ABSTRACT
Tyrosinase is a key enzyme in melanin production. Therefore, tyrosinase inhibitors are used in cosmetic and medicinal industries to prevent or treat overproduction of melanin such as melasma, solar lentigo and post inflammatory melanoderma. Due to safety of natural whitening agents, in the present study, in-vitro anti-tyrosinase and in-vivo anti-melanogenesis activities of some selected red macroalgae of the Persian Gulf were investigated. The effects of various concentrations (100, 250 and 500 µg/mL) of methanolic extracts of three red macroalgae including Digenea simplex (D. simplex), Laurencia papillosa, and Laurencia paniculata on the activity of diphenolase of mushroom tyrosinase were studied by using L-Dopa as substrate. Subsequently, the activity of macroalgae with high inhibitory effect on hydroxylation of L-tyrosine was investigated by mushroom tyrosinase and zebrafish model. Anti-melanogenesis effects of algae extracts were studied on zebrafish as an alternative in-vivo model. Kojic acid was used as a positive control. All the tested macroalgae showed significantly a lower inhibitory effect on activities of diphenolase and monophenolase (of mushroom tyrosinase) compared to kojic acid. D. simplex showed the most anti-tyrosinase activity in zebrafish model among the samples. D. simplex extract and Kojic acid inhibited tyrosinase activity by 43.18% and 50.45%, and decreased total melanin content of zebrafish by 47.27% and 50.21%, respectively.
ABSTRACT
Abstract Melanogenesis is a biological process which led to the synthesis of melanin pigment. Abnormal melanin production results in melasma, solar lentigo, post inflammatory melanoderma, etc. In this study, we examined the potential inhibitory effects of 17 brown macroalgae from Persian Gulf on melanogenesis. The effects of various concentrations (100, 250 and 500 µg/mL) of methanolic extracts of macroalgae belonging to four genera (including: Padina, Colpomonia, Cystoseira and Sargassum) were studied on oxidation of L-Dopa by mushroom tyrosinase. Subsequently, the activity of macroalgae with high inhibitory effect on monophenolase activity of mushroom tyrosinase and zebrafish was investigated using L-tyrosine as a substrate. Anti-melanogenesis effects of algae extracts were studied on zebrafish as an alternative in vivo model. Kojic acid was used as a positive control. All the tested macroalgae showed inhibitory effect on activities of diphenolase and monophenolase (of mushroom tyrosinase). P. boergesinii exhibited the most in vivo anti-tyrosinase activity compared with other samples. P. boergesenii inhibited zebrafish tyrosinase more potent than kojic acid (83% vs 50% inhibition for kojic acid). Moreover, it reduced melanin synthesis in zebrafish 42% (kojic acid: 50%).
Subject(s)
Monophenol Monooxygenase/analysis , Microalgae/chemistry , Zebrafish , Indian OceanABSTRACT
BACKGROUND: The key enzyme in the process of melanin biosynthesis is tyrosinase. Skin hyperpigmentation and browning of foods are undesirable phenomena which tyrosinase represents. Therefore, tyrosinase inhibitors have been used increasingly for medicinal and cosmetic products. OBJECTIVES: In this study, inhibitory effects of four plants including: physalis alkekengi L., Alcea rosea L., Bunium persicum B. Fedtsch. and Marrubium vulgare L. on diphenolase activity of mushroom tyrosinase were evaluated. MATERIALS AND METHODS: The inhibitory activities of hydroalcoholic extracts of plants against oxidation of L-Dopa (as a substrate) by mushroom tyrosinase were investigated. RESULTS: The hydroalcoholic extract of P. alkekengi showed the most tyrosinase inhibitory effect with IC50 of 0.09 mg/mL vs. 0.38, 0.38 and 2.82 mg/mL of B. persicum, A. rosea and M. vulgare, respectively. M. vulgare exhibited uncompetitive inhibition and other plants showed mixed type inhibition on mushroom tyrosinase. CONCLUSIONS: All plants could inhibit mushroom tyrosinase, but more investigations on human tyrosinase and clinical studies are needed.
