Inhibition of respiration in yeast by 2-phenylethylamine

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. This study has explored the effects of 2-PEA on growth of various yeast strains in order to establish its capacity to cause toxicity through oxidative stress. Yeast cells are ideal for this application because, unlike mammalian cells, they do not require respiration to survive in the presence of glucose as the sole carbon source. 2-phenylethylamine was indeed found to be toxic to all strains of yeast where respiratory function was necessary. Almost all inhibitory effects 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.