β-Carboline Alkaloids in Soy Sauce and Inhibition of Monoamine Oxidase (MAO)

Abstract

Monoamine oxidase (MAO) oxidizes neurotransmitters and xenobiotic amines, including vasopressor and neurotoxic amines such as the MPTP neurotoxin. Its inhibitors are useful as antidepressants and neuroprotectants. This work shows that diluted soy sauce (1/3) and soy sauce extracts inhibited human MAO-A and -B isozymes in vitro, which were measured with a chromatographic assay to avoid interferences, and it suggests the presence of MAO inhibitors. Chromatographic and spectrometric studies showed the occurrence of the β-carboline alkaloids harman and norharman in soy sauce extracts inhibiting MAO-A. Harman was isolated from soy sauce, and it was a potent and competitive inhibitor of MAO-A (0.4 µM, 44 % inhibition). The concentrations of harman and norharman were determined in commercial soy sauces, reaching 243 and 52 μg/L, respectively. Subsequently, the alkaloids 1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (THCA) and 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) were identified and analyzed in soy sauces reaching concentrations of 69 and 448 mg/L, respectively. The results show that MTCA was a precursor of harman under oxidative and heating conditions, and soy sauces increased the amount of harman under those conditions. This work shows that soy sauce contains bioactive β-carbolines and constitutes a dietary source of MAO-A and -B inhibitors.

Simira cordifolia protects against metal induced-toxicity in Caenorhabditis elegans

“…The chemical mixture in HAE-Sc may not only interfere with the oxidative stress induced by the metals, it also provides metabolites, such as harman, with protective actions on neurological function via anti-inflammatory effects ( Piechowska et al, 2019 ) or by inhibition of monoamine oxidase, working as antidepressant ( Herraiz, 2023 ). This action of HAE-Sc may be extrapolated to the control of neurodegenerative diseases, where beneficial impacts on oxidative stress, inflammation and neuronal stimulation are main objectives of treatments ( Murphy and Hartley, 2018 ; Peng et al, 2022 ).…”

Yeast-Hydrolysate-Derived 1-Methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic Acid Inhibits Fat Accumulation during Adipocyte Differentiation

“…The effect of MTCA was confirmed by analyzing the expression of genes encoding adipogenic factors and those related to lipid synthesis. MTCA is abundant in various food sources, including soy sauce, alcoholic beverages, and citrus fruits [ 15 , 18 , 49 ]. MTCA is a tryptophan derivative also commonly found in fermentation products of S. cerevisiae [ 16 , 50 ].…”

Formation, Identification, and Occurrence of the Furan-Containing β-Carboline Flazin Derived from l-Tryptophan and Carbohydrates

“…β-Carboline (βC) alkaloids are bioactive compounds with antitumoral, antimicrobial, antiparasitic, and antioxidant properties, among others. They inhibit key enzymes such as monoamine oxidase (MAO) and kinases and interact with receptors of the human central nervous system (CNS). − These alkaloids exert antidepressant and behavioral effects, which are associated with changes in neurotransmitters and MAO inhibition − and may also show neuroprotective and antioxidant effects. − On the other hand, βC alkaloids have attracted toxicological interest because they can be bioactivated to give endogenous neurotoxins (β-carbolinium cations), bind to DNA, and are comutagenic in the presence of aromatic amines. , The βC alkaloids are naturally occurring compounds that appear in foods and in vivo. − These alkaloids are divided into tetrahydro-β-carbolines (THβCs) and aromatic βCs. THβCs form from indoleethylamines and aldehydes, or α-keto acids, by the Pictet–Spengler reaction .…”