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Received Jul 7, 2017; Revised Oct 23, 2017; Accepted Nov 27, 2017
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1. 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. To detect the free radical scavenging ability of antioxidants, 1,1-diphenyl-2-picrylhydrazyl (DPPH) is commonly used [3]. Different types of tea extracts were produced to investigate their respective antioxidant activity. Chelating capacity involves a central metal ion attached to a large molecule, which is a ligand, and forms a ring structure. 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].
Melanoma typically starts from melanocytes, which are the cells that produce melanin. Melanoma often originates from melanocytes within moles on the skin during early stages. However, when treatments are ineffective and melanoma cells spread rapidly, metastatic melanoma occurs. The ultraviolet (UV) rays are one of the known causes of melanoma [6]. Our skin has the ability to protect us from exterior factors, controls body temperature, and stores water and fat. However, skin cancer happens during extended exposure of sunlight, leading to cancerous benign or malignant tumors, which is now a major cause of death among patients [7].
Tea is a well-known beverage across the world. Tea polyphenols, which are antioxidative, includes epigallocatechin (EGC), epicatechin (EC), epigallocatechin gallate (EGCG), and epicatechin gallate (ECG). EGCG is the most abundant catechin within a tea leaf, which accounts for 30% of the total polyphenol in...