Cancer Chemoprevention by Natural Carotenoids as an Efficient Strategy

The use of specific compounds to suppress the growth of tumors or reverse carcinogenesis is defined as chemoprevention. Natural products have been known as one of the most important resources of anticancer agents. Among them, carotenoids are lipophilic molecules accumulating in lipophilic compartments including lipoproteins and/or membranes. Various carotenoids were used as major phytonutrients to inhibit the development of tumors in vitro and in vivo. They have shown different functions such as scavenging free radicals, inhibition of angiogenesis, prevention of cell propagation, and apoptosis induction in lung, colon, breast and prostate. Regarding these roles, most carotenoids possess anti-oxidant properties. However, their therapeutic use is problematic due to the lack of solubility of carotenoids in water. Hence, recent studies have been focused on uncommon carotenoids soluble in water because of their glycosylated form, such as crocin(s) extracted from saffron. These structures with their cytotoxicity effects on human cancer cells are suggested as the most suitable compounds for cancer treatment. Herein, we summarize different functions of carotenoids for suppressing tumor growth.