Natural Agents Affecting Excitatory and Inhibitory Neurotransmission Adenosine Receptor Glycine Receptor Antagonists: K Channel Antagonists: Na Channel Agents: Antagonists: • Oenanthe fistulosa (Water Dropwort) [Toxin] • Cicutoxin/Cicuta maculata (Water • Aconitine/Aconitum spp • Caffeine • Strychnine/Strychnos Nux Vomica Hemlock) AND Cicuta Virosa (Monkshood/Wolfsbane) (Cowbane or Northern Water Hemlock) • Taxine/Taxus (Yew) Ca Cl Cl Na Adenosine Adenosine Glycine DA/NE/E/S PRE-SYNAPTIC POST-SYNAPTIC K + Glutamate Other Glutamate GABA (NMDA, KA) O PLP CO O Sympathomimetics: Na +/- Ca 2 Cl + + INHIBITORY NEURON • Cathinones (Khat/Qat) H3N H3N O- O- • Cocaine/Coca Glutamic acid • Ephedra/Ephedra spp. (Ma Huang) EXCITATORY NEURON-O O decarboxylase Competitive Non-competitive • Synanceia (Stonefish) [Toxin] Glutamate Agonists: Glutamate GABA Antagonists: Antagonists: • β-N-oxalylamino-L-alanine • Bicuculline/Dicentra • Anisatin/Illicium anisatum Serotonergics: (BOAA)/Lathyrus Sativa cucullaria (Dutchman's (Japanese star anise) GAD Inhibitors: breeches) • Cicutoxin & Virol A/ Cicuta • Hypericum perforatum/ St. (Chickling Pea) • Cyanide/cyanogenic glycosides • Colchicine/Colchicum maculata (Water Hemlock) AND John's Wort • Domoic Acid/Pseudo-nitzschia australis [Amnestic Shellfish [Stonefruit] autumnale (Autumn crocus) Cicuta Virosa (Cowbane or Poisoning] • Domoic Acid/Pseudo-nitzschia • Oenanthe fistulosa (Water Northern Water Hemlock) • Ibotenic Acid/Amanita Muscaria australis [Amnestic Shellfish Dropwort) [Toxin] *Probably • Picrotoxin/Anamirta cocculus (Fly Agaric) Poisoning] competitive (Fishberries) • Kainic Acid/Digenea simplex • Gyromitrin/Gyromitra Esculenta • Thujone/Artemisia absinthium (species of seaweed) (False Morel) (Wormwood) • Kainic Acid/Digenea simplex (species of seaweed) GABA site Agonists Antagonists Barbiturate site Depressants (also ethanol?) Cl ACh Excitants? Benzodiazepine site Agonists (depressants) Antagonists Inverse agonists Steroid site Nicotinic: Unknown: Anesthetics Excitants? • Nicotine/Coniine/ conium • Camphor/Cinnamomum camphora maculatum/Nicotiana spp./etc Adapted from http://www.ncbi.nlm.nih.gov/books/ Picrotoxin site NVK28090/figure/A1185/?report=objectonly Chloride Channel Convulsants Depressants?.