Relationship between tyrosinase inhibitory action and oxidation-reduction potential of cosmetic whitening ingredients and phenol derivatives

Abstract

The oxidation-reduction potentials of cosmetic raw materials, showing tyrosinase inhibitory action, and phenolic compounds structurally similar to L-tyrosine were determined by cyclic voltammetry. The voltammograms obtained could be classified into 4 patterns (patterns 1-4). Pattern 1, characterized by oxidation and reduction peaks as a pair, was observed with catechol, hydroquinone or phenol, and pattern 2 exhibiting another oxidation peak in addition to oxidation and reduction peaks as a pair was found with arbutin, kojic acid, resorcinol, methyl p-hydroxybenzoate and L-tyrosine as the substrate of tyrosinase. Pattern 3 with an independent oxidation peak only was expressed by L-ascorbic acid, and pattern 4 with a reduction peak only at high potentials, by hinokitiol. The tyrosinase inhibitory activity of these compounds was also evaluated using the 50% inhibitory concentration (IC50) and the inhibition constant (Ki) as parameters. Hinokitiol, classified as pattern 4, showed the highest inhibitory activity (lowest IC50 and Ki). Hydroquinone showing the second highest activity belonged to pattern 1, which also included compounds showing no inhibition of tyrosinase activity. The inhibitory activity of compounds exhibiting pattern 2 was relatively low with Ki values being in the order of 10(-4) M. Although there was no consistent relationship between oxidation-reduction potentials and tyrosinase inhibitory action, the voltammetry data can be used as an additional index to establish the relationship between the structure and the tyrosine inhibitory activity.

Differential regulation of melanosomal proteins after hinokitiol treatment

“…Hinokitiol has been reported to strongly inhibit human and mushroom TYR activity, and reductions in TYR activity are known to be associated with marked reductions in melanin synthesis [14,17].…”

Safety and efficacy of parenteral glutathione as a promising skin lightening agent: A controlled assessor blinded pharmacohistologic and ultrastructural study in an animal model

“…Although there are many therapeutic modalities available, these usually have potentially significant side effects, including mutagenicity and ochronosis (Alghamdi, ; Draelos, ; Parvez et al, ; Solano, Briganti, Picardo, & Ghanem, ). Hydroquinone (Kasraee et al, ), kojic acid, and arbutin are commonly used to whiten the skin color, as they all have inhibitory effects on tyrosinase (Briganti, Camera, & Picardo, ; Puizina‐Ivić, Mirić, Carija, Karlica, & Marasović, ; Sakuma, Ogawa, Sugibayashi, Yamada, & Yamamoto, ).…”

Inhibitory effects of hinokitiol on tyrosinase activity and melanin biosynthesis and its antimicrobial activities

“…Hinokitiol has been reported to strongly inhibit human and mushroom tyrosinase activity, and reductions in tyrosinase activity are known to be associated with marked reductions in melanin synthesis 8 . Sakuma et al 20 reported that hinokitiol acted as a representative type of competitive inhibitor and exhibited the most potent inhibition (IC 50 = 8.22 μM) followed by hydroquinone, resorcinol, hydroxyhydroquinone, kojic acid, l-ascorbic acid, phloroglucinol, p-nitrophenol, methyl p-hydroxybenzoate, and arbutin, while l-Tyr was used as substrate. Our results showed an approximate IC 50 value of 9.67 μM for monophenolase activity inhibited by hinokitiol, when the enzymatic oxidation reaction used l-Tyr as the substrate.…”