L-Theanine Ameliorated Rotenone-Induced Parkinsonism-like Symptoms in Rats.

Rotenone (RO)-induced neurotoxicity exhibits pathophysiological features similar to those reported in patients with Parkinson's disease (PD), such as nitrosative and oxidative stress, mitochondrial dysfunction, and neural cytoarchitecture alterations in the substantia nigra pars compacta (SNpc)/striatum (ST), which has been used for decades as an animal model of PD in humans. L-Theanine (LT), a major amino acid component of green tea, exhibits potent antioxidant and anti-inflammatory activities and protects against various neural injuries. We investigated the potential therapeutic effects of LT on RO-induced behavioral and neurochemical dysfunction in rats and the neuroprotective mechanisms underlying these effects. Unilateral stereotaxic intranigral infusion of RO into the SNpc to induce PD-like manifestations induced significant behavioral impairment as evaluated using an open field test, rotarod test, grip strength measurement, and beam-crossing task in rats. LT treatment (300 mg/kg i.p., 21 days) ameliorated most RO-induced behavioral impairments. In addition, LT treatment reduced nitric oxide level and lipid peroxidation production, increased mitochondrial function and integrity, as well as the activities of mitochondrial complexes I, II, IV, and V, and reduced the levels of neuroinflammatory and apoptotic markers in the SNpc and ameliorated the levels of catecholamines, GABA and glutamate in the ST induced by RO. These results demonstrate the possible therapeutic effects of LT against RO-induced behavioral impairments, including antioxidative effects, prevention of mitochondrial dysfunction, prevention of neurochemical deficiency, anti-neuroinflammatory effects, and anti-apoptotic effects. This is the first report on the neuroprotective effect of LT against RO-induced behavioral impairments, and the above evidence provides a potential clinically relevant role for LT in the management of human PD.

Gender Gap and Risk Factors for Poor Stroke Outcomes: A Single Hospital-Based Prospective Cohort Study.

BACKGROUND: This study intended to investigate whether etiological stroke subtypes and their corresponding major risk factors have differential effects on outcomes between genders. PATIENTS AND METHODS: We enrolled 403 consecutive patients with first-ever acute ischemic stroke (170 women, 233 men), from a referral hospital in Taiwan over a 2-year period. Gender differences in demographics, vascular risk factors, access to health care, etiological stroke subtypes, stroke severity, and outcomes were examined. The primary outcome variable of the study was any unfavorable outcome due to acute ischemic stroke, defined as a modified Rankin Scale score of 3 or higher at 90 days after stroke. Multivariable logistic regression models were used to identify predictors of poor outcomes. RESULTS: There were no gender disparities in baseline severity, stroke subtypes, access to health care, and medical comorbidities. Although women had poorer outcomes, female gender was not a predictor of unfavorable outcomes. Important predictors included age of 75years or older (odds ratio [OR] = 2.67; 95% confidence interval [CI], 1.46-4.90), National Institutes of Health Stroke Scale greater than or equal to 8 (OR = 8.38; 95% CI, 4.61-15.2), lack of cohabitation (OR = 2.13; 95% CI, 1.26-3.61), subtypes of cardioembolism (OR = 2.76; 95% CI, 1.29-5.93), and large-artery atherosclerosis (OR = 2.93; 95% CI, 1.47-5.85). In subgroup analyses, the gender-specific independent predictors were cardioembolism (OR = 7.42; 95% CI, 2.21-24.9) or atrial fibrillation (OR = 3.57; 95% CI, 1.31-9.74) in women, and large-artery atherosclerosis (OR = 3.35; 95% CI, 1.30-8.64) or symptomatic large-artery stenosis (OR = 3.42; 95% CI, 1.69-6.96) in men. The differential effects of these predictors according to gender were revealed by interaction tests. CONCLUSION: Atrial fibrillation and symptomatic large-artery stenosis are predictors of poor stroke outcomes in women and men, respectively.

L-Theanine Decreases Orofacial Dyskinesia Induced by Reserpine in Rats.

Reserpine (RES)-induced orofacial dyskinesia (OD) has been used as an animal model for human tardive dyskinesia (TD) for decades, due to its strong pathophysiological association with striatal oxidative stress and neural cytoarchitecture alteration. L-Theanine (LT), one of the major amino acid components in green tea, has potent antioxidative, anti-inflammatory, and neuroprotective effects. In this study, we examined the potential protective effects of LT on RES-induced behavioral and neurochemical dysfunction in rats. RES treatment (1 mg/kg s.c., 3 injections 1 day apart) induced significant increases (p < 0.001) in the frequency of vacuous chewing movements (VCM), tongue protrusion (TP), as well as the duration of facial twitching (FT). LT treatment (100, 300 mg/kg orally for 14 days, starting 10 days before RES injection) was able to prevent most of the RES-induced OD. Moreover, LT treatment reduced the RES-induced lipid peroxidation (LPO) production, increased the antioxidation power and catecholamines in the striatum, and significantly reduced the levels of neuroinflammatory and apoptotic markers. Our results indicated that LT was able to counteract the increased oxidative damage, neurotransmitter deficiency, neuroinflammation, and apoptosis induced by RES, and these results have demonstrated the possible neuroprotective effects of LT against RES-induced OD, including antioxidation, neurochemical deficiency prevention, antineuroinflammation, and antiapoptosis. These findings, therefore, suggest a potential role for LT to have a clinically relevant therapeutic effect in delaying or treating human TD.

Protective Effect of L-Theanine on Haloperidol-Induced Orofacial.

Tardive dyskinesia (TD) is a severe side effect of chronic neuroleptic treatment consisting of abnormal involuntary movements, characterized by orofacial dyskinesia (OD). Haloperidol (HAL)- induced OD has been widely used as an animal model to study the neuropathophysiology of human TD with its pathophysiology strongly associated with striatal oxidative stress. L-Theanine (LT), one of the major amino acid components in green tea, has potent antioxidative effects and is able to protect against various oxidative injuries. In this study, we examined the potential protective effects of LT on HAL-induced behavioral and neurochemical dysfunction in rats. HAL treatment (1 mg/kg i.p. for 21 days) induced significant increases (P < 0.001) in the frequency of vacuous chewing movement (VCM) and tongue protrusion (TP) as well as the duration of facial twitching (FT). LT treatment (100, 300 mg/kg orally for 35 days, starting 14 days before HAL injection) was able to prevent most of the HAL-induced OD. LT treatment was also able to reduce the lipid peroxidation (LPO) production, and enhance the antioxidation power in striatum from rats with HAL treatment. The above results indicate that LT has a protective role against HAL-induced OD, probably via its powerful antioxidative properties. Thus, LT may have a clinically relevant therapeutic effect in delaying or treating TD.

Nitric oxide pathway activity modulation alters the protective effects of (-)Epigallocatechin-3-gallate on reserpine-induced impairment in rats.

Reserpine (RES) has been reported to increase the brain's neural oxidative stress and cause cognitive dysfunction. Having powerful antioxidative properties, green tea catechins, especially (-)epigallocatechin-3-gallate (EGCG), are able to protect against many oxidative injuries. In this study, we examined the protecting properties of EGCG on RES-induced impairment of short-term memory in three-month-old male Wistar rats. RES (1mg/kg i.p.) induced memory impairment (p<0.001) as evaluated by the social recognition task. EGCG treatment (100mg/kg i.p. for 7days, starting 6days before RES injection) was able to improve the impaired memory caused by RES. RES treatment increased the nitric oxide (NO) level and lipid peroxidation (LPO) production, and decreased the antioxidation power in hippocampi. EGCG treatment was able to counteract the RES-induced NO level and LPO production, as well as enhanced the hippocampal antioxidation power in RES-treated rats. In order to examine the implication of NO pathway activity in RES treatment, either NO precursor (L-arginine; L-A) or NO synthase inhibitor (L-NAME; L-N) was co-pretreated with EGCG; NO precursor treatment eliminated the protective effect of EGCG, in contrast to that NO synthase inhibitor treatment significantly increased the EGCG effects on cognitive and biochemical protection in RES-treated rats. These results suggested that the NO pathway was implicated, at least in part, in the RES-induced impairment, as well as in the protective effect of EGCG in treating RES-induced impairment of memory. The above evidence provides a clinically relevant value for EGCG in preventing RES-induced cognitive dysfunction.