The presence and role of bromine in the human body has always been controversial. Belonging to the group of halogens together with chlorine, fluorine and iodine, unlike these, its biological chemistry has not been very thorough. Bromide ions are known to be present in the blood, in the proportion of 1mg / 100ml, as well as in the internal organs in extremely low doses. For example, in the liver it is present in quantities of around 5.7mg / Kg weight, 8.4mg / Kg in the ovaries, 67mg / Kg in the thyroid gland, about 16.5mg / Kg in the midbrain and 87mg / Kg in the pituitary gland, a brain gland which governs many hormones in our body. On the one hand, it is no wonder to find a lot of bromine in the brain structures, also because the classic therapeutic use of bromine in the past has been precisely that of nervous and hypnotic sedative (sleep inducer). Induction of regular night sleep is thought to result in a bromine flow of the pituitary gland to the midbrain, where the reticular substance is present, a group of neurons specialized in the sleep-wake rhythm. According to many biologists, his brain concentration would tend to decrease with age, which could partially explain why the elderly are prone to insomnia. Up to 60% reduction in blood bromine has been reported by many analyzes in cases of manic-depressive syndrome.
Tangerines are enriched in bromine
Up to 2014, twenty-seven of the 92 chemical elements found in nature were considered essential for human life. Since 2015 they have officially become 28; the “new entry” is bromine, according to Prof Billy G. Hudson and his colleagues in the Department of Pharmacology of the Vanderbilt University School of Medicine. In an elegant study, published in the journal Cell, they showed that Drosophila fruit flies died when bromine was removed from their diet but survived when bromine was restored. The basis of this discovery dates back to 35 years ago. In the mid-80s, curiosity for two rare kidney diseases brought prof. Hudson discovered two previously unknown proteins that twist together to form the triple helical molecule of collagen IV, like the cables that support a bridge. Illness occurs when these cables are defective or damaged. In 2009, another research team discovered a new sulfilimin bond between a sulfur atom and a nitrogen atom that acts as a “fastener” to connect collagen IV molecules by forming scaffolds for cells. This is a type of bond hitherto unknown in human biology, although industrial chemists are familiar with it.
Until then, biochemists knew that collagen modifications included phosphorylation, hydroxylation and the formation of cross-links between amino acids. A sulfiliminic link is typical of compounds present in plant substances and of some marine organisms. What is it doing in our body? Professor Hudson realized that a defective sulfine link can trigger the rare autoimmune disease of Goodpasture syndrome. That discovery led to a simple question: how is the bond formed? In 2012, the co-authors of the current discovery – Vanderbilt University scientists Prof Gautam Bhave and dr. Christopher Cummings – they conducted the study that found the answer: the peroxidasin enzyme is responsible. Stored throughout the animal kingdom, peroxidasin can also play a role in pathology. A hyperactive enzyme can lead to excessive deposition of collagen IV and thickening of the basement membrane, which can impair kidney function. In their study, Prof Hudson’s team demonstrated the unique and essential role of ionic bromide as a co-factor, allowing peroxidasin to form the sulfilimine bond.
Professor Hudson’s team found that thiocyanate (-SCN) is a potent inhibitor of peroxidin-mediated cross-linkage formation. Therefore, in some smokers with high SCN levels, the reinforcement of IV collagen scaffolds with sulphine crosslinks can be substantially reduced. In addition, a functional Br deficiency may occur in smokers despite normal Br plasma levels due to elevated serum thiocyanate (SCN) levels, which inhibits the formation of sulfilimin bonds. In fact, smoking has been associated with architectural changes within the basement membranes in the kidneys and is an inhibitor of the synthesis of thyroid hormones, an organ that contains bromine in addition to iodine. The first author of the Scott McCall study of the Vanderbilt University School of Medicine, concluded by saying: “Bromine is therefore essential for the development of animals and the architecture of tissues. The discovery has important implications for human pathology: different types of patients have been shown to be deficient in bromine. Dietary supplementation of bromine can improve the health of patients on dialysis or total parenteral nutrition, for example. Not to mention that it can pave the way for further understanding of autoimmune diseases such as autoimmune glomerulonephritis, systemic lupus nephropathy and various autoimmunity for internal organs”.
- Edited by Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
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