Properties of Aloesin
Properties of Aloesin
Aloesin is cited in literature to have multi-functional benefits for the cosmetic industry.
Skin whitening properties
Aloesin, a compound isolated from the aloe plant, has been proven to prevent the formation of melanin, the compound causing darkening of the skin, through competitively inhibiting the action of the enzyme, tyrosinase. Studies have shown that melanin is inhibited by Aloesin in a dose-dependent manner (Jones et al., 2002)
Rovi Cosmetics has recently launched Unitone at the In- Cosmetics show in 2011 Unitone contains Aloesin and Vitamin C . They made the following claims amongst other – ‘UniTone’ lightens skin in two ways – by inhibiting tyrosinase as well as reducing intracellular and extracellular melanin content. It has been proven that skin lightening products that target several aspects of melanogenesis work better than ones that only target one aspect. Also see Rovi Cosmetics claims on Unitone at http://allaboutskinlightening.net/2011/03/new-ingredient-unitone-to-be-launched-by-rovi-cosmetics.html
Synergistic action in combinative therapies
Aloesin, along with arbutin, a skin whitener, was observed to synergistically inhibit melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity (Jin et al., 1999)
Treatment of hypopigmentation
Although less effective than hydroquinone when used as single therapy, aloesin is safer, and has been most successfully used in hypopigmenting regimens for its syngergistic activity in combination therapies with two or more agents acting on various mechanisms (Pigment. Cell. Res. 2006;19:550-71)
Even though Aloesin appears to be an important component in the armament against hyperpigmentation disorders, its hydrophilic nature renders it less able than hydroquinone to penetrate the skin (Dermatol. Ther. 2007;20:308-13).
However, some believe that its slower penetration of the skin endows Aloesin with greater potential as a skin-lightening agent for cosmetic purposes (Pigment. Cell. Res. 2006;19:550-71).
Evidence of the UV protection of Aloesin was shown by Choi et al, when a topical application of aloesin on UV-irradiated (210 mJ) human volar forearm (four times a day for 15 days) showed pigmentation suppression in a dosedependent manner (Choi et al., 2002). It has also excellent properties of absorption in the ultraviolet and particularly in the UV-B region. For this reason it is also used as constituent of various sunscreen formulations. An excerpt from the link: (Clin. Exp. Dermatol.2002;27:513-5). ‘…investigators noted that Aloesin dose-dependently inhibited UV-induced pigmentation and concluded that the compound may be a suitable agent for blocking UV-induced melanin formation’ . T
he following citation is also relevant: ‘Antioxidant, free radical scavenging and anti-inflammatory effects of aloesin derivatives in Aloe vera’. http://www.ncbi.nlm.nih.gov/pubmed/12451482
The possible anti Inflamatory properties of Aloesin is cited in Anti-inflammatory constituents, aloesin and aloemannan in Aloe Species http://www.ncbi.nlm.nih.gov/pubmed/12875235 . A comparison of anti-inflamatory activities between aloe gel extracts, aloesin and aloin was perfomed by Park and colleagues (Park et al., 2011). This work indicated that in rats, Aloesin was the most effective inhibitor of inflammation in the model employed.
Recent work has indicated that Aloesin is safe, with no, or minimal toxological activity towards rats (Lynch et al 2011a). Genotoxic assays also indicated its safety as a food additive (Lynch et al 2011b). Even though these works have shown Aloesin to be safe, we will have to prove it for ourselves.
Biological Properties 1. Non-competitive inhibitor of tyrosinase enzyme responsible for melanin pigment formation in human skin (Yagi et al., 1987)
- Hepatoprotective factor: stimulates cell proliferation in vitro and in vivo
- Derivatives of aloesin have been observed to exhibit free radical scavenging and anti-inflammatory activity, and this compound has also been reported to modulate the formation of melanin (melanogenesis).