Part:BBa_K5238002
Produce theanine for the treatment of Alzheimer's disease
L-Theanine: Neuroprotective and Antidepressant Effects, and Safety Profile
L-theanine is a unique amino acid found in tea leaves, constituting 1-2% of their dry weight. It is known for its various health benefits, including the improvement of learning and memory, relaxation, anti-cancer properties, and neuroprotection [1].
Neuroprotective Effects in Neurodegenerative Diseases
Chemically similar to glutamate, L-theanine acts as a competitive antagonist at glutamate receptors such as NMDAR and AMPAR, albeit weakly, thus inhibiting neuronal death. It also regulates the glutamate-glutamine cycle by inhibiting glutamine transport and promoting neurogenesis through increased expression of the glutamine transporter protein slc38a1, providing neuroprotection against neurodegenerative diseases [1].
L-theanine degrades into glutamate in normal cells, subsequently increasing intracellular concentrations of glutamine and glutathione. Glutathione is a crucial antioxidant, reducing oxidative damage, maintaining striatal neurotransmitter homeostasis, and inhibiting nitric oxide production [1]. In the context of Alzheimer's disease (AD), L-theanine has been shown to alleviate cognitive dysfunction and neurotoxicity induced by beta-amyloid by reducing oxidative damage and inactivating the ERK/p38 kinase and NF-κB pathways [2].
Antidepressant Effects
L-theanine demonstrates significant preventive effects on depression. Mass spectrometry studies have revealed that L-theanine impacts the central and peripheral metabolomics in juvenile rats subjected to chronic unpredictable mild stress (CUMS), indicating its role in regulating amino acids, lipids, and inflammation to prevent depression [4]. Additionally, L-theanine ameliorates depressive-like behaviors in CUMS models by modulating monoamine levels in brain regions related to the limbic-cortical-striatal-pallidal-thalamic circuit [5]. It also induces hippocampal metabolic changes and exhibits antidepressant effects in stress-loaded mice [6].
Safety Profile
L-theanine has shown a high safety profile. It has been recognized as safe by the U.S. Food and Drug Administration (FDA) since 1985, classified as a Generally Recognized As Safe (GRAS) substance without usage limitations. Acute and subacute toxicity tests, as well as mutagenicity tests conducted by the Japan Food Additives Association, confirm its safety. No toxicity has been observed in either animal or human studies [1][6]. References
1. Chen SQ, Wang ZS, Ma YX, et al. Neuroprotective Effects and Mechanisms of Tea Bioactive Components in Neurodegenerative Diseases. Molecules. 2018;23(3):512. doi:10.3390/molecules23030512 2. Kim TI, Lee YK, Park SG, et al. l-Theanine, an amino acid in green tea, attenuates beta-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kappaB pathways. Free Radic Biol Med. 2009;47(11):1601-1610. doi:10.1016/j.freeradbiomed.2009.09.008 3. Zhu G, Yang S, Xie Z, Wan X. Synaptic modification by L-theanine, a natural constituent in green tea, rescues the impairment of hippocampal long-term potentiation and memory in AD mice. Neuropharmacology. 2018;138:331-340. doi:10.1016/j.neuropharm.2018.06.030 4. Zhu Y, Wang F, Han J, et al. Untargeted and targeted mass spectrometry reveal the effects of theanine on the central and peripheral metabolomics of chronic unpredictable mild stress-induced depression in juvenile rats. J Pharm Anal. 2023;13(1):73-87. doi:10.1016/j.jpha.2022.10.001 5. Shen M, Yang Y, Wu Y, et al. L-theanine ameliorate depressive-like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic-cortical-striatal-pallidal-thalamic-circuit related brain regions. Phytother Res. 2019;33(2):412-421. doi:10.1002/ptr.6237 6. Unno K, Muguruma Y, Inoue K, et al. Theanine, Antistress Amino Acid in Tea Leaves, Causes Hippocampal Metabolic Changes and Antidepressant Effects in Stress-Loaded Mice. Int J Mol Sci. 2020;22(1):193. doi:10.3390/ijms22010193
We successfully transformed the plasmid into Lactobacillus plantarum L168, and validation through PCR and agarose gel electrophoresis confirmed this achievement. Following this, we cultured Lactobacillus plantarum L168 and conducted RNA extraction using bacteriophage, while the supernatant was used for metabolite analysis. We then performed reverse transcription and quantitative polymerase chain reaction (qPCR) to quantify the gene expression levels in Lactobacillus plantarum L168, both with and without the recombinant plasmid. The qPCR results imply that our designed plasmid significantly upregulated the expression of key genes for theanine in Lactobacillus plantarum L168 compared to the control group (Fig. 5).
Figure 5. Relative Expression Analysis of genes glnA by qPCR.
Sequence and Features
- 10INCOMPATIBLE WITH RFC[10]Illegal EcoRI site found at 406
Illegal PstI site found at 623
Illegal PstI site found at 1154 - 12INCOMPATIBLE WITH RFC[12]Illegal EcoRI site found at 406
Illegal PstI site found at 623
Illegal PstI site found at 1154 - 21INCOMPATIBLE WITH RFC[21]Illegal EcoRI site found at 406
Illegal BamHI site found at 324 - 23INCOMPATIBLE WITH RFC[23]Illegal EcoRI site found at 406
Illegal PstI site found at 623
Illegal PstI site found at 1154 - 25INCOMPATIBLE WITH RFC[25]Illegal EcoRI site found at 406
Illegal PstI site found at 623
Illegal PstI site found at 1154
Illegal AgeI site found at 956 - 1000COMPATIBLE WITH RFC[1000]
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