Tyrosinase inhibition by water and ethanol extracts of a Far Eastern sea cucumber, Stichopus japonicus

• Published in: Journal of the science of food and agriculture Vol. 91; no. 9; pp. 1541 - 1547
• Main Authors: Husni, Amir, Jeon, Je-Seung, Um, Byung-Hun, Han, Nam Soo, Chung, Donghwa
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2011; Wiley; John Wiley and Sons, Limited
• Subjects: Adenosine - isolation & purification; Adenosine - pharmacology; Agaricales - enzymology; Animals; Aquatic life; Binding; Biological and medical sciences; Biological Products - chemistry; Biological Products - isolation & purification; Biological Products - pharmacology; Chromatography; Chromatography, High Pressure Liquid; Cucumbers; Dihydroxyphenylalanine - isolation & purification; Enzyme Inhibitors - pharmacology; Enzymes; Ethanol; Ethyl alcohol; ethyl-α-D-glucopyranoside; Food industries; Food science; Foods; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Glucosides - isolation & purification; Glucosides - pharmacology; Holothurioidea; Indolequinones - isolation & purification; Inhibition; Inhibitors; Inhibitory Concentration 50; Marine; mixed type; Monophenol Monooxygenase - antagonists & inhibitors; sea cucumber; Stichopus - chemistry; Stichopus japonicus; Tyrosinase; tyrosinase inhibitor; Water; tyrosinase inhibitor; Vegetables; Ethanol; ethyl-α-D-glucopyranoside; mixed type; Extract; Inhibitor; Inhibition; Cucumber; sea cucumber; Stichopus japonicus
• ISSN: 0022-5142; 1097-0010; 1097-0010
• DOI: 10.1002/jsfa.4335

BACKGROUND: Tyrosinase plays a key role in hyperpigmentaion and enzymatic browning. The present study was aimed at investigating the inhibitory effects of water and 70% aqueous ethanol extracts of Stichopus japonicus, a sea cucumber long consumed as a tonic food and traditional medicine, on the diphenolase activity of tyrosinase. RESULTS: In the tyrosinase inhibition study, high‐performance liquid chromatography completely separated L‐3,4‐dihydroxyphenylalanine and dopachrome from other compounds present in the extracts, and provided more reliable results than the commonly used spectrophotometry. The ethanol extract (IC50 = 0.49–0.61 mg mL−1) showed higher inhibitory activity than the water extract (IC50 = 1.80–1.99 mg mL−1). Enzyme inhibition by the extracts was reversible and of mixed type. For both extracts, the dissociation constants for binding to free enzyme were significantly smaller than those for binding to enzyme–substrate complex. Ethyl‐α‐D‐glucopyranoside (IC50 = 0.19 mg mL−1), isolated for the first time from sea cucumber, and adenosine (IC50 = 0.13 mg mL−1), were identified as key tyrosinase inhibitors. CONCLUSION: The sea cucumber extracts were demonstrated to possess considerable inhibitory potency against the diphenolase activity of tyrosinase, suggesting that the sea cucumber may be a good source of safe and effective tyrosinase inhibitors. Copyright © 2011 Society of Chemical Industry