theanine and Seizures

Theanine, an additive, holds several effects on the central nervous system without toxicity and affects CNS drugs. Theanine bilaterally alters β wave of the EEG with or without caffeine and pentobarbital-induced locomotor activity. Theanine also enhances hypnosis of pentobarbital sodium (PB) and antidepression of midazolam, suggesting there are complicated interactions between theanine and CNS drugs. On the other side, theanine induces glycine release. Glycine potentiates the strychnine toxicity via NMDA receptor activation. Moreover, PB facilitates GABAA receptor activation by GABA, and it is commonly prescribed for strychnine poison. However, what the role that theanine plays in the anticonvulsion of PB against strychnine poison is still unknown.. Theanine, pentobarbital sodium or strychnine was injected intraperitoneally. EEG was monitored by BIOPAC 16 EEG amplifiers. LD50 of strychnine and hypnotic ED50 of pentobarbital sodium with or without theanine for mice were tested according to Bliss' case.. (1) Theanine enhanced the strychnine toxicity. Both theanine and strychnine 1.0 mg/kg increased the power of the β wave. Theanine aggravated that of strychnine 1.0 mg/kg. Theanine attenuated the LD50 of strychnine. (2) Theanine enhanced the anticonvulsion of PB. Theanine increased the power of α, β wave and decreased hypnotic ED50 of PB; PB attenuated strychnine-induced EEG excitation and mortality with or without theanine, and theanine enhanced the effects of PB. Further, theanine enhanced the anticonvulsion of PB dose-dependently against the strychnine toxicity but not the lethal toxicity of strychnine.. These results indicated theanine interacted with PB and strychnine. Theanine enhanced both the strychnine toxicity and anticonvulsion of PB against strychnine poison.

Topics: Animals; Dose-Response Relationship, Drug; Drug Interactions; Electroencephalography; Female; Glutamates; Hypnotics and Sedatives; Lethal Dose 50; Male; Mice, Inbred ICR; Pentobarbital; Seizures; Strychnine

The effects of coadministration of melatonin and theanine (Mel/Thea) on pentylenetetrazole (PTZ)-induced seizures and brain tissue oxidative damage were investigated in ovariectomized (OVX) and sham-operated rats.. The rats were divided into the following groups: 1) sham, 2) ovariectomized (OVX), 3) sham-PTZ, 4) OVX- PTZ, 5) sham-Mel/Thea-PTZ, and 6) OVX-Mel/Thea-PTZ. Groups 1-4 received saline, while groups 5 and 6 received a combination of Mel/Thea for 6 weeks. All animals except for those in groups 1 and 2 received a single injection of PTZ.. The OVX-PTZ group had higher generalized tonic-clonic seizure (GTCS) latency compared to the sham-PTZ group. Administration of Mel/Thea increased minimal clonic seizure and GTCS latencies in both the sham-Mel/Thea-PTZ and OVX-Mel/Thea-PTZ groups compared to the controls. Additionally, PTZ exposure increased malondialdehyde levels and reduced thiol concentrations in brain tissues of both the sham-PTZ and OVX-PTZ groups. Mel/Thea pretreatment resulted in MDA reduction and thiol increase in brain tissues.. The results of this study demonstrated the antioxidant and anticonvulsant activities of Mel/Thea despite the presence or absence of ovarian hormones.

Topics: Animals; Antioxidants; Biological Availability; Brain; Central Nervous System Depressants; Disease Models, Animal; Female; Glutamates; Malondialdehyde; Melatonin; Ovariectomy; Oxidative Stress; Pentylenetetrazole; Rats; Rats, Wistar; Seizures

L-Theanine, an ethylamide derivate of glutamate found in abundance in green tea, has been shown to exert beneficial actions in animal models for several neurological disorders. We here investigated for the first time the effect of L-theanine intake on seizure susceptibility using acute pilocarpine and pentylenetetrazol (PTZ) mouse models for studying, respectively, limbic seizures or primarily generalized seizures. Moreover, we studied the effect of l-theanine intake on extracellular hippocampal and cortical glutamate and gamma-aminobutyric acid (GABA) levels, using in vivo microdialysis. Feeding mice with a 4% L-theanine solution significantly decreased their susceptibility to pilocarpine-induced seizures whereas susceptibility to PTZ-induced seizures was increased. The latter effect was linked to decreased extracellular GABA concentrations in frontal cortex.

Topics: Animals; Disease Models, Animal; GABA Agents; gamma-Aminobutyric Acid; Glutamates; Glutamic Acid; Hippocampus; Male; Mice; Mice, Inbred Strains; Microdialysis; Pentylenetetrazole; Pilocarpine; Seizures; Tea