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Activities:
Tyrosinase inhibition, antioxidant, anti-inflammatory
Important Chemical Components:
Aloesin (2-acetyonyl-8-glucopyranosyl-7-hydroxy-5-methylchromone)
Origin Classification:
This ingredient is natural, and a key constituent of Aloe. Organic forms exist.
Personal Care Category:
Depigmenting, sun protective (UVB)
Recommended for the following Baumann Skin Types:
DRPT, DRPW, DSPT, DSPW, ORPT, ORPW, OSPT, and OSPW
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A moderately-high-molecular-weight hydroxymethyl C-glycosylated chromone derivative isolated from fresh Aloe vera leaves (as well as those from other Aloe species), aloesin is a natural compound that has been found to exert appreciable depigmenting activity. It is among the top choices for cosmetic and therapeutic applications to lighten skin.1–4 While aloesin appears to be an important component in the armamentarium against hyperpigmentation disorders, its hydrophilic nature renders it less able than hydroquinone to penetrate the skin.5 Some argue that its slower penetration into the skin endows aloesin with greater potential as a skin-lightening agent for cosmetic purposes as compared to hydroquinone, however.6
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In traditional folk medicine, topical A. vera is used to treat inflammation, cicatrization, and dyspigmentation. Its constituent aloesin has been demonstrated to inhibit tyrosinase activity from human, murine, and mushroom sources.7
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Aloesin dose-dependently inhibits tyrosinase by blocking the hydroxylation of tyrosine to 3,4-dihydroxyphenylalanine (DOPA) as well as the oxidation of DOPA to dopaquinone; it has also been found to suppress melanin production in cultured normal melanocytes.7 Aloesin and a few chemically related chromones, particularly the 5-methyl-7-methoxy-2(2’-benzyl-3’-oxobutyl)-chromone, have been demonstrated to exhibit stronger inhibitory activity on tyrosinase than arbutin and kojic acid.6,8,9 This is especially noteworthy because tyrosinase is the rate-limiting enzyme in melanin production and, thus, directly influences the development of skin pigment.
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Interestingly, aloesin has been suggested as having a potential role as a functional food. Lynch et al. have recently shown in experiments with Sprague-Dawley rats that aloesin appears to confer benefits pertaining to prediabetic states, including metabolic syndrome.10 Aloesin is available in oral supplements and in aloe juice.
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Although less effective than hydroquinone when used as single therapy (Table 34-1), aloesin is safer, and has been most successfully used in hypopigmenting regimens for its synergistic activity in combination therapies with two or more agents acting on various mechanisms.6
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