Identification of an inhibitor for interleukin 4-induced epsilon germline transcription and antigen-specific IgE production in vivo

Strictinin: A Key Ingredient of Tea

Strictinin is a relatively tiny ellagitannin, which is found in many plants as a minor constituent. Catechins are known as the major constituents in the young leaves of most tea plants, while strictinin was found as a major constituent in the Pu'er tea plant. In some Pu'er tea varieties, strictinin was identified as the most abundant phenolic compound rather than catechins. In the past decade, strictinin was demonstrated to possess several functional activities, including antiviral, antibacterial, anti-obesity, laxative, anticaries, anti-allergic, antipsoriatic, antihyperuricemia, antidiabetic, and anticancer effects. These functional activities were in accordance with the therapeutic effects empirically perceived for Pu'er tea. Evidently, strictinin is the key ingredient in Pu'er tea that acts as a herbal medicine. In functionally-based applications, an instant powder of Pu'er tea infusion was formulated as an active raw material to be supplemented in food, cosmetics, and beverages; a new type of tea named Bitter Citrus Tzen Tea was developed by combining three teas empirically consumed to expel the cold, and new edible oral care products were designed for caries prevention by supplementation with Pu'er tea extract. More functional activities and practical applications of strictinin are scientifically anticipated in follow-up research.

Novel Strategies for Enantio- and Site-Selective Molecular Transformations

A strategy for symmetric synthesis based on dynamic chirality of enolates (memory of chirality) has been developed. Asymmetric alkylation, conjugate addition, aldol reaction, and arylation via C-N axially chiral enolate intermediates are described. Asymmetric alkylation and conjugate addition via C-O axially chiral enolate intermediates with a half-life of racemization as short as approx. 1 s. at -78 °C have been accomplished. Organocatalysts for asymmetric acylation and site-selective acylation have been developed. Kinetic resolution of racemic alcohols via remote asymmetric induction by the catalyst is shown. Catalyst-controlled site-selective acylation of carbohydrates and its application to total synthesis of natural glycoside are described. Chemo-selective monoacylation of diols and selective acylation of secondary alcohols with reversal of inherent reactivity are also discussed. Geometry-selective acylation of tetrasubstituted alkene diols is achieved, where acylation takes place independent from the steric environments of the substrates.

Anti-Allergic Effects of Quercetin and Quercetin Liposomes in RBL-2H3 Cells

BACKGROUND

Quercetin is a kind of flavonoid with important bioactivities, such as hypoglycemic, antioxidant, anti-inflammatory, and anti-allergic properties. Although it is unstable, it is worth exploring how to better exert its anti-allergic effect.

OBJECTIVE

The current study aimed to elucidate the anti-allergic effect of quercetin liposomes on RBL-2H3 cells in vitro.

METHODS

Quercetin liposomes were prepared to improve the anti-allergic activity of quercetin through a green thin-film dispersion method. We compared the anti-allergic effects of quercetin and quercetin liposomes in RBL-2H3 cells. The anti-allergic activity of the quercetin liposomes was evaluated by the level of β-hexosaminidase, histamine, Ca2+, IL-4, IL-8, and MCP-1.

RESULTS

The results showed that quercetin liposomes could significantly restrain the release of β-hexosaminidase and histamine, calcium influx, and the expression of inflammatory factors, whose effect is stronger than quercetin.

CONCLUSION

Collectively, our research suggests that the quercetin liposome can be used as a potential allergy antagonist.

67-kDa Laminin Receptor-Mediated Cellular Sensing System of Green Tea Polyphenol EGCG and Functional Food Pairing

The body is equipped with a “food factor-sensing system” that senses food factors, such as polyphenols, sulfur-containing compounds, and vitamins, taken into the body, and plays an essential role in manifesting their physiological effects. For example, (–)-epigallocatechin-3-O-gallate (EGCG), the representative catechin in green tea (Camellia sinensi L.), exerts various effects, including anti-cancer, anti-inflammatory, and anti-allergic effects, when sensed by the cell surficial protein 67-kDa laminin receptor (67LR). Here, we focus on three representative effects of EGCG and provide their specific signaling mechanisms, the 67LR-mediated EGCG-sensing systems. Various components present in foods, such as eriodictyol, hesperetin, sulfide, vitamin A, and fatty acids, have been found to act on the food factor-sensing system and affect the functionality of other foods/food factors, such as green tea extract, EGCG, or its O-methylated derivative at different experimental levels, i.e., in vitro, animal models, and/or clinical trials. These phenomena are observed by increasing or decreasing the activity or expression of EGCG-sensing-related molecules. Such functional interaction between food factors is called “functional food pairing”. In this review, we introduce examples of functional food pairings using EGCG.

Medicinal Importance, Pharmacological Activities, and Analytical Aspects of Strictinin: A Mini-Review

BACKGROUND

Plants and their derived products have been used in history as food and medicine. Plant materials are rich sources of fiber, minerals, vitamins, and bioactive phytochemicals, which are useful for human beings. Strictinin is an important phytoconstituent of green tea.

METHODS

Present work mainly focuses on the biological importance, therapeutic potential, and pharmacological activities of strictinin in medicine. Numerous scientific data have been collected from various literature databases such as Google Scholar, Science Direct, PubMed, and Scopus database in order to realize the health beneficial potential of strictinin. Pharmacological data has been collected and analyzed in the present work to find the effectiveness of strictinin against human disorders and complications. Analytical data of strictinin has been also collected and analyzed in the present work.

RESULTS

Scientific data analysis revealed the biological importance of strictinin in medicine. Scientific data analysis signified the therapeutic benefit of strictinin mainly due to its anticancer, antimicrobial, antibacterial, antiviral, and antioxidant activity. However, enzymatic activities, cytotoxicity, effectiveness on skin disorders, and osteogenic potential of strictinin have also been discussed. Analytical data revealed the importance of modern analytical techniques in medicine for the separation, identification, and isolation of strictinin.

CONCLUSION

Present work signified the biological importance and therapeutic benefits of strictinin in medicine and other allied health sectors.

Site-Selective Molecular Transformation: Acylation of Hydroxy Groups and C-H Amination

Control of site selectivity is an exciting direction for synthetic organic chemistry owing to the possibility of selective modification of multifunctionalized molecules, ultimately including biomacromolecules. In this review, our recent research related to site selectivity in two types of transformation, namely, the acylation of hydroxy groups and C-H amination, is summarized. Regarding the acylation of hydroxy groups, catalyst-controlled site selectivity enables unconventional retrosynthetic analysis, leading to efficient syntheses of sugar-related natural and unnatural products. Regarding C-H amination, the discovery of unprecedented reaction sites in intermolecular amination mediated by dirhodium nitrenes is described. The findings of this research demonstrate the power of site-selective transformation in the synthesis of a particular class of compounds.

Applications of ultrasound in total synthesis of bioactive natural products: A promising green tool

Total synthesisis frequently compared to climbing as it provides a suitable route to reach a high point from the floor, the complex natural product from simple and commercially available materials. The total synthesis has a privileged position of trust in confirming the hypothetical complex structures of natural products despite sophisticated analytical and spectroscopic instrumentation and techniques that are available presently. Moreover, total synthesis is also useful to prepare rare bioactive natural products in the laboratory as several bioactive secondary metabolites are obtained in small quantities from natural sources. The artistic aspect of the total synthesis of bioactive natural products continues to be praised today as it may provide environmental protection through the concept of green or clean chemistry. The use of ultrasound waves as a non-polluting source of energy is of great interest in the field of sustainable and pharmaceutical chemistry as it differs from conventional energy sources in terms of reaction rates, yields, selectivities, and purity of the products. The present review highlights the application of ultrasound as a green tool in the total synthesis of bioactive natural products as well as this article is also aimed to offer an overview of natural sources, structures, and biological activities of the promising natural products for the first time from 2005 to 2020 elegantly.

Inhibitory Effects of Green Asparagus Extract, Especially Phospholipids, on Allergic Responses in Vitro and in Vivo

Asparagus (Asparagus officinalis L.) is one of the widely consumed vegetables. To investigate the mechanism underlying the anti-allergic responses of asparagus, we extracted different fractions from asparagus and measured their inhibitory effects on β-hexosaminidase release in RBL-2H3 cells in vitro and an atopic dermatitis NC/Nga mouse model in vivo. The lipid fractions from asparagus were extracted with 50% ethanol, separated using chloroform by liquid-liquid phase separation, and fractionated by solid-phase extraction. Among them, acetone fraction (rich in glycolipid) and MeOH fraction (rich in phospholipid) markedly inhibited β-hexosaminidase release from RBL-2H3 cells. In NC/Nga mice treated with picryl chloride, atopic dermatitis was alleviated following exposure to the 50% EtOH extract, acetone fraction, and methanol fraction. The inhibitory effects of asparagus fractions in vivo were supported by the significant decrease in serum immunoglobulin E (IgE) levels. The phospholipid fractions showed significantly better inhibitory effects, and phosphatidic acid from this fraction showed the best inhibitory effect on β-hexosaminidase release. In mice challenged with ovalbumin (OVA), oral administration of asparagus extract and its fractions decreased the OVA-specific IgE level and total IgE, indicating that these effects may be partly mediated through the downregulation of antigen-specific IgE production. Taken together, the present study shows for the first time that asparagus extract and its lipid fractions could potentially mitigate allergic reactions by decreasing degranulation in granulocytes. Our study provides useful information to develop nutraceuticals and functional foods fortified with asparagus.

Lactobacillus helveticus SBT2171 alleviates allergic symptoms in a murine model for pollen allergy

Lactic acid bacteria are known to have various health-promoting effects and are highly expected to find applications in anti-allergic food materials. In this study, we focused on Lactobacillus helveticus SBT2171 (LH2171), which reportedly modifies some unique immune responses and ameliorated symptoms of patients allergic to mites and house dust in the previous studies. We examined the effect of LH2171 on cytokine production by antigen-stimulated murine naïve splenocytes in vitro and demonstrated that it inhibited IL-4 and IL-13 production while enhancing IFN-γ and IL-10 production. Then, we examined the anti-allergic effect of LH2171 in vivo using a murine model of pollen allergy and found that LH2171 reduced the sneezing frequency when orally administered to mice. We successfully confirmed the immune modulatory activity of LH2171 and its anti-allergic activity against inhaled antigens. These evidences would contribute to identifying the anti-allergic mechanism of LH2171.Abbreviations: ALDH: aldehyde dehydrogenase; EGCG: epigallocatechin gallate; LAB: lactic acid bacteria; LH2171: Lactobacillus helveticus SBT2171; NALT: nasal-associated lymphoid tissue; OVA: ovalbumin.

A Phytochemical-Sensing Strategy Based on Mass Spectrometry Imaging and Metabolic Profiling for Understanding the Functionality of the Medicinal Herb Green Tea

Low-molecular-weight phytochemicals have health benefits and reduce the risk of diseases, but the mechanisms underlying their activities have remained elusive because of the lack of a methodology that can easily visualize the exact behavior of such small molecules. Recently, we developed an in situ label-free imaging technique, called mass spectrometry imaging, for visualizing spatially-resolved biotransformations based on simultaneous mapping of the major bioactive green tea polyphenol and its phase II metabolites. In addition, we established a mass spectrometry-based metabolic profiling technique capable of evaluating the bioactivities of diverse green tea extracts, which contain multiple phytochemicals, by focusing on their compositional balances. This methodology allowed us to simultaneously evaluate the relative contributions of the multiple compounds present in a multicomponent system to its bioactivity. This review highlights small molecule-sensing techniques for visualizing the complex behaviors of herbal components and linking such information to an enhanced understanding of the functionalities of multicomponent medicinal herbs.

Antibacterial and laxative activities of strictinin isolated from Pu'er tea (Camellia sinensis)

Strictinin, the major phenolic compound in Pu'er teas produced from young leaves and buds of wild trees, was isolated to evaluate its antibacterial and laxative activities. The minimum inhibitory concentrations of strictinin against Propionibacterium acnes and Staphylococcus epidermidis were determined as 250 μM and 2000 μM, respectively, apparently higher than those of several antibiotics commonly used for bacterial infections. The additive and synergistic effects on the inhibitory activities of strictinin combined with other commercial antibiotics were observed in two bacteria tested in this study via the analysis of fractional inhibitory concentrations. Laxative activity was observed on defecation of the rats fed with strictinin. Further analysis showed that the laxative effect of strictinin was presumably caused by accelerating small intestinal transit, instead of enhancing gastric emptying, increasing food intake, or inducing diarrhea in the rats. Taken together with the antiviral activities demonstrated previously, it is suggested that strictinin is one of the active ingredients responsible for the antiviral, antibacterial, and laxative effects of wild Pu'er tea, and has the potential to be developed as a mild natural substitute for antibiotics and laxatives.

Prevention of allergic rhinitis by ginger and the molecular basis of immunosuppression by 6-gingerol through T cell inactivation

The incidence of allergies has recently been increasing worldwide. Immunoglobulin E (IgE)-mediated hypersensitivity is central to the pathogenesis of asthma, hay fever and other allergic diseases. Ginger (Zingiber officinale Roscoe) and its extracts have been valued for their medical properties including antinausea, antiinflammation, antipyresis and analgesia properties. In this study, we investigated the antiallergic effects of ginger and 6-gingerol, a major compound of ginger, using a mouse allergy model and primary/cell line culture system. In mice with ovalbumin (OVA)-induced allergic rhinitis, oral administration of 2% ginger diet reduced the severity of sneezing and nasal rubbing by nasal sensitization of OVA and suppressed infiltration of mast cells in nasal mucosa and secretion of OVA-specific IgE in serum. 6-Gingerol inhibited the expression of not only Th2 cytokines but also Th1 cytokines in OVA-sensitized spleen cells. Accordingly, 6-gingerol suppressed in vitro differentiation of both Th1 cells and Th2 cells from naïve T cells. In addition, 6-gingerol suppressed both superantigen staphylococcal enterotoxin B (SEB)- and anti-CD3-induced T cell proliferation. 6-Gingerol also abrogated PMA plus ionomycin- and SEB-induced IL-2 production in T cells, suggesting that 6-gingerol affected T cell receptor-mediated signal transduction rather than the antigen-presentation process. Indeed, 6-gingerol inhibited the phosphorylation of MAP kinases, calcium release and nuclear localization of c-fos and NF-κB by PMA and ionomycin stimulation. Thus, our results demonstrate that 6-gingerol suppresses cytokine production for T cell activation and proliferation, thereby not causing B cell and mast cell activation and resulting in prevention or alleviation of allergic rhinitis symptoms.

Significant elevation of antiviral activity of strictinin from Pu'er tea after thermal degradation to ellagic acid and gallic acid

Compared with abundant catechins, strictinin is a minor constituent in teas and has been demonstrated to possess inhibitory potency on influenza virus. In this study, strictinin was found as the major phenolic compound in Pu’er teas produced from leaves and buds of wild trees. Due to its thermal instability, strictinin, in tea infusion or in an isolated form, was completely decomposed to ellagic acid and gallic acid after being autoclaved for 7 minutes. A plaque reduction assay was employed to compare the relative inhibitory potency between strictinin and its thermally degraded products against human influenza virus A/ Puerto Rico/8/34. The results showed that the antiviral activity of ellagic acid regardless of the presence or absence of gallic acid was significantly higher than that of strictinin. Thermal degradation of strictinin to ellagic acid and gallic acid seems to be beneficial for the preparation of Pu’er teas in terms of enhancing antiviral activity.

In situ label-free visualization of orally dosed strictinin within mouse kidney by MALDI-MS imaging

Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) is a powerful technique for visualizing the distribution of a wide range of biomolecules within tissue sections. However, methodology for visualizing a bioactive ellagitannin has not yet been established. This paper presents a novel in situ label-free MALDI-MSI technique for visualizing the distribution of strictinin, a bioactive ellagitannin found in green tea, within mammalian kidney after oral dosing. Among nine representative matrix candidates, 1,5-diaminonaphthalene (1,5-DAN), harmane, and ferulic acid showed higher sensitivity to strictinin spotted onto a MALDI sample plate. Of these, 1,5-DAN enables visualization of a two-dimensional image of strictinin directly spotted on mouse kidney sections with the highest sensitivity. Furthermore, 1,5-DAN-based MALDI-MSI could detect the unique distribution of orally dosed strictinin within kidney sections. This in situ label-free imaging technique will contribute to the localization analysis of strictinin and its biological mechanisms.

IL-4 receptor α in non-lipid rafts is the target molecule of strictinin in inhibiting STAT6 activation

Strictinin has been shown to suppress interleukin (IL)-4-induced signal transducer and activator of transcription (STAT)-6 phosphorylation, which is a critical event for IgE class switching. However, it is unclear how strictinin inhibits STAT6 activation. Strictinin inhibited STAT6 phosphorylation by suppressing IL-4 receptor α (IL-4Rα) activation. Strictinin was bound to the cell surface and only localized in non-lipid raft fraction of the cells where IL-4Rα was also located. In addition, strictinin directly bound to IL-4Rα and inhibited binding of IL-4 to IL-4Rα. These results suggest that IL-4Rα locating in non-lipid raft region is a target molecule for strictinin in inhibiting STAT6 activation.

Tannic acid, a higher galloylated pentagalloylglucose, suppresses antigen-specific IgE production by inhibiting ɛ germline transcription induced by STAT6 activation

Interleukin (IL)-4 is a critical stimulator that induces ɛ germline transcripts (ɛGT) for switch recombination to initiate immunoglobulin (Ig) E and is important in allergic disease pathogenesis. We found pentagalloylglucose (PGG) inhibited IL-4-induced ɛGT expression. PGG exerted its inhibitory function by suppressing IL-4-induced activation of IL-4Rα, JAK3 and STAT6. Furthermore, tannic acid, a higher galloylated PGG, attenuated ovalbumin-induced IgE production in vivo by inhibiting IL-4-induced ɛGT expression and the IL-4 signaling pathway. In conclusion, our results suggest that tannic acid may attenuate allergic diseases by suppressing IgE production by inhibiting IL-4-induced signaling.

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Tannic acid (TA) is highly galloylated pentagalloylglucose derived from oriental herbs.

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Germline transcript (GT) expression is indispensable for immunoglobulin (Ig) E class switching.

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PGG and TA inhibit ɛGT expression by attenuating IL-4 signaling.

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TA attenuates ovalbumin-induced IgE production in vivo.

Chemical analysis and acetylcholinesterase inhibitory effect of anthocyanin-rich red leaf tea (cv. Sunrouge)

BACKGROUND

The purpose of this study was to evaluate the effects of leaf order or crop season on anthocyanins and other chemicals in the anthocyanin-rich tea cultivar 'Sunrouge' (Camellia sinensis x C. taliensis) by using high-performance liquid chromatography, and to study the effect of 'Sunrouge' extract on acetylcholinesterase (AChE) activity in human neuroblastoma SK-N-SH cells.

RESULTS

The total anthocyanin content was higher in the third (3.09 mg g⁻¹) than in the second (2.24 mg g⁻¹) or first crop season (1.79 mg g⁻¹). The amount of anthocyanins contained in the stem was high (1.61 mg g⁻¹). In the third crop season, the concentrations of delphinidin-3-O-β-D-(6-(E)-p-coumaroyl)galactopyranoside (DCGa), cyanidin-3-O-β-D-(6-(E)-p-coumaroyl)galactopyranoside, delphinidin-3-O-β-D-galactopyranoside, delphinidin-3-O-β-D-(6-O-(Z)-p-coumaroyl)galactopyranoside, cyanidin-3-O-β-D-galactoside, and delphinidin-3-O-β-D-glucoside were 1.57 mg g⁻¹, 0.52 mg g⁻¹, 0.40 mg g⁻¹, 0.22 mg g⁻¹, 0.14 mg g⁻¹, and 0.11 mg g⁻¹, respectively. DCGa accounted for about 50% of the anthocyanins present. The suppressive effect of 'Sunrouge' water extract on AChE activity in human neuroblastoma SK-N-SH cells was the strongest among the three tea cultivars ('Sunrouge', 'Yabukita' and 'Benifuuki').

CONCLUSION

These results suggested that 'Sunrouge' might protect humans from humans from AChE-related diseases by suppressing AChE activity. To obtain sufficient amounts of anthocyanins, catechins and/or caffeine for a functional food material, 'Sunrouge' from the third crop season should be used.

Epicatechin-3-O-(3″-O-methyl)-gallate content in various tea cultivars (Camellia sinensis L.) and its in vitro inhibitory effect on histamine release

It has been reported that epigallocatechin-3-O-(3″-O-methyl)-gallate (EGCG3″Me) and the EGCG3″Me-rich green tea ( Camellia sinensis L.) cultivar 'Benifuuki' exhibit antiallergic effects. The objective of this study was to investigate the effect of various tea leaf catechins on histamine release from murine bone marrow mast cells (BMMC). At a dose of 50 μg/mL, the rank order of histamine release inhibition was observed to be epicatechin-3-O-(3″-O-methyl)-gallate (ECG3″Me) > gallocatechin-3-O-(3″-O-methyl)-gallate (GCG3″Me) > EGCG3″Me > gallocatechin-gallate (GCG) > catechin-gallate (CG) > EGCG > epicatechin-gallate (ECG) > epigallocatechin (EGC) > gallocatechin (GC). Of the various tea cultivars analyzed by HPLC, the greatest content of ECG3″Me was found in the third crop of 'Benifuuki' (1.05% dry weight). Moreover, ECG3″Me content was positively correlated with EGCG3″Me content in 'Benifuuki' tea leaves. In an assay of mixtures of ECG3″Me and EGCG3″Me, inhibitory activity (50 μg/mL in total) was increased as the content of ECG3″Me increased. This suggests that ECG3″Me might link to the antiallergic effect of 'Benifuuki' tea, as has been reported for EGCG3″Me.

Inhibitory Effect of Polyphenol-Rich Fraction from the Bark of Acacia mearnsii on Itching Associated with Allergic Dermatitis

We examined the inhibitory effect of polyphenol-rich aqueous extract from the bark of Acacia mearnsii (PrA) on itching associated with atopic dermatitis (AD). HR-1 mice were fed a normal diet, special diet (AD group), or special diet containing 3% PrA (PrA group) for 6 weeks. In the AD group, itching frequency and transepidermal water loss increased compared to the control group. In the PrA group, an improvement in atopic dermatitis symptoms was observed. Ceramide expression in the skin decreased in the AD group compared to the control group, but no decrease was observed in the PrA group. mRNA expression of ceramidase decreased in the PrA group compared to the AD group. The results of this study have revealed that PrA inhibits itching in atopic dermatitis by preventing the skin from drying. It is considered that the mechanism by which PrA prevents the skin from drying involves the inhibition of increased ceramidase expression associated with atopic dermatitis.

Alleviation of allergic rhinitis symptoms with Pyeongwee-San extract (KMP6)

CONTEXT

Allergy is characterized by the overreaction of the immune system. Pyeongwee-San is a traditional Korean medicine which has been used for the treatment of the allergic disorder but the mechanism of action is not clear.

OBJECTIVE

To investigate the effect of Pyeongwee-San extract (KMP6) and its component, hesperidin (HES) in the allergic rhinitis (AR) animal model.

METHOD

We sensitized mice on 1, 5, and 14 days by intraperitoneal injections of 100 μg ovalbumin (OVA) emulsified in 20 mg of aluminum hydroxide and we challenged mice with 1.5 mg OVA. Mice received KMP6 and HES before the intranasal OVA challenge for 10 days.

RESULTS

The number of nose rubs after the OVA challenge in the OVA-sensitized mice was significantly higher than that in the OVA-unsensitized mice. The increased number of nose rub was inhibited by the oral administration of KMP6 or HES. The increased levels of IgE and histamine level in serum of the OVA-sensitized mice were reduced by KMP6 or HES administration. The level of interferon-γ was enhanced while the level of IL-4 was reduced on the spleen tissue of the KMP6 or HES-administered AR mice. Inflammatory proteins level was reduced by KMP6 or HES administration in the nasal mucosa tissue of the OVA-sensitized mice. In the KMP6 or HES-administered mice, mast cells and eosinophils infiltration increased by OVA-sensitization was decreased.

CONCLUSION

These results indicate that KMP6 and HES ameliorate the allergic inflammatory reactions such as AR.

Effect of green tea powder (Camellia sinensis L. cv. Benifuuki) particle size on O-methylated EGCG absorption in rats; The Kakegawa Study

Tea polyphenols, e.g., (-)-epigallocatechin-3-O-(3-O-methyl gallate (EGCG3"Me), (-)-epigallocatechin-3-O-gallate (EGCG), (-)-epigallocatechin (EGC), (-)-epicatechin-3-O-gallate (ECG), and (-)-epicatechin (EC), are believed to be responsible for the beneficial effects of tea. 'Benifuuki', a tea (Camellia sinensis L.) cultivar grown in Japan, is rich in the anti-allergic molecule epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me). Pulverized Benifuuki green tea powder (BGP) is more widely distributed than leaf tea in Japan. Japanese people mix their pulverized tea with water directly, whereas it is common to drink leaf tea after extraction. However, few studies of the effects of BGP particle size on polyphenol bioavailability have been performed. This study was conducted to investigate the absorption of catechins in rats after the intragastric administration of Benifuuki green tea. Therefore, we assessed the plasma concentrations of catechins following the ingestion of BGP with different mean particle sizes (2.86, 18.6, and 76.1 μm) or Benifuuki green tea infusion (BGI) as a control in rats. The bioavailabilities of EGCG3"Me, EGCG, ECG, EGC, and EC were analyzed after the oral administration of a single dose of Benifuuki green tea (125 mg/rat) to rats. The plasma concentrations of tea catechins were determined by HPLC analysis combined with of electrochemical detection (ECD) using a coulometric array. The AUC (area under the drug concentration versus time curve; min μg/mL) of ester-type catechins (EGCG3"Me, EGCG, and ECG) for the BGP 2.86 μm were significantly higher than those in the infusion and 18.6 and 76.1 μm BGP groups, but the AUC of free-type catechins (EGC and EC) showed no differences between these groups. Regarding the peak plasma level of EGCG3"Me adjusted for intake, BGP 2.86 μm and BGI showed higher values than the BGP 18.6 and 76.1 μm groups, and the peak plasma levels of the other catechins displayed the same tendency. The present study demonstrates that the bioavailability of ester-type catechins (EGCG and ECG) can be improved by reducing the particle size of green tea, but the plasma level of EGCG3"Me in the BGI group was similar to that in the BGP 2.86 μm group. This result suggests that drinking Benifuuki green tea with a particle size of around 2 μm would deliver the anti-allergic EGCG3"Me and the anti-oxidant EGCG efficiently.

Effect of Perilla frutescens var. acuta Kudo and rosmarinic acid on allergic inflammatory reactions

Allergy is characterized by an overreaction of the immune system. Perilla frutescens leaf extract has been reported to exhibit antiallergic inflammatory activity. To investigate precisely the effect and mechanism of 30% ethanol extract powder of P. frutescens var. acuta Kudo (EPPF) and rosmarinic acid (RA), a component of EPPF in allergic rhinitis and rhinoconjunctivitis, the antiallergic effects of EPPF and RA were analyzed using in vivo and in vitro models. Cytokine production was analyzed by means of an enzyme-linked immunosorbent assay. Cytokine expression was analyzed via reverse transcription-polymerase chain reaction and Western blotting. Transcription factor and caspase-1 activity were analyzed by a luciferase assay and caspase-1 assay, respectively. The number of nasal, ear and eye rubs after an ovalbumin (OVA) challenge in OVA-sensitized mice was significantly higher than that in OVA-unsensitized mice. Increased number of rubs was inhibited by administration of EPPF or RA. Increased levels of IgE in the serum, spleen and nasal mucosa of OVA-sensitized mice were reduced by EPPF or RA administration. The histamine level was also reduced by EPPF or RA administration in the serum of OVA-sensitized mice. Protein levels and mRNA expressions of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α were inhibited by EPPF or RA administration in the nasal mucosa tissue or spleen of OVA-sensitized mice. In EPPF or RA-administered mice, the mast cell and eosinophil infiltration increase as caused by OVA-sensitization was decreased. In addition, EPPF or RA inhibited both cyclooxygenase-2 protein expression and caspase-1 activity in the same nasal mucosa tissue. In activated human mast cells, nuclear factor-kappa B (NF-κB)/Rel A and caspase-1 activation increased, whereas NF-κB/Rel A and caspase-1 activation was inhibited after a treatment of EPPF or RA. These results indicate that EPPF and RA ameliorate allergic inflammatory reactions such as allergic rhinitis and allergic rhinoconjunctivitis.

Beneficial effects of chelidonic acid on a model of allergic rhinitis

Chelidonic acid (CA) is known as an inhibitor of the rat brain glutamate decarboxylase. However, the pharmacological effects of CA in allergic reactions have not yet been defined. Here, we show the effects and the mechanism of CA in the ovalbumin (OVA)-sensitized allergic rhinitis (AR) model. CA significantly decreased the number of nasal/ear rubs and increment of IgE levels in the AR mice. The level of interferon-γ was enhanced while the level of IL-4 was reduced on the spleen tissue of the CA-administered AR mice. Expressions of IL-1β and cyclooxygenase-2 were inhibited by CA administration in the nasal mucosa tissues. Infiltration of eosinophils and mast cells was decreased in the CA-administered AR mice. Furthermore, CA decreased the caspase-1 activity in the same nasal mucosa tissue and human mast cell line, HMC-1. Our results indicate that CA may attenuate allergic reaction by inhibition of caspase-1 activity.

Identifications of inhibitors of IgE production by human lymphocytes isolated from 'Cha Chuukanbohon Nou 6' tea leaves

BACKGROUND

Tea (Camellia sinensis L.) is consumed all over the world and in especially large quantities in Japan and China, where it has been used not only as a daily beverage but also for medicinal purposes for thousands of years. Tea has been found to exhibit various bioregulatory activities, including antiallergic, anticarcinogenic, antimetastatic, antioxidative, antihypertensive, antihypercholesterolemic, anti-dental caries and antibacterial effects, and to influence intestinal flora.

RESULTS

Cha Chuukanbohon Nou 6 is a tea cultivar improved by the National Institute of Vegetable and Tea Science (NIVTS) in Japan. On comparing chemical constituents of 11 varieties of tea leaves by high-performance liquid chromatography, we found two new major compounds in Cha Chuukanbohon Nou 6. Nuclear magnetic resonance spectroscopy revealed these compounds to be theogallin and 1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-beta-D-glucopyranose. The two were similar in chemical structure to strictinin, an inhibitor of immunoglobulin (Ig) production. Thus their effects on the production of Igs by peripheral blood lymphocytes were tested. Both compounds, like strictinin, inhibited IgE production.

CONCLUSION

The results suggest Cha Chuukanbohon Nou 6 to be the basis of an antiallergic beverage.

Metabolomics analysis reveals the compositional differences of shade grown tea (Camellia sinensis L.)

The different cultivation methods affect tea quality by altering the basic metabolite profiles. In this study, the metabolome changes were investigated in green tea and shade cultured green tea (tencha) by liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS) coupled with a multivariate data set. The principal component analysis (PCA) and orthogonal projection to latent structures discriminate analysis (OPLS-DA) of green tea clearly showed higher levels of galloylquinic acid, epigallocatechin, epicatechin, succinic acid, and fructose, together with lower levels of gallocatechin, strictinin, apigenin glucosyl arabinoside, quercetin p-coumaroylglucosyl-rhamnosylgalactoside, kaempferol p-coumaroylglucosylrhamnosylgalactoside, malic acid, and pyroglutamic acid than tencha. The effects of some seasonal variations were also observed in the primary metabolite concentrations such as amino acids and organic acids. In addition, green tea showed stronger antioxidant activity than tencha in both April and July. The antioxidant activity of green tea samples were significantly correlated with their total phenol and total flavonoid contents. This present study delineates the possibility to get high umami and less astringent green teas in shade culture. It highlights the metabolomic approaches to find out the effect of cultivation methods on chemical composition in plants and the relationship with antioxidant activity.

Flavones suppress type I IL-4 receptor signaling by down-regulating the expression of common gamma chain

Immunoglobulin E (IgE) production is induced by interleukin (IL)-4 signaling mediated by type I IL-4 receptor (IL-4R) in B cells. We found that flavones inhibited IL-4-induced epsilon germline transcription which is essential for IgE class switching, and the phosphorylation of signal transducer and activator of transcription 6, janus kinase 3, and IL-4Ralpha, whereas IL-4 signaling mediated through type II IL-4R was unaffected by flavones. Furthermore, flavones reduced the expression of common gamma chain, a characteristic constituent subunit of type I IL-4R, suggesting that flavones suppress type I IL-4R signaling.

The efficacy of early treatment of seasonal allergic rhinitis with benifuuki green tea containing O-methylated catechin before pollen exposure: an open randomized study

BACKGROUND

We previously reported that 'benifuuki' green tea containing O-methylated catechin significantly relieved the symptoms of perennial or seasonal rhinitis compared with a placebo green tea that did not contain O-methylated catechin in randomized double-blind clinical trials. In this study we assessed the effects of 'benifuuki' green tea on clinical symptoms of seasonal allergic rhinitis.

METHODS

An open-label, single-dose, randomized, parallel-group study was performed on 38 subjects with Japanese cedar pollinosis. The subjects were randomly assigned to long-term (December 27, 2006-April 8, 2007, 1.5 months before pollen exposure) or short-term (February 15, 2007: after cedar pollen dispersal--April 8, 2007) drinking of a 'benifuuki' tea drink containing 34 mg O-methylated catechin per day. Each subject recorded their daily symptom scores in a diary. The primary efficacy variable was the mean weekly nasal symptom medication score during the study period.

RESULTS

The nasal symptom medication score in the long-term intake group was significantly lower than that of the short-term intake group at the peak of pollen dispersal. The symptom scores for throat pain, nose-blowing, tears, and hindrance to activities of daily living were significantly better in the long-term group than the short-term group. In particular, the differences in the symptom scores for throat pain and nose-blowing between the 2 groups were marked.

CONCLUSIONS

We conclude that drinking 'benifuuki' tea for 1.5 months prior to the cedar pollen season is effective in reducing symptom scores for Japanese cedar pollinosis.

In vitro and in vivo anti-allergic effects of 'benifuuki' green tea containing O-methylated catechin and ginger extract enhancement

'Benifuuki', a tea (Camellia Sinensis L.) cultivar in Japan, is rich in anti-allergic epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3''Me). 'Benifuuki' green tea and simultaneous addition of ginger extract remarkably suppressed cytokine (TNF-alpha and MIP-1alpha) secretion from mouse bone marrow-derived mast cells after antigen stimulation and, as expected, suppressed delay-type allergy. After drinking 'benifuuki' green tea containing 43.5 mg of EGCG and 8.5 mg of EGCG3''Me, the AUC (area under the drug concentration time curve; min mug/ml) of EGCG was 6.72 +/- 2.87 and EGCG3''Me was 8.48 +/- 2.54 in healthy human volunteers. Though the dose of EGCG was 5.1 times the dose of EGCG3''Me, the AUC of EGCG3''Me was higher than that of EGCG. A double blind clinical study on subjects with Japanese cedar pollinosis was carried out. At the 11th week after starting the study, in the most severe cedar pollen scattering period, symptoms, i.e., blowing the nose and itching eyes, were significantly relieved in the 'benifuuki' intake group compared with the placebo group, and blowing the nose, itching eyes and nasal symptom score, and at the 11th and 13th weeks, stuffy nose, throat pain and the nasal symptom medication score were significantly relieved in the 'benifuuki' containing ginger extract group compared with the placebo group. These results suggested that over one consecutive month, drinking 'benifuuki' green tea was useful to reduce some of the symptoms from Japanese cedar pollinosis, and did not affect any normal immune response in subjects with seasonal rhinitis, and the ginger extract enhanced the effect of 'benifuuki' green tea.

Simultaneous analysis of catechins, gallic acid, strictinin, and purine alkaloids in green tea by using catechol as an internal standard

We developed a high-performance liquid chromatography-based method for simultaneous analysis of nine catechins, gallic acid, strictinin, caffeine, and theobromine in green tea by using catechol as an internal standard. Although the high cost and instability of the catechin reference standards limit the application of this method, the addition of ascorbic acid to the standard stock solution preserved the stability of the reference standards in the solution for 1 year when stored at -30 degrees C. Furthermore, we found that the slopes of the calibration curves plotted were stable for a run time of 2000 h. Our method proved to be appropriate for quantification and yielded good correlation coefficients, detection levels, repeatability, reproducibility, and recovery rates. Quantitative data revealed that the contribution of only 200 mL of brewed tea to the total dietary catechins was approximately 220-420 mg, while that of 500 mL of bottled tea was approximately 170-900 mg.

Dietary flavones suppresses IgE and Th2 cytokines in OVA-immunized BALB/c mice

BACKGROUND

The flavonoids are a diverse family of chemicals commonly found in fruits and vegetables. Previously, we have shown that the two flavones, chrysin and apigenin could suppress the expression of the high affinity IgE receptor FcepsilonRI in human basophilic KU812 cells. We also demonstrated that dietary apigenin decreased IgE level in C57BL/6N mice sera.

AIM OF THE STUDY

To evaluate the anti-allergic effect of the two flavones in vivo, we evaluated the effect of the two flavones, chrysin and apigenin, on the immune system in BALB/c mice sensitized with ovalbumin (OVA).

METHODS

Mice were fed experimental diets containing either of the flavones for 3 weeks and immunized with OVA. After the experimental feeding period, measurement of Igs concentration in the mice sera was performed using a sandwich ELISA. Cytokines expression in mice sera was assessed using a cytokine array. Furthermore, cytokines mRNA levels in spleen lymphocytes from mice sensitized with OVA were measured by RT-PCR.

RESULTS

The total IgE level in mice fed one of the two flavones were suppressed, whereas levels of IgG, IgM, and IgA were not affected. The production of interleukin (IL)-4, which is known as one of Th2 cytokines and regulates the production of IgE, was down-regulated by the chrysin or the apigenin diet. Moreover, OVA-induced mRNA expression of Th2 cytokines in spleen lymphocytes from mice sensitized with OVA, such as IL-4 and IL-13 were down-regulated by the chrysin or the apigenin diet.

CONCLUSIONS

The results suggest that the diet containing one of the two flavones might suppress the up-regulation of serum IgE induced by OVA-immunization through the suppression of Th2-type immune response.

The role of human mast cell-derived cytokines in eosinophil biology

Eosinophil-mediated diseases, such as allergic asthma, eosinophilic fasciitis, and certain hypersensitivity pulmonary disorders, are characterized by eosinophil infiltration and tissue injury. Mast cells and T cells often colocalize to these areas. Recent data suggest that mast cells can contribute to eosinophil-mediated inflammatory responses. Activation of mast cells can occur by antigen and immunoglobulin E (IgE) via the high-affinity receptor (FcepsilonRI) for IgE. The liberation of proteases, leukotrienes, lipid mediators, and histamine can contribute to tissue inflammation and allow recruitment of eosinophils to tissue. In addition, the synthesis and expression of a plethora of cytokines and chemokines (such as granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin-1 [IL-1], IL-3, IL-5, tumor necrosis factor-alpha [TNF-alpha], and the chemokines IL-8, regulated upon activation normal T cell expressed and secreted [RANTES], monocyte chemotactic protein-1 [MCP-1], and eotaxin) by mast cells can influence eosinophil biology. Stem cell factor (SCF)-c-kit, cytokine-cytokine receptor, and chemokine-chemokine receptor (CCR3) interactions leading to nuclear factor kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK) expression, and other signaling pathways can modulate eosinophil function. Eosinophil hematopoiesis, activation, survival, and elaboration of mediators can all be regulated thus by mast cells in tissue. Moreover, because eosinophils can secrete SCF, eosinophils can regulate mast cell function in a paracrine manner. This two-way interaction between eosinophils and mast cells can pave the way for chronic inflammatory responses in a variety of human diseases. This review summarizes this pivotal interaction between human mast cells and eosinophils.

Tea polyphenols inhibit acetyl-CoA:1-alkyl-sn-glycero-3-phosphocholine acetyltransferase (a key enzyme in platelet-activating factor biosynthesis) and platelet-activating factor-induced platelet aggregation

BACKGROUND

Tea extracts have antiallergic and anti-inflammatory actions in rats and mice. However the mechanism through which tea polyphenols act in vivo are still incompletely understood. We found inhibitory effects of black tea extracts on an fMLP-induced aggregating response in a rabbit platelet-polymorphonuclear leukocyte (PMN) system.

METHOD

To elucidate whether 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine (PAF) production in PMNs and/or PAF-stimulated platelet activation were inhibited, the effects of tea polyphenols were investigated on the enzyme activity of acetyl-CoA:1-alkyl-sn-glycero-3-phosphocholine acetyltransferase (EC 2.3.1.67), PAF biosynthesis in A23187-activated rabbit PMNs, and rabbit platelet aggregation. By comparing the inhibitory effects of 31 galloyl esters and gallic acid, the structure-inhibitory activity relationship was characterized.

RESULTS

Theaflavin and its galloyl esters and pentagalloyl glucose were found to be potent inhibitors of the acetyltransferase (IC(50) = 28-58 microM) and the PAF biosynthesis as well as (-)-epicatechin-3-O-gallate (IC(50) = 72 +/- 13 microM) and (-)-epigallocatechin-3-O-gallate (IC(50) = 46 +/- 6 microM). On the other hand, flavan-3-ols without galloyl group at C-3 and gallic acid did not show significant enzyme inhibition. In addition, theaflavin and its galloyl esters (IC(50) = 32-77 microM) and geranyl gallate, farnesyl gallate and geranylgeranyl gallate (IC(50) = 6.4-7.6 microM) were found to be potent inhibitors of PAF- and TPA-induced rabbit platelet aggregation but not A23187-induced aggregation.

CONCLUSIONS

Theaflavin and its galloyl esters in black tea extract, and isoprenyl gallates were potent inhibitors of PAF synthesis and platelet aggregation and these activities may be relevant to the claimed therapeutic effects of tea extracts.

Extract of Perilla frutescens enriched for rosmarinic acid, a polyphenolic phytochemical, inhibits seasonal allergic rhinoconjunctivitis in humans

Extract of Perilla frutescens enriched for rosmarinic acid, a polyphenolic phytochemical, suppresses allergic immunoglobulin responses and inflammation caused by polymorphonuclear leukocytes (PMNL) in mice. However, few placebo-controlled clinical trials have examined the efficacy and safety of polyphenolic phytochemicals for treatment of allergic inflammatory diseases in humans. The present study determined whether oral supplementation with rosmarinic acid is an effective intervention for patients with seasonal allergic rhinoconjunctivitis (SAR). In this 21-day, randomized, double-blind, age-matched, placebo-controlled parallel group study, patients with mild SAR were treated daily with extract of Perilla frutescens enriched for rosmarinic acid (200 mg [n=10] or 50 mg [n=9]) or placebo (n=10). Patients recorded symptoms daily in a diary. Profiles of infiltrating cells and concentrations of eotaxin, IL-1beta, IL-8, and histamine were measured in nasal lavage fluid. Serum IgE concentrations and routine blood tests were also examined. As compared with placebo supplementation, supplementation with extract of Perilla frutescens enriched for rosmarinic acid resulted in a significant increase in responder rates for itchy nose, watery eyes, itchy eyes, and total symptoms (P<0.05). Active treatment significantly decreased the numbers of neutrophils and eosinophils in nasal lavage fluid (P<0.05 vs. placebo). Patients reported no adverse events, and no significant abnormalities were detected in routine blood tests. In conclusion, extract of Perilla frutescens enriched for rosmarinic acid can be an effective intervention for mild SAR at least partly through inhibition of PMNL infiltration into the nostrils. Use of this alternative treatment for SAR might reduce treatment costs for allergic diseases.

Anthelminthic and antiallergic activities of Mangifera indica L. stem bark components Vimang and mangiferin

This study investigated the antiallergic and anthelmintic properties of Vimang (an aqueous extract of Mangifera indica family stem bark) and mangiferin (the major polyphenol present in Vimang) administered orally to mice experimentally infected with the nematode, Trichinella spiralis. Treatment with Vimang or mangiferin (500 or 50 mg per kg body weight per day, respectively) throughout the parasite life cycle led to a significant decline in the number of parasite larvae encysted in the musculature; however, neither treatment was effective against adults in the gut. Treatment with Vimang or mangiferin likewise led to a significant decline in serum levels of specific anti-Trichinella IgE, throughout the parasite life cycle. Finally, oral treatment of rats with Vimang or mangiferin, daily for 50 days, inhibited mast cell degranulation as evaluated by the passive cutaneous anaphylaxis test (sensitization with infected mouse serum with a high IgE titre, then stimulation with the cytosolic fraction of T. spiralis muscle larvae). Since IgE plays a key role in the pathogenesis of allergic diseases, these results suggest that Vimang and mangiferin may be useful in the treatment of diseases of this type.