Chemical and Instrumental Approaches to Treat Hyperpigmentation

Abstract

Many modalities of treatment for acquired skin hyperpigmentation are available including chemical agents or physical therapies, but none are completely satisfactory. Depigmenting compounds should act selectively on hyperactivated melanocytes, without short-or long-term side-effects, and induce a permanent removal of undesired pigment. Since 1961 hydroquinone, a tyrosinase inhibitor, has been introduced and its therapeutic efficacy demonstrated, and other whitening agents specifically acting on tyrosinase by different mechanisms have been proposed. Compounds with depigmenting activity are now numerous and the classification of molecules, based on their mechanism of action, has become difficult. Systematic studies to assess both the efficacy and the safety of such molecules are necessary. Moreover, the evidence that bleaching compounds are fairly ineffective on dermal accumulation of melanin has prompted investigations on the effectiveness of physical therapies, such as lasers. This review which describes the different approaches to obtain depigmentation, suggests a classification of whitening molecules on the basis of the mechanism by which they interfere with melanogenesis, and confirms the necessity to apply standardized protocols to evaluate depigmenting treatments.

Down-Regulation of Tyrosinase Expression by Acetylsalicylic Acid in Murine B16 Melanoma

“…Kojic acid and arbutin were used as references which are well-known tyrosinase inhibitors. 20,21) DOPA Staining Assay (Tyrosinase Zymography) The DOPA staining assay was performed as reported by Ichihashi and other authors. [24][25][26] B16 melanoma cells were treated with either a-MSH alone or a-MSH plus test chemicals (ASA at 0.5-2.0 mM, arbutin at 2 mM and kojic acid at 200 mM) for 5-d. To identify tyrosinase, samples lysed in 0.1 M sodium phosphate buffer (pH 6.8) containing 1% Triton X-100, 1 mM phenylmethylsulfonyl fluoride (PMSF), 10 mg/ml aprotinin, and 10 mg/ml leupeptin (but without mercaptoethanol or heating) were resolved by 8% SDS-polyacrylamide gel electrophoresis.…”

Anisaldehyde, a Melanogenesis Potentiator

“…ase activity was reported not to correlate with that of cellular tyrosinase or with melanin production in cultured melanocytes (Maeda and Fukuda, 1996;Briganti et al, 2003). On the other hand, arbutin (2), a well-known depigmenting agent, did not inhibit the tyrosinase-catalyzed oxidation of l-DOPA (Nihei and Kubo, 2003) but significantly suppressed the melanin formation in cultured murine melanoma cells.…”

Whitening Effects of Adamantyl Benzamide Derivatives

“…또한 멜라닌 생성효소인 타이로시네이즈의 합성을 억 제하거나 그 활성을 저해하여 멜라닌의 생성을 감소 시킬 수 있다 [1][2][3]. 많은 미백연구에서 시험관 내 실험 에서 좋은 결과를 보이는 화합물들이 임상적으로 충 분한 효과를 내기 위해서는 화합물의 안정성이나 피 부적용시의 문제점 등을 고려한 연구가 필요하다 [4]. 현재까지 다양한 미백활성 화합물이 알려져 있는데 대부분 타이로시네이즈(tyrosinase)의 분해를 촉진하거 나 당화를 조절하여 멜라닌 생성을 조절할 수 있는 것 으로 알려져 있으며, 특히 항산화 작용을 갖는 polyhydroxylated phenolic compound가 많이 알려져 있다 [5,6].…”