interleukin-8 and theanine

We investigated the effects of supplementation with cystine, a dipeptide of cysteine, and theanine (CT), a precursor of glutamate, on immune variables during high-intensity resistance exercise. Cysteine and glutamate are involved in the formation of glutathione, which modulates the activity of natural killer (NK) cells. In this double-blinded clinical trial, 15 well-trained men (aged 22.8 +/- 4.0 years) were divided into 2 groups: placebo (n = 7) and CT (n = 8). The placebo group was administered a powder containing cellulose (950 mg) and glutamate (30 mg), whereas the CT group was administered a powder containing cystine (700 mg) and theanine (280 mg), once daily for 2 weeks. The subjects trained according to their normal schedule (3 times per week) in the first week and trained at double the frequency (6 times per week) in the second week. Concentrations of immunoglobulin (Ig)M, interleukin (IL)-6, IL-8, and salivary IgA and the leukocyte count did not change significantly in either group. There was a significant decrease (p < or = 0.05) in the NK cell activity (NKCA) in the placebo group after the second week compared with that in the CT group (placebo: 69.2 +/- 16.1% vs. CT: 101.7 +/- 38.7%). Phytohemagglutinin-induced lymphocyte blastoid transformation did not change significantly in either group. These results suggest that NKCA is not affected in a normal training schedule with or without CT supplementation. However, high-intensity and high-frequency resistance exercises cause attenuation of NKCA, which CT supplementation appears to restore. Therefore, in practical application, CT supplementation would be useful for athletes to restore the attenuation of NKCA during high-intensity and high-frequency training.

Topics: Cystine; Dietary Supplements; Double-Blind Method; Glutamates; Humans; Immunoglobulin A; Immunoglobulin M; Interleukin-6; Interleukin-8; Killer Cells, Natural; Leukocyte Count; Male; Resistance Training; Saliva; Young Adult

L-theanine has been documented to possess anti-oxidant, anti-inflammatory and neuroprotective potential in various animal models of neurological disorders. The present study was anticipated to investigate the effect of L-theanine against quinolinic acid induced motor deficits, oxido-nitrosative stress, neuro-inflammation and neurotransmitters alteration in rats. Rats were stereotaxically injected QA (200nmol/2µl saline; intrastriatal); bilaterally on 0 day and L-theanine (25 & 50mg/kg; p.o.) was administered for 21 days starting from day 1 of QA injection. Either, L-NAME (10mg/kg; i.p.), a nitric oxide synthase inhibitor and L-arginine (50mg/kg; i.p.), a nitric oxide synthase precursor were administered with L-theanine in respective groups. Behavioral observations were evaluated on weekly basis using rota-rod, grip strength, narrow beam walking and open field test. QA treatment induces significant alteration in body weight, motor coordination, oxidative defense, pro-inflammatory cytokines and striatal neurotransmitters level. L-theanine treatment alone, at both the tested doses, significantly attenuated QA induced alterations. In addition, treatment of L-theanine with L-NAME significantly enhances the protective effect of L-theanine whereas treatment of L-theanine with L-arginine significantly ameliorated the protective effect of L-theanine. The protective effect of L-theanine is attributed to its anti-oxidant, anti-inflammatory and modulatory effect on nitric oxide pathway and neurotransmitters level in striatum. This suggests use of L-theanine in the clinical settings of HD.

Topics: Animals; Dose-Response Relationship, Drug; Glutamates; Hand Strength; Interleukin-6; Interleukin-8; Male; Motor Activity; Neostriatum; Neurotoxins; Neurotransmitter Agents; Nitrosative Stress; Oxidative Stress; Quinolinic Acid; Rats; Rats, Wistar; Tumor Necrosis Factor-alpha