Dynamic Observation of the Effect of L-Theanine on Cerebral Ischemia-Reperfusion Injury Using Magnetic Resonance Imaging under Mathematical Model Analysis

L-theanine abates oxidative stress and mitochondrial dysfunction in myocardial ischemia-reperfusion injury by positively regulating the antioxidant response

L-theanine (L-THE), a non-protein amino acid isolated from Camelia sinensis, has antioxidant properties that could prevent oxidative damage and mitochondrial dysfunction generated by myocardial ischemia and reperfusion (I/R) injury. The present study aimed to identify the effects of pretreatment with L-THE in rat hearts undergoing I/R. Wistar rats received vehicle or 250 mg/Kg L-THE intragastrically for 10 days. On day 11, hearts were removed under anesthesia and exposed to I/R injury in the Langendorff system. Measurement of left ventricular developed pressure and heart rate ex vivo demonstrates that L-THE prevents I/R-induced loss of cardiac function. Consequently, the infarct size of hearts subjected to I/R was significantly decreased when L-THE was administered. L-THE also mitigated I/R-induced oxidative injury in cardiac tissue by decreasing reactive oxygen species and malondialdehyde levels, while increasing the activity of antioxidant enzymes, SOD and CAT. Additionally, L-THE prevents oxidative phosphorylation breakdown and loss of inner mitochondrial membrane potential caused by I/R, restoring oxygen consumption levels, increasing respiratory control and phosphorylation efficiency, as well as buffering calcium overload. Finally, L-THE modifies the expression of genes involved in the antioxidant response through the overexpression of SOD1, SOD2 and CAT; as well as the transcriptional factors PPARα and Nrf2 in hearts undergoing I/R. In conclusion, L-THE confers cardioprotection against I/R injury by preventing oxidative stress, protecting mitochondrial function, and promoting overexpression of antioxidant genes. More studies are needed to place L-THE at the forefront of cardiovascular research and recommend its therapeutic use.

Retracted: Dynamic Observation of the Effect of L-Theanine on Cerebral Ischemia-Reperfusion Injury Using Magnetic Resonance Imaging under Mathematical Model Analysis

[This retracts the article DOI: 10.1155/2021/5679665.].

L-Theanine Improves Locomotor Function in a Model of Multiple Sclerosis Mice

This study designed to investigate the protective effects of L-theanine on experimental Multiple sclerosis in mice. Frothy Male C57BL/6 mice were allocated into 4 experimental groups: control no treatment received a regular chew pellet, and the cuprizone (CPZ) group received a standard chew pellet containing 0.2% (w/w) CPZ. In group 3, mice were fed a regular diet and administered p.o. with L-theanine (50mg/kg). In group 4, mice received a diet containing CPZ and were administered p.o. with L-theanine (50mg/kg). Finally, reflexive motor behavior and serum antioxidant levels were determined. Based on findings, CPZ significantly decreased ambulation score, hind-limb suspension, front limb suspension, and grip strength (P<0.05). The CPZ + L-theanine reduced the adverse effect of the CPZ on ambulation score, hind-limb foot angle, surface righting, and negative geotaxis (P<0.05). The CPZ + L-theanine increased front and hind-limb suspension, grip strength, number of the cross, and duration of a stay on the rotarod compared to the control animal (P<0.05). CPZ administration significantly elevated serum malondialdehyde (MDA) while superoxide dismutase (SOD) and glutathione peroxidase (GPx) and total antioxidant status (TAS) levels decreased compared to control mice (P<0.05). The CPZ + L-theanine leads to the cessation of MDA production while increasing SOD, GPx, and TAS levels (P<0.05). These results suggested L-theanine has a protective effect against CPZ-induced MS in mice.