Related Experiment Video
Updated: Feb 27, 2026

Quantification of Hypopigmentation Activity In Vitro
Published on: March 6, 2019
Kinetics of Tyrosinase Inhibitory Activity Using Vitis vinifera Leaf Extracts
Yung-Sheng Lin1, Hui-Ju Chen2, Jung-Ping Huang3
1Department of Chemical Engineering, National United University, Miaoli, Taiwan.
Abstract:
Natural medical plant is considered as a good source of tyrosinase inhibitors. Red vine leaf extract (RVLE) can be applied to a wide variety of medical disciplines, such as treatments for chronic venous insufficiency over many decades. This study investigated the tyrosinase inhibitory activity of RVLE containing gallic acid, chlorogenic acid, epicatechin, rutin, and resveratrol which are effective for skin hyperpigmentation. The five components contents are 1.03, 0.2, 18.55, 6.45, and 0.48 mg/g for gallic acid, chlorogenic acid, epicatechin, rutin, and resveratrol. The kinetic study showed the tyrosinase inhibitory of RVLE via a competitive reaction mechanism. RVLE solution has an IC50 (the half inhibitory concentration) value of 3.84 mg/mL for tyrosinase inhibition, that is, an effective tyrosinase inhibitory activity, and can be used as a whitening agent for cosmetic formulations in the future.
Related Concept Videos
Introduction to Enzyme Kinetics
The experimenter can then plot the initial reaction rate or velocity (Vo) of a given trial against the substrate concentration ([S]) to obtain a graph of the reaction properties. For many enzymatic reactions involving a...
Enzyme Inhibition
Enzyme Kinetics
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...

