Resveratrol is a plant compound found primarily in red grapes and Japanese knotweed. Its synthetic variant has been approved as a food ingredient in the EU since 2016. At least in cell-based test systems, the substance has anti-inflammatory properties. A recent collaborative study by the Leibniz Institute for Food Systems Biology at the Technical University of Munich and the Institute of Physiological Chemistry at the University of Vienna has now shown that the bitter receptor TAS2R50 is involved in this effect. The team of scientists led by Veronika Somoza published its results in the Journal of Agricultural and Food Chemistry.
Bitter food ingredients not only influence the taste of a food, but often also exert other physiological effects. For example, resveratrol not only tastes bitter, but also reduces biomarkers of inflammation as shown in various clinical trials including, e.g., patients with metabolic syndrome and related disorders. No research group had yet investigated whether bitter receptors also play a role in this.
Gum cells as a test system
To investigate this question, the team led by Veronika Somoza carried out experiments with a human cell line derived from a gum biopsy. The cells of this cell line are a suitable test system for investigating interactions between bitter substances, bitter receptors and the release of inflammatory markers. As the team shows for the first time, these cells have active bitter receptor genes and are also immunocompetent. That is, when the cells are treated with surface antigens from bacteria that trigger gingival inflammation, they release quantifiable amounts of the inflammatory marker interleukin-6.
Resveratrol reduces inflammatory markers
In the current study, resveratrol reduced the amount of inflammatory marker released by about 80 percent. Additional administration of the bitter-masking substance homoeriodictyol reduced this anti-inflammatory effect by about 17 percent. "This is remarkable because homoeriodictyol is a natural substance that has been shown to reduce the bitterness of food ingredients mediated via certain bitter receptors. These receptors include the bitter receptor TAS2R50, which is also expressed by the cells of our test system," explains Veronika Somoza, deputy director of the Institute of Physiological Chemistry in Vienna and director of the Leibniz Institute in Freising. Additional knock-down experiments performed by the researchers as well as computer-assisted structure-function analyses support this finding. "Therefore, it is reasonable to conclude that this receptor type is involved in mediating the anti-inflammatory resveratrol effect," Somoza says.
She adds: "Of course, there is still a great deal of research to be done. Nevertheless, the study results already provided new insights to help elucidate the molecular interactions between bitter-tasting food ingredients, bitter receptors and immune responses. In the future, it will also be exciting to find out whether bitter substances and bitter receptors could play a role with regard to inflammatory gum diseases such as periodontitis."
Publication: Tiroch J, Sterneder S, Di Pizio A, Lieder B, Hoelz K, Holik AK, Pignitter M, Behrens M, Somoza M, Ley JP, Somoza V (2021) J Agric Food Chem, DOI: 10.1021/acs.jafc.0c07058. Bitter Sensing TAS2R50 Mediates the trans-Resveratrol-Induced Anti-inflammatory Effect on Interleukin 6 Release in HGF-1 Cells in Culture
Synthetically produced trans-resveratrol is available as a dietary supplement and is intended for adults only. The recommended maximum daily intake is 150 milligrams. The health-promoting effects of resveratrol are currently being investigated in a variety of ways and cannot yet be conclusively assessed. Consumers should be aware that excessive consumption of 1 gram of resveratrol per day may result in diarrhea or other gastrointestinal disorders.
3. Trabrizi R et al. (2018) Food Funct, 9(12):6116-6128, DOI: 10.1039/c8fo01259h. The effects of resveratrol supplementation on biomarkers of inflammation and oxidative stress among patients with metabolic syndrome and related disorders: a systematic review and meta-analysis of randomized controlled trials
Prof. Dr. Veronika Somoza
Leibniz Institute for Food Systems Biology at the Technical University of Munich
Lise-Meitner-Str. 34, 85354 Freising
Tel.: +49 8161 71 2700
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The Leibniz Institute for Food Systems Biology at the Technical University of Munich (Leibniz-LSB@TUM) has a unique research profile. Its researchers combine methods of basic biomolecular research with analytical methods of bioinformatics and analytical high-performance technologies. Their goal is to decode the complex ingredient profiles from raw materials to the final food products and to elucidate their function as biological active molecules on humans. Based on their studies, the scientists develop products, which are as healthy as they are tasty. These foods will help to provide a sustainable and sufficient stream of food for future generations. In addition, the new scientific findings will be used to develop personalized nutritional concepts that, for example, help people with food intolerance without compromising quality of life and endangering their health.
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Journal of Agricultural and Food Chemistry