Oxid Med Cell Longev. 2021 ;2021:8850112. Epub 2021 Jul 19. PMID: 34336115
Abstract Title:Â
l-Theanine Ameliorates d-Galactose-Induced Brain Damage in Rats via Inhibiting AGE Formation and Regulating Sirtuin1 and BDNF Signaling Pathways.
Abstract:Â
The maintenance of homeostasis is essential for mitigating stress and delaying degenerative diseases such as Alzheimer's disease (AD). AD is generally defined as the abnormal production of-amyloid (A) and advanced glycation end products (AGEs). The effects of l-theanine on Aand AGE generation were investigated in this study. Decreased AGEs and Alevels were reflected by increased acetylcholine (ACh) concentration and acetylcholinesteraseAChEactivity inhibition compared to model rats. l-Theanine also inhibited nuclear factor-B (p65) protein expression by activating sirtuin1 (SIRT1), reducing inflammatory factor expression, and downregulating the mRNA and protein expression of AGE receptors (RAGE). Superoxide dismutase 2 and catalase protein expressions were markedly upregulated by l-theanine, whereas oxidative stress-related injury was alleviated. The expression of peroxisome proliferator-activated receptor-coactivator 1(PGC-1) was also found to be increased. H&E staining showed that the apoptosis of hippocampal neurons was mitigated by decreased Bax and cleaved-caspase-3 protein expression and the increase of Bcl-2 protein expression. Moreover, l-theanine increased the gene and protein expression of brain-derived neurotrophic factor (BDNF). These findings suggest that the potential preventive effects of l-theanine against AD may be attributed to its regulation of SIRT1 and BDNF proteins and its mitigation of AGEs/RAGE signaling pathways in the brain tissue of AD model rats.
