Antioxidative and Antimelanoma Effects of Various Tea Extracts via a Green Extraction Method

Yihui Chen,Yichi Lin,Yi-Ru Lu,Jyun-Yin Huang,I-Fan Lin,Hui-Min David Wang,Li-Heng Liu

doi:10.1155/2018/5156073

Abstract

Tea (Camellia sinensis) contains high level of antioxidant elements and is a well-known beverage consumed worldwide. The purpose of this study is to compare different concentrations of green tea, black tea, oolong tea 861, oolong tea 732, and jasmine green tea. These five types of tea extracts were known to have antioxidative properties, reducing power, and metal ion chelating activity. The current study compared these five extracts in terms of their inhibiting effects on human malignant melanoma: A2058 and A375. To determine the cell viability between normal cell and malignant melanoma cells, an MTT assay was applied to evaluate the cytotoxic potential on human melanoma cells, with all tea extracts showing decreased cell viability with increasing tea extract concentrations. Cytotoxicity on HaCat (normal skin cells) showed no effect on the cell viabilities at lower concentrations of the tea extracts. These results suggest the antioxidative effect of five tea extracts that protect against oxidation and melanoma production, with green tea and jasmine green tea showing the lowest cell viability when tested against malignant melanoma cells.

Highlights

Antioxidative compounds derived from natural plant species may help keep human skin at a physiologically healthy state by decreasing oxidative stress [1]
Ascorbic acid (Vitamin C), ethylenediaminetetraacetic acid (EDTA), L-3,4-dihydroxyphenylalanine (L-DOPA), dimethyl sulfoxide (DMSO), 1,1diphenyl-2 picrylhydrazyl (DPPH), ethanol, ferrouschloride (FeCl2⋅4H2O), ferric chloride (FeCl3), kojic acid, methanol, potassium ferricyanide (K3Fe(CN)6), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 3-tertbutyl-4-hydroxyanisole (BHA), and L-tyrosine were purchased from Sigma-Aldrich Company
The absorbance at 517 nm was monitored when the DPPH radical is neutralized, as the solution turns from blue violet to light yellow in color

Summary

Introduction

Antioxidative compounds derived from natural plant species may help keep human skin at a physiologically healthy state by decreasing oxidative stress [1]. By reducing oxidative stress from reactive oxygen species (ROS), antioxidative compounds can prevent ROS-induced skin damage [2]. Oxidation produces free radicals that may lead to chain reactions, which can potentially lead to cell damage. The ferric reducing potential assay is another way to analyze antioxidative properties, which involves the quantification of the reducing ability of antioxidants in reaction with a 2,4,5-tripyridyl-S-triazine Fe(III) (TPTZ) complex that forms a ferrous Fe(II)-TPTZ complex with a dark blue color [4]. A2058 is a highly invasive cell line from a 43-year-old male patient with malignant melanoma. A375 is cell line from a 54-year-old female patient with malignant melanoma. HaCaT cells are immortalized human keratinocytes, which are used for the study of epidermal homeostasis [5]

Objectives

Methods

Results

Conclusion