Inhibition of Respiration in Yeast by 2-Phenylethylamine

Background: 2-phenylethylamine (2-PEA) is an organic neurotransmitter which belongs to a class of biogenic amines that are essential for regulation of cellular development, differentiation and homeostasis. This class of compounds have been reported to cause oxidative stress to neuronal cells in the brain, which have a high oxygen consumption rate, elevated iron content and low antioxidant concentration. 2-phenylethylamine can metabolise into hydroxyl radicals which have been found to be a direct cause of oxidative stress within cells. Methods: This study has examined the toxicity of 2-phenylethylamine in the yeasts, Saccharomyces cerevisiae and Candida glabrata by examining growth with glucose or ethanol as sources, in the presence of 2-phenylethylamine. Results: 2-phenylethylamine was found to be inhibitory to all strains of yeast where respiratory function was necessary, while growth where glucose was the carbon source was unaffected. Almost all growth inhibition could be reversed by antioxidants ascorbate and glutathione, indicating oxidative stress was the likely cause of toxicity through 2-PEA or one of its metabolites. Conclusion: Yeast studies show that the biogenic amine, 2-phenylethylamine, targets respiratory function and that the inhibition can be reversed alleviated by the addition of glutathione or ascorbate.