Licorice is a perennial plant, well known for its sweet-tasting root. Licorice extract is obtained from the root of Glycyrrhia Glabra Linneva and has been used in traditional Chinese medicine.
Rich in glabridin, glycyrrhizin, liquiritin and isoliquertin.
MELANOGENESIS INHIBITOR
Glabridin, a polyphenolic flavonoids in Licorice extract, has been shown to inhibit tyrosinase enzyme (specifically the activities of T1 and T3 isozymes), the rate limiting enzyme on the sequential pathway to melanin formation with no detectable effect on the DNA synthesis. The hydroxyl functions in position C-2’ and C-4’ were necessary for the anti-tyrosinase effect of Glabridin.
MELANIN DISPERSION AND REMOVAL
Liquirtin is a glycoside containing flavonoid that induces skin lightening by dispersing and removing melanin.
ANTIOXIDANT PROPERTIES
Licorice has antioxidant property by scavenging free radicals and inhibiting microsomal lipid peroxidation. Therefore, it protects the skin macromolecules against the oxidative damage caused by the free radicals and UV radiation such as UVB-induced skin hyperpigmentation.
ANTI-INFLAMMATORY PROPERTIES
Licorice has anti-inflammatory properties through inhibiting bacterial lipopolysaccharide induced PGE-2, IL-1, nitric oxide and TNF-α cellular release. All of these effects were shown to be directly linked to a reduction of the superoxide anion production and the expression of COX and iNOS. Thus, it reduces the post-inflammatory skin hyperpigmentation.
Licorice root extract is safe as cosmetic ingredients in the practices of use and concentration given in this safety assessment.
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