Health promoting effects of brassica-derived phytochemicals: from chemopreventive and anti-inflammatory activities to epigenetic regulation

Abstract

A high intake of brassica vegetables may be associated with a decreased chronic disease risk. Health promoting effects of Brassicaceae have been partly attributed to glucosinolates and in particular to their hydrolyzation products including isothiocyanates. In vitro and in vivo studies suggest a chemopreventive activity of isothiocyanates through the redox-sensitive transcription factor Nrf2. Furthermore, studies in cultured cells, in laboratory rodents, and also in humans support an anti-inflammatory effect of brassica-derived phytochemicals. However, the underlying mechanisms of how these compounds mediate their health promoting effects are yet not fully understood. Recent findings suggest that brassica-derived compounds are regulators of epigenetic mechanisms. It has been shown that isothiocyanates may inhibit histone deacetylase transferases and DNA-methyltransferases in cultured cells. Only a few papers have dealt with the effect of brassica-derived compounds on epigenetic mechanisms in laboratory animals, whereas data in humans are currently lacking. The present review aims to summarize the current knowledge regarding the biological activities of brassica-derived phytochemicals regarding chemopreventive, anti-inflammatory, and epigenetic pathways.

Figure 1

Myrosinase-mediated hydrolysis of glucosinolates with main break-down products (modified according to [114]).

Figure 2

Chemical structures of selected aliphatic and aromatic brassica-derived phytochemicals.

Figure 3

CpG islands in the promoter of Nrf2 (a) and Keap1 (b) identified by using the database dbcat (http://dbcat.cgm.ntu.edu.tw/).

Figure 4

Predicted binding sites of conserved microRNAs of Nrf2 (a) and Keap1 (b) as identified by http://www.microrna.org/microrna/home.do.

Figure 5

MicroRNAs being involved in the regulation of Nrf2 and Keap1.

Figure 6

Potential chemopreventive, anti-inflammatory and epigenetic mechanisms by which brassica-derived phytochemicals may mediate health benefits (partly adapted from [, –118]).