Some women have turned to hop extract as an alternative natural remedy to hormone replacement therapy to ease symptoms of menopause.
The researchers, from a center in the University of Illinois at Chicago (UIC) that investigates the safety and health effects of botanical dietary supplements, report their findings in the journal Chemical Research in Toxicology.
To help ease hot flashes and other symptoms of menopause, some women take hormone replacement therapy (HRT), which replaces the hormones that have been lost, including estrogen.
However, HRT has been linked to raised risk of breast cancer and heart disease, so some women have turned to natural alternatives, one of which is hops extract, which contains phytoestrogens or plant-based estrogens. However, their effect on cancer risk is unclear.
The UIC researchers note that preliminary studies using lab tests have suggested some active compounds found in hops may have protective effects, so they decided to investigate further.
Hop extract and 6-PN boost a cell detoxification pathway
In their paper, Dr. Judy L. Bolton, whose research interests include chemical toxicology, and colleagues describe how they ran lab tests on breast cells to investigate the effect of hop extract.
They tested the effect of enriched hop (Humulus lupulus L.) extract on estrogen metabolism - a process that is involved in the development of breast cancer.
The team tested the effect on two different breast cell lines. They found one hops compound in particular - 6-prenylnaringenin or 6-PN - boosted a pathway the cells use to remove toxins. Other studies have linked this pathway to lower risk for breast cancer.
The authors note the "results indicated that the hop extract and 6-PN preferentially induced the 2-hydroxylation pathway in both cell lines."
They conclude that their findings suggest 6-PN may have anti-cancer properties, which now need to be more deeply investigated and confirmed with further research.
In the United States in 2012 (the most recent year for which numbers are available), 224,147 women and 2,125 men were diagnosed with breast cancer, and 41,150 women and 405 men died of the disease.