ABSTRACT
The major polyphenols in green tea, (-)-epigallocatechin and (-)-epigallocatechin gallate, have been shown to enhance the phagocytic activity of macrophage-like cells; however, the mechanism involved was not clarified. In this study, we have identified that the catechins induced phagocytosis can be blocked by catalase and an inhibitor of transient receptor potential melastatin 2.
ABSTRACT
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⻹) than in the second (2.24 mg g⻹) or first crop season (1.79 mg g⻹). The amount of anthocyanins contained in the stem was high (1.61 mg g⻹). In the third crop season, the concentrations of delphinidin-3-O-ß-D-(6-(E)-p-coumaroyl)galactopyranoside (DCGa), cyanidin-3-O-ß-D-(6-(E)-p-coumaroyl)galactopyranoside, delphinidin-3-O-ß-D-galactopyranoside, delphinidin-3-O-ß-D-(6-O-(Z)-p-coumaroyl)galactopyranoside, cyanidin-3-O-ß-D-galactoside, and delphinidin-3-O-ß-D-glucoside were 1.57 mg g⻹, 0.52 mg g⻹, 0.40 mg g⻹, 0.22 mg g⻹, 0.14 mg g⻹, and 0.11 mg g⻹, 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.
Subject(s)
Anthocyanins/pharmacology , Cholinesterase Inhibitors/pharmacology , Drug Discovery , Nerve Tissue Proteins/antagonists & inhibitors , Neurons/drug effects , Tea/chemistry , Acetylcholinesterase/metabolism , Alzheimer Disease/drug therapy , Anthocyanins/analysis , Anthocyanins/metabolism , Camellia sinensis/chemistry , Camellia sinensis/growth & development , Camellia sinensis/metabolism , Cell Line , Cholinesterase Inhibitors/analysis , Cholinesterase Inhibitors/metabolism , Chromatography, High Pressure Liquid , Crosses, Genetic , GPI-Linked Proteins/antagonists & inhibitors , GPI-Linked Proteins/metabolism , Glycosides/analysis , Glycosides/metabolism , Humans , Japan , Molecular Targeted Therapy , Nerve Tissue Proteins/metabolism , Neurons/enzymology , Neurons/metabolism , Pigmentation , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Leaves/chemistry , Plant Leaves/growth & development , Plant Leaves/metabolism , Plant Stems/chemistry , Plant Stems/growth & development , Plant Stems/metabolism , Seasons , Species SpecificityABSTRACT
It has been reported that epigallocatechin-3-O-(3â³-O-methyl)-gallate (EGCG3â³Me) and the EGCG3â³Me-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-(3â³-O-methyl)-gallate (ECG3â³Me) > gallocatechin-3-O-(3â³-O-methyl)-gallate (GCG3â³Me) > EGCG3â³Me > 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 ECG3â³Me was found in the third crop of 'Benifuuki' (1.05% dry weight). Moreover, ECG3â³Me content was positively correlated with EGCG3â³Me content in 'Benifuuki' tea leaves. In an assay of mixtures of ECG3â³Me and EGCG3â³Me, inhibitory activity (50 µg/mL in total) was increased as the content of ECG3â³Me increased. This suggests that ECG3â³Me might link to the antiallergic effect of 'Benifuuki' tea, as has been reported for EGCG3â³Me.
Subject(s)
Camellia sinensis/chemistry , Gallic Acid/analogs & derivatives , Histamine Release/drug effects , Plant Leaves/chemistry , Animals , Bone Marrow Cells/metabolism , Catechin/analogs & derivatives , Catechin/pharmacology , Female , Gallic Acid/analysis , Gallic Acid/pharmacology , Hypersensitivity/drug therapy , Mast Cells/metabolism , Mice , Species SpecificityABSTRACT
Toll-like receptor 7 (TLR7) senses viral single-stranded RNA (ssRNA), induces the production of type I interferons (IFNs), IFN-α and -ß, in macrophages such as dendritic cells (DCs), and its immune system protects the host from virus infection. Here, we found that a crude extract from immature green tea leaves (iTPS) containing a macromolecule with ssRNA fragments, induces IFN-α production in human macrophage-like cells. In addition IFN-α production was inhibited by treatment with TLR7 inhibitors or a phagocytosis inhibitor.
ABSTRACT
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.
ABSTRACT
We attempted to improve the bioavailability of green tea catechins by using food ingredients. The catechin bioavailability of a green tea extract administered to mice was significantly (p<0.05) increased by supplementing with steamed rice. This enhanced bioavailability was due to the increased concentration of plasma non-gallated catechins, especially epigallocatechin (EGC).
Subject(s)
Camellia sinensis/chemistry , Catechin/analogs & derivatives , Cooking , Dietary Supplements , Oryza , Plant Extracts/administration & dosage , Plant Extracts/pharmacology , Administration, Oral , Animals , Biological Availability , Catechin/blood , Catechin/pharmacokinetics , Diet , Female , MiceABSTRACT
We found that the epigallocatechin gallate (EGCG)/epigallocatechin (EGC) ratio in a green tea (Camellia sinensis L.) extract was affected by the extraction temperature. The EGCG/EGC ratio in the 4 °C extract was around 1:3-4, whereas in the 100 °C extract, it was around 1:0.7. Oral administration of the mixture with a high EGC ratio (1:2-3 = EGCG/EGC) resulted in greater IgA production by murine Peyer's patch cells.
Subject(s)
Camellia sinensis/chemistry , Catechin/analysis , Catechin/pharmacology , Chemical Fractionation/methods , Immunoglobulin A/immunology , Tea/chemistry , Temperature , Animals , Catechin/analogs & derivatives , Catechin/isolation & purification , Female , Immunologic Factors/analysis , Immunologic Factors/isolation & purification , Immunologic Factors/pharmacology , Mice , Mice, Inbred BALB C , Peyer's Patches/cytology , Peyer's Patches/drug effects , Peyer's Patches/immunologyABSTRACT
To identify the immunostimulants included in green tea extract, we investigated a crude tea polysaccharide related to increases in phagocytic activity using macrophage-like cells, and found that the crude tea polysaccharide from immature tea leaves included many RNAs as compared with that from mature tea leaves. Furthermore, the crude tea polysaccharide increased phagocytosis through toll-like receptor 7.
Subject(s)
Camellia sinensis/chemistry , Macrophages/cytology , Phagocytosis/drug effects , Plant Extracts/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , HL-60 Cells , Humans , Nucleic Acids/metabolism , Toll-Like Receptor 7/metabolismABSTRACT
We investigated the phagocytosis-enhancing activity of green tea polyphenols, such as epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), epicatechin (EC) catechin (+C) and strictinin, using VD3-differentiated HL60 cells. EGCG, EGC, ECG and strictinin, but not EC and +C, increased the phagocytic activity of macrophage-like cells, and a caspase inhibitor significantly inhibited phagocytic activities. These results suggest that the pyrogallol-type structure in green tea polyphenols may be important for enhancement of the phagocytic activity through caspase signaling pathways.