Neutrophils are a type of white blood cell that is responsible for healing and an essential part of the immune system. However, neutrophils secrete neutrophil elastase, an enzyme with degradative properties.
According to Pola Orbis, neutrophils can secrete excessive amounts of neutrophil elastase when skin is exposed to UV rays or subjected to physical pressure. This causes components of the dermis such as collagen and elastin to breakdown.
Pola Orbis claimed that NEI-L1, an active ingredient found in its quasi-drug cosmetic product, POLA Wrinkle Shot serum, could prevent the activity of neutrophil elastase.
NEI-L1 was recently confirmed by Pola Orbis to improve skin elasticity in as little as four weeks by preventing the breakdown of collagen and elastin inside the skin. This in turn can diminish the appearance of wrinkles.
The company’s researchers, however, believed NEI-L1 could be more effective if it could prevent neutrophils from “collecting excessively” on the skin.
“If we can suppress the action of neutrophils on the skin in a different way from NEI-L1, we can expect a more effective anti-aging solution,” said the firm.
The study explained that neutrophils are usually transported in the blood vessels along with red blood cells. When inflammation occurs in the surrounding tissue, it adheres to the inner wall of the relevant blood vessels.
To impede the increase of neutrophils in the skin, the team sought to prevent adhesion of neutrophils to the inner wall of the blood vessel.
The team identified that an oil-soluble peach leaf extract was effective in suppressing the expression of “neutrophil adhesion promoting factors”.
At the same time, the researchers needed to supress the factors that attract neutrophils to the skin. UV rays were found to stimulate dermal fibroblasts to release a factor that attracts neutrophils to the skin.
Researchers discovered two ingredients that were effective in suppressing the expression of these factors.
They were horsetail extract, a plant with anti-inflammatory properties, as well as cyclohexylglycerin (CHG), a type of glycerin derivative which is effective at retaining skin moisture.
The study found that these three ingredients, combined with NEI-L1, were able to suppress the ageing effects of neutrophils from multiple angles.
“When combined with NEI-L1, which acts on neutrophil elastase, neutrophils can be suppressed in many ways and more effective aging care can be expected,” it concluded, adding that it plans to further its research to incorporate these new findings into its products.