Tissue Distribution and Intracellular Localization of Catechins in Tea Leaves

Suzuki, Takao; Yamazaki, Naoki; Sada, Yasutoshi; Oguni, Itaro; Moriyasu, Yuji

doi:10.1271/bbb.67.2683

Cited by 41 publications

(26 citation statements)

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“…However, studies of the localization of catechins in tea-leaf tissues have been contradictory. Suzuki et al (2003) showed that catechins are mainly localized in the vacuoles of mesophyll cells, and not in epidermal cells.…”

Section: Resultsmentioning

confidence: 99%

Localization of aluminium in tea (Camellia sinensis) leaves using low energy X-ray fluorescence spectro-microscopy

et al. 2010

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Information on localization of Al in tea leaf tissues is required in order to better understand Al tolerance mechanism in this Al-accumulating plant species. Here, we have used low-energy X-ray fluorescence spectro-microscopy (LEXRF) to study localization of Al and other low Z-elements, namely C, O, Mg, Si and P, in fully developed leaves of the tea plant [Camellia sinensis (L.) O. Kuntze]. Plants were grown from seeds for 3 months in a hydroponic solution, and then exposed to 200 microM AlCl(3) for 2 weeks. Epidermal-mesophyll and xylem phloem regions of 20 microm thick cryo-fixed freeze-dried tea-leaf cross-sections were raster scanned with 1.7 and 2.2 keV excitation energies to reach the Al-K and P-K absorption edges. Al was mainly localized in the cell walls of the leaf epidermal cells, while almost no Al signal was obtained from the leaf symplast. The results suggest that the retention of Al in epidermal leaf apoplast represent the main tolerance mechanism to Al in tea plants. In addition LEXRF proved to be a powerful tool for localization of Al in plant tissues, which can help in our understanding of the processes of Al uptake, transport and tolerance in plants.

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Section: Resultsmentioning

confidence: 99%

Localization of aluminium in tea (Camellia sinensis) leaves using low energy X-ray fluorescence spectro-microscopy

et al. 2010

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“…The enzymes responsible for this step are polyphenol oxidase (PPO) and peroxidase (POD), which are also situated in the tea leaves but spatially separated from the polyphenolic constituents, which are stored in micrometer sized compartments. 4 When flavanols and enzymes get into contact, e.g., after crushing of the leaves and disruption of the internal cell structures, the 3′,4′-hydroxyl groups of the polyphenolic B-rings are oxidized to their corresponding o-quinones, which are then subject to further reactions. This step leads initially to dimeric flavanols with presently four generic structures established: theaflavins 7−10 ( Figure 2), theacitrins, theasinensins, and theanaphthoquinones.…”

Section: ■ Introductionmentioning

confidence: 99%

Investigation of Processes in Black Tea Manufacture through Model Fermentation (Oxidation) Experiments

Stodt

Blauth

Niemann

et al. 2014

J. Agric. Food Chem.

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Flavanol depleted whole fresh green tea leaf powder, as reported in the literature, was used as matrix for a systematic study of the endogenous oxidative enzymatic conversion of selected flavanol combinations to theaflavins and thearubigins. The activity of the two crucial enzymes polyphenol oxidase (PPO) and peroxidase (POD) was controlled individually through addition of H2O2 and/or O2. Using the endogenous peroxidase only it was shown that (-)-epicatechin alone did not react with POD. According to these results it is possible that theaflavin formation occurs via reaction of a flavanol quinone with a nonquinone flavanol. It was confirmed that only a dihydroxy-B-ring flavanol with a trihydroxy-B-ring flavanol gave a theaflavin upon enzymatic oxidation. Use of horseradish peroxidase in the presence of a flavanol depleted tea leaf matrix led to significantly higher kinetics on theaflavin 3-gallate degradation compared to the absence of leaf matrix, suggesting a catalytic effect of the leaf matrix not reported before.

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“…Deng et al (2001) demonstrated that Realgar with a smaller particle size of 150 or 100 nm markedly reduced cell viability through apoptosis compared with that with a particle size of 200 or 500 nm. Suzuki et al (2003) demonstrated that synthesized catechins were localized to restricted regions within the large central vacuoles (5-15 lm) or some small vacuoles (0.5-3 lm) in tea leaf mesophyll cells. It is conceivable that catechin form complexes with metal ions such as Ca(II) and Mg(II) and special proteins in central vacuole.…”

Section: Discussionmentioning

confidence: 99%

“…It is conceivable that catechin form complexes with metal ions such as Ca(II) and Mg(II) and special proteins in central vacuole. Suzuki et al (2003) supposed that synthesized catechins in ER or Golgi apparatus are packed in the formation of a small vacuole and small vacuoles fuse with each other and as a result, catechins are transported into the large central vacuole. However, localization of individual catechin was not fully elucidated.…”

Section: Discussionmentioning

confidence: 99%

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

et al. 2011

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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.

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Tissue Distribution and Intracellular Localization of Catechins in Tea Leaves

Cited by 41 publications

References 1 publication

Localization of aluminium in tea (Camellia sinensis) leaves using low energy X-ray fluorescence spectro-microscopy

Localization of aluminium in tea (Camellia sinensis) leaves using low energy X-ray fluorescence spectro-microscopy

Investigation of Processes in Black Tea Manufacture through Model Fermentation (Oxidation) Experiments

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

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