Kinobeon A as a potent tyrosinase inhibitor from cell culture of safflower: in vitro comparisons of kinobeon A with other putative inhibitors

• Published in: Planta medica Vol. 69; no. 5; p. 457
• Main Authors: Kanehira, Tsutomu, Takekoshi, Susumu, Nagata, Hidetaka, Osamura, R Yoshiyuki, Homma, Takao
• Format: Journal Article
• Language: English
• Published: Germany 01-05-2003
• Subjects: Agaricales - enzymology; Alkenes - administration & dosage; Alkenes - chemistry; Alkenes - pharmacology; Arbutin - pharmacology; Ascorbic Acid - pharmacology; Carthamus tinctorius; Dose-Response Relationship, Drug; Humans; Inhibitory Concentration 50; Levodopa; Monophenol Monooxygenase - drug effects; Peptides - administration & dosage; Peptides - chemistry; Peptides - pharmacology; Phytotherapy; Pyrones - pharmacology
• ISSN: 0032-0943
• DOI: 10.1055/s-2003-39708

Kinobeon A is produced from cell cultures of the medicinal plant, safflower. Mushroom tyrosinase activity was inhibited in a concentration-dependent manner when treated with kinobeon A using L-tyrosine or L-3,4-dihydroxyphenylalannine (L-DOPA) as substrates. IC50 values were 22 microM (substrate: L-tyrosine) and 27 microM (L-DOPA). Inhibition of human tyrosinase activity also increased with increasing concentrations of kinobeon A using L-DOPA as the substrate, with an IC50 value of 2.5 microM. Kinobeon A was a more potent competitive inhibitor than kojic acid, arbutin or L-ascorbic acid for both mushroom and human tyrosinase as determined from Lineweaver-Burk plots. These results suggested that kinobeon A could be a potent natural tyrosinase inhibitor.