茶氨酸对中枢神经系统多层级调控作用的研究进展OA

L-Theanine is a unique amino acid abundant in tea leaves,it is characterized by its high biosafety and fa-vorable blood-brain barrier permeability.In recent years,research on L-theanine has expanded from its simple neu-roprotective effects to its multilevel regulatory roles in the intervention of neurodegenerative diseases and the modu-lation of emotions and behavior.Accumulating evidences indicate that L-theanine exerts beneficial effects in Al-zheimer's disease and Parkinson's disease models through multiple mechanisms,including regulation of neurotrans-mitter homeostasis,suppression of oxidative stress and neuroinflammation,improvement of mitochondrial function,enhancement of synaptic plasticity,and modulation of autophagy.In addition,L-theanine exhibits significant regula-tory effects on sleep quality,anxiety and depression,which are associated with glutamate-GABA balance,monoami-nergic neurotransmission,inhibition of the hypothalamic-pituitary-adrenal axis,and gut-brain axis modulation.This review systematically summarized the physicochemical properties,metabolic characteristics,and recent research progress of L-theanine in neurodegenerative disease intervention and neuroregulatory functions.The underlying mechanisms were comprehensively analyzed from the perspectives of neurotransmitter regulation,oxidative stress and inflammation,mitochondrial function,synaptic plasticity,and gut-brain axis interactions.Furthermore,current limitations and future research directions were discussed.