Curcumin, the natural pigment that gives the spice turmeric its yellow colour, may protect against heart failure - in mice at least - suggests a new study from Canada.
When the pigment was given to mice with enlarged hearts (hypertrophy), heart function was restored and scar formation reduced, report the researchers in the February edition of the Journal of Clinical Investigation.
Lead researcher Peter Liu, scientific director at the Canadian Institutes of Health Research - Institute of Circulatory and Respiratory Health said that curcumin might be a safe and effective means of preventing heart failure in the future, given that it is naturally occurring and readily available at a low cost.
"Whether you are young or old; male or female; the larger your heart is, the higher your risk is for developing heart attacks or heart failure in the future. However, until clinical trials are done, we don't recommend patients to take curcumin routinely. You are better off to take action today by lowering blood pressure, reducing cholesterol, exercising and healthy eating," he said.
Curcumin has come under the scientific spotlight in recent years, with studies investigating its potential benefits for reducing cholesterol levels, improving cardiovascular health, and fighting cancer.
Some experts recommend however that consumers wishing to make use of curcumin's properties consume it in supplement form rather than eating more curries, which tend to be rather high in fat in their Western form.
The Canadian researchers found that curcumin appeared to work by preventing abnormal unravelling of the chromosome under stress, in addition to preventing excessive abnormal protein production. The pigment was administered as a curcumin suspension using 0.5 per cent carboxy-methylcellulose solution,
"Curcumin's ability to shut off one of the major switches right at the chromosome source where the enlargement and scarring genes are being turned on is impressive," said Liu. However he cautioned that moderation is important, "the beneficial effects of curcumin are not strengthened by eating more of it."
Specifically, the pigment was found to act on p300-histone acetyltransferase (HAT), reportedly the most important HAT in muscle that "modifies chromatin and associated transcription factors and promotes gene activation," wrote the researchers.
The study was funded by the Heart and Stroke Foundation and the Canadian Institutes of Health Research.
"This study is relevant to the understanding of the inhibitory effect of curcumin on cardiac hypertrophy and related molecular mechanisms," wrote the researchers. "It also serves to elucidate the dominant signaling pathways leading to cardiac hypertrophy, inflammation, and fibrosis in response to hypertrophic stimuli."
"Curcumin is a natural polyphenolic compound that has already been used clinically and is approved by the FDA as a safe food additive. Future studies should examine the hypothesis that curcumin may be a safe and effective approach to preventing and treating cardiac hypertrophy and the transition to failure," they concluded.
In a related article in the same journal, Tatsuya Morimoto and co-workers from the National Hospital Organization in Kyoto report similar findings from a study with rats. The Japanese researchers tested curcumin in two models of heart failure - heart disease associated with high blood pressure in salt-sensitive rats, and surgically-induced myocardial infarction in rats.
They report that, in both cases, the pigment prevented increases in heart muscle wall thickness after heart failure.
"We believe that the use of curcumin, which targets nuclear signaling pathways in cardiomyocytes, will provide a novel therapeutic strategy against heart failure," wrote Morimoto and co-workers. "Future application of this nontoxic dietary natural compound as a therapeutic agent for heart failure in humans would be particularly interesting."
Curcumin-based treatments are currently in clinical trials for pancreatic and colorectal cancer patients with promising results.
Sources: Journal of Clinical Investigation
Available online, Free Access, doi: 10.1172/JCI32865
"Curcumin prevents and reverses murine cardiac hypertrophy"
Authors: Hong-Liang Li, C. Liu, G. de Couto, M. Ouzounian, M. Sun, A.-B. Wang, Y. Huang, C.-W. He, Y. Shi, X. Chen, M.P. Nghiem, Y. Liu, M. Chen, F. Dawood, M. Fukuoka, Y. Maekawa, L. Zhang, A. Leask, A.K. Ghosh, L.A. Kirshenbaum, P.P. Liu
Journal of Clinical Investigation
Available online, Free Access, doi: 10.1172/JCI33160
"The dietary compound curcumin inhibits p300 histone acetyltransferase activity and prevents heart failure in rats"
Authors: T. Morimoto, Y. Sunagawa, T. Kawamura, T. Takaya, H. Wada, A. Nagasawa, M. Komeda, M. Fujita, A. Shimatsu, T. Kita, K. Hasegawa