GLABRIDINPrincipal indication: hyperpigmented skinPURE ACTIVE A71Bibliographical summary INCI name : GLYCYRRHIZA GLABRA (LICORICE) ROOT EXTRACTLiquorice (Glycyrrhiza glabra L.) root extract titrated into Glabridin (content 40%) Glabridin is the principal constituent of the hydrophobic fraction of liquorice extracts and is used in cosmetics for its lightening properties.The history of liquorice dates back several centuries. It was already mentioned in Chinese treatises on traditional herbalism and in the papyrus scrolls of ancient Egypt. In traditional Chinese medicine, liquorice root, called Gan Cao, is commonly used as an energy tonic to treat problems caused by "Qi" or energy deficiency.Its uses administered orally are numerous. Liquorice is a plant remedy particularly well known for treating coughs, phthisis and chest pain, principally bronchitis. The anti-inflammatory, expectorant and adrenocorticotropic activities of liquorice are described in the British Herbal Compendium. The E Germanic commission recommends the internal use of liquorice root for disorders of the upper respiratory tract and intestinal disorders. ACTION MECHANISMS / PROOFS OF EFFECTIVENESS Glabridin inhibits melanogenesis by inhibiting tyrosinase isoenzymes T1 and T3 [1].This enzyme is behind melanin synthesis. One should be aware that they catalyze the formation of L-Dopa from L-Tyrosin. They also catalyze the conversion of L-Dopa into Dopaquinone. As this (Dopaquinone) is the precursor of skin pigments such as black melanins (via indole-5,6-quinone) and red melanins (after reacting with a cysteine and cyclization). Glabridin inhibits the monophenolase (addition of an OH function to a phenol) and diphenolase (oxidation of 2 OH functions into cetones) activity of tyrosinase [2]. In addition, glabridin was the first confirmed inhibitor presenting 15 times the activity of kojic acid and a broader depigmenting activity than arbutin [3].Glabridin influences pigmentation by inhibiting melanin synthesis and tyrosinase activity in a dose-dependent manner [4].Glabridin inhibits the inflammatory reaction by blocking cyclooxygenase and preventing the formation of free radicals such as superoxide anions [1]. OUR EXPERT'S OPINIONThe molecule belongs to the tyrosinase class of inhibitors but, chemically, its structure is complexified and differs from it. Natural in origin, the product combines greater inhibition of melanogenesis than kojic acid and better tolerance.Under these conditions, lower active doses at 1% are possible.The same can be said as for other depigmenting actives on the combination of several molecules acting in different ways, or leading to better tyrosinase saturation, in order to optimize the results. EFFECTIVE DOSEThe body of publications and scientific studies, customary usages of this active and our expert's opinion concur in using Glabridin pure Active at the dose of 2.5 mg per bottle. BIBLIOGRAPHICAL REFERENCES[1] The Inhibitory Effect of Glabridin from Licorice Extracts on Melanogenesis. Yokota T et al. Pigment Cell Res, 11:955-961. 1998.[2] Glabrene and isoliquiritigenin as tyrosinase inhibitors from licorice roots. Nerya O et al. J Agric Food Chem. 51(5):1201-1207. 2003.[3] An Updated review of tyrosinase inhibitors. Chang TS. Int J Mol Sci, 10(6) : 2440-2475. 2009.[4] Mechanisms regulating skin pigmentation : the rise and fall of complexation coloration. Ebanks JP et al. Int J Mol Sci, 10(9):4066 4087. 2009.This information is given for informative purposes. In no event does it constitute medical information, nor engage our liability. These documents may be copied and reproduced exclusively for informative purposes for personal and private use. All and any use of copies or reproductions for other purposes is expressly forbidden and shall engage the user's liability under Article L 122-3 of the Intellectual Property Code.