Orange lichens could be source of future anti-cancer drug

20 Oct 2015

It’s always a bold claim, but researchers analysing samples of orange lichens suggest that its pigment could hold the key to developing an anti-cancer drug.

The pigment, also found in rhubarb, is quite abundant in the natural world, and with the help of some tweaking, could develop an anti-cancer drug for the treatment of leukaemia.

According to the researchers who have made the discovery at the Winship Cancer Institute at Emory University in Georgia in the US, the pigment, officially called either physcion or parietin, could potentially slow the growth of, as well as kill, human leukaemia cells obtained directly from patients.

Most importantly, it will prevent toxicity to human blood cells, the authors report in their paper posted to Nature Cell Biology.

The research team led by Prof Jing Chen said the pigment could also inhibit the growth of human cancer cell lines, derived from lung and head and neck tumours, when grafted into mice.

Explaining the base concept, Prof Chen said: “This is part of the Warburg effect, the distortion of cancer cells’ metabolism. We found that 6PGD is an important metabolic branch point in several types of cancer cells.”

By obtaining samples of cancer cells from a patient diagnosed with acute lymphoblastic leukaemia, a dose of the parietin was found to have killed half the leukaemia cells in a culture within a period 48 hours, without damaging the other healthy cells.

Meanwhile, a more potent version of parietin, dubbed S3, is believed to be capable of having uses in treating lung cancer also as it was shown to have cut the growth of a lung cancer cell line by a factor of three over 11 days when the cells were implanted into mice.

There is still more research to be undertaken, however, with the 6PGD inhibitors used for this new potential treatment of leukaemia, in order to assess any potential side effects, as well as to see whether it could negatively affect people with inherited conditions, leading to greater sensitivity.

Orange lichens image via Shutterstock

Colm Gorey was a senior journalist with Silicon Republic