Plant flavonoid inhibits growth of colon cancer cells

23 January 2012

Luteolin, a compound commonly found in fruit and vegetables, has been found to block cell processes important for the growth of colon cancer cells.

New research published in BioMed Central’s open access journal BMC Gastroenterology shows that the plant flavonoid luteolin is able to inhibit the activity of the cell signalling pathways (IGF and PI3K) which promote growth of colon cancer cells.

Luteolin has been shown in laboratory conditions to also have anti-inflammatory, anti-oxidant and anti-cancer properties, but results from epidemiological studies have been less certain.

Colon cancer is the second most frequent cause of cancer-related death in the Western World. Colon cancer cells have elevated levels of IGF-II compared to normal colon tissues. It is thought that this is part of the mechanism driving uncontrolled cell division and cancer growth. Researchers from Korea showed that luteolin was able to block the secretion of IGF-II by colon cancer cells and within two hours decreased the amount of receptor (IGF-IR) precursor protein. Luteolin also reduced the amount of active receptor (measured by IGF-I dependent phosphorylation).

Luteolin inhibited the growth stimulatory effect of IGF-I and the team led by Prof Jung Han Yoon Park found that luteolin affected cell signalling pathways which are activated by IGF-I in cancer.  Prof Jung Han Yoon Park explained, “Luteolin reduced IGF-I-dependent activation of the cell signaling pathways PI3K, Akt, and ERK1/2 and CDC25c. Blocking these pathways stops cancer cells from dividing and leads to cell death.”

Prof Jung Park continued, “Our study, showing that luteolin interferes with cell signalling in colon cancer cells, is a step forward in understanding how this flavonoid works. A fuller understanding of the in vivo results is essential to determine how it might be developed into an effective chemopreventive agent.”