Effects of Dietary Components on Mast Cells: Possible Use as Nutraceuticals for Allergies?

Allergic diseases affect an estimated 30 percent of the world's population. Mast cells (MC) are the key effector cells of allergic reactions by releasing pro-inflammatory mediators such as histamine, lipid mediators, and cytokines/chemokines. Components of the daily diet, including certain fatty acids, amino acids, and vitamins, as well as secondary plant components, may have effects on MC and thus may be of interest as nutraceuticals for the prevention and treatment of allergies. This review summarizes the anti-inflammatory effects of dietary components on MC, including the signaling pathways involved, in in vitro and in vivo models. Butyrate, calcitriol, kaempferol, quercetin, luteolin, resveratrol, curcumin, and cinnamon extract were the most effective in suppressing the release of preformed and de novo synthesized mediators from MC or in animal models. In randomized controlled trials (RCT), vitamin D, quercetin, O-methylated epigallocatechin gallate (EGCG), resveratrol, curcumin, and cinnamon extract improved symptoms of allergic rhinitis (AR) and reduced the number of inflammatory cells in patients. However, strategies to overcome the poor bioavailability of these nutrients are an important part of current research.

Targeting beta-catenin signaling for prevention of colorectal cancer - Nutraceutical, drug, and dietary options

Progressive up-regulation of β-catenin signaling is very common in the transformation of colorectal epithelium to colorectal cancer (CRC). Practical measures for opposing such signaling hence have potential for preventing or slowing such transformation. cAMP/PKA activity in colon epithelium, as stimulated by COX-2-generated prostaglandins and β2-adrenergic signaling, boosts β-catenin activity, whereas cGMP/PKG signaling has the opposite effect. Bacterial generation of short-chain fatty acids (as supported by unrefined high-carbohydrate diets, berberine, and probiotics), dietary calcium, daily aspirin, antioxidants opposing cox-2 induction, and nicotine avoidance, can suppress cAMP production in colonic epithelium, whereas cGMP can be boosted via linaclotides, PDE5 inhibitors such as sildenafil or icariin, and likely high-dose biotin. Selective activation of estrogen receptor-β by soy isoflavones, support of adequate vitamin D receptor activity with UV exposure or supplemental vitamin D, and inhibition of CK2 activity with flavanols such as quercetin, can also oppose β-catenin signaling in colorectal epithelium. Secondary bile acids, the colonic production of which can be diminished by low-fat diets and berberine, can up-regulate β-catenin activity by down-regulating farnesoid X receptor expression. Stimulation of PI3K/Akt via insulin, IGF-I, TLR4, and EGFR receptors boosts β-catenin levels via inhibition of glycogen synthase-3β; plant-based diets can down-regulate insulin and IGF-I levels, exercise training and leanness can keep insulin low, anthocyanins and their key metabolite ferulic acid have potential for opposing TLR4 signaling, and silibinin is a direct antagonist for EGFR. Partially hydrolyzed phytate can oppose growth factor-mediated down-regulation of β-catenin by inhibiting Akt activation. Multifactorial strategies for safely opposing β-catenin signaling can be complemented with measures that diminish colonic mutagenesis and DNA hypomethylation - such as avoidance of heme-rich meat and charred or processed meats, consumption of phase II-inductive foods and nutraceuticals (e.g., Crucifera), and assurance of adequate folate status.

Characterization of two O-methyltransferases involved in the biosynthesis of O-methylated catechins in tea plant

Tea is known for having a high catechin content, with the main component being (-)-epigallocatechin gallate (EGCG), which has significant bioactivities, including potential anti-cancer and anti-inflammatory activity. The poor intestinal stability and permeability of EGCG, however, undermine these health-improving benefits. O-methylated EGCG derivatives, found in a few tea cultivars in low levels, have attracted considerable interest due to their increased bioavailability. Here, we identify two O-methyltransferases from tea plant: CsFAOMT1 that has a specific O-methyltransferase activity on the 3''-position of EGCG to generate EGCG3''Me, and CsFAOMT2 that predominantly catalyzes the formation of EGCG4″Me. In different tea tissues and germplasms, the transcript levels of CsFAOMT1 and CsFAOMT2 are strongly correlated with the amounts of EGCG3''Me and EGCG4''Me, respectively. Furthermore, the crystal structures of CsFAOMT1 and CsFAOMT2 reveal the key residues necessary for 3''- and 4''-O-methylation. These findings may provide guidance for the future development of tea cultivars with high O-methylated catechin content.

Bioactivity-boosting strategy based on combination of anti-allergic O-methylated catechin with a Citrus flavanone, hesperetin

Many patients with allergies have anxiety about taking anti-allergic medicines due to their side effects and increased medical expenses. Thus, developing functional foods/agricultural products for allergy prevention is strongly desired. In this study, we revealed that a Citrus flavanone, hesperetin, amplified IgE/antigen-mediated degranulation-inhibitory potency of anti-allergic catechin, (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3''Me), in the rat basophilic/mast cell line RBL-2H3. Hesperetin also significantly elevated the activation of acid sphingomyelinase (ASM), essential for eliciting anti-allergic effect of EGCG3''Me through the cell surficial protein, 67-kDa laminin receptor (67LR). Furthermore, oral administration of the highly absorbent hesperidin, α-glucosyl hesperidin, also enhanced the inhibitory potency of EGCG3''Me-rich 'Benifuuki' green tea (Camellia sinensis L.) on passive cutaneous anaphylaxis (PCA) reaction evoked by IgE/antigen in BALB/c mice. These observations indicate that hesperetin amplifies the ability of EGCG3''Me to inhibit the IgE/antigen-mediated degranulation through activating ASM signaling.

Iron-Deficiency in Atopic Diseases: Innate Immune Priming by Allergens and Siderophores

Although iron is one of the most abundant elements on earth, about a third of the world's population are affected by iron deficiency. Main drivers of iron deficiency are beside the chronic lack of dietary iron, a hampered uptake machinery as a result of immune activation. Macrophages are the principal cells distributing iron in the human body with their iron restriction skewing these cells to a more pro-inflammatory state. Consequently, iron deficiency has a pronounced impact on immune cells, favoring Th2-cell survival, immunoglobulin class switching and primes mast cells for degranulation. Iron deficiency during pregnancy increases the risk of atopic diseases in children, while both children and adults with allergy are more likely to have anemia. In contrast, an improved iron status seems to protect against allergy development. Here, the most important interconnections between iron metabolism and allergies, the effect of iron deprivation on distinct immune cell types, as well as the pathophysiology in atopic diseases are summarized. Although the main focus will be humans, we also compare them with innate defense and iron sequestration strategies of microbes, given, particularly, attention to catechol-siderophores. Similarly, the defense and nutritional strategies in plants with their inducible systemic acquired resistance by salicylic acid, which further leads to synthesis of flavonoids as well as pathogenesis-related proteins, will be elaborated as both are very important for understanding the etiology of allergic diseases. Many allergens, such as lipocalins and the pathogenesis-related proteins, are able to bind iron and either deprive or supply iron to immune cells. Thus, a locally induced iron deficiency will result in immune activation and allergic sensitization. However, the same proteins such as the whey protein beta-lactoglobulin can also transport this precious micronutrient to the host immune cells (holoBLG) and hinder their activation, promoting tolerance and protecting against allergy. Since 2019, several clinical trials have also been conducted in allergic subjects using holoBLG as a food for special medical purposes, leading to a reduction in the allergic symptom burden. Supplementation with nutrient-carrying lipocalin proteins can circumvent the mucosal block and nourish selectively immune cells, therefore representing a new dietary and causative approach to compensate for functional iron deficiency in allergy sufferers.

Clinical Evidence of the Benefits of Phytonutrients in Human Healthcare

Phytonutrients comprise many different chemicals, including carotenoids, indoles, glucosinolates, organosulfur compounds, phytosterols, polyphenols, and saponins. This review focuses on the human healthcare benefits of seven phytochemical families and highlights the significant potential contribution of phytonutrients in the prevention and management of pathologies and symptoms in the field of family health. The structure and function of these phytochemical families and their dietary sources are presented, along with an overview of their potential activities across different health and therapeutic targets. This evaluation has enabled complementary effects of the different families of phytonutrients in the same area of health to be recognized.

The prevalence of complementary and alternative medicines (CAM) usage among allergic rhinitis patients in Malaysia

PURPOSE

We conducted this study to estimate the prevalence of complementary and alternative medicines (CAM) usage among allergic rhinitis (AR) patients in Malaysia and understand the practice of CAM usage among them. We also included a literature review on the commonly used CAM for AR.

METHODS

A cross-sectional study which included a questionnaire-based study and information of allergic rhinitis from patient's clinic records. Patients with AR who attended the ORL-HNS department in Hospital Universiti Sains Malaysia and Hospital Sultanah Aminah, Malaysia were enrolled after consented, on a first-come first-serve basis as convenience sampling from July 2020 until February 2021. A pre-tested self-administered, 16-item questionnaire in Malay language was distributed to the participants. The questionnaire consists of a set of 16 questions with subsets to enquire about the sociodemographic data and pattern of usage of CAM and its effectiveness.

RESULTS

372 patients were enrolled in this study consisting of 217 (58.3%) female and 155 (41.7%) male patients. 231 (62.1%) participants had used CAM for AR in the past 10 years. A higher proportion of females (p = 0.015) and those with higher income (p = 0.004) had used CAM. Among the users, 87.9% found CAM to be effective. No differences were found in terms of age (p = 0.888) and education level (p = 0.057) for CAM usage.

CONCLUSION

CAM is widely used in Malaysia to alleviate AR symptoms, with a large proportion of users think it is effective. Therefore, more researches should be conducted to provide evidence and guidance to integrate CAM into AR management.

Nutraceutical Aid for Allergies - Strategies for Down-Regulating Mast Cell Degranulation

Interactions of antigens with the mast cell FcεRI-IgE receptor complex induce degranulation and boost synthesis of pro-inflammatory lipid mediators and cytokines. Activation of spleen tyrosine kinase (Syk) functions as a central hub in this signaling. The tyrosine phosphatase SHP-1 opposes Syk activity; stimulation of NADPH oxidase by FcεRI activation results in the production of oxidants that reversibly inhibit SHP-1, up-regulating the signal from Syk. Activated AMPK can suppress Syk activation by the FcεRI receptor, possibly reflecting its ability to phosphorylate the FcεRI beta subunit. Cyclic GMP, via protein kinase G II, enhances the activity of SHP-1 by phosphorylating its C-terminal region; this may explain its inhibitory impact on mast cell activation. Hydrogen sulfide (H₂S) likewise opposes mast cell activation; H₂S can boost AMPK activity, up-regulate cGMP production, and trigger Nrf2-mediated induction of Phase 2 enzymes - including heme oxygenase-1, whose generation of bilirubin suppresses NADPH oxidase activity. Phycocyanobilin (PCB), a chemical relative of bilirubin, shares its inhibitory impact on NADPH oxidase, rationalizing reported anti-allergic effects of PCB-rich spirulina ingestion. Phase 2 inducer nutraceuticals can likewise oppose the up-regulatory impact of NADPH oxidase on FcεRI signaling. AMPK can be activated with the nutraceutical berberine. High-dose biotin can boost cGMP levels in mast cells via direct stimulation of soluble guanylate cyclase. Endogenous generation of H₂S in mast cells can be promoted by administering N-acetylcysteine and likely by taurine, which increases the expression of H₂S-producing enzymes in the vascular system. Mast cell stabilization by benifuuki green tea catechins may reflect the decreased surface expression of FcεRI.

Eriodictyol-Amplified 67-kDa Laminin Receptor Signaling Potentiates the Antiallergic Effect of O-Methylated Catechin

(-)-Epigallocatechin-3-O-(3-O-methyl) gallate (1, EGCG3″Me), an antiallergic O-methylated catechin, is present in high quantities in the green tea cultivar "Benifuuki" (Camellia sinensis L.). Previous studies have shown that EGCG3″Me inhibited basophil degranulation mediated through the cell-surface 67-kDa laminin receptor (67LR), but the mechanisms are not fully elucidated. This study aimed to investigate the mechanisms underlying the inhibitory effect of EGCG3″Me on IgE/antigen (Ag)-mediated degranulation and the combined effect of EGCG3″Me with eriodictyol (2), a bioactive flavanone. EGCG3″Me inhibited β-hexosaminidase release from the rat basophilic/mast cell line RBL-2H3 stimulated by IgE/Ag and induced acid sphingomyelinase (ASM) activity. This induction was inhibited by anti-67LR antibody treatment. The ASM-specific inhibitor desipramine inhibited EGCG3″Me-induced suppression of degranulation. The soluble guanylate cyclase (sGC) inhibitor NS2028 weakened the potency of EGCG3″Me, and the sGC activator BAY41-2272 suppressed degranulation. The ability of EGCG3″Me to induce ASM activity and inhibit degranulation was amplified by eriodictyol. Furthermore, oral administration of the lemon-peel-derived eriodyctiol-7-O-glucoside (3) potentiated the suppressive effect of EGCG3″Me-rich "Benifuuki" green tea on the IgE/Ag-induced passive cutaneous anaphylaxis (PCA) reaction in BALB/c mice. These results suggest that EGCG3″Me inhibits IgE/Ag-mediated degranulation by inducing the 67LR/sGC/ASM signaling pathway, and eriodictyol amplifies this signaling.

Inhibitory effects of cyanidin-3-O-glucoside in black soybean hull extract on RBL-2H3 cells degranulation and passive cutaneous anaphylaxis reaction in mice

Black soybean hull extract (BSHE) exhibits a variety of biological activities. However, little is known about the effects of BSHE on immunoglobulin E (IgE)-mediated type I allergic reactions. The anti-allergic effect of BSHE was assessed with the degranulation assay using rat basophilic leukemia RBL-2H3 cells and the passive cutaneous anaphylaxis (PCA) reaction in mice. An active compound in BSHE was identified by ultra-performance liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry analysis. BSHE inhibited the release of β-hexosaminidase and histamine in RBL-2H3 cells, and cyanidin-3-O-glucoside (C3G) was identified as one of its active compounds. Oral administering of 200 μmol/kg of C3G to IgE-sensitized mice prior to antigen injection suppressed the PCA reaction, as compared with control (p < 0.01). Intravenous administration of BSHE (C3G content, 5.4%) more strongly inhibited PCA responses at lower doses (100 mg/kg, p < 0.01) than oral administration (1,000 mg/kg, p = 0.059). Intravenous C3G also suppressed PCA response at a low dose (40 mg/kg, p < 0.05), showing the same trend as BSHE. This information can be useful to design appropriate formulations of anthocyanin-based drug products to suppress allergic reactions. This study provides evidence for the potential use of BSHE and C3G for the prevention or the treatment of type I allergies.

Herbal Medicines for Allergic Rhinitis: a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

To assess the effects of herbal medicine (HM) therapy in various durations and analyze the effects of HM separately by mechanism of action in the treatment of allergic rhinitis (AR).

RECENT FINDINGS

Thirty-two studies were included (2,697 patients, mean age 34.6 years). For the ≤ 4 weeks of treatment duration, HM brought greater benefits over placebo in reduction of total nasal symptoms score (standardized mean difference (SMD) -0.68; 95% confidence interval (CI) -0.98, -0.38; p <0.01) and improvement in Rhinoconjunctivitis Quality of Life Questionnaire score (SMD -0.53; 95% CI -0.81, -0.25; p <0.01). For the 4-12 weeks duration, total nasal symptoms score (SMD -0.22; 95%CI -0.4, -0.05; p =0.01) and Rhinoconjunctivitis Quality of Life Questionnaire score (SMD -0.48; 95% CI -0.89, -0.06; p =0.03) favored the HM. However, HM therapy for longer than 12 weeks was related to tachyphylaxis and showed no benefit over placebo in any outcomes. There was no difference between the HM and standard treatment on symptoms improvement. Anti-allergic effect, anti-inflammatory effect, anti-leukotriene effect, and anti-histaminic effect of HM were revealed. HM was safe and their adverse effects were comparable placebo. HM therapy is safe and provides better results than placebo in improving nasal symptoms and disease-specific quality of life in patients with AR. Its beneficial effects are demonstrated only in less than 12 weeks of treatment.

TRIAL REGISTRATION

PROSPERO ID: CRD42020168367.

In vitro anti-inflammatory properties of honey flavonoids: A review

Honey is a natural ready-to-eat product rich in flavonoids, which is known by the wound healing properties due to both antibacterial and antioxidant activity. Flavonoids mitigate inflammatory processes, and thus it could currently support studies of anti-inflammatory potential of honeys. In this review, in vitro anti-inflammatory properties of flavonoids found in honey were prioritized. Mechanistic information of specific isolated flavonoids as modulators of inflammatory processes are summarized aiming to stimulate studies regarding the action of honey in inflammatory events. Lastly, a structure-activity relationship (SAR) of flavonoids was also included. Flavonoids found in honey have demonstrated antioxidant properties and ability to inhibit pro-inflammatory enzymes such as COX, LOX, iNOS, and pro-inflammatory mediators, including nitric oxide, cytokines and chemokines. Transcriptional factors such as NF-κB are also modulated by flavonoids, controlling the expression of several inflammatory mediators. SAR studies demonstrate the effect of flavonoids in the prevention of inflammatory cascades. Despite the promising reports of in vitro anti-inflammatory activity, well-designed clinical trials need yet to be performed to confirm the benefits of honeys from different botanical sources in diseases that include episodes of inflammation.

Lactobacillus helveticus SBT2171 Alleviates Perennial Allergic Rhinitis in Japanese Adults by Suppressing Eosinophils: A Randomized, Double-Blind, Placebo-Controlled Study

This article examines the effects of fermented milk (FM) containing Lactobacillus helveticus SBT2171 (LH2171) on the subjective symptoms of individuals with mild and moderate perennial allergy. Two hundred subjects were divided into two groups and consumed FM containing LH2171 or placebo FM once per day for 16 weeks. The primary endpoints were defined as per the degree of nasal and ocular symptoms and difficulty in daily life as determined by the Japanese guidelines for allergy rhinitis and the Japanese allergic rhinitis standard quality of life questionnaire, respectively. The secondary endpoints included parameters related to allergic symptoms in the blood and nasal fluids, as well as the mental status. The severity of allergic rhinitis significantly improved in the LH2171 group compared to that in the placebo group. Additionally, the LH2171 group showed a significantly lower degree of "stuffy nose" (as per the diary survey) than the placebo group. Eosinophil counts in the nasal fluids and in the blood were significantly lower in the LH2171 group compared to the placebo group. Thus, the oral administration of FM containing LH2171 cells alleviated perennial allergic rhinitis in individuals with mild and moderate symptoms, possibly via suppression of eosinophils in both the blood and nasal fluids.

Flavonoids and Related Members of the Aromatic Polyketide Group in Human Health and Disease: Do They Really Work?

Some aromatic polyketides such as dietary flavonoids have gained reputation as miraculous molecules with preeminent beneficial effects on human health, for example, as antioxidants. However, there is little conclusive evidence that dietary flavonoids provide significant leads for developing more effective drugs, as the majority appears to be of negligible medicinal importance. Some aromatic polyketides of limited distribution have shown more interesting medicinal properties and additional research should be focused on them. Combretastatins, analogues of phenoxodiol, hepatoactive kavalactones, and silymarin are showing a considerable promise in the advanced phases of clinical trials for the treatment of various pathologies. If their limitations such as adverse side effects, poor water solubility, and oral inactivity are successfully eliminated, they might be prime candidates for the development of more effective and in some case safer drugs. This review highlights some of the newer compounds, where they are in the new drug pipeline and how researchers are searching for additional likely candidates.

Anti-inflammatory effects of flavonoids

Inflammation plays a key role in diseases such as diabetes, asthma, cardiovascular diseases and cancer. Diet can influence different stages of inflammation and can have an important impact on several inflammatory diseases. Increasing scientific evidence has shown that polyphenolic compounds, such as flavonoids, which are found in fruits, vegetables, legumes, or cocoa, can have anti-inflammatory properties. Recent studies have demonstrated that flavonoids can inhibit regulatory enzymes or transcription factors important for controlling mediators involved in inflammation. Flavonoids are also known as potent antioxidants with the potential to attenuate tissue damage or fibrosis. Consequently, numerous studies in vitro and in animal models have found that flavonoids have the potential to inhibit the onset and development of inflammatory diseases. In the present review, we focused in flavonoids, the most abundant polyphenols in the diet, to give an overview of the most recent scientific knowledge about their impact on different inflammatory diseases.

Metabolomics for a Millenniums-Old Crop: Tea Plant ( Camellia sinensis)

Tea cultivation and utilization dates back to antiquity. Today it is the most widely consumed beverage on earth due to its pleasant taste and several beneficial health properties attributed to specific metabolites. Metabolomics has a tremendous potential to correlate tea metabolites with taste and health properties in humans. Our review on the current application of metabolomics in the science of tea suggests that metabolomics is a promising frontier in the evaluation of tea quality, identification of functional genes responsible for key metabolites, investigation of their metabolic regulation, and pathway analysis in the tea plant. Furthermore, the challenges, possible solutions, and the prospects of metabolomics in tea science are reviewed.

Regiospecific methylation of all the hydroxyls in (+)-catechin by a stepwise differentiation strategy

BACKGROUND

Methylated derivatives of catechins have received great attention for health beneficial effects, especially antiallergic activity. However, the scarce natural abundance of methylated catechins limits further bioactive studies. The objective of this work was to investigate regiospecific methylation of the hydroxyls of (+)-catechin through a stepwise differentiation strategy based on electronic difference between the hydroxyl groups.

RESULTS

Selective methylation of the hydroxyls on different rings was realized by employing Meerwein salt as the methylation reagent. Preferential acylation of the phenolic hydroxyls on A and B rings allowed selective exposure of the aliphatic hydroxyl on C ring to methylation. The vicinal phenolic hydroxyls on B ring were preferentially methylated under mild basic condition due to the acidic properties. Methylation of the phenolic hydroxyls on A ring was achieved by sequential protection and deprotection operations. Finally, antioxidant activities of all the individual methylated (+)-catechins were explored by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assay.

CONCLUSION

Regiospecific methylation of the phenolic and aliphatic hydroxyls was systematically achieved under mild conditions. Preparation of all the individual methylated (+)-catechins was accomplished with a greener methylation reagent: nonvolatile Meerwein salt. This work laid a solid foundation for preparation of diverse O-methylated catechins for bioactivity studies. © 2019 Society of Chemical Industry.

Chemistry and Health Effect of Tea Polyphenol (-)-Epigallocatechin 3- O-(3- O-Methyl)gallate

Catechins are major polyphenols in tea and have been related to the health promotion of tea. Recently, a unique O-methylated catechin, (-)-epigallocatechin 3- O-(3- O-methyl)gallate (EGCG3″Me) has been identified in limited green and oolong tea. EGCG3″Me-enriched tea has shown distinct physiological functions in animal models and humans compared to common tea, including antiallergy, antiobesity, the prevention of cardiovascular disease risks, etc. This perspective aims to present current knowledge of EGCG3″Me, including its natural occurrence, chemical synthesis, chemical structure, and bioavailability, as well as the molecular mechanisms underlying its biological activities.

Recent Advances in the Understanding of the Health Benefits and Molecular Mechanisms Associated with Green Tea Polyphenols

Tea, leaf, or bud from the plant Camellia sinensis, make up some of the beverages popularly consumed in different parts of the world as green tea, oolong tea, or black tea. More particularly, as a nonfermented tea, green tea has gained more renown because of the significant health benefits assigned to its rich content in polyphenols. As a main constituent, green tea polyphenols were documented for their antioxidant, anti-inflammation, anticancer, anticardiovascular, antimicrobial, antihyperglycemic, and antiobesity properties. Recent reports demonstrate that green tea may exert a positive effect on the reduction of medical chronic conditions such as cardiovascular disease, cancer, Alzheimer's disease, Parkinson's disease, and diabetes. The health benefits of green teas, in particular EGCG, are widely investigated, and these effects are known to be primarily associated with the structure and compositions of its polyphenols. This Review focuses on the diverse constituents of green tea polyphenols and their molecular mechanisms from the perspective of their potential therapeutic function. Recent advances of green tea polyphenols on their bioavailability, bioaccessibility, and microbiota were also summarized in this article. Dietary supplementation with green tea represents an attractive alternative toward promoting human health.

Postprandial glycaemia-lowering effect of a green tea cultivar Sunrouge and cultivar-specific metabolic profiling for determining bioactivity-related ingredients

Although the major green tea catechins can inhibit the activity of carbohydrate-hydrolyzing enzymes, there is a paucity of information describing the potential of other green tea ingredients and numerous green tea cultivars. Herein, we reveled that a green tea cultivar Sunrouge significantly suppressed the postprandial blood glucose level in mice. Unlike the most representative Japanese green tea cultivar, Yabukita, the suppression by Sunrouge was observed clearly during the initial period after oral dosing of starch. Sunrouge also strongly inhibited the carbohydrate-hydrolyzing enzymes α-glucosidase and α-amylase when compared with that of Yabukita and many other cultivars. Liquid chromatography-mass spectrometry (LC-MS)-based metabolic profiling (MP) of 42 Japanese green tea cultivars was performed. Multivariate statistical analysis enabled visualization of the differences among cultivars with respect to their ability to inhibit carbohydrate-hydrolyzing activities. Analysis of metabolites, contributing to the discrimination and prediction of the bioactivity of cultivars, showed that O-methylated catechins, epicatechin-3-O-(3-O-methyl) gallate (ECG3"Me) and epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me), were newly identified α-glucosidase inhibitors. Such ability was also observed in epigallocatechin-3-O-gallate (EGCG), epicatechin-3-O-gallate (ECG), delphinidin-3-O-glucoside and myricetin-3-O-glucoside. The amounts of these compounds in Sunrouge were higher than that in many other cultivars. These results suggest that Sunrouge has high potential for suppressing the elevation of the postprandial blood glucose level, and an MP approach may become a valuable strategy for evaluating the anti-hyperglycemic activity of green tea and for screening its active ingredients.

Computational Molecular Docking and X-ray Crystallographic Studies of Catechins in New Drug Design Strategies

Epidemiological and laboratory studies have shown that green tea and green tea catechins exert beneficial effects on a variety of diseases, including cancer, metabolic syndrome, infectious diseases, and neurodegenerative diseases. In most cases, (-)-epigallocatechin gallate (EGCG) has been shown to play a central role in these effects by green tea. Catechins from other plant sources have also shown health benefits. Many studies have revealed that the binding of EGCG and other catechins to proteins is involved in its action mechanism. Computational docking analysis (CMDA) and X-ray crystallographic analysis (XCA) have provided detailed information on catechin-protein interactions. Several of these studies have revealed that the galloyl moiety anchors it to the cleft of proteins through interactions with its hydroxyl groups, explaining the higher activity of galloylated catechins such as EGCG and epicatechin gallate than non-galloylated catechins. In this paper, we review the results of CMDA and XCA of EGCG and other plant catechins to understand catechin-protein interactions with the expectation of developing new drugs with health-promoting properties.

Biological and epidemiological evidence of anti-allergic effects of traditional Japanese food ume (Prunus mume)

Japanese apricot (Prunus mume; ume) is a traditional food in Japan that has been shown to have various beneficial health effects. There is some evidence to suggest that ume is also effective against allergic disease. Here, we conducted a cross-sectional epidemiological pilot study to examine the association between ume intake frequency and allergic symptoms including rhinitis in 563 adults (288 men and 275 women) who resided in Wakayama, Japan. After adjusting for age, present illness and medication, women with high ume intake had significantly lower odds ratio (OR) for the presence of symptoms of allergy [OR: 0.49 with 95% confidence interval (CI): 0.25-0.97]. Therefore, we investigated the anti-allergic effect of ume on passive cutaneous anaphylaxis (PCA) reaction in immunoglobulin E (IgE)-sensitized mice. The animal study demonstrated that oral administration of ume extract attenuated the PCA reaction and mast cell degranulation. Furthermore, RBL-2H3 mast cells were used to identify anti-allergic ume compounds. The following ume compounds inhibited IgE-mediated mast cell degranulation: vanillin, syringic acid, protocatechuic aldehyde, lyoniresinol and p-coumaric acid. These results suggested that ume has the potential to inhibit mast cell degranulation and may be associated with reduced risk of allergic symptoms in women.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Development of functional agricultural products utilizing the new health claim labeling system in Japan

In April 2015, Consumer Affairs Agency of Japan launched a new food labeling system known as "Foods with Function Claims (FFC)." Under this system, the food industry independently evaluates scientific evidence on foods and describes their functional properties. As of May 23, 2017, 1023 FFC containing 8 fresh foods have been launched. Meanwhile, to clarify the health-promoting effects of agricultural products, National Agriculture and Food Research Organization (NARO) implemented the "Research Project on Development of Agricultural Products" and demonstrated the risk reduction of osteoporosis of β-cryptoxanthin rich Satsuma mandarins and the anti-allergic effect of the O-methylated catechin rich tea cultivar Benifuuki. These foods were subsequently released as FFC. Moreover, NARO elucidated the health-promoting effects of various functional agricultural products (β-glucan rich barley, β-conglycinin rich soybean, quercetin rich onion, etc.) and a healthy boxed lunch. This review focuses on new food labeling system or research examining functional aspects of agricultural products.

Effect of Benifuuki Tea on Cytochrome P450-mediated Metabolic Activity in Rats

BACKGROUND/AIM

Benifuuki tea has recently been used as an alternative therapy for pollinosis, and it may be consumed with pharmaceutical drugs. This study aimed to examine cytochrome P450 (CYP)-mediated food-drug interactions with Benifuuki tea in rats.

MATERIALS AND METHODS

The inhibitory effects of Benifuuki tea and (-)-epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me) on CYP activities were evaluated in vitro. Midazolam pharmacokinetics was investigated after two treatments with Benifuuki tea. In an ex vivo study, CYP activities were determined after 1-week-treatment with the tea.

RESULTS

Benifuuki tea and EGCG3"Me inhibited CYP2D and CYP3A activities in a concentration-dependent manner in vitro. However, MDZ metabolism did not change by Benifuuki treatment in vivo and ex vivo. In contrast, CYP2D activity was decreased ex vivo.

CONCLUSION

Normal intake of Benifuuki tea is not likely to cause food-drug interactions by CYP3A inhibition or induction. In contrast, Benifuuki tea consumption may lead to food-drug interactions through the inhibition of CYP2D.

Linking iron-deficiency with allergy: role of molecular allergens and the microbiome

Atopic individuals tend to develop a Th2 dominant immune response, resulting in hyperresponsiveness to harmless antigens, termed allergens. In the last decade, epidemiological studies have emerged that connected allergy with a deficient iron-status. Immune activation under iron-deficient conditions results in the expansion of Th2-, but not Th1 cells, can induce class-switching in B-cells and hampers the proper activation of M2, but not M1 macrophages. Moreover, many allergens, in particular with the lipocalin and lipocalin-like folds, seem to be capable of binding iron indirectly via siderophores harboring catechol moieties. The resulting locally restricted iron-deficiency may then lead during immune activation to the generation of Th2-cells and thus prepare for allergic sensitization. Moreover, iron-chelators seem to also influence clinical reactivity: mast cells accumulate iron before degranulation and seem to respond differently depending on the type of the encountered siderophore. Whereas deferoxamine triggers degranulation of connective tissue-type mast cells, catechol-based siderophores reduce activation and degranulation and improve clinical symptoms. Considering the complex interplay of iron, siderophores and immune molecules, it remains to be determined whether iron-deficiencies are the cause or the result of allergy.

A Randomized Controlled Trial of Green Tea Beverages on the in vivo Radical Scavenging Activity in Human Skin

BACKGROUND

Oxidative stress plays an important role in the pathogenesis of various skin diseases. Thus, the antioxidant network of the skin relies on the uptake of exogenous antioxidants to ensure cell protection against radical formation. Green tea is one of the main sources of polyphenolic antioxidant compounds, but only few data are available on its cutaneous antioxidant effects.

METHODS

The radical scavenging properties of Benifuuki and Yabukita green tea were investigated in the human skin. Thirty-two participants who met the inclusion criteria were randomized to consume 3 cups per day of either Benifuuki tea, Yabukita tea, or water (control group) for 2 weeks. Electron paramagnetic resonance (EPR) spectroscopy was applied to measure the radical scavenging capacity of the skin in vivo before and after the intervention.

RESULTS

Both Yabukita and Benifuuki tea led to an increase in the radical scavenging activity of the skin by 28 and 29%, respectively, and the difference was significant when compared to the control group. Benifuuki tea, previously reported to be superior in bioavailability due to a highly absorbable methylated catechin, did not prove to be more effective than the common Yabukita tea.

CONCLUSION

The results show that green tea enhances the radical scavenging capacity of the skin and support the hypothesis that green tea may offer protection against cutaneous oxidative stress.

Complementary and Alternative Treatment for Allergic Conditions

This article explains the proposed pathophysiology, evidence of efficacy, and adverse effects of several complementary and alternative medicine modalities, for the treatment of allergic conditions, such as traditional Chinese medicine formula, herbal treatments, acupuncture, and homeopathy.