The depigmenting effect of RALGA in C57BL/6 mice.
BACKGROUND
It has been known for a long time that the topical use of retinoic acid (RA) produces mild depigmentation of human skin. However, RA has two major disadvantages for its utilisation as a topical depigmenting compound. First, RA can act as an irritant and can produce considerable erythema and exfoliation of skin. Second, RA has a relatively weak depigmenting ability compared to other known depigmenting chemicals.


OBJECTIVE
In this study, we show that RALGA, a combination of the less irritant retinoid retinaldehyde (RAL; 0.1%) and glycolic acid (6.4%), has a higher skin-depigmenting potential than RA 0.05% in the tail skin of C57BL/6 mice. This effect was observed in reducing the number of functioning melanocytes and/or in inhibiting their ability to synthesise melanin. In addition, the visually recognisable depigmenting effect of RALGA was evident earlier than that of RA, i.e. only after 1 week of application. RALGA may therefore serve as a depigmenting product for the treatment of skin hyperpigmentary disorders. Postacne hyperpigmented lesions represent a very common pigmentary problem among acne patients. RALGA may thus act as an anti-acne product, due to the presence of RAL--an RA precursor--which could simultaneously remove the postacne hyperpigmented lesions in such patients.
Kasraee
B
B
Department of Dermatology, Geneva University Hospital, Geneva, Switzerland. kasraeeb@sums.ac.ir
Tran
C
C
Sorg
O
O
Saurat
J-H
JH
D000152:Acne Vulgaris / Q000188:drug therapy; D000818:Animals; D003879:Dermatologic Agents / Q000494:pharmacology*; D004338:Drug Combinations; D006016:Glycolates / Q000494:pharmacology*; D017495:Hyperpigmentation / Q000188:drug therapy; D007641:Keratolytic Agents / Q000494:pharmacology*; D008543:Melanins / Q000037:antagonists & inhibitors; D008544:Melanocytes / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D012172:Retinaldehyde / Q000494:pharmacology*; D012867:Skin / Q000187:drug effects / Q000473:pathology; D012880:Skin Pigmentation / Q000187:drug effects*; D013623:Tail; D013997:Time Factors
D003879:Dermatologic Agents; D004338:Drug Combinations; D006016:Glycolates; D007641:Keratolytic Agents; D008543:Melanins; C501639:diacneal; C031149:glycolic acid; D012172:Retinaldehyde