Sialic acid can effectively inhibit the expression of dual activities of tyrosine hydroxylase and dopa hydroxylase, and prevent melanin production.

From the figure above, it can be seen that when the concentration of sialic acid reaches about 0.5%, the activity of tyrosine hydroxylase and dopa hydroxylase can be inhibited with maximum efficiency.

Compared with the control group, different concentrations (15.6 μg/mL, 31.3 μg/mL, 62.5 μg/mL) of N-acetylneuraminic acid can significantly reduce the content of free radical ROS (detected by relative fluorescence value), which helps in resisting cellular senescence.

The content of type I collagen increases with the concentration of N-acetylneuraminic acid. Experiments show that N-acetylneuraminic acid can effectively promote the formation of type I collagen and help maintain the skin support structure.

N-acetylneuraminic acid is a new ingredient that can satisfy consumer demand for natural and safety. It exists widely in nature, and the human body also contains a large amount of this substance, mainly in the form of glycoprotein, glycolipid, and other combined forms. In humans, N-acetylneuraminic acid is abundantly distributed at the ends of sugar chains on the surface of cell membranes and is particularly abundant on the surface of nerve cells. It can also be combined with lipids or proteins to play different functions. As it's an essential component of biological membranes, most of which are connected with membrane proteins and distributed on the surface of the plasma membrane to form a layer of polysaccharide-protein complexes. The negatively charged surface of SA is a core carrier in information transmission, so sialic acid is called the antenna on the cell surface, helping to improve cell activity.