Polymethoxyflavones Research Articles

Therapeutic overview of sudachitin.

Citrus fruits are extensively cultivated and eaten both raw and in refined forms. Citrus fruit peels are highly concentrated in polyphenolic substances. This makes them useful resources. Polymethoxyflavones (PMFs), found in citrus peels, belong to a specific subclass of flavonoids where most or all hydroxyl groups are methylated. PMFs have been documented to possess chemopreventive actions, anticancer, anti-inflammatory, and anti-atherosclerosis properties, as well as neuroprotective effects. Sudachitin, a PMF, is primarily found in Citrus sudachi. Japan's Tokushima prefecture is home to this famous fruit. In recent years, there has been a growing interest among researchers in exploring the potential health benefits of sudachitin, spurred by its presence in traditional diets and its association with various positive health outcomes. Studies conducted over the past decade have revealed promising effects of sudachitin in multiple health conditions, including cancer, skin disorders, inflammatory conditions, diabetes, obesity, and neurodegenerative disorders. Although these promising results exist, there is still a need for thorough preclinical and clinical research to confirm sudachitin's effectiveness in treating chronic conditions. This review seeks to summarize animal and cell studies exploring sudachitin's pharmacological properties and the potential molecular pathways underlying its therapeutic effects. Through this, we aim to clarify the clinical potential of sudachitin across various disorders, paving the way for future research and the development of sudachitin-based therapies.

Dynamic changes in the metabolome and microbiome during Citrus depressa Hayata liquid fermentation

Citri Reticulatae Pericarpium (CRP) is a common traditional Chinese herbal medicine, valued for its multi-bioactivity. However, its processing time, environment, and microorganisms all affect its quality and bioactivity. To address this, the study replaced solid-state fermentation with liquid fermentation using microorganisms and isolated Bacillus amyloliquefaciens, respectively. This aimed to discover a more stable processing method and examine metabolite-micobiota correlations. Non-targeted metabolomics identified 70 differential metabolites, focusing on amino acids, polymethoxyflavones (PMFs), and carbohydrates. Long-read sequencing showed a shift in dominant bacterial genera from Lactobacillus to Pediococcus, then to Clostridium. Spearman analysis revealed a positive correlation between specific Clostridium species and PMFs production. B. amyloliquefaciens fermentation notably increased PMFs content without reducing hesperidin levels, suggesting its potential as an alternative processing method. This study offers valuable insights into metabolome-microbiome interactions for future biotransformation research.

Kaempferia parviflora extract and its component polymethoxyflavones suppress adipogenic differentiation of human bone marrow-derived mesenchymal stem cells via the AMPK pathway.

Kaempferia parviflora Wall. ex. Baker (KP) has been reported to exhibit anti-obesity effects. However, the detailed mechanism of the anti-obesity effect of KP extract (KPE) is yet to be clarified. Here, we investigated the effect of KPE and its component polymethoxyflavones (PMFs) on the adipogenic differentiation of human mesenchymal stem cells (MSCs). KPE and PMFs fraction (2.5µg/mL) significantly inhibited lipid and triacylglyceride accumulation in MSCs; lipid accumulation in MSCs was suppressed during the early stages of differentiation (days 0-3) but not during the mid (days 3-7) or late (days 7-14) stages. Treatment with KPE and PMFs fractions significantly suppressed peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein α (C/EBPα), and various adipogenic metabolic factors. Treatment with KPE and PMFs fraction induced the activation of AMP-activated protein kinase (AMPK) signaling, and pretreatment with an AMPK signaling inhibitor significantly attenuated KPE- and PMFs fraction-induced suppression of lipid formation. Our findings demonstrate that KPE and PMFs fraction inhibit lipid formation by inhibiting the differentiation of undifferentiated MSCs into adipocyte lineages via AMPK signaling, and this may be the mechanism underlying the anti-obesity effects of KPE and PMFs. Our study lays the foundation for the elucidation of the anti-obesity mechanism of KPE and PMFs.

Fabrication of chitosan/guar gum/polyvinyl alcohol films incorporated with polymethoxyflavone-rich citrus extracts: Postharvest shelf-life extension of strawberry fruits

In this study, chitosan/guar gum/polyvinyl alcohol (CGP) matrix (CGPC) films with different concentrations of polymethoxyflavone (PMF)-rich citrus extracts were developed. The results showed that these films had 11.90–16.77 μm of thickness, 32.53 %–41.53 % of moisture content, 33.16 %–121.64 % of water solubility, 2.14–3.18 × 10−10 g m−1 s−1 Pa−1 of water vapor permeability, 65.57 %–148.74 % degree of swelling, 6.08–16.05 MPa of tensile strength and 28.25 %–62.82 % of elongation at break. SEM and TEM observations indicated that the content of PMF-rich extracts affected the distribution and structure of the film matrix, which were confirmed by FT-IR and XPS outcomes. TGA-DTG and DMTA analysis revealed that the presence of 0.02 % PMF-rich extracts enhanced the thermal stability and cross-linking density of the film. Moreover, the incorporation of the PMF-rich citrus extract significantly improved the DPPH radical scavenging rate (increased from 26.22 % to 94.19 %) and antifungal property (against Rhizopus stolonifera in vitro). Furthermore, the inclusion of citrus extracts in the CGP matrix effectively inhibited the deterioration and weight loss of strawberry fruits. Thus, the CGP film incorporated with PMF-rich citrus extract has significant potential as an active packaging material for preserving fresh fruit.

Citrus polymethoxyflavones degrade estrogen receptor-alpha (ERα) and combine with tamoxifen for the treatment of estrogen receptor-positive breast cancer

Estrogen receptor-positive (ER+) breast cancer seriously endangers the women's physical and mental health worldwide and ER targeting therapy is vital. Here, we found that a citrus polymethoxyflavones (PMFs)-rich hydrolysate (C–H) and its major components (nobiletin and 3-methoxynobiletin) potently degrade ERα protein via the ubiquitin-proteasome pathway, thereby impairing the proliferation of ER+ breast cancer cells. Moreover, our study exhibited that C–H combined with tamoxifen (TAM) inhibited the cell proliferation of ER+ breast cancer in vitro. It was further confirmed that C–H decreased tumor growth of ER+ breast cancer in tumor-bearing 129 mice in vivo and improved the efficacy of tamoxifen. Our study revealed that the citrus PMFs have potential applications as pharmaceutical and healthcare products in breast cancer treatment by targeting ERα protein degradation.

Neofunctionalization of an OMT cluster dominates polymethoxyflavone biosynthesis associated with the domestication of citrus

Polymethoxyflavones (PMFs) are a class of abundant specialized metabolites with remarkable anticancer properties in citrus. Multiple methoxy groups in PMFs are derived from methylation modification catalyzed by a series of hydroxylases and O-methyltransferases (OMTs). However, the specific OMTs that catalyze the systematic O-methylation of hydroxyflavones remain largely unknown. Here, we report that PMFs are highly accumulated in wild mandarins and mandarin-derived accessions, while undetectable in early-diverging citrus species and related species. Our results demonstrated that three homologous genes, CreOMT3, CreOMT4, and CreOMT5, are crucial for PMF biosynthesis in citrus, and their encoded methyltransferases exhibit multisite O-methylation activities for hydroxyflavones, producing seven PMFs in vitro and in vivo. Comparative genomic and syntenic analyses indicated that the tandem CreOMT3, CreOMT4, and CreOMT5 may be duplicated from CreOMT6 and contributes to the genetic basis of PMF biosynthesis in the mandarin group through neofunctionalization. We also demonstrated that N17 in CreOMT4 is an essential amino acid residue for C3-, C5-, C6-, and C3'-O-methylation activity and provided a rationale for the functional deficiency of OMT6 to produce PMFs in early-diverging citrus and some domesticated citrus species. A 1,041-bp deletion in the CreOMT4 promoter, which is found in most modern cultivated mandarins, has reduced the PMF content relative to that in wild and early-admixture mandarins. This study provides a framework for reconstructing PMF biosynthetic pathways, which may facilitate the breeding of citrus fruits with enhanced health benefits.

Tangeretin Mitigates Trimethylamine Oxide Induced Arterial Inflammation by Disrupting Choline-Trimethylamine Conversion through Specific Manipulation of Intestinal Microflora.

Previous studies have revealed the microbial metabolism of dietary choline in the gut, leading to its conversion into trimethylamine (TMA). Polymethoxyflavones (PMFs), exemplified by tangeretin, have shown efficacy in mitigating choline-induced cardiovascular inflammation. However, the specific mechanism by which these compounds exert their effects, particularly in modulating the gut microbiota, remains uncertain. This investigation focused on tangeretin, a representative PMFs, to explore its influence on the gut microbiota and the choline-TMA conversion process. Experimental results showed that tangeretin treatment significantly attenuated the population of CutC-active bacteria, particularly Clostridiaceae and Lactobacillus, induced by choline chloride in rat models. This inhibition led to a decreased efficiency in choline conversion to TMA, thereby ameliorating cardiovascular inflammation resulting from prolonged choline consumption. In conclusion, tangeretin's preventive effect against cardiovascular inflammation is intricately linked to its targeted modulation of TMA-producing bacterial activity.

Quality Control of Coumarins, Furocoumarins and Polymethoxyflavones in Citrus Essential Oils: In Silico Analysis

AbstractCitrus essential oils (EOs) contain a variety of secondary metabolites, including coumarins (Cs), furocoumarins (FCs) and polymethoxyflavones (PMFs), all with different biological activities. While Regulation (EC) No 1334/2008 strictly regulates the use of coumarins, undesirable side effects of consuming furocoumarins remain without established maximum toxicity limits for human dietary intake. This study is based on an in‐silico approach aimed at determining these toxicity limits for the oxygenated heterocyclic compounds of citrus EOs approved for use in food. In addition, an innovative quantitative structure‐property relationship (QSPR) using the linear retention index system was explored to characterize the oxygenated heterocyclic compounds (COHs) present in these essential oils. Molecular docking of the studied compounds provided crucial insights into the structure‐odor relationships, offering insights into their mechanisms of action. In addition, an analysis of the pharmacokinetic and pharmacodynamic properties through ADME‐Tox deconstruction provides insight into the potential side effects of their consumption. The results are consolidated by dynamic simulations, providing crucial data for the development of regulations on the maximum toxicity limits of citrus EOs, given the health implications of the various compounds such as coumarins, furocoumarins and polymethoxyflavones present in these essential oils.

제주산 미숙과 향산 감귤의 과실특징, 품질 및 과피 추출물의 PMF 성분함량 비교 및 구조분석

제주산 미숙과 향산 감귤의 과실특징, 품질 및 과피 추출물의 PMF 성분함량 비교 및 구조분석

Polymethoxyflavones in citrus extract has a beneficial effect on hypercholesterolemia rats by promoting liver cholesterol metabolism

Ethnopharmacological relevanceHyperlipidemia is characterized by the disorder of lipid metabolism accompanied by oxidative stress damage, and low-grade inflammation, with the pathway of cholesterol and bile acid metabolic are an important triggering mechanism. Polymethoxyflavones (PMFs) are the active constituents of Aurantii Fructus Immaturus, which have many biological effects, including anti-inflammatory, antioxidant activities, anti-obesity, suppressing adipogenesis in adipocytes, and ameliorate type 2 diabetes, with potential roles for regulation of lipid metabolism. However, its associated mechanisms on hyperlipidemia remain unclear. Aim of the studyThis study aims to identify the anti-hypercholesterolemia effects and mechanisms of PMFs in a hypercholesterolemia model triggered by high-fat compounds in an excessive alcohol diet (HFD). Materials and methodsA hypercholesterolemia rat model was induced by HFD, and PMFs was intragastric administered at 125 and 250 mg/kg daily for 16 weeks. The effects of PMFs on hypercholesterolemia were assessed using serum lipids, inflammatory cytokines, and oxidative stress levels. Hematoxylin & eosin (H&E) and Oil Red O staining were performed to evaluate histopathological changes in the rat liver. The levels of total cholesterol (TC) and total bile acid (TBA) in the liver and feces were determined to evaluate lipid metabolism. RAW264.7 and BRL cells loaded with NBD-cholesterol were used to simulate the reverse cholesterol transport (RCT) process in vitro. The signaling pathway of cholesterol and bile acid metabolic was evaluated by Western Blotting (WB) and qRT-PCR. ResultsLipid metabolism disorders, oxidative stress injury, and low-grade inflammation in model rats were ameliorated by PMFs administration. Numerous vacuoles and lipid droplets in hepatocytes were markedly reduced. In vitro experiments results revealed decreased NBD-cholesterol levels in RAW264.7 cells and increased NBD-cholesterol levels in BRL cells following PMFs intervention. PMFs upregulated the expression of proteins associated with the RCT pathway, such as LXRα, ABCA1, LDLR, and SR-BI, thereby promoting TC entry into the liver. Meanwhile, the expression of proteins associated with cholesterol metabolism and efflux pathways such as CYP7A1, CYP27A1, CYP7B1, ABCG5/8, ABCB1, and BSEP were regulated, thereby promoting cholesterol metabolism. Moreover, PMFs treatment regulated the expression of proteins related to the pathway of enterohepatic circulation of bile acids, such as ASBT, OSTα, NTCP, FXR, FGF15, and FGFR4, thereby maintaining lipid metabolism. ConclusionsPMFs might ameliorate hypercholesterolemia by promoting the entry of cholesterol into the liver through the RCT pathway, followed by excretion via metabolism pathways of cholesterol and bile acid. These findings provide a promising therapeutic potential for PMFs to treat hypercholesterolemia.

Potential role of nobiletin in Alzheimer’s disease

Alzheimer's disease (AD) is a neurodegenerative disease characterized by amyloid plaques and neurofibrillary tangles. At present, there is no specific drugs for the prevention and treatment of AD, so it is urgent to find natural products contributing to alleviation of AD. Nobiletin is one of polymethoxyflavones (PMFs) extracted mainly from citrus peels. Nobiletin has multiple bioactivities, good bioavailability and low side effects. Studies have shown that nobiletin improves cognitive impairment and pathological features in animal models of AD and exerts neuroprotective effects. In addition, 5-demethylnobiletin (5-DN), the main derivative of nobiletin, achieves neuroprotection through anti-inflammatory, neurotrophic and cholinergic effects for the treatment of neurodegenerative diseases. Other PMFs (for example tangeretin) also have the potential to prevent neurodegenerative diseases due to their anti-inflammatory and neuroprotective effects similar to nobiletin. Taken together, PMFs, including nobiletin, have potential as therapeutic agents for AD.

Polymethoxyflavone from Citrus depressa as an inhibitor against various variants of SARS-CoV-2 spike protein

Ethnopharmacological relevanceIn traditional Taiwanese medicine, Citrus depressa Hayata serves as the raw material of Chen-Pi which has been widely used to treat respiratory ailments. Scientific investigations have validated the attributes of C. depressa, elucidating its valuable properties, including antioxidative, anti-inflammatory, anticancer, neuroprotion, hepatoprotection, and hypolipidemic effects. Aim of the studyThis study aims to isolate a universal inhibitor of the SARS-CoV-2 spike protein from C. depressa and confirm the mechanism by which these inhibitors disrupt the binding of the spike protein to hACE2. Materials and methodsThe whole fruit of C. depressa was subjected to ethanol extraction, following by partitioning to obtain water, butanol, and ethyl acetate fractions. To identify the inhibitory components in citrus fruits, we performed both the SPR assay and the SARS-CoV-2 pseudo-virus assays. Subsequently, we employed a bioassay-guided approach to efficiently isolate and characterize the bioactive constituents that hindered the interaction between the SARS-CoV-2 spike protein and hACE2, using a combination of MPLC and Semi-preparative HPLC for compound isolation. ELISA based spike protein binding assay evaluate the inhibitory activities of the extract and potential constituents against multiple spike protein variants. To further shed light on the inhibitory mechanism, candidate inhibitors were validated through the SPR assay and molecular docking. ResultsThe crude extract and ethyl acetate layer derived from C. depressa showed significant inhibitory activity on SARS-CoV-2 Omicron BA.4/5, with IC50 of 77.4 μg/mL and 100 μg/mL, respectively. Ten potential compounds from C. depressa have been identified with inhibitory activity against various SARS-CoV-2 spike proteins. 2′-hydroxy-4,4′,5′,6′-tetramethoxychalcone (Cd3) and 5-hydroxy-3′,4′,6,7,8-pentamethoxyflavone (Cd8) also showed good inhibitory activity to the spike protein, with KD of 0.79 μM and 37.3 nM, respectively. These findings are in line with prior study, indicating Cd3 and Cd8 can bind to key amino acid residue, disrupting the formation of the spike protein and h-ACE2 complex. ConclusionThis study presents the initial evidence showcasing the inhibitory effect of polymethoxyflavones (PMFs) on the spike protein of SARS-CoV-2. Moreover, the inhibitory activity of C. depressa extracts indicates their potential to prevent infections of different SARS-CoV-2 variants.

Rapid and comprehensive metabolites identification of 5-demethylnobiletin in rats using UPLC/Triple-TOF-MS/MS based on multiple mass defect filter and their neuroprotection against ferroptosis

5-Demethylnobiletin (5-deNOB) is a hydroxylated polymethoxyflavone (PMF) from Citrus plants known for its neurotrophic, anti-tumor, and antioxidant bioactivities. An ultra-high performance liquid chromatography coupled with triple-time of flight tandem mass spectrometry (UPLC/Triple-TOF-MS/MS) analysis combining with multiple mass defect filter (MMDF) and MetabolitePilot™ was employed to detect and characterize the metabolites of 5-deNOB in rats. A total of 130 metabolites were identified in rats, with 100, 25, 34, and 52 metabolites found in urine, plasma, bile, and feces, respectively. The major metabolic pathways involved demethylation, hydroxylation, dehydroxylation, glucuronidation, and methylation. In a bioassay of evaluating neuroprotection against ferroptosis in PC12 cells, most of the metabolites exhibited superior activity compared to 5-deNOB. These results provide valuable insights into the in vivo pharmacodynamic properties of 5-deNOB and offer potential active small molecules for neuroprotective therapy. Furthermore, the findings demonstrate the effectiveness of UPLC/Triple-TOF-MS/MS combined with MMDF and MetabolitePilot™ for rapid discovery and identification of the in vivo metabolites of natural products.

Isolation, Characterization, and Antiproliferative Activity of Polymethoxy Flavones from Mentha dumetorum

Background: Natural products have been used commonly in the pharmaceutical industry as well as traditional medicine due to their bioactive contents. Objective: The objective of this study is to isolate the polymethoxy flavones (PMFs) and evaluate the antiproliferative activity. Methods: The PMFs were extracted from Mentha dumetorum with boiling hot water and then partitioned with hexane and the extract was subjected to chromatographic techniques such as Sephadex LH-20, silica gel, and preparative TLC, and HPLC to isolate the compounds. The structures of isolated compounds were elucidated by spectroscopic techniques such as 1H-NMR, 13C-NMR, LC-TOF-MS, and UV-Vis. The antiproliferative effects of isolated compounds were evaluated using a real-time cell analyzer–single plate (RTCA-SP) instrument against HeLa and HT29 cell lines. Results: The isolated PMFs were identified as xanthomicrol (1), 5-hydroxy-6,7,8,4'-tetrametoxy flavanone (2), 5-desmetil sinensetin (3), 5-demetil nobiletin (4), gardenin B (5), 5-hydroxy-6,7,8,3',4'- penta methoxy flavanone (6) and 5-hydroxy-6,7,4'-trimethoxy flavone (7). Compounds 2 and 5 were found to be the most active against both cell lines. Conclusion: The isolated compounds as well as the plant extract of Mentha dumetorum could be promising agents for the drug development process, especially drugs for cancer treatment. Moreover, isolation methods were developed for the corresponding compounds.

Identification of Polymethoxyflavones (PMFs) from Orange Peel and Their Inhibitory Effects on the Formation of Trimethylamine (TMA) and Trimethylamine-N-oxide (TMAO) Using cntA/B and cutC/D Enzymes and Molecular Docking.

This study investigates the inhibitory effects of polymethoxyflavones (PMFs) on enzymes involved in the production of trimethylamine (TMA) and trimethylamine-N-oxide (TMAO). PMFs were isolated from Valencia orange peel and identified using column separation and NMR techniques. The findings reveal that nobiletin and 3,6,7,8,2',5'-hexamethoxyflavone significantly suppress cntA/B and cutC/D, respectively. Furthermore, 3,6,7,8,2',5'-hexamethoxyflavone decreases the level of TMAO formation by suppressing the FMO3 mRNA level. This study elucidates that specific structural features of PMFs can contribute to their interactions with enzymes. Our study represents the first demonstration of the ability of PMFs to mitigate the risk of cardiovascular disease (CVD) by inhibiting enzymes responsible for TMA production, which are generated by gut microbiomes. Furthermore, we introduce a novel model system utilizing TMA-induced HepG2 cells to assess and compare the inhibitory effects of PMFs on TMAO production. These findings could pave the way for the development of novel therapeutic approaches to manage CVD.

Polymethoxyflavone (PMF) Accumulation and PMF Biosynthesis-Related Gene Expression in Tachibana (Citrus tachibana Tanaka) Fruit Treated Using a Combination of Gibberellic Acid and Prohydrojasmon and Post-harvest Deep-Ultraviolet Light-Emitting Diode Irradiation

Polymethoxyflavone (PMF) Accumulation and PMF Biosynthesis-Related Gene Expression in Tachibana (Citrus tachibana Tanaka) Fruit Treated Using a Combination of Gibberellic Acid and Prohydrojasmon and Post-harvest Deep-Ultraviolet Light-Emitting Diode Irradiation

Mesoporous silica-based nanocarriers with dual response to pH and ROS for enhanced anti-inflammation therapy of 5-demethylnobiletin against psoriasis-like lesions

Psoriasis is an inflammatory skin disease accompanied with chronic papulosquamous lesions and multiple comorbidities that considerably affect patients’ quality of life. In order to develop an enhanced therapeutic strategy for psoriasis, 5-demethylnobiletin (5-DN), a kind of polymethoxyflavones (PMFs) with high anti-inflammatory activity, was delivered in vitro and in vivo by the nanocarrier of mesoporous silica nanoparticles (MSNs) both in the human keratinocytes HaCaT cell line and the mouse model with psoriasis-like lesions. The drug-loaded nanocarrier system (MSNs@5-DN) significantly improved the biocompatibility and bioavailability of 5-DN. Investigations at cell biological, histopathological, and molecular levels revealed the pharmacological mechanism of the drug delivery system, including the inhibition of inflammatory responses by downregulating the proinflammatory cytokine levels of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6). The upregulation of anti‑inflammatory cytokine of transforming growth factor-β1 (TGF-β1) and microRNA-17-5p, a critical regulator of the PTEN/AKT pathway, was also observed. The psoriasis-like lesions were markedly ameliorated in the mouse models treated with MSNs@5-DN. The designed drug-loading system shows an enhanced therapeutic outcome for psoriasis-like lesion compared with free 5-DN. This study revealed the synergistic effect of functionalized MSNs loaded with PMFs on the clinical treatment of human psoriasis.

Experimental and DFT Atomistic Insights into the Mechanism of Corrosion Protection of Low-Carbon Steel in an Acidic Medium by Polymethoxyflavones from Citrus Peel Waste

Developing green anticorrosive films is gaining great attention in science and engineering. Citrus fruit peels are mainly discarded as waste, although they can be an excellent repository of phytochemicals, that can be exploited as mitigating agents for corrosion. Herein, we report the high anticorrosion activity of a citrus extract for low-carbon steel in 1 M HCl solution at different temperatures. The main extract constituents were identified by MS and NMR. Two polymethoxyflavones (PMFs), namely nobiletin and heptamethoxyflavone, were identified as major constituents of the extract and the crude PMFs-based extract was investigated for corrosion protection. Using potentiodynamic polarization, weight loss and electrochemical impedance spectroscopy (EIS) methods, this extract revealed improved inhibition efficiency of 94%. The inhibition mechanism was elucidated by considering electrochemical kinetics and adsorption thermodynamics. SEM and UV–vis supported the electrochemical results. PMFs-based extract acted as a mixed-type inhibitor with a Langmuir model of adsorption. Importantly, DFT simulations provided atomic-level insights into the inhibition mechanism and unraveled donor-acceptor interactions between the methoxy groups of PMFs and iron atoms, facilitating the formation of a stable inhibition adsorption layer, and thus supporting the experimental findings. In addition to the physical barrier effect of PMF inhibitor, π-back bonding effect between PMF and steel was suggested.

Reduction of Th2 inflammation and fibrosis in eosinophilic esophagitis in a murine model by citri reticulatae pericarpium

Ethnopharmacological relevanceInflammation and subepithelial fibrosis play major roles in the early pathology of eosinophilic esophagitis (EoE). However, there are currently no pharmacotherapeutic interventions that directly target eosinophilic esophagitis. Citri Reticulatae Pericarpium (CRP, known as Chen-Pi) is one of most frequently used qi-regulating drugs in Chinese medicine and nutrition. CRP is rich with flavonones and polymethoxy flavones, both of which exhibit superior anti-inflammatory, anti-allergic and anti-fibrosis effects. This study is to investigate intervention effect of CRP on EoE, to identify its active compounds and to explore its underlying mechanisms. MethodsThe CRP extract was obtained by liquid-liquid extraction with 70% ethanol, and its main components were identified by HPLC and TLC chromatography as hesperidin, nobiletin, tangeretin, and narirutin in turn. Furthermore, we evaluated its effect and underlying mechanisms in an PN (Peanut protein extract)-sensitized murine model of food allergy induced EoE. ResultsCRP treatment attenuated EoE model mice symptomatology, blocked hypothermia, reduced the production of PN-specific IgE and IgG1 and TH2 cytokines (interleukin (IL)-4 and IL-5), and increased the level of anti-inflammatory cytokines IL-10 and interferon (IFN)-γ. CRP treatment also significantly alleviated the pathological damage and reduced fibrosis in inflamed tissues like esophagus, lung, and intestine. These results were strongly associated with reducing the expression of p-p38 mitogen-activated protein kinase (MAPK), transforming growth factor beta1 (TGF-β1) and p-Smad 3 proteins. ConclusionCRP extract markedly inhibited TH2 immune response and attenuated subepithelial fibrosis with a dose-dependent manner through down-regulating MAPK/TGF-β signaling pathway. It is suggested that CRP extract might serve as a potential therapy for food allergy-induced EoE like disease.

Comparative flavonoid profile of orange (Citrus sinensis) flavedo and albedo extracted by conventional and emerging techniques using UPLC-IMS-MS, chemometrics and antioxidant effects.

Citrus fruits are one of the most frequently counterfeited processed products in the world. In the juice production alone, the peels, divided into flavedo and albedo, are the main waste product. The extracts of this by-product are enriched with many bioactive substances. Newer extraction techniques generally have milder extraction conditions with simultaneous improvement of the extraction process. This study presents a combinatorial approach utilizing data-independent acquisition-based ion mobility spectrometry coupled to tandem mass spectrometry. Integrating orthogonal collision cross section (CCS) data matching simultaneously improves the confidence in metabolite identification in flavedo and albedo tissues from Citrus sinensis. Furthermore, four different extraction approaches [conventional, ultrasonic, High Hydrostatic Pressure (HHP) and Pulsed Electric Field (PEF)] with various optimized processing conditions were compared in terms of antioxidant effects and flavonoid profile particularly polymethoxy flavones (PMFs). A total number of 57 metabolites were identified, 15 of which were present in both flavedo and albedo, forming a good qualitative overlapping of distributed flavonoids. For flavedo samples, the antioxidant activity was higher for PEF and HHP treated samples compared to other extraction methods. However, ethyl acetate extract exhibited the highest antioxidant effects in albedo samples attributed to different qualitative composition content rather than various quantities of same metabolites. The optimum processing conditions for albedo extraction using HHP and PEF were 200 MPa and 15 kJ/kg at 10 kV, respectively. While, HHP at medium pressure (400 MPa) and PEF at 15 kJ/kg/3 kV were the optimum conditions for flavedo extraction. Chemometric analysis of the dataset indicated that orange flavedo can be a valid source of soluble phenolic compounds especially PMFs. In order to achieve cross-application of production, future study should concentrate on how citrus PMFs correlate with biological engineering techniques such as breeding, genetic engineering, and fermentation engineering.