2023/09/15
Keio University
Kitasato University
Keigo Fujita (then a master's student at the Graduate School of Science and Technology, Keio University), Professor Kotaro Oka of the university's Faculty of Science and Technology and the School of Future Engineering at Kitasato University, Associate Professor Koji Hotta and Senior Assistant Professor Yutaka Shindo of the Faculty of Science and Technology, Keio University, in collaboration with Dr. Yuji Katsuta and Dr. Makiko Goto of the Shiseido Future Creation Research Center, have discovered that when human keratinocytes are exposed to reactive oxygen species, the intracellular magnesium ion concentration rises. This increase has the effect of protecting mitochondria—the cell's energy-producing organelles—from oxidative stress.
Human skin is constantly exposed to reactive oxygen species generated by exposure to ultraviolet rays. Oxidative stress from reactive oxygen species is said to cause skin aging, inflammation, and various diseases. One reason for this is that oxidative stress inhibits the activity of mitochondria, which are crucial intracellular energy-producing organelles. Magnesium ions, the focus of this study, were previously known to help promote the proliferation of skin cells and restore the skin barrier function, but the dynamics and role of magnesium ions inside skin cells had not been clarified. Using fluorescence imaging, this study revealed that when keratinocytes, which make up the majority of the skin's epidermis, are exposed to hydrogen peroxide (a type of reactive oxygen species), they increase their intracellular magnesium ion concentration. This increase suppresses mitochondrial dysfunction and protects the cells from oxidative stress. Furthermore, the researchers discovered that this protective effect can be enhanced by introducing magnesium ions from outside the cell. Thus, this research not only clarified the antioxidant effect of magnesium ions but also successfully demonstrated their effectiveness as an ingredient for protecting the skin.
These findings were published in the international journal Communications Biology on August 24, 2023.
For the full press release, please see below.