Previous studies have already demonstrated that the spice has an anti-cancer effect.
The new research, published online today (DOI: 10.1002/cncr.21216) and scheduled for the 15 August print issue of Cancer, also reveals how curcumin acts against this type of tumour.
Incidence of melanoma, or skin cancer, is increasing rapidly in countries like the UK, where there are more than 70,000 cases of melanoma and non-melanoma reported each year. Malignant melanoma affects over 7,000 people in the UK with 1,600 deaths a year.
Researchers led by Razelle Kurzrock of the University of Texas Anderson Cancer Center in Houston treated three melanoma cell lines with curcumin at different doses and for different duration.
Results show that curcumin treatment decreased cell viability in all three cell lines in a dose-dependent manner. Moreover, curcumin induced apoptosis in tumour cells at high concentrations for short periods of time and low concentrations for long periods of time - a new finding in the study of curcumin, said the researchers.
Curcumin was found to suppress two specific proteins normally part of an intracellular pathway that prevents apoptosis when stimulated.
Curcumin partially inhibited NF-êB and strongly inhibited its upstream stimulator and another independent inhibitor of apoptosis, IKK. However, it did not suppress two other signaling pathways associated with melanomas and tumour proliferation, B-Raf/MEK/ERK and Akt pathways.
"Based on our studies, we conclude the curcumin is a potent suppressor of cell viability and inducer of apoptosis in melanoma cell lines," said the authors.
They added: "Future investigation to determine the effects of curcumin in animal models of melanoma and clinical trials are planned."
Turmeric has also been shown to stop the spread of breast cancer in mice, while epidemiological studies have linked high consumption of turmeric to lower rates of breast cancer, prostate cancer, lung cancer and colon cancer.