Posted by: Hourglass PJ30 OCT 2013
When I qualified as a pharmacist rarely a day went by when I did not measure out liquorice liquid extract to make a cough mixture, whether Mist Ammon Ipecac, Mist Ammon Chlor et Morph or Mist Morph et Ipecac. All these popular cough mixtures contained liquorice liquid extract. But that is a long time ago. Yet my interest in liquorice, which did not begin with eating liquorice allsorts in childhood — I never liked them — hangs on from my early dispensing experiences. Sad, perhaps, but I did miss preparing those cough bottles.
Liquorice has been used as a food or in medicine for thousands of years, but recent research from the University of Minnesota suggests a possible new use for liquorice in treating melanoma, a particularly dangerous form of skin cancer if not found early. Liquorice root has long been known to have anti-inflammatory and anticancer activities. However, this knowledge has been of limited practical use in medicine because glycyrrhizin, the most abundant constituent in dried liquorice root, is associated with several side effects, such as hypertension, hypertensive encephalopathy and hypokalaemia, particularly when used in high doses or long-term.
Risk of adverse effects has led to the search for other compounds in liquorice, a search that has recently led to the discovery of isoangustone A (IAA), a novel flavonoid present in liquorice root, which suppresses proliferation of human melanoma cells. When applied directly to human melanoma cancer cells in the laboratory, IAA was found to block progression of the so-called G1 phase of the cancer cell cycle and inhibit the expression of G1-phase regulatory proteins, including cyclin D1 and cyclin E.
This novel compound also inhibits various other activities within the human cancer cell lines, suppressing growth of the tumour. When the researchers applied IAA in a mouse model, the findings were the same.
A variety of molecular targets seem to be involved in the anticancer activity of this novel liquorice compound, mainly phosphatidylinositol 3-kinase (PI3-K), mitogen-activated protein kinase 4 (MKK4) and MKK7. The researchers hope these will provide a biological basis for the development of new chemotherapeutic agents for melanoma.
So, although I have long stopped pouring liquorice extract in the dispensary, liquorice may find a new use in the 21st century as a treatment for melanoma.