Heart-health Benefits of Broccoli Extract Pinpointed
Lee Swanson Research Update
A new study from the United Kingdom says that a compound found in vegetables like broccoli, cabbage and cauliflower may protect arteries from disease by boosting a natural defense mechanism.
Researchers from Imperial College London (ICL) report that sulforaphane, a compound most widely associated with broccoli, may activate a protein called Nrf2 in arteries. While the protein is normally protective, in areas of arteries that are susceptible to disease the London-based researchers found that Nrf2 is inactive.
"We found that the innermost layer of cells at branches and bends of arteries lack the active form of Nrf2, which may explain why they are prone to inflammation and disease," explained Dr. Paul Evans, from the national Heart and Lung Institute at ICL.
"[Exposure to] the natural compound sulforaphane reduced inflammation at the high-risk areas by ‘switching-on’ Nrf2," he added.
"Sulforaphane is found naturally in broccoli, so our next steps include testing whether simply eating broccoli, or other vegetables in their ‘family,’ has the same protective effect. We also need to see if the compound can reduce the progression of disease in affected arteries."
The tissue of cruciferous vegetables like broccoli, cauliflower, cabbage and Brussels sprout, contains high levels of the active plant chemicals glucosinolates. These are metabolized by the body into isothiocyanates, which are known to be powerful anti-carcinogens. The main isothiocyanate from broccoli is sulforaphane.
The researchers used mice engineered to lack the Nrf2 protein and compared their arteries with those of normal mice. Prof. Evans and his team found that in straight sections of arteries Nrf2 was present in the endothelial "lining" cells. Through its action on other proteins, it prevented the cells from becoming inflamed, which is an early stage in the development of atherosclerosis. Known as hardening or furring of the arteries, atherosclerosis is a key risk factor for cardiovascular disease, the cause of over 50% of deaths in Europe and the US.
When the researchers looked at the lining cells of disease-prone sites they found that Nrf2 was attached to a protein that made it inactive. This effectively prevented it from exhibiting its protective properties.
When these cells were exposed to sulforaphane, a re-activation of Nrf2 in the disease-prone regions of the artery was observed. This indicated that the cells’ ability to protect themselves from becoming inflamed was restored, said the researchers.
Atherosclerosis Thrombosis and Vascular Biology Published online ahead of print.