Effects of alpha-Asarone on the Glutamate Transporter EAAC1 in Xenopus Oocytes.

Effects of alpha-Asarone on the Glutamate Transporter EAAC1 in Xenopus Oocytes.

Planta Med. 2009 Nov 20;

Authors: Gu Q, Du H, Ma C, Fotis H, Wu B, Huang C, Schwarz W

The major excitatory neurotransmitter transporter EAAC1 in the mammalian central nervous system is considered a possible target for Chinese herbal medicine. Extracts of ACORUS TATARINOWII (Schott) were tested for their effects on EAAC1 activity. XENOPUS oocytes with heterologously expressed EAAC1 were used as the model system. Rate of glutamate uptake was determined by means of the isotopic tracer technique. Glutamate-induced current was recorded under a two-electrode voltage clamp. As a highly effective component, alpha-asarone was identified. The rate of glutamate uptake was stimulated by 200 microM of alpha-asarone by about 15 %. In contrast, the same concentration reduced the EAAC1-mediated current by about 35 % at a holding potential of – 60 mV; half maximum inhibition was obtained at about 60 microM. Our experimental data suggest that both stimulation of glutamate uptake and inhibition of EAAC1-mediated current by alpha-asarone could contribute to reduced excitatory activity.

BOTTOM LINE: In brain, EAAC1 is the primary neuronal glutamate transporter.  Glutamate is an important neurotransmitter, or the chemical part of how electrical activity works in the brain to make things work.   Overactivity of glutamate transporters is a possible mechanism in seizures, schizophrenia  and other mental illnesses.  Chinese TCM herbal function in this area of treatment may be at least partly explained by this mechannsm.  Pretty intricate and detailed research, but it points to the level we need to drill down to in order to explore what is real and plausible vs. what is hype and useless.