Inhibitory effects of compounds isolated from Lepechinia meyenii on tyrosinase. (March 2019)

• Record Type: Journal Article
• Authors: Crespo, María Inés; Chabán, Macarena Funes; Lanza, Priscila Ailín; Joray, Mariana Belén; Palacios, Sara María; Vera, D. Mariano Adolfo; Carpinella, María Cecilia
• Is Part Of: Food and chemical toxicology. Volume 125(2019)
• Page Start: 383
• Page End: 391
• Publication Date: 2019-03
• Subjects: Phenolic acids -- Tyrosinase inhibitors -- Molecular docking -- Lepechinia meyenii; Toxicology -- Periodicals; Food poisoning -- Periodicals; Food Poisoning -- Periodicals; Toxicology -- Periodicals; Toxicologie -- Périodiques; Intoxications alimentaires -- Périodiques; Food poisoning; Toxicology; Periodicals; Electronic journals; 615.9
• DOI: 10.1016/j.fct.2019.01.019
• Languages: English
• ISSNs: 0278-6915

Abstract

Abstract: To contribute enzymatic browning inhibitors to the food industry and also extend knowledge about the phytochemical profile of the anti-tyrosinase plant Lepechinia meyenii, its ethanol extract was subjected to bioguided fractionation. Three hydroxycinnamic acids, p -coumaric acid (1 ), caffeic acid (2 ) and rosmarinic acid (3 ), were isolated as mainly responsible for its activity. Compounds1, 2 and3 showed themselves highly effective for inhibiting tyrosinase with IC50 values of 0.30, 1.50 and 4.14 μM, respectively, for monophenolase activity and 0.62, 2.30 and 8.59 μM, respectively for diphenolase activity. This is the first report describing the isolation of the compounds causing the tyrosinase inhibitory activity of L. meyenii extract. The inhibitory kinetics of1 –3 using both L-tyrosine and L-DOPA as substrates was investigated and the results obtained were discussed at molecular level by docking analysis. The resulting compounds1 –3 and a phenolic-enriched fraction of the extract, 2.9-fold more active than the starting material, may be suitable as non-toxic and inexpensive alternatives for the control of deleterious enzymatic darkening. Highlights: Plants from the flora of Argentina such as Lepechinia meyenii, provide effective and non-toxic anti-tyrosinase compounds. From L. meyenii, three hydroxycinnamic acids were identified as the compounds causing tyrosinase inhibitory effect. Two QM/MM-based structural models for the metallic site of the oxy and met tyrosinases were developed and used for docking. Kinetic and docking analysis showed that the type of inhibition of the hydroxycinnamic acids were non-competitive. A phenolic enrichment of L. meyenii extract was performed causing an outstanding increase in tyrosinase inhibitory activity.