The Involvement of L-Type Amino Acid Transporters in Theanine Transport

Yamamoto, Sachiko; Kimura, Tōru; Tachiki, Takashi; Anzai, Naohiko; Sakurai, Takeshi; Ushimaru, Makoto

doi:10.1271/bbb.120519

Cited by 9 publications

(5 citation statements)

References 25 publications

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“…Theanine was shown to be mainly transported by the Na + -independent neutral amino acids system L transport pathway [ 12 ]. It was hypothesized that the ingredients strengthen the transporter activity.…”

Section: Resultsmentioning

confidence: 99%

“…Theanine has been shown to be transported rapidly by the Na + -independent neutral amino acids system L transport pathway [ 12 ]. It was speculated that theanine has high membrane permeability and that its absorption is dependent on intestinal blood flow.…”

Section: Discussionmentioning

confidence: 99%

“…As described above, theanine has been shown to have a variety of effects and it has attracted much attention among functional food components. Some studies have shown the absorption mechanism of theanine [ 10 – 12 ]. Theanine would be transported by the Na + -independent neutral amino acids system L transporter.…”

Section: Introductionmentioning

confidence: 99%

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An imaging approach for determining the mechanism of enhancement of intestinal absorption of an L-theanine supplement

et al. 2021

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Background & objective Theanine (L-glutamylethylamide) contained in green tea is a functional food component that has been attracting attention due to its relaxation effect. It was shown that the ingredients added to the theanine formulations increased the absorption of theanine. If this mechanism can be elucidated, it would be possible to contribute to development of evidence-based formulations. In this study, we investigated the effect of ingredients in the formulations on the absorption of theanine in detail. Main methods After oral administration of a mixture of theanine and additional components to Wistar rats the plasma concentration was determined by an HPLC and the pharmacokinetic parameters were calculated. In addition, a new system for evaluating intestinal blood flow was developed since the involvement of intestinal blood flow was considered as a factor that increased absorption of theanine. Key findings Plasma concentration of theanine increased significantly in the combined use group with eight ingredients containing piperine as compared with theanine only group. Piperine would increase theanine absorption by increased blood flow, not an inhibition of metabolism. We succeeded to develop a visual and quantitative system to evaluate the effect of these ingredients directly including piperine on the intestinal blood flow using indocyanine green while maintaining physiological conditions. Significance Increased intestinal blood flow by these ingredients including piperine enhanced the absorption of theanine. Other mechanisms may also be considered as the mechanism by which theanine absorption is increased in addition to increased blood flow.

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Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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An imaging approach for determining the mechanism of enhancement of intestinal absorption of an L-theanine supplement

et al. 2021

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“…However, it has been reported that oxaliplatin enhances the oxidative stress in also the central nerve system, such as brain and spinal cord 38 – 43 . Theanine can cross the blood–brain barrier (BBB) via L-type amino acid transporter 1 (LAT1) and LAT2 44 , 45 . Cystine is taken up by BBB endothelial cells via the complex of the cystine/glutamic acid transporter (xCT) and the heavy chain of 4F2 cell surface antigen (4F2hc) subunits 46 , 47 .…”

Section: Discussionmentioning

confidence: 99%

Oral administration of Cystine and Theanine ameliorates oxaliplatin-induced chronic peripheral neuropathy in rodents

Kawashiri

Kobayashi

Egashira

et al. 2020

Sci Rep

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Oxaliplatin frequently causes severe peripheral neuropathy as a dose-limiting toxicity. However, this toxicity lacks a strategy for prevention. Cystine/Theanine is a supplement, which includes precursors for the biosynthesis of glutathione. In this study, we investigated the effects of Cystine/Theanine on oxaliplatin-induced peripheral neuropathy using an in vivo model. Repeated injection of oxaliplatin (4 mg/kg intraperitoneally twice a week for 2 weeks) caused mechanical allodynia, cold hyperalgesia and axonal degeneration of the sciatic nerve in rats. Mechanical allodynia and axonal degeneration, but not cold hyperalgesia, were ameliorated by daily co-administration of Cystine [200 mg/kg orally (p.o.)] and Theanine (80 mg/kg p.o.). Moreover, co-administration of Cystine and Theanine to rats significantly increased the glutathione level in the sciatic nerve compared with the oxaliplatin group. Furthermore, Cystine and Theanine did not attenuate the tumour cytotoxicity of oxaliplatin in C-26 tumour cell-bearing mice. These findings suggest that Cystine and Theanine may be beneficial for preventing oxaliplatin-induced peripheral neuropathy.

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“…It plays a crucial role in assessing the quality of green tea due to its distinct umami taste (Haskell et al, 2008). Theanine is primarily synthesised in the roots of tea plants and is subsequently transported to the shoots (Yamamoto et al, 2012; Zhao et al, 2020). The dynamic changes of theanine accumulation are closely related to nutrients, especially nitrogen (Fan et al, 2019; Huang et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

The effect of intercropping leguminous green manure on theanine accumulation in the tea plant: A metagenomic analysis

Duan,

Wang,

Zhang

et al. 2023

Plant Cell & Environment

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Intercropping is a widely recognised technique that contributes to agricultural sustainability. While intercropping leguminous green manure offers advantages for soil health and tea plants growth, the impact on the accumulation of theanine and soil nitrogen cycle are largely unknown. The levels of theanine, epigallocatechin gallate and soluble sugar in tea leaves increased by 52.87% and 40.98%, 22.80% and 6.17%, 22.22% and 29.04% in intercropping with soybean–Chinese milk vetch rotation and soybean alone, respectively. Additionally, intercropping significantly increased soil amino acidnitrogen content, enhanced extracellular enzyme activities, particularly β‐glucosidase and N‐acetyl‐glucosaminidase, as well as soil multifunctionality. Metagenomics analysis revealed that intercropping positively influenced the relative abundances of several potentially beneficial microorganisms, including Burkholderia, Mycolicibacterium and Paraburkholderia. Intercropping resulted in lower expression levels of nitrification genes, reducing soil mineral nitrogen loss and N2O emissions. The expression of nrfA/H significantly increased in intercropping with soybean–Chinese milk vetch rotation. Structural equation model analysis demonstrated that the accumulation of theanine in tea leaves was directly influenced by the number of intercropping leguminous green manure species, soil ammonium nitrogen and amino acid nitrogen. In summary, the intercropping strategy, particularly intercropping with soybean–Chinese milk vetch rotation, could be a novel way for theanine accumulation.

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The Involvement of L-Type Amino Acid Transporters in Theanine Transport

Cited by 9 publications

References 25 publications

An imaging approach for determining the mechanism of enhancement of intestinal absorption of an L-theanine supplement

An imaging approach for determining the mechanism of enhancement of intestinal absorption of an L-theanine supplement

Oral administration of Cystine and Theanine ameliorates oxaliplatin-induced chronic peripheral neuropathy in rodents

The effect of intercropping leguminous green manure on theanine accumulation in the tea plant: A metagenomic analysis

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