Supplementing Where the Sun Does Shine: NMN Supports Healthy Skin in the Face of UV
How many times do we run out the door and hours or even minutes later start to feel the effects of the sun’s ultraviolet radiation (UV) on our skin? Whether headed to the beach or just running a simple errand, our skin’s health is at risk every moment we go unprotected from the sun’s rays. We often forget and neglect our skin’s health by not putting on sunscreen, often because of these creams and sprays’ goopy, oily, and acne-inducing nature.
New research shows that the application of nicotinamide mononucleotide (NMN) positively affects the skin’s response to UV radiation. So, you may no longer need sunscreen bottles and spray cans to keep your skin healthy.
UV Creates The Wrong Kind of Iron Man
UV-radiations are the invisible part of light spectra having a wavelength between visible rays and X-rays. Ultraviolet radiation can affect skin health in many ways, primarily through oxidative stress. It turns out that one way this may happen is through the essential trace element iron, which plays a vital role in a wide range of critical biological processes in all living organisms.
Just like rust — the typically reddish-brown oxidated compound formed by the reaction of iron and oxygen in the presence of water or air moisture — can destroy iron-containing materials like cars, this oxidative form of iron is toxic to cells. Ferroptosis is a recently described form of regulated cell death that is dependent on iron oxidation. When the levels of oxidated iron go unchecked and out of balance, highly reactive compounds can cause oxidative stress, harming the health of many tissues and organs, such as the brain, heart, liver, and kidney.
NMN Recruits Antioxidants to Support Skin Health
In this study, Zhuan Feng and colleagues show that mice and human skin cells subjected to UV radiation generated loads of ferroptosis-related particles. In addition, the activity of ferroptosis-related genes was increased in the groups repeatedly treated with UV without much change in antioxidant molecule levels.
On top of that, they found that the function of GPX4, a key inhibitor of ferroptosis, appeared to be damaged by UV radiation. GPX4 depends on a significant antioxidant called glutathione to carry out its enzymatic activity, turning it into oxidized glutathione to inhibit cell death caused by ferroptosis.
In the human body, NMN is the precursor of NAD+, which is critical for balancing out the levels of oxidated molecules in cells. Along these lines, NAD+ is crucial in regulating glutathione and oxidized glutathione levels, putting it at the center of ferroptosis regulation. Indeed, previous studies have demonstrated that restoring NAD+ levels by NMN treatment exert protective effects by reducing levels of oxidative stress.
Zhuan Feng and colleagues found that supplementing with NMN normalized the oxidative levels related to NAD+ during UV irradiation of skin cells, restoring glutathione levels. By recruiting glutathione production, it appears that NMN suppresses the accumulation of lipid peroxides via GPX4.
These data support a model in which UV irradiation leads to cellular “rust” accumulation in skin cells. In this state, GPX4 cannot wholly block the propagation of specific oxidated components because of insufficient glutathione. Through rescuing the imbalance of NAD+, NMN attenuates the accumulation of oxidative compounds, stopping the oxidative stress caused by UV.
“Taken together, our data suggest that NMN recruits glutathione to enhance GPX4-mediated ferroptosis defense,” said Zhuan Feng and colleagues. The researchers propose that NMN or a ferroptosis inhibitor might become promising approaches for dealing with oxidative stress induced by UV rays to promote healthy skin.
A Growing Collection of Congruent NMN Research
This article by Zhuan Feng and colleagues isn’t the only one to evaluate the role of NMN in supporting skin health. Several other research articles have been published this year looking at this same problem from slightly different angles. One report showed that boosting levels of the enzyme that produces NMN to restore NAD+ levels helps support skin health subjected to UV. Another study mixed NMN with a bacteria that has antioxidant qualities that support healthy skin aging.
Indeed, many studies have shown that NAD+ levels decline in various tissues and organs during aging, including the skin. So, it makes sense that recuperating NAD+ levels in the skin could be a way to support skin health during aging since we’re exposed to UV throughout the day. We’re yet to understand which would be the best way to do so: whether it would be through a cream or supplementation. But as long as we’re living on the third rock from the sun, we’re going to be dealing with showers of UV constantly. Maybe NMN will be the “sunscreen” of the future, whether taken in a pill or put directly onto the skin.
References:
Feng Z, Qin Y, Huo F, et al. NMN recruits GSH to enhance GPX4-mediated ferroptosis defense in UV irradiation induced skin injury [published online ahead of print, 2021 Oct 6]. Biochim Biophys Acta Mol Basis Dis. 2021;166287. doi:10.1016/j.bbadis.2021.166287
Katayoshi T, Nakajo T, Tsuji-Naito K. Restoring NAD+ by NAMPT is essential for the SIRT1/p53-mediated survival of UVA- and UVB-irradiated epidermal keratinocytes. J Photochem Photobiol B. 2021;221:112238. doi:10.1016/j.jphotobiol.2021.112238
Zhou X, Du HH, Ni L, et al. Nicotinamide Mononucleotide Combined With Lactobacillus fermentum TKSN041 Reduces the Photoaging Damage in Murine Skin by Activating AMPK Signaling Pathway. Front Pharmacol. 2021;12:643089. Published 2021 Mar 25. doi:10.3389/fphar.2021.643089