ORIGINAL ARTICLES

HYPERTENSIVE CRISIS DUE TO MONOAMINE-OXIDASE INHIBITORS

One of the key modes of microbial metabolism occurring in the gut microbiome is fermentation. This energy-yielding process transforms common macromolecules like polysaccharides and amino acids into a wide variety of chemicals, many of which are relevant to microbe-microbe and microbe-host interactions. Analogous transformations occur during the production of fermented foods, resulting in an abundance of bioactive metabolites. In foods, the products of fermentation can influence food safety and preservation, nutrient availability, and palatability and, once consumed, may impact immune and metabolic status, disease expression, and severity. Human signaling pathways perceive and respond to many of the currently known fermented food metabolites, though expansive chemical novelty remains to be defined. Here we discuss several aspects of fermented food-associated microbes and metabolites, including a condensed history, current understanding of their interactions with hosts and host-resident microbes, connections with commercial probiotics, and opportunities for future research on human health and disease and food sustainability.

Biogenic amines (BA) are molecules with biological functions, which can accumulate at toxic concentrations in foods. Several microorganisms have been identified as responsible for their accumulation at elevated concentrations. Histamine, tyramine and putrescine are the BA most commonly found at highest concentrations. The ingestion of food containing high BA concentrations leads to intoxication with symptoms depending on the BA and the amount consumed. Moreover, there is evidence of synergy between different BA, something of toxicological importance given that some foods accumulate different BA.

This work reviews the BA toxic effects and examines recent discoveries regarding their synergy, cytotoxicity and genotoxicity. These advances in the toxicological consequences of ingesting BA contaminated foods support the need to regulate their presence in foods to preserve the consumer’s health. However, more research efforts -focused on the establishment of risk assessments- are needed to reach a consensus in their limits in different food matrices.

Monoamine oxidase enzyme is necessary for the management of brain functions. It oxidatively metabolizes monoamines and produces ammonia, aldehyde and hydrogen peroxide as by-products. Excessive production of by-products of monoamine metabolism generates free radicals which cause cellular apoptosis and several neurodegenerative disorders for example Alzheimer's disease, Parkinson's disease, depression and autism. The inhibition of MAOs is an attractive target for the treatment of neurological disorders. Clinically approved MAO inhibitors for example selegiline, rasagiline, clorgyline, pargyline etc. are irreversible in nature and cause some adverse effects while recently studied reversible MAO inhibitors are devoid of harmful effects of old monoamine oxidase inhibitors. In this review article we have listed various synthesized molecules containing different moieties like coumarin, chalcone, thiazole, thiourea, caffeine, pyrazole, chromone etc. along with their activity, mode of action, structure activity relationship and molecular docking studies.

In spite of the low quantities of biogenic amines present in wines compared to other fermented foods, these compounds represent one of the most important risks for wine quality and safety. In addition, biogenic amines may constitute an economic problem in commercial transactions of wines. The aim of this chapter is to present an overview of the current knowledge about the incidence of biogenic amines in wines, the factors that affect their formation, their toxicological impact on humans, the main analytical tools for their identification and quantification in wines or the molecular approaches for the decarboxylase positive detection of microorganisms. Finally, the most suitable preventive measurements during the wine chain production are emphasized.

Smear-ripened cheeses develop a viscous, red-orange smear on their surfaces during ripening. For this reason, they are also called red-smear cheeses or bacterial surface-ripened cheeses. During the past decade, tremendous progress has been made in the understanding of the microbiology of the surface microbiota of these cheeses. This progress stems from the knowledge of their microbial diversity gained through the use of culture-dependent and independent methods including high-throughput sequencing, the genomics of the microorganisms composing the smear microbiota with the sequencing of yeast and bacterial species of technological interest, the functions of these microorganisms and their interactions. In this chapter, we will review the current knowledge on the smear cheese microbiota including the factors affecting ripening of smear cheeses, their microbial diversity, the sources of these microorganisms, their genomic features and functions and the pathogens associated with smear cheeses and their control.

Biogenic amines (BA) are nitrogenous compounds involved in natural biological processes, and their main exogenous sources are fermented foods and beverages. In foods BA are formed by microorganisms, such as yeast, Gram-negative and positive bacteria capable to decarboxylate amino acids. In dairy products the main BA formers are lactic acid bacteria. The intake of foods with high BA contents constitutes a health hazard and BA formation and accumulation should be avoided mainly by good hygienic practices as well as usage of high quality of raw material. In the case of fermented products, it is important to choose as starters or coadjutants strains that are not BA-forming. This chapter will present current information concerning the occurrence of BA in dairy products, mainly in cheeses, and the health risks and strategies to avoid BA accumulation in foods.