Extracts of turmeric - a condiment commonly used in Indian cuisine - can be rendered soluble and delivered to tumours to kill cancer cells, scientists say. Turmeric is known for its therapeutic effect and as a way to kill germs present in raw meat. Recently, scientists have also discovered that curcumin, a naturally occurring substance isolated from turmeric, is an effective agent for killing cancer cells. "Until now, however, curcumin is what we call in pharmaceutical science as a 'false lead' - it is therapeutic, but the full effect can't be utilised because it's poorly soluble in water," said Dipanjan Pan, an associate professor at the University of Illinois at Urbana-Champaign in the US. "When you try to deliver a drug, it requires solubility in water, otherwise it won't flow through the bloodstream," said Santosh Misra, a post-doctoral researcher working with Pan. Researchers including those from the University of Utah in the US created a sophisticated metallocyclic complex using platinum that enabled curcumin's solubility. The study, published in the journal PNAS, showed that the complex was 100 times more effective in treating various cancer types such as melanoma and breast cancer cells than using curcumin and platinum agents separately. Curcumin has shown to prevent the phosphorylation of STAT3, a well-known signalling pathway that triggers the growth of cancer cells and allows them to survive, in in vivo studies. The platinum-curcumin combination kills the cells by fragmenting its DNA. Although the researchers have only tested the method in delivering curcumin, its contribution to cancer treatment will ultimately also come from the likelihood the method will work with other drugs as well. "In cancer therapy, one of the measures that constrains a number of the drugs is their poor solubility," Pan said. "Viability only becomes prominent when the drug becomes soluble in water. So, no matter how the drug is given, intravenously or orally, it needs to eventually be absorbed by the organs in the body," he said. Pan's team also hopes to prove that this method will be effective in killing cancer stem cells, in effect cancer's root system, preventing the diseases from recurring in patients.