An orange pigment found in lichens and rhubarb called parietin could slow the growth and kill human leukaemia cells, scientists at Winship Cancer Institute of Emory University in Atlanta have discovered.
The findings are published in the journal Nature Cell Biology.
Parietin, also known as physcion, shows no toxicity to human blood cells, the authors report. It could also be effective in treating lung and head and neck tumours they say.
Parietin appears to inhibit the metabolic enzyme 6PGD (6-phosphogluconate dehydrogenase), which is part of the response that causes rapid cellular growth. Researchers have already found 6PGD enzyme activity increased in several types of cancer cells.
“This is part of the Warburg effect, the distortion of cancer cells’ metabolism,” says team leader Jing Chen, professor of hematology and medical oncology at Emory University School of Medicine and Winship Cancer Institute.