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Tyrosinase inhibition by p-coumaric acid ethyl ester identified from camellia pollen.

ABSTRACT: A tyrosinase inhibitor was separated from camellia pollen with the aid of solvent fraction, macroporous adsorptive resin chromatography, and high-speed countercurrent chromatography. The inhibitor was identified to be p-coumaric acid ethyl ester (p-CAEE) by nuclear magnetic resonance and mass spectrum. Its inhibitory activity (IC₅₀ = 4.89 ?g/ml) was about 10-fold stronger than arbutin (IC₅₀ = 51.54 ?g/ml). The p-CAEE inhibited tyrosinase in a noncompetitive model with the K _I and K _m of 1.83 ?g/ml and 0.52 mM, respectively. Fluorescence spectroscopy analysis showed the p-CAEE quenched an intrinsic fluorescence tyrosinase. UV-Vis spectroscopy analysis showed the p-CAEE did not interact with copper ions of the enzyme. Docking simulation implied the p-CAEE induced a conformational change in the catalytic region and thus changed binding forces of L-tyrosine. Our findings suggest that p-CAEE plays an important role in inhibiting tyrosinase and provides a reference for developing pharmaceutical, cosmetic, and fruit preservation products using pollen.

SUBMITTER: Li L

PROVIDER: S-EPMC7802545 | biostudies-literature | 2021 Jan

REPOSITORIES: biostudies-literature

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Tyrosinase inhibition by p-coumaric acid ethyl ester identified from camellia pollen.

Li Lijun L Cai Yuchen Y Sun Xu X Du Xiping X Jiang Zedong Z Ni Hui H Yang Yuanfan Y Chen Feng F

Food science & nutrition 20201211 1

A tyrosinase inhibitor was separated from camellia pollen with the aid of solvent fraction, macroporous adsorptive resin chromatography, and high-speed countercurrent chromatography. The inhibitor was identified to be p-coumaric acid ethyl ester (p-CAEE) by nuclear magnetic resonance and mass spectrum. Its inhibitory activity (IC50 = 4.89 μg/ml) was about 10-fold stronger than arbutin (IC50 = 51.54 μg/ml). The p-CAEE inhibited tyrosinase in a noncompeti ...[more]

PMID: 33473301

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Project description:BackgroundIcosapent ethyl (IPE) is a high-purity prescription form of eicosapentaenoic acid ethyl ester approved by the US Food and Drug Administration as an adjunct to diet to reduce triglyceride (TG) levels in adult patients with severe (≥500 mg/dL) hypertriglyceridemia. In addition to TG-lowering effects, IPE also reduces non-high-density lipoprotein cholesterol and apolipoprotein B levels without significantly increasing low-density lipoprotein cholesterol (LDL-C) in patients with very high TG levels ≥500 mg/dL (MARINE study) and in patients with well-controlled LDL-C and residually high TG levels 200-500 mg/dL (ANCHOR study). This analysis examined the effect of IPE on inflammatory markers in patients from MARINE and ANCHOR.MethodsMARINE (N = 229) and ANCHOR (N = 702) were Phase III, double-blind studies that randomized hypertriglyceridemic patients to IPE 4 g/day, 2 g/day, or placebo. This analysis assessed the median placebo-adjusted percentage change from baseline in markers representing various stages of atherosclerotic inflammation such as intercellular adhesion molecule-1 (ICAM-1), oxidized low-density lipoprotein (Ox-LDL), lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hsCRP).ResultsCompared to placebo, IPE 4 g/day significantly decreased Ox-LDL (13 %, p < 0.0001, ANCHOR), Lp-PLA(2) (14 %, p < 0.001, MARINE; 19 %, p < 0.0001, ANCHOR), and hsCRP levels (36 %, p < 0.01, MARINE; 22 %, p < 0.001, ANCHOR), but did not significantly change ICAM-1 and IL-6 levels. In the MARINE study, IPE 2 g/day did not significantly change ICAM-1, Ox-LDL, Lp-PLA(2), IL-6, or hsCRP levels. Also, compared to placebo in the ANCHOR study, IPE 2 g/day significantly decreased Lp-PLA(2) levels (8 %, p < 0.0001), but did not significantly change levels of other assessed inflammatory markers.ConclusionCompared to placebo, in hypertriglyceridemic patients, IPE 4 g/day significantly decreased Ox-LDL, Lp-PLA(2), and hsCRP levels.

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Tyrosinase inhibition by p-coumaric acid ethyl ester identified from camellia pollen.

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Tyrosinase inhibition by <i>p</i>-coumaric acid ethyl ester identified from camellia pollen.

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