Octopamine and biogenic amines

Octopamine is prohibited as stimulant according to “The 2010 Prohibited List” of the World Anti-Doping Agency (WADA). Synefrine is enclosed in the WADA monitoring program. Both, octopamine and synefrine, are neurotransmitters in invertebrates and supposed to be co-transmitters for neurotransmitters (noradrenaline, serotonine, dopamine) in the mammalian brain and the sympathic nervous system. Since Ephedra was banned from the market in 2004, Citrus aurantium, a bitter orange extract containing synefrine and octopamine in minor amounts, is promoted as alternative in nutritional supplements and fatburning products. Octopamine is synthesized endogenously from tyramine and metabolized to p-hydroxy-mandelic acid and in minor amounts to synefrine. The aim of this study was to find out to what extent octopamine and synefrine are detectable in the urine after ingestion of nutritional supplements containing Citrus aurantium and tyramine-containing food. In an excretion study it was shown that after a single dose of different nutritional supplements or after food intake with high tyramine-content, octopamine was not traceable in collected urine samples. Indeed after a p.o. dose of a pharmaceutical containing 150 mg of octopamine the active compound was verified in urine. However, conclusions about cumulative effects of repeated intake of the nutritional supplements used in our study are not possible on the basis of these data. Verf.-Referat