Amines, in general, are organic compounds in which one or more atoms of hydrogen of ammonia have been replaced by substituent groups such as alkyl or aryl. They are widely found in nature, and some valuable amines include alkaloids (medicinal properties), amino acids (protein constituents), biogenic amines (biological reactions), aniline (precursor of industrial chemicals).
Biogenic amines (BA’s) are a class of molecules that contain several neurotransmitters including serotonin, tryptamine, tyramine, and phenethylamine. These molecules are produced by a single decarboxylation reaction from aromatic amino acids, which are readily available to gut organisms.
Biogenic amines in particular are naturally occurring bioactive amines formed mainly by bacterial enzymatic decarboxylation of free amino acids or by amination and transamination of aldehydes and ketones. For example, biogenic amines such as tyramine, histamine, cadaverine, tryptamine, phenylethylamine, and putrescine are derived from the decarboxylation of amino acids tyrosine, histidine, lysine, tryptophan, phenylalanine, and ornithine respectively.
Biogenic amines are also formed as degradation products of proteins and by the autolysis process in which endogen enzymes in food catalyze the proteolytic process during biosynthesis.2 Based on their chemical structures, biogenic amines can be classified as aliphatic (putrescine, cadaverine spermine, spermidine), aromatic (tyramine, phenylethylamine), or polyamines (putrescine, cadaverine, spermidine, spermine).
Functions and Roles of Biogenic Amines
Biogenic amines are found in living cells (plants, animal, and microorganism), foods and food products, and beverages. They assume multiple important roles in living cells, foods and food products, and beverages. They are nitrogen providers in a variety of biosynthesis processes including biosynthesis of hormones, proteins, nucleic acids, and alkaloids.
In the body, the roles of biogenic amines include cell growth, regulation of nucleic acid and protein synthesis, and helping with amino acid uptake in the tissues. These amines are also responsible for maintaining high metabolic activity by playing a major role in the growth and renovation of organs. Psychoactive biogenic amines such as dopamine and serotonin are neurotransmitters in the central nervous system. They are also implicated in the regulation of body temperature, blood pressure (high or low), and intake of nutrients.
In micro-organisms, biogenic amines have been shown to maintain cell envelop integrity. In addition, cadaverine and putrescine assure the normal growth of certain bacteria by forming covalent linkage to the peptidoglycan. In plants, important physiological processes including fruit development and ripening, cell division, flowering, and senescence are all influenced by polyamines such as putrescine, spermidine and spermine. In cancer therapy, due to their roles in cell growth and metabolism, the biosynthesis of certain biogenic amines such as polyamines (putrescine, spermidine, cadaverine and spermine) is targeted for inhibition in tumor-bearing individuals. In the food industry, not only biogenic amines contribute to the taste and flavor of some foods and beverages, but BA’s are also useful indicators of food freshness. Fatty food such as bacon that contains putrescine and spermidine, when heated at high temperature and in presence of water, can be sources of the carcinogenic N-nitrosopyrrolidine. In beverages and specifically in wine, BA’s have been shown to influence taste and flavor. They typically exist as odorless salt in wines and others beverages, but become distasteful flavors at higher pH in the mouth. Other functions attributed to biogenic amines includes free radical scavengers (putrescine, cadaverine, and spermidine), and antioxidant (tyramine).
Toxicological Effects of Biogenic Amines
Biogenic amines are natural constituents of various foods. However, the build up of these amines during food processing and storage has been found to be a toxicological risk and a health hazard. In seafood, consumption of spoiled fish of the Scombridae and Scomberesocidae families with high concentrations of biogenic amines, e.g. histamine, has been found to be causative of scombrotoxicosis. Scombrotoxicosis (scombroid poisoning), also known as histamine toxicosis, is a human intoxication characterized by rapid onset. Other seafood such as shellfish are also linked to food toxicity.
The consumption of alcoholic beverages containing BA’s and other components of the beverages such as acetaldehyde causes severe intoxication in headache, vomiting, and diarrhea. BA are also implicated in alcohol dependency. Scombroid fish poisoning has also been linked to consumption of fish species of nonScombroid family, on rare occasions with consumption of cheese of Swiss origin, and on consumption certain wines.
Some biogenic amines have been found to be the causative agent of certain specific illnesses. Phenylethylamine and tyramine have been linked to migraine and hypertention. Histamine has been implicated in respiratory disorders, hypotention, flushing, headache, skin rashes, sweating, and cardio vascular problems. Abdominal cramps, diarrhea, and vomiting are also caused by histamine induced contraction of intestinal muscles. The toxicological effect of consumption of high concentrations of tryptamine is the increase of blood pressure resulting in hypertension.
Other biogenic amines such as putrescine, cadaverine, spermidine, and spermine have not been linked to a specific health hazard. But these amines have been implicated in the formation of carcinogenic nitrosamine in foods, especially in meat (bacon) by reaction with nitrite and nitrate salts. In addition, along with agmatine, these amines have been found to be histamine potentiators as they increase histamine toxicity by competing for the enzymes involve in histamine detoxication in human. As a result, agmatine, putrescine, cadaverine, spermine, and spermidine increase the intestinal absorption and decrease the catabolism of histamine.
Under normal conditions in human, biogenic amines absorbed from foods consumption are naturally metabolized by enzymes such as amine oxidases to maintain their concentration at low steady-state levels. However, for individuals with reduced monoamine oxidase (MAO) ex