranging from 1.08 to 2.28 μg mL−1, and limit of quantification (LOQ) ranging from 1.45 to 4.52 μg mL−1, respectively. The coefficients of determination (R 2) of the calibration curves were higher than 0.9950. The recoveries of the four target compounds at three different concentrations were in the range of 82.4–117.6%. The validation results demonstrated that the proposed method is simple, accurate, time-saving and environment friendly, and it is applicable to a variety of complex samples such as medicine-food dual purpose herbs and functional foods.

Simultaneous qualitative and quantitative analysis of eight alkaloids in Corydalis Decumbentis Rhizoma (Xiatianwu) and Corydalis Rhizoma (Yanhusuo) by HPLC and high-resolution MS combined with chemometric methods

In this study, we established a comprehensive high-performance liquid chromatography coupled with diode array detection and high-resolution mass spectrometry method to identify ten and quantified eight constituents in Corydalis Decumbentis Rhizoma ('Xiatianwu' in Chinese) and Corydalis Rhizoma ('Yanhusuo' in Chinese). Chemometric methods were applied to distinguish the botanical origins of the Xiatianwu and Yanhusuo samples. Chromatographic separation was achieved using an Agilent Poroshell EC-C₁₈ column with mobile phases A (1000 mL of 0.2% acetic acid solution containing 2.8 mL of triethylamine) and B (acetonitrile) and stepwise gradient elution. The analytical method was fully validated in terms of linearity, sensitivity, intra- and interday precision and repeatability, limit of detection, limit of quantitation and recovery. Twenty-six Xiatianwu samples and ten Yanhusuo samples were analysed for quality evaluation. In addition, hierarchical clustering analysis and principal component analysis were used to discriminate among samples of different botanical origins. The results showed that the contents of eight alkaloids in Xiatianwu and Yanhusuo were significantly different. Moreover, it was found that chemometric methods could be applied to accurately distinguish these two often conflated Chinese medicinal materials. In conclusion, this study provides a relatively comprehensive method for botanical origin identification and Xiatianwu and Yanhusuo quality control. This article is protected by copyright. All rights reserved.

Citri Reticulatae Pericarpium alleviates postmyocardial infarction heart failure by upregulating PPARγ expression

Heart failure after myocardial infarction (MI) is the leading cause of death worldwide. Citri Reticulatae Pericarpium (CRP) is a traditional Chinese herbal medicine that has been used in the clinic for centuries. In this study, we aimed to investigate the roles of CRP in cardiac remodeling and heart failure after MI, as well as the molecular mechanisms involved. Male C57BL/6 mice aged 8 weeks were subjected to coronary artery ligation to mimic the clinical situation in vivo. Echocardiography was used to assess the systolic function of the mouse heart. Masson trichrome staining and Wheat germ agglutinin (WGA) staining were utilized to determine the fibrotic area and cross-sectional area of the mouse heart, respectively. Cardiomyocytes and fibroblasts were isolated from neonatal rats aged 0-3 days in vitro using enzyme digestion. TUNEL staining and EdU staining were performed to evaluate apoptosis and proliferation, respectively. Gene expression changes were analyzed by qRT-PCR, and protein expression changes were assessed by Western blotting. Our findings revealed that CRP attenuated cardiac hypertrophy, fibrosis and apoptosis and alleviated heart failure after MI in vivo. Furthermore, CRP mitigated cardiomyocyte apoptosis and fibroblast proliferation and differentiation into myofibroblasts. In addition, the PPARγ inhibitor T0070907 completely abolished the abovementioned beneficial effects of CRP, and the PPARγ activator rosiglitazone failed to further ameliorate cardiac apoptosis and fibrosis in vitro. CRP alleviates cardiac hypertrophy, fibrosis, and apoptosis and can ameliorate heart failure after MI via activation of PPARγ. This article is protected by copyright. All rights reserved.

Multiple fingerprints and quantitative analysis for comprehensive quality evaluation of Citri reticulatae pericarpium within different storage years

The multi-wavelength fused HPLC fingerprint, and UV and DSC quantum fingerprints were used for quality evaluation of CRP by QRFM.

Dynamic variation of the phytochemical and volatile compounds in the pericarp of Citrus reticulata ''Chachi'' (Rutaceae) during 2 years of storage

The pericarp of Citrus reticulata "Chachi" (CRCP) is used as nutritional food and traditional medicine in China, usually harvested at three periods, namely, immature (CRCP-G1), semi-mature (CRCP-G2), and fully mature (CRCP-G3). Traditionally, if the CRCP is stored for a longer period, then the quality will be better. In this study, the dynamic variation of phytochemical and volatile compounds was profiled in the same batches of CRCP during 2 years of storage. Results illustrated that most of the phytochemical compounds showed a decreasing trend during storage, that is, total flavonoids, total phenolic acids, hesperidin, 3,5,6,7,8,3',4'-heptamethoxyflavone, 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone, synephrine, and limonin. The ferulic acid increased significantly, whereas no significant changes were observed in the total polymethoxyflavones, nobiletin, and tangeretin after 2 years of storage. In addition, we found that the extraction yield of volatile oil decreased significantly in CRCP-G1 during storage, and the herb odors were enhanced with the increase of phenols and esters. No significant difference in the extraction yield of volatile oil of CRCP-G2 and CRCP-G3 was found after 2 years of storage, but the citrus-like notes were increased with the promoted generation of alkenes. In particular, the multivariate statistical analysis indicated that 7 volatiles showed a higher level after 1 year of storage, whereas 11 volatiles decreased and 4 volatiles increased after 2 years of storage, respectively. This study could show the early aging mechanism of CRCP harvested at different periods and provide a scientific guidance in the storage of CRCP. PRACTICAL APPLICATION: This study indicated a comprehensive method for rapid analysis of phytochemical and volatile compounds in pericarp of Citrus reticulata ''Chachi'' (Rutaceae) (CRCP) harvested at different periods during 2 years of storage. The results obtained from this study would be valuable for revealing the early aging mechanism and sustainable storage of CRCP.

Intraspecific DNA Barcoding and Variation Analysis for Citri Reticulatae Pericarpium of Citrus reticulata "Chachi"

Citri Reticulatae Pericarpium, the desiccative mature peel of Citrus reticulata Blanco or its cultivated varieties, is a national geographical indicated product that has the concomitant function of both medicine and foodstuff. The primary source of Citri Reticulatae Pericarpium is Citrus reticulata “Chachi,” called “Guang chenpi,” while it differs in variety, propagation, grafting rootstock, and tree age, and the hereditary stability of its biological information between intraspecific plants is worthy of our attention. Homologous analysis result of 4 DNA barcodings in the ribosome or the chloroplast showed that the homology of them (ITS2, rbcl, matK, and psbA-trnH) of 22 samples was 100.00%, 99.97%, 99.99%, and 99.81%, respectively, which indicated that 4 DNA barcodes maintained a high degree of genetic stability in Citrus reticulata “Chachi.” Also, ITS2 was considered to identify Citrus reticulata “Chachi” from other varieties because it presented not only low variability within a certain taxon but also a high level of interspecies variability. Simultaneously, variant site detection of Citrus reticulata “Chachi” was analyzed by comparing with the reference Citrus reticulata genome, and 2652697 SNP sites and 533906 InDel sites were detected from whole-genome resequencing data of 22 samples, providing the data resources and theoretical foundation for the future study about the relevant molecular makers of “Guang chenpi.”

Rapid Discrimination of Citrus reticulata 'Chachi' by Electrospray Ionization-Ion Mobility-High-Resolution Mass Spectrometry

A common idea is that some dishonest businessmen often disguise Citrus reticulata Blanco varieties as Citrus reticulata 'Chachi', which places consumers at risk of economic losses. In this work, we combined high-resolution ion mobility (U-shaped mobility analyzer) with high-resolution mass spectrometry to rapidly distinguish Citrus reticulata 'Chachi' from other Citrus species. The samples were analyzed directly through simple extraction and the analytes were separated in one second. It only took about 1 min to perform a cycle of sample analysis and data acquisition. The results showed that polymethoxylated flavones and their isomers were separated easily by the ion mobility analyzer and preliminarily identified according to the accurate mass. Moreover, the collision cross-section values of all analytes, which could be used as auxiliary parameters to characterize and identify the compounds in the samples, were measured. Twenty-four samples were grouped as two clusters by multivariate analysis, which meant that Citrus reticulata 'Chachi' could be effectively differentiated. It was confirmed that the developed method had the potential to rapidly separate polymethoxylated flavones and distinguish between Citrus reticulata 'Chachi' and other Citrus reticulata Blanco varieties.

Comparative Metabolomics Analysis of Citrus Varieties

Many citrus varieties are hybridized to improve their quality and to overcome the effects of climate change. However, there is limited information on the effect of the chemical profiles of hybrid varieties on their quality. In this study, we analyzed 10 citrus varieties and evaluated the correlation with their general characteristics and antioxidant activities. Chemical profiles, including the contents of sugars, organic acid compounds, flavonoids, limonoids, and carotenoids, which are related to taste, color, and health benefits, were significantly different depending on the citrus varieties, leading to different antioxidant capacities and general quality parameters. Based on these data, the correlations were investigated, and 10 citrus varieties were clustered into four groups-Changshou kumquat and Jeramon (cluster I); Setoka (cluster II-1); Natsumi, Satsuma mandarin, and Navel orange (cluster II-2); Kanpei, Tamnaneunbong, Saybyeolbong, and Shiranui (cluster II-3). Moreover, a metabolomic pathway was proposed. Although citrus peels were not analyzed and the sensory and functional qualities of the citrus varieties were not investigated in this study, our results are useful to better understand the relationship between citrus quality and metabolite profiles, which can provide basic information for the development and improvement of new citrus varieties.

Metabolomic insights into the inhibition mechanism of methyl N-methylanthranilate: A novel quorum sensing inhibitor and antibiofilm agent against Pseudomonas aeruginosa

The quorum sensing (QS) inhibition effect of methyl N-methylanthranilate (MMA) from Pericarpium Citri Reticulatae Chachiensis against foodborne pathogen Pseudomonas aeruginosa was reported for the first time. MMA effectively attenuated QS related virulence factors production and biofilm formation, while suppressed expression of a dozen of QS related genes. Untargeted LC-MS metabolomics revealed 108 significantly altered metabolites after MMA treatment. They indicated that MMA addition reduced the efficiency of TCA cycle and antioxidant systems, disturbed amino acid and nucleotide metabolism, increased unsaturated fatty acid and decreased peptidoglycan components, which might ultimately attenuate P. aeruginosa pathogenicity and restrain biofilm formation. Physiological characterization confirmed the compromised membrane integrity and increased intracellular oxidative stress after MMA treatment. Furthermore, metabolomics data implied that MMA inhibition on QS might exert through disrupting QS autoinducer PQS biosynthesis, which was supported by molecular docking. Our data indicated that MMA could be used as a novel QS inhibitor and anti-biofilm agent to improve food safety. It also provided new insight in the possible underlying inhibition mechanism of MMA and the response of P. aeruginosa to MMA.

Simultaneous quantitative analysis of ten bioactive flavonoids in Citri Reticulatae Pericarpium Viride (Qing Pi) by ultrahigh-performance liquid chromatography and high-resolution mass spectrometry combined with chemometric methods

INTRODUCTION

Citri Reticulatae Pericarpium Viride (Qing Pi in Chinese) is a clinically effective Chinese herb, which contains biologically valuable flavonoids. Qing Pi is divided into two commodity specifications, Si Hua Qing Pi (SHQP) and Ge Qing Pi (GQP), based on the harvesting time. The flavonoid contents in Qing Pi from different origins and commodity specifications may vary significantly, which will affect their therapeutic functions. Thus, it is crucial to set up a reliable and comprehensive quality evaluation method for flavonoid analysis in Qing Pi.

OBJECTIVES

We aimed to establish a rapid and sensitive ultrahigh-performance liquid chromatography method coupled with diode-array detection and high-resolution mass spectrometry (UPLC-DAD-HRMS) for identification and quantification of ten flavonoids in Qing Pi. Chemometric methods were further applied to distinguish Qing Pi of different origins and specifications.

METHODOLOGY

An UPLC-DAD-HRMS method was developed for the simultaneous separation and quantification of ten flavonoids in 46 batches of Qing Pi samples from different sources in China. Chemometric approaches were applied to discriminate Qing Pi from different origins and commodity specifications.

RESULTS

The chemometric procedures (i.e., hierarchical clustering analysis and principal component analysis) were employed to identify the differences of Qing Pi samples with different origins and commodity specifications. The results showed that the contents of ten flavonoids in Qing Pi samples of different origins were significantly different, and the same results were found out between SHQP and GQP.

CONCLUSIONS

This study provides a chemical basis for quality control of Qing Pi.

Dynamic changes of phenolic acids and antioxidant activity of Citri Reticulatae Pericarpium during aging processes

Citri reticulatae pericarpium (CRP) shows multiple bioactivities, including antioxidant, anti-tumor, and anti-inflammation. The folk proverb "CRP, the older, the better" means storing for longer time would improve its quality, which attributed to the influence of bioactive compounds. The aim of this work was to study which compounds are the factors that long storage would influence the quality of CRP. 161 compounds, including 65 flavonoids, 51 phenolic acids, 27 fatty acids, and 18 amino acids were identified through derivatization and non-derivatization liquid chromatography mass spectrometry approaches. Their dynamic changes indicated phenolic acids, which were reported to have various activities, were the main increased components. Furthermore, the representative phenolic acids were quantified and correlation analysis between their contents and antioxidant activity implicated they were the possible indicators that long storage would improve CRP quality. The results would provide basis for quality control of CRP during storage.

Comparison of Volatile Oils and Primary Metabolites of Raw and Honey-Processed Ephedrae Herba by GC-MS and Chemometrics

BACKGROUND

Ephedrae Herba (EH) is the terrestrial stem of Ephedra sinica Stapf, E. intermedia Schrenk et C. A. Mey., or E. equisetina Bge, which has been used as a diaphoretic, antiasthmatic, and diuretic. Honey-processed EH (HEH) is a widely used traditional Chinese medicine, and has a better effect of dispersing lung qi and relieving asthma and a lower effect of dispelling cold than raw EH (REH).

OBJECTIVE

To understand the differences of volatile oils and primary metabolites between REH and honey-processed HEH, and to provide a reference for elucidating the mechanism behind the effect of this processing.

METHODS

A system data acquisition and mining strategy was designed to investigate the differences of volatiles and primary metabolites between the REH and HEH, based on gas chromatography-mass spectrometry coupled with multivariate statistical analysis, including principal component analysis and orthogonal partial least squares discriminant analysis.

RESULTS

Overall, 15 volatile oils and 14 primary metabolites were shown to be potential characteristic markers differentiating REH and HEH.

CONCLUSION

The results may provide a scientific foundation for comprehensively revealing the honey-processing mechanism of EH.

HIGHLIGHT

Volatile oils and primary metabolites were used to distinguish REH and HEH and elucidate the processing mechanism of EH for the first time.

Citrus alkaline extracts prevent endoplasmic reticulum stress in type II alveolar epithelial cells to ameliorate pulmonary fibrosis via the ATF3/PINK1 pathway

BACKGROUND

Idiopathic pulmonary fibrosis is a chronic, progressive, fibrotic disease. Although the pathogenesis remains unclear, the effect of endoplasmic reticulum (ER) stress in type II alveolar epithelial cells (AEC IIs) is increasingly thought to be a critical mechanism.

PURPOSE

We investigated the effects of citrus alkaline extracts (CAE) on AEC IIs and elucidated the underlying mechanism for their possible use in ameliorating pulmonary fibrosis (PF).

METHODS

A bleomycin-induced mouse model of PF, and an in vitro tunicamycin (TM) -induced ER stress model in A549 cells were successfully established. Accumulation of collagen in lung tissues in vivo was assessed using histological analysis and western blotting. The expression levels of the ER-stress marker BiP and other related proteins were assessed by western blotting and immunofluorescence staining. Mitochondrial membrane potential was assessed to evaluate mitochondrial homeostasis.

RESULTS

CAE mitigated collagen deposition to ameliorate PF in vivo. CAE suppressed the bleomycin or TM-induced increases in ER-stress biomarker, BiP, and PERK pathway proteins, resulting in a decrease in ER stress in mouse lung tissues and A549 cells, respectively. Additionally, CAE treatment suppressed the bleomycin or TM-induced increase in the ER-stress downstream proteins, activating ATF3 and increased the levels of PINK1 in AEC IIs, both in vivo and in vitro. The reduced mitochondrial homeostasis induced by TM was restored by CAE-treatment in A549 cells. Furthermore, conditioned media from TM-treated A549 cells increased collagen deposition in MRC5 cells mainly via TGF-β1. The increased collagen deposition was not seen using conditioned media from CAE-treated A549 cells.

CONCLUSION

These results provide novel insights into the potential mechanism of CAE in inhibiting ER stress in AEC IIs, and suggests that it has great potential to ameliorate PF via the ATF3/PINK1 pathway.

Characterization of two closely related citrus cultivars using UPLC-ESI-MS/MS-based widely targeted metabolomics

Citrus cultivars are widely spread worldwide, and some of them only differ by specific mutations along the genome. It is difficult to distinguish them by traditional morphological identification. To accurately identify such similar cultivars, the subtle differences between them must be detected. In this study, UPLC-ESI-MS/MS-based widely targeted metabolomics analysis was conducted to study the chemical differences between two closely related citrus cultivars, Citrus reticulata 'DHP' and C. reticulata 'BZH'. Totally 352 metabolites including 11 terpenoids, 35 alkaloids, 80 phenolic acids, 25 coumarins, 7 lignans, 184 flavonoids and 10 other compounds were detected and identified; Among them, 15 metabolites are unique to DHP and 16 metabolites are unique to BZH. Hierarchical cluster analysis (HCA), principal component analysis (PCA), and orthogonal signal correction and partial least squares-discriminant analysis (OPLS-DA) can be used to clearly discriminate between DHP and BZH. 93 metabolites including 36 down-regulated and 57 up-regulated are significantly different in DHP and BZH. They are mainly involved in the biosynthesis of flavonoids, flavones, flavonols, and isoflavonoids. In addition, the relative content levels of flavonoids, alkaloids, and terpenoids are much higher in the peel of DHP than that of BZH, the presence of which may correlate with the quality difference of the peels. The results reported herein indicate that metabolite analysis based on UPLC-ESI-MS/MS is an effective means of identifying cultivars with different genotypes, especially those that cannot be distinguished based on traditional identification methods.

Insights into the chemical composition and bioactivities of citrus peel essential oils

Citrus peel (CP), a by-product of the citrus fruit processing, comprises nearly forty to fifty percent of the fruit portion. Interestingly, the essential oil (EO) is primarily concentrated in the peel portion of the citrus fruit. Extraction of CP essential oil (CPEO) is an effective way of utilizing the citrus fruit processing waste. The CPEO can be more efficiently recovered from CP waste by improving the efficiency of conventional extraction processes. The main components of CPEO include monoterpenes, sesquiterpenes and their oxygenated derivatives. Specifically, limonene is the major oil component identified in the peel of different citrus species. The health promoting biological activities of CPEO are functioning as antioxidant, anti-inflammatory, analgesic, antimicrobial and anticancer agents, thereby can be used as a source of functional components and preservatives for the development of nutritionally safe newer food products. This paper provides an in-depth knowledge about the chemical constituents and bioactivities of EOs extracted from peels of different citrus species.

Systems Pharmacology-Based Strategy to Explore the Pharmacological Mechanisms of Citrus Peel (Chenpi) for Treating Complicated Diseases

Citri Reticulatae Pericarpium (CRP), also known as Chenpi in Chinese, is the dry mature peel of Citrus reticulata Blanco or its cultivated varieties. CRP as the health-care food and dietary supplement has been widely used in various diseases. However, the potential pharmacological mechanisms of CRP to predict and treat various diseases have not yet been fully elucidated. A systems pharmacology-based approach is developed by integrating absorption, distribution, metabolism, and excretion screening, multiple target fishing, network pharmacology, as well as pathway analysis to comprehensively dissect the potential mechanism of CRP for therapy of various diseases. The results showed that 39 bioactive components and 121 potential protein targets were identified from CRP. The 121 targets are closely related to various diseases of the cardiovascular system, respiratory system, gastrointestinal system, etc. These targets are further mapped to compound-target, target-disease, and target-pathway networks to clarify the therapeutic mechanism of CRP at the system level. The current study sheds light on a promising way for promoting the discovery of new botanical drugs.

A novel method for the nondestructive classification of different-age Citri Reticulatae Pericarpium based on data combination technique

The quality of Citri Reticulatae Pericarpium (CRP) is closely correlated with the aging time. However, CRPs in different storage ages are similar in appearance, and the young CRP may be labeled as the aged one to obtain the excess profit by some unscrupulous traders. Most traditional analysis methods are laborious and time-consuming, and they can hardly realize the nondestructive classification. In this paper, a novel method based on near-infrared diffuse reflectance spectroscopy (NIRDRS) and data combination technique for the nondestructive classification of different-age CRPs was proposed. The CRPs in different storage ages (5, 10, 15, 20, and 25 years) were measured. The near-infrared spectra of outer skin and inner capsule were obtained. Principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), and Fisher's linear discriminant analysis (FLD), with different data pretreatment methods, were used for the classification analysis. Data combination of the outer skin and inner capsule spectra was discussed for further improving the classification results. The results show that multiple sensors provide more useful and complementary information than a single sensor does for improving the prediction accuracy. With the help of data combination strategy, 100% prediction accuracy can be obtained with both second-order derivative-FLD and continuous wavelet transform-multiplicative scatter correction-FLD methods.

A novel fluorescence sensing strategy based on nanoparticles combined with spectral splicing and chemometrics for the recognition of Citrus reticulata 'Chachi' and its storage year

BACKGROUND

The fluorescence sensing method has been increasingly applied in food quality control because it is fast and sensitive. However, its application in quality evaluation is challenging. Using Citri Reticulatae Pericarpium (CRP; dried mandarin orange peel) as an example, we developed a simple and low-cost fluorescence sensing strategy based on nanoparticles combined with spectral splicing and chemometrics for quality evaluation. This method can recognize Citrus reticulata 'Chachi' (CRC) from other CRP cultivars and further identify the storage year.

RESULTS

Nanogold particles and cadmium telluride quantum dots were selected as nanosensors and mixed with aqueous extracts of CRP separately to produce fluorescence quenching spectra. Then, a simple spectral splicing procedure was applied to obtain spliced spectra comprising different combinations of the self-fluorescence and fluorescence quenching spectra of CRP samples. With the aid of partial least-squares discriminant analysis, the new strategy achieved recognition rates of 100% in distinguishing CRC samples from other CRP samples, as well as recognition rates of 100% for the training set and 98.04% for the prediction set in the discrimination of the storage year of CRC. The recognition mechanism is dominated by interactions between the nanoparticles and the fluorescent components in the CRP samples, but other components also have concurrent effects.

CONCLUSIONS

This novel fluorescence sensing strategy not only provides a new tool for the quality evaluation of CRC but also has good prospects for the authentication and traceability of other foods and herbs. Crucially, the developed method is convenient, simple and effective. © 2020 Society of Chemical Industry.

Yin Yang Gong Ji pill is an ancient formula with antitumor activity against hepatoma cells

ETHNOPHARMACOLOGICAL RELEVANCE

Yin Yang Gong Ji pill (YYGJ) is a formula that was used in the Ming Dynasty. This study investigated the effects of YYGJ on HepG2 and MHCC97H hepatoma cells.

MATERIAL AND METHODS

The effects of YYGJ drug-containing rat serum (YYGJ serum) on cell proliferation and the cell cycle were investigated by a tetrazolium dye-based MTS assay and flow cytometry. Apoptosis was assayed by TUNEL and flow cytometry. E-cadherin, vimentin, c-Myc, Smad4, and MMP2 expression were assayed by real-time quantitative PCR and Western blot assays. The effects on cell invasiveness and migration were evaluated by wound healing and transwell assays. The antitumor activity of 10% YYGJ serum was compared to that of blank control, 10% rat serum control and 5-fluorouracil(FU).

RESULTS

HepG2 and MHCC97H cell proliferation was inhibited by YYGJ serum in a time- and concentration-dependent manner. Cells accumulated in G0/G1 and apoptosis was increased in both cell lines by 10% YYGJ serum. The effects of apoptosis in 10% YYGJ serum were weaker than those in response to 5-FU. E-cadherin and Smad4 expression were upregulated by 10% YYGJ serum, but c-Myc, vimentin and MMP2 expression were downregulated in both hepatoma cell lines. The protein expression of Smad4 in HepG2, and mRNA expression of MMP2 and E-cadherin in both cell lines had no difference between 10% YYGJ serum and 5-FU treated groups. Cell invasion and migration were decreased by 10%YYGJ serum while cell cytotoxicity was shown in 5-FU treated group.

CONCLUSIONS

YYGJ drug-containing serum inhibited HepG2 and MHCC97H cell proliferation, induced apoptosis, and regulated the expression of tumor-related genes and proteins. It reduced tumor cell invasion and migration. Further study to investigate the antitumor activity of YYGJ is warranted.