In lab tests, NCG showed multiple benefits, including anti-ageing, brightening, and anti-inflammation effects. It was found to protect different types of skin cells from UV-induced damage, which leads to stress, collagen breakdown, inflammation, and excessive melanin production.
The researchers believe this data supports NCG as a potential key active ingredient for products that target “inflammageing” (ageing driven by low-grade inflammation).
However, they also emphasised the need for real-world testing on people, and work on how to best incorporate NCG into a cream or serum.
Testing on four skin cell types
The researchers from Chonnam National University, Dongshin University, and BIO-FD&C tested NCG on four common cell types used in skin care research: human keratinocytes (main cells on the skin surface), human dermal fibroblasts (cells that make collagen in the skin’s deeper layer), mouse melanoma cells (used to study pigmentation), and mouse macrophages (immune cells that drive inflammation).
These models are standard tools for screening ingredients that are thought to fight ageing, whiten skin or reduce redness before they move to human trials. After determining safe concentrations, the researchers created stress on the cells to mimic real-world ageing and damage.
They used UVB light, a bacterial toxin (LPS) or a pigment-driving hormone (α-MSH). After treating the stressed cells with NCG, they used standard lab tests to measure how well it fought damage, protected collagen, stopped pigment creation, and reduced signs of inflammation.
Protection against damage and collagen loss
In UVB-damaged keratinocytes, NCG showed powerful antioxidant activity. At higher doses, it reduced unstable oxygen molecules, or reactive oxygen species (ROS), by over 90%. ROS are harmful molecules created by UV rays and pollution that damage the skin’s DNA, proteins and fats, leading to faster visible ageing.
The researchers compared NCG to N-acetylcysteine (NAC), a well-known antioxidant. NCG’s ability to clear away ROS was similar to a much higher concentration of NAC, suggesting NCG was highly potent.
This indicated that even small amounts of NCG in a final product might offer strong protection, though more studies are needed to prove it can reach the target area in real skin.
In deeper skin cells (fibroblasts) exposed to UVB, NCG also showed potential to fight wrinkles. It helped restore the creation of type I procollagen (the building block for firm skin) by up to 30%.
It also cut the activity of two enzymes (MMP-1 and MMP-3) that break down collagen and elastin as well as cause wrinkles and sagging by over 53%. In fact, further testing confirmed that NCG reduced the actual amount of MMP-1 and MMP-3 protein.
Brightening effects comparable to arbutin
To check how well NCG could brighten skin, the research team used pigment-producing (melanoma) cells stimulated by the hormone α-MSH. They used arbutin, a popular brightening ingredient, as the benchmark.
NCG reduced the total amount of melanin and lowered the activity of tyrosinase by about 18.3%. Tyrosinase is a key pigment-making enzyme and the most common target for skin-lightening products.
At a comparable dose, NCG’s brightening effect was similar to arbutin in both reducing melanin and tyrosinase activity.
Detailed protein analysis revealed NCG’s mechanism. It dialled down the “master switch” protein for pigment production (MITF) and two supporting enzymes (TRP-1 and TRP-2) by over 50%.
By working on MITF and the supporting machinery (tyrosinase, TRP-1, TRP-2), NCG appeared to slow down pigment creation at several points. This makes NCG a promising ingredient for products that combine anti-ageing, antioxidant, and spot-fading effects.
Anti-inflammatory action targets root of ageing
Inflammageing, the idea that low, constant inflammation silently damages tissue, is now understood as a main driver of ageing and pigment problems in the skin. To study this, the researchers looked at NCG’s effects on immune cells (macrophages) stimulated to be inflamed.
NCG reduced the production of nitric oxide (NO), which contributes to stress and inflammation when in excess, by up to 47.5% without harming the cells.
The results also that showed NCG lowered the protein levels of key inflammatory messengers iNOS, COX-2, TNF-α and IL-6, which are often high in aged or stressed skin. By calming them down, NCG might help reduce the background inflammation that speeds up collagen loss and triggers uneven skin tone.
The study’s authors suggested that NCG’s anti-inflammatory power was linked to its known ability to manage certain cell communication pathways and boost the skin’s natural defence systems. While they did not map every step, the overall pattern strongly supported a broad effect against inflammation.
What’s next
The study showed NCG to be a single molecule with four major benefits — antioxidant, anti-wrinkle, brightening, and anti-inflammatory.
Since NCG is already used safely as a precursor or helper molecule for arginine in other health products, this may help in creating safety stories, though its safety and appropriate dosage for topical use (such as irritation or allergic reactions) must still be fully tested for cosmetics.
The researchers acknowledged some limitations of the study. For one, it did not measure if NCG could penetrate and be absorbed by human skin. There remains no data from human volunteers on changes in wrinkle depth, spots, or inflammation.
The best way to package NCG, keep it stable in different product types, and ensure it mixes well with other common ingredients, also needs to be further elucidated.
The researchers concluded: “The current in vitro data highlight NCG’s potential as a safe and multifunctional active compound for use in cosmetic and dermatological products. Still, in vivo validation and clinical assessments remain necessary before it can be considered for practical application in commercial formulations.”
Source: Cosmetics
“Multifunctional Effects of N-Carbamylglutamate on Skin-Related Cells: Antioxidant, Anti-Aging, Anti-Melanogenic and Anti-Inflammatory Activities”
https://doi.org/10.3390/cosmetics12060250
Authors: Choi Sa Rang, et al.
