Tea polyphenols and prevention of epigenetic aberrations in cancer

Abstract

Tea polyphenols are secondary metabolites of tea plants and are well known for beneficial health effects. They can protect from a variety of illnesses including cancers. Tea polyphenols can prevent cancer by modulating epigenetic aberrations taking place in DNA methylation, histone modifications, and micro-RNAs. By altering these epimutations, they regulate chromatin dynamics and expression of genes those induce or suppress cancer formation. However, majority of the studies in existing literature are carried out for green tea polyphenols rather than black tea polyphenols despite the fact that black tea is the most commonly consumed form of tea (78%) followed by green tea (20%) and other forms of tea. Research findings indicate that tea polyphenols may be potential source from which drugs with less side effects and affordable price can be developed.

Beneficial Properties of Green Tea Catechins

“…Therefore, many in vivo studies determine the effect of the amount of consuming green tea on the reduction of incidence of malignant tumors, including colorectal cancer, stomach cancer, liver cancer [19] or lung cancer [38]. These results concern drinking more than ten cups of green tea infusions per day [40]. However, on the other side, one study indicates an increased risk of developing bladder cancer when consuming five to nine cups of green tea infusions per day.…”

“…Available literature data indicate that polyphenols derived from green tea exert their antitumor activity due to modification of histones, micro-RNA as well as DNA methylation [40]. Figure 3 presents a summary of molecular signaling pathways of green tea catechin.…”

Synthesis method‐dependent photothermal effects of colloidal solutions of platinum nanoparticles used in photothermal anticancer therapy

“…Nevertheless, high percentage of cell mortality was observed after irradiation and 24‐h incubation (Figure URE 8), especially for Pt NPs synthesized by green chemistry methods. Green tea has been reported to prevent carcinogenesis . It has also been reported that catechins from green tea have a synergetic effect with anticancer drugs in tertiary cancer prevention .…”

“…In the literature, anticancer properties of green tea have been reported, which are attributed to the presence of polyphenols, such as epicatechin, epigallocatechin, epicatechin‐3‐gallate, and epigallocatechin‐3‐gallate . Several studies have shown that drinking green tea can prevent carcinogenesis and the development of various types of cancers Moreover, green tea polyphenols are responsible for the regulation of different cancer‐related processes and factors, including DNA methylation and microRNA, histone, and protein modification . Recently, it was shown that green tea plays a very important role in cancer prevention .…”

“…Green tea has been reported to prevent carcinogenesis. [21,[62][63][64] It has also been reported that catechins from green tea have a synergetic effect with anticancer drugs in tertiary cancer prevention. [68][69][70] Therefore, we assume that in our experiment a synergetic effect of laser irradiation and anticancer properties of green tea occurs.…”