Saffron takes on cancer

Best known as a food seasoning and dye, saffron can also stifle liver cancer in rats, tests show. In a report in the September Hepatology, researchers find that the spice suppresses a slew of known cancer-related compounds and boosts several beneficial ones.

Saffron is an expensive spice made from the Crocus sativus flower. Past studies have hinted it has benefits against depression, inflammation, memory loss and as an antioxidant. Studies in animals and in human cells have even suggested that saffron can inhibit certain cancers. “But the exact mechanism of the anticancer effect of saffron is unclear,” says Amr Amin, a molecular biologist at United Arab Emirates University in Al-Ain.

Although the spice has been used as a folk remedy for centuries, only in recent decades has its value been tested in the laboratory. In the new study, Amin and his colleagues fed saffron to 24 rats daily for 24 weeks. Two weeks into the regimen the researchers injected the animals with diethylnitrosamine and 2-acetylaminofluorene, a chemical combination known to cause liver cancer.

Eight other rats getting a similar injection combo received distilled water instead of saffron. Six of them developed cancerous growths called nodules on the liver during the course of the study, whereas only four of the 24 rats getting saffron developed nodules. Of eight rats that got the highest dose of saffron, none developed any nodules.

Amin says his team chose to study liver cancer because cancers that spread from other organs, such as the colon or breast, often end up there.

Saffron kept in check a cell-proliferation protein called Ki-67 and reduced other compounds linked to liver damage and oxidative stress. Oxidative stress results from an imbalance between unstable, reactive molecules called free radicals and the antioxidants that sop them up. This tilt can lead to aberrant cell growth, a precursor to cancer, Amin says. Antioxidants, including one called superoxide dismutase, were restored in the rats getting saffron.

A separate series of tests on human liver cancer cells showed that saffron inhibits the action of key proteins — NF-kappa B, interleukin-8 and tumor necrosis factor receptor 1 — that contribute to cell proliferation and inflammation. Other evidence shows that saffron switches on programmed cell death in cancerous cells, a failsafe mechanism that is often shut down in cancer.

“This is very extensive work, and the quality is very good,” says Tapas Saha, a molecular biologist at the Georgetown University Lombardi Comprehensive Cancer Center. But Saha, who wasn’t involved in this study, says that scaling up these findings to apply them as a treatment in people might be a challenge. Saffron must be hand-picked, he notes, and so the price remains high. “Saffron is such a costly material,” he says, “that it’s very difficult to understand how it can be a drug.”

Synthetic versions of the important saffron components might be less expensive. Amin says further research may delineate those constituents.  Meanwhile, the team plans to test the spice in liver cancer patients.