The Role of Isothiocyanates as Cancer Chemo-Preventive, Chemo-Therapeutic and Anti-Melanoma Agents

Abstract

Many studies have shown evidence in support of the beneficial effects of phytochemicals in preventing chronic diseases, including cancer. Among such phytochemicals, sulphur-containing compounds (e.g., isothiocyanates (ITCs)) have raised scientific interest by exerting unique chemo-preventive properties against cancer pathogenesis. ITCs are the major biologically active compounds capable of mediating the anticancer effect of cruciferous vegetables. Recently, many studies have shown that a higher intake of cruciferous vegetables is associated with reduced risk of developing various forms of cancers primarily due to a plurality of effects, including (i) metabolic activation and detoxification, (ii) inflammation, (iii) angiogenesis, (iv) metastasis and (v) regulation of the epigenetic machinery. In the context of human malignant melanoma, a number of studies suggest that ITCs can cause cell cycle growth arrest and also induce apoptosis in human malignant melanoma cells. On such basis, ITCs could serve as promising chemo-therapeutic agents that could be used in the clinical setting to potentiate the efficacy of existing therapies.

Keywords: cell cycle; chemo-therapy; cruciferous vegetables; glucosinolates; growth arrest; isothiocyanates; malignant melanoma; skin cancer.

Figure 1

The structures of major isothiocyanates (ITCs).

Figure 2

Hydrolysis of glucosinolates by myrosinase.

Figure 3

Schematic representation of the proposed molecular pathways targeted by isothiocyanates (ITCs), glutathione (GSH), uridine 5′-diphospho-glucuronosyltransferase (UDPG), quinone reductase (QR).