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Food allergy is one of the hot issues in the field of food safety, and there have been a lot of concerns on how to reduce the allergenicity of food allergens. Food processing can change the allergenicity of allergens in the food matrix. In this study, ten IgE linear epitopes of the major allergen tropomyosin (TM) in Perna viridis were identified by bioinformatics prediction and serological experiments. The transglutaminase-catalyzed glycosylation modification sites glutamine, lysine and arginine were highly represented in the IgE linear epitopes of TM. The Perna viridis food matrix was treated with transglutaminase-catalyzed glycosylation. This reaction changed the secondary structure of protein in the food matrix, increased the content of β-sheets and decreased the content of β-turns. The intensity of intrinsic fluorescence and surface hydrophobicity were reduced. The IgE-binding activity of TM in the food matrix was reduced by modifying seven amino acid residues on six IgE linear epitopes. Transglutaminase-catalyzed glycosylation products decreased allergic symptoms in allergic mice, reduced the proportion of CD4 + IL-4 + Th2 cells, and increased the proportion of CD4 + IFN-γ + Th1 cells and Treg cells. Mouse serum levels of IgE and IgG1 antibodies in the food matrix and TM were reduced. Therefore, this study provided a theoretical basis for the development of hypoallergenic Perna viridis products.

Immunoglobulin E (IgE)-mediated food allergy is a rapidly growing public health problem. The interaction between allergens and IgE is at the core of the allergic response. One of the best ways to understand this interaction is through structural characterization. This review focuses on animal-derived food allergens, overviews allergen structures determined by X-ray crystallography, presents an update on IgE conformational epitopes, and explores the structural features of these epitopes. The structural determinants of allergenicity and cross-reactivity are also discussed. Animal-derived food allergens are classified into limited protein families according to structural features, with the calcium-binding protein and actin-binding protein families dominating. Progress in epitope characterization has provided useful information on the structural properties of the IgE recognition region. The data reveals that epitopes are located in relatively protruding areas with negative surface electrostatic potential. Ligand binding and disulfide bonds are two intrinsic characteristics that influence protein structure and impact allergenicity. Shared structures, local motifs, and shared epitopes are factors that lead to cross-reactivity. The structural properties of epitope regions and structural determinants of allergenicity and cross-reactivity may provide directions for the prevention, diagnosis, and treatment of food allergies. Experimentally determined structure, especially that of antigen-antibody complexes, remains limited, and the identification of epitopes continues to be a bottleneck in the study of animal-derived food allergens. A combination of traditional immunological techniques and emerging bioinformatics technology will revolutionize how protein interactions are characterized., (© 2024 Institute of Food Technologists®.)

Background: Hawthorn fruit (HF) is a well-known traditional medicine in China with the effects of improving digestion and regulating qi-flowing for removing blood stasis. Modern pharmacological experiments showed that HF extract has various pharmaceutical properties and flavonoids are considered as the main bioactive compounds. In this paper, Diaion HP-20 adsorption chromatography was used to enrich flavonoids in PHF, and the phytochemical composition of EPHF was analyzed by high performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC-MS). In addition, EPHF's antioxidant capacity, acetylcholinesterase (AChE) inhibitory activity and cytotoxic activity were evaluated., Methods: EPHF was obtained by Diaion HP-20 adsorption chromatography. Phytochemical composition of EPHF was analyzed qualitatively and quantitatively using HPLC and LC-MS. Radical scavenging capacity of EPHF was estimated using 2,2-diphenyl-1-picryhydrazyl (DPPH) assay and oxygen radical absorbance capacity (ORAC) assay. The AChE inhibitory activity of EPHF was evaluated by Ellman method. Cytotoxic activity of EPHF was assessed by means of MTT assay., Results: Eight kinds of components were identified, in which ideain with the value of 179.4 mg/g was identified to be present in the highest level in EPHF, followed by (-)-epicatechin, chlorogenic acid, cyanidin 3-arabinoside, hyperoside and isoquercitrin at the concentrations of 40.9, 10.0, 1.4, 0.4 and 0.2 mg/g, respectively. The contents of these compounds in EPHF were much higher than those in PHF and HF. In addition, EPHF exhibited strong antioxidant and AChE inhibitory activity (ORAC value: 11.65 ± 2.37 μM Trolox equivalents (TE)/mg, DPPH IC 50 value: 6.72 μg/mL, anti-AChE activity IC 50 value: 11.72 μg/mL) compared with PHF and HF. Moreover, EPHF exhibited high levels of cytotoxicity on MCF-7 and SKOV-3 human tumour cell lines in a dose-dependent manner with the IC 50 of 2.76 and 80.11 μg/mL, respectively., Conclusions: Macroporous resin is useful for the extraction and separation of the total flavonoids from PHF. The contents of flavonoids especially anthocyanin in EPHF were increased significantly compared with the PHF, and EPHF exhibited strong antioxidant, AChE inhibitory activity and cytotoxicity on human tumour cells.

Rapid discovery of novel compounds of a traditional herbal medicine is of vital significance for pharmaceutical industry and plant metabolic pathway analysis. However, discovery of unknown or trace natural products is an ongoing challenge. This study presents a universal targeted data-independent acquisition and mining strategy to globally profile and effectively match novel natural product analogues from an herbal extract. The famous medical plant Gastrodia elata was selected as an example. This strategy consists of three steps: (i) acquisition of accurate parent and adduct ions (PAIs) and the product ions data of all eluting compounds by untargeted full-scan MS(E) mode; (ii) rapid compound screening using diagnostic product ions (DPIs) network and in silico analogue database with SUMPRODUCT function to find novel candidates; and (iii) identification and isomerism discrimination of multiple types of compounds using ClogP and ions fragment behavior analyses. Using above data mining methods, a total of 152 compounds were characterized, and 70 were discovered for the first time, including series of phospholipids and novel gastroxyl derivatives. Furthermore, a number of gastronucleosides and phase II metabolites of gastrodin and parishins were discovered, including glutathionylated, cysteinylglycinated and cysteinated compounds, and phosphatidylserine analogues. This study extended the application of classical DPIs filter strategy and developed a structure-based screening approach with the potential for significant increase of efficiency for discovery and identification of trace novel natural products., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Introduction: The beneficial health effects of traditional Chinese medicines are often attributed to their potent antioxidant activities, usually established in vitro. However, these wet chemical methods for determining antioxidant activities are time-consuming, laborious, and expensive., Objectives: This study was conducted to establish a rapid determination of antioxidant activity of Radix Scutellariae using near-infrared (NIR) and mid-infrared (MIR) spectroscopy., Material and Methods: Antioxidant capabilities were evaluated using 2,2-diphenyl-1-picrylhydrazyl hydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. The total flavonoid contents (TFCs) of Radix Scutellariae were measured by the aluminium chloride colorimetric method. The same sample was then scanned using NIR and MIR spectroscopy. Chemometrics analysis using partial least-squares (PLS) regression was performed to establish the models for predicting the antioxidant activities of Radix Scutellariae., Results: A better predictive performance was achieved using PLS models based on NIR data. The determination coefficient (R(2)) and the residual predictive deviation (RPD) for the validation set were 0.9298 and 2.84 for DPPH, and 0.9436 and 2.66 for TFCs, respectively. MIR-PLS algorithms gave a slightly lower reliability (R(2) = 0.9090 and 0.9374, RPD = 2.01 and 2.42, for DPPH and TFC, respectively). Very comparable results for ORAC were obtained with the two methods., Conclusion: The developed spectroscopic method can be successfully applied in high-throughput screening of the antioxidant capability of Radix Scutellariae samples. It can also be a viable and advantageous alternative to laborious chemical procedures., (Copyright © 2015 John Wiley & Sons, Ltd.)

In this study, a novel enrichment technique based on magnetic core-mesoporous shell microspheres with C8-modified interior pore-walls (C8-Fe₃O₄@mSiO₂) was successfully developed for the determination of diazepam in rat plasma by LC-MS. Due to the unique properties of the synthesized C8-Fe₃O₄@mSiO₂ microspheres (C8-modified magnetic mesoporous microsphere), small drug molecules like diazepam can enter the mesopore channels and be efficiently absorbed through hydrophobic interaction by interior C8-groups (Octyl functional groups). Large molecules like proteins are excluded from the mesopore channels as a result of size exclusion effect, leading to direct extraction of drug molecules from protein-rich biosmaples such as plasma without any other pretreatment procedure. Moreover, diazepam adsorbed C8-Fe₃O₄@mSiO₂ microspheres could be simply and rapidly isolated through placing a magnet on the bottom of container, and then diazepam could be easily eluted from C8-Fe₃O₄@mSiO₂ microspheres for further LC-MS analysis. Extraction conditions such as amounts of C8-Fe₃O₄@mSiO₂ microspheres added, adsorption time, elution solvent and elution time were investigated. Method validations including linear range, the limit of detection, precision, and recovery were also studied. The results indicated that the proposed method based on C8-Fe₃O₄@mSiO₂ microspheres was simple and accurate for the analysis of diazepam in the rat plasma. And it will provide new ideas for analyzing plasma concentration and pharmacokinetics of similar drugs., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Flat warts are a common presenting complaint in adolescents and adults and may be a cosmetic problem as well. Patients suffering from flat warts are often unsatisfied with conventional medical care because of adverse effects such as intolerable pain, hyperpigmentation, hypopigmentation, or occasionally allergic contact dermatitis. To offset the possibilities of hyperpigmentation, hypopigmentation, and scar formation, the method of auricular acupuncture was used., Methods: Single-blind method adopted, 60 subjects with flat warts were all outpatients and randomly allocated to a treatment group or a control group, with 30 patients in each group. Thirty subjects in the treatment group were treated with weekly auricular acupuncture for 10 weeks while the other subjects in the control group were treated with 0.1% of tretinoin ointment topically for 10 weeks., Results: Sixteen subjects in the treatment group (53.33%) recovered fully from flat warts without recurrence during the ensuing six months' follow-up after 10 weeks' surgery compared with only one subject in the control group (3.33%). The therapeutic effect of the treatment group was statistically better than that of the control group by Mann-Whitney U-test with SPSS software (P < 0.01). During the treatment period and the ensuing six months' follow-up, no adverse effects were observed by the investigators or reported by patients., Conclusions: Our findings suggest that auricular acupuncture may be a viable alternative for the treatment of flat warts. Larger randomized studies are needed to fully evaluate auricular acupuncture against more conventional treatments, and these are planned., (© 2012 The International Society of Dermatology.)

Inhibition of translocator protein (18 kDa) (TSPO) can effectively prevent reperfusion-induced arrhythmias and improve postischemic contractile performance. Mitochondrial permeability transition pore (mPTP) opening, mediated mainly through oxidative stress during ischemia/reperfusion (I/R), is a key event in reperfusion injury. 4'-Chlorodiazepam is a widely used TSPO antagonist. However, whether 4'-chlorodiazepam can improve cardiac functional recovery during postischemia reperfusion by affecting oxidative enzymes, reducing reactive oxygen species (ROS) and thereby inhibiting mPTP opening is still unknown. Cardiac function including heart rate, coronary flow rate, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), maximal time derivatives of pressure (+/-dP/dt max) and the severity of ventricular arrhythmias were analyzed in isolated rat hearts during I/R. mPTP opening, ROS and oxidative enzyme activities were measured with fluorometric or spectrophotometric techniques. 4'-Chlorodiazepam did not affect heart rate and coronary flow rate, but abolished the increase in LVEDP, accelerated the recovery of LVDP and +/-dP/dt max, and reduced the severity of ventricular arrhythmias. The mPTP opening probability was reduced by 4'-chlorodiazepam, accompanied by a reduction in ROS level. In addition, the activities of mitochondrial electron transport chain complex I and complex III were increased, while those of xanthine oxidase and NADPH oxidase were reduced. Therefore, 4'-chlorodiazepam may improve cardiac functional recovery during reperfusion, potentially by affecting the activities of oxidative enzymes, reducing ROS and thereby inhibiting mPTP opening. The present study presents evidence that 4'-chlorodiazepam could be a novel adjunct to reperfusion.