More barrier proteins in human skin
LaboratoryHuman skin in organ culturePrimary keratinocytesBetaine and taurine
Skin expresses betaine transporters. When exposed to betaine or taurine, it produces more claudin-1, claudin-4 and occludin, which are tight junction proteins, and tight junction function increases in cultured keratinocytes. The effect disappears when the transporter is blocked2.
An effect on epidermal differentiation
LaboratoryBetaine 10 mMRat keratinocytes, 3D cultureWith or without UVB
Of 89 genes modified by betaine, keratin 2, a differentiation marker, is the most increased. The authors note that betaine is widely used in skincare despite the lack of studies on its own effects3.
Organic osmolytes protect tight junctions after UVB
LaboratoryRat keratinocytesA single UVB dose
In the presence of organic osmolytes, the function of developing tight junctions is preserved after UVB. The effect does not go through cell volume or free radicals. The abstract does not say which osmolyte carries the effect: it applies to the betaine family, not to betaine alone7.
An aloe vera and trimethylglycine complex increases aquaporin 3
LaboratoryAloe vera and trimethylglycine 1:1HaCaT keratinocytes
The complex increases aquaporin 3, a water channel of the epidermis, by up to 380% compared with the negative control. The effect is attributed to the combination, not to trimethylglycine alone4.