So long, sweat!
There is a growing demand for aluminium-free antiperspirants and deodorants that are based on natural substances. Dr Torsten Ertongur-Fauth explains novel test systems for identifying natural substances that can be used to reduce human perspiration.
Using biological methods to control perspiration
In 2015, the global market for antiperspirants and deodorants corresponded to annual sales of USD 65 billion, including around USD 1.6 billion for sales of the ingredients used in these products. Up to 2021, experts envisage an average compound annual growth rate (CGAR) of almost 7% for these ingredients. This segment is experiencing particularly strong growth due to the high demand for natural ingredients.
BRAIN has developed novel technologies to meet this demand for biological deodorants and antiperspirants. The United States Patent and Trademark Office (USPTO) recently granted a corresponding patent for special test systems designed to reduce human perspiration by biological means (WO 2014/027050). The European Patent Office (EPO) is expected to grant a patent for the EU area in the course of 2018. BRAIN is currently holding talks with potential industrial partners in order to prepare joint product developments.

Special expert reports on sweat gland cells
The patented molecular-biology systems are based on a key molecule discovered by BRAIN scientists, which enables the systematic screening of natural active ingredients that reduce perspiration. This is based on a scientific breakthrough achieved by BRAIN together with the Department of Dermatology at the Klinikum Darmstadt, which affords a better understanding of how perspiration is formed in the human skin.
For a long time, it was not possible to identify the membrane protein that drives the formation of sweat in the sweat gland cells. Scientists at BRAIN and dermatologists at the Klinikum Darmstadt finally succeeded in tracking down this elusive key player in human sweat glands. While similar proteins were known in other types of tissue, the structure of the relevant ion channel of the sweat glands displayed surprising features. The reputed dermatology department of Ludwig-Maximilians-Universität (LMU) in Munich was also brought on board for this research project. With their support, it was possible to produce an even more precise high-resolution image showing the exact location of the ion channel in sweat glands.

Efficient test systems
Whenever new proteins are discovered, the question always arises as to how they work. Measuring the function of these proteins directly in the organ as a whole is usually very demanding and in many cases impossible. Cell cultures derived from these organs are therefore used, which can be cultured for long-term use in Petri dishes in the laboratory. The additional challenge faced by industrial research is to modify these cell cultures in such a way that their functions can be measured rapidly and reproducibly in high-throughput format.
BRAIN has succeeded in generating a suitable test system for the ion channel that is based on sweat gland cell cultures and fluorescent ion sensors. This test system offers fascinating insights into how the ion channel works in sweat gland cells. It shows that the structural features of the ion channel are linked to its special mode of operation. Thanks to these new findings, we now have a much better understanding of the processes involved in sweat formation. A corresponding publication by the participating scientists in a 2014 issue of Experimental Dermatology is still considered path-breaking even today both for basic research and for the development of skin-friendly personal care products to reduce sweat formation.

Status quo of development work
BRAIN’s patent claims to the test system it has developed for sweat glands protect the company’s work on this specific membrane protein that occurs in the secretory cells of the sweat glands and is directly involved in sweat formation. Development work on this basis enables in vitro processes to be carried out to identify natural active ingredients for cosmetics that inhibit perspiration.
These in vitro processes involve working with sweat gland cell cultures into which the protected molecule is naturally occurring in active form. We have succeeded in testing the first natural ingredients taken from BRAIN’s BioArchive in this cell-based test system using novel fluorescent ion sensors to directly test their inhibitory activity. These natural ingredients are already being further developed.
The development of suitable cosmetic formulations that ensure the availability and stability of the various active ingredients poses a special challenge. BRAIN has already developed such deodorant formulations for individual active ingredients in its development lab. The next major aim of development work is to test the actual effectiveness of the new cosmetic formulations in independent studies.

Aluminium-free cosmetics
The search for new personal care products is buoyed up by growing consumer demand for natural active ingredients that also offer reliable protection against perspiration and body odour. The approach taken by BRAIN combines these quality features by biologically reducing the formation of sweat directly at the sweat glands. There is also potential for using BRAIN’s cellular and microbiological process as a therapy for pathologies that entail excessive sweat formation (hyperhidrosis).
Another reason that explains the growing demand for nature-based ingredients is the wish to avoid products containing aluminium. Aluminium is a light metal that occurs naturally on earth. Humans absorb aluminium via foods and drinking water. The metal is also found in cosmetic products such as antiperspirants which act by mechanically blocking the sweat pores. Aluminium is classed as harmful to health in high doses and given long-term exposure. To avoid excessive exposure, the German Federal Institute for Risk Assessment (BfR) recommends in agreement with other bodies that the aluminium content of antiperspirants should be limited.
The natural active ingredients currently offered by BRAIN for gentle cosmetics and skin-care products offer a response to this demand. Based on our ever-growing understanding of the biological processes in the human skin and using sophisticated screening processes, BRAIN is successively expanding its development portfolio for bio-based care products.
More information
Ertongur-Fauth, T., Hochheimer, A., Buescher, J. M., Rapprich, S. and Krohn, M. (2014): A novel TMEM16A splice variant lacking the dimerization domain contributes to calcium-activated chloride secretion in human sweat gland epithelial cells. Exp Dermatol, 23: 825–831. doi:10.1111/exd.12543, www.onlinelibrary.wiley.com.
Wilson, T. E. and Metzler-Wilson, K. (2015): Sweating chloride bullets: understanding the role of calcium in eccrine sweat glands and possible implications for hyperhidrosis. Exp Dermatol, 24: 177–178. doi:10.1111/exd.12595, www.onlinelibrary.wiley.com.
German Federal Institute for Risk Assessment (BfR): Aluminiumhaltige Antitranspirantien tragen zur Aufnahme von Aluminium bei, statement no. 007/2014, 26 February 2014, www.bfr.bund.de.
BRAIN granted patent protection for the development of biological antiperspirants: www.brain-biotech.de.