Ginseng extract may help cancer sufferers

Synthesised derivatives of a compound extracted from ginseng appear to reduce the destructive side-effects of cancer therapies, according to a report this week in the journal PNAS.

Effective disease treatments often come from defensive compounds produced naturally by plants or other organisms. Chinese red ginseng (Panax ginseng) is a plant that has a variety of uses in Asian traditional medicine, and has been studied closely in recent years. Consuming the root has been shown to have therapeutic effects on cancer patients, some of which have been attributed to the antioxidant activities of the compound panaxytriol (PXT). Researchers at the Memorial Sloan-Kettering Center for Cancer Research led by Professor Samuel Danishefsky synthesised PXT and then carefully altered the original structure to try and enhance its therapeutic properties.

To determine whether these chemically synthesised derivatives had similar properties to naturally occurring PXT, they tested their effects on mice grafted with human breast or colon cancer tumours.

These compounds did not make a difference to tumour development when used alone, but when used alongside the chemotherapy drugs taxol, iso-fludelone and 5-fluorouracil they significantly reduced weight loss, peripheral nerve damage and hematotoxicity (loss of blood cells). Weight loss and hematotoxicity were also reduced in mice exposed to X-radiation that were first treated with a PXT-derivative. These mice also survived for longer after exposure than those that were not treated.

These findings have important implications for cancer treatment. Side-effects of chemo or radiotherapy include severe nausea, weight loss and damage to healthy cells that can hinder recovery, and as derivatives of PXT appear to have cytoprotective properties which limit these effects, they could potentially help ease the suffering of cancer patients.

Professor Danishefsky and his colleagues concluded that these compounds show great promise as potential drugs, although their chemical structures need to be optimised before any clinical trials can begin.