Linoleic acid molecule

Unsaturated fatty acids including oleic acid, linoleic acid or α-linolenic acid suppresses melanogenesis and tyrosinase activity, while saturated fatty acids such as palmitic acid or stearic acid increases it.

Linoleic acid reduces the activity of tyrosinase in melanocytes, while mRNA levels remain unchanged. No evidence of change in TYRP-1 and TYRP-2 protein levels suggest that fatty acids selectively target tyrosinase. This may influence the enzyme’s degradation via a physiologic proteasome-dependent mechanism, altering the tyrosinase protein content in hyperactive melanocytes.

Linoleic acid also influences skin pigmentation by stimulating epidermal turnover and increased desquamation of melanin pigment from the epidermis.

Studies completed to assess the skin lightening capabilities of unsaturated fatty acids, linoleic acid or α-linoleic acid, on UV induced hyperpigmentation of brown guinea pig skin, showed an efficient lightening effect.

It is thought that the unsaturated bonds of these molecules can be easily peroxidized, which in combination with an increase in epidermal turnover, correlate with an inhibitory effect on melanogenesis in vivo.