Fucoxanthin and Colorectal Cancer Prevention

Abstract

Colorectal cancer (CRC), which ranks among the top 10 most prevalent cancers, can obtain a good outcome with appropriate surgery and/or chemotherapy. However, the global numbers of both new cancer cases and death from CRC are expected to increase up to 2030. Diet-induced lifestyle modification is suggested to be effective in reducing the risk of human CRC; therefore, interventional studies using diets or diet-derived compounds have been conducted to explore the prevention of CRC. Fucoxanthin (Fx), a dietary carotenoid, is predominantly contained in edible brown algae, such as Undaria pinnatifida (wakame) and Himanthalia elongata (Sea spaghetti), which are consumed particularly frequently in Asian countries but also in some Western countries. Fx is responsible for a majority of the anticancer effects exerted by the lipophilic bioactive compounds in those algae. Interventional human trials have shown that Fx and brown algae mitigate certain risk factors for CRC; however, the direct mechanisms underlying the anti-CRC properties of Fx remain elusive. Fx and its deacetylated type "fucoxanthinol" (FxOH) have been reported to exert potential anticancer effects in preclinical cancer models through the suppression of many cancer-related signal pathways and the tumor microenvironment or alteration of the gut microbiota. We herein review the most recent studies on Fx as a potential candidate drug for CRC prevention.

Keywords: cancer prevention; carotenoid; colorectal cancer; fucoxanthin; gut microbiota; tumor microenvironment.

Figure 1

Ingestible routes of Fx in humans. (A) Chemical structures of fucoxanthin (Fx) and fucoxanthinol (FxOH). (B) Ingestible routes of Fx in humans. Whole brown algae, such as Undaria pinnatifida (Wakame) and Sargassum horneri (Akamoku), collected in the winter, when the content of Fx is the highest, may be beneficial for human health. Furthermore, Fx extracted from brown algae and microalgae can be added to various edible items to customize their route of ingestion by humans.

Figure 2

Possible mechanisms underlying the cancer chemopreventive effects of whole brown algae, fucoxanthin (Fx)-rich extract, Fx and fucoxanthinol (FxOH) against colorectal cancer (CRC). ACF, aberrant crypt foci; TME, tumor microenvironment. ↑, induction or increase; ↓, inhibition or decrease.