Researchers from the University of Warwick concluded the compound could function as a “dietary activator”, and thereby “prevent biochemical dysfunction and related functional responses of endothelial cells induced by hyperglycemia”.
Endothelial cells are those that form a thin layer on the interior of blood vessels. Their dysfunction is a major cause of morbidity and mortality among diabetics and has also been linked to problems such as kidney disease.
Hyperglycemia is the condition of having elevated blood sugar levels.
Lead researcher Professor Paul Thornalley and his colleagues found the compound – sulforaphane – provoked production of a protein called nrf2 that was beneficial to blood vessel health, even those damaged by hyperglycemia.
Thornalley’s team observed a 73 per cent reduction of Reactive Oxygen Species (ROS), which are commonly known as free radicals. ROS levels have been known to increase by as much as 300 per cent in diabetics.
“Our study suggests that compounds such as Sulforaphane from broccoli may help counter processes linked to the development of vascular disease in diabetes,” said Thornalley.
“In future, it will be important to test if eating a diet rich in Brassica vegetables has health benefits for diabetic patients. We expect that it will.”
A free-radical reducing, antioxidant effect was observed among the incubated human endothelial cells kept in low and high glucose concentrations (five and 30mM). Activation of nrf2 was assessed by nuclear translocation.
The presence of sulforaphane doubled the activation of nrf2.
“Sulforaphane prevented hyperglycemia-induced activation of the hexosamine and protein kinase C pathways, and prevented increased cellular accumulation and excretion of the glycating agent, methylglyoxal,” the researchers wrote.
The study adds to a small but growing body of evidence demonstrating the potential for Brassica vegetables such as broccoli, Brussels sprouts, suedes, turnips and cabbages to benefit diabetic conditions.
Other studies have shown their consumption can ward off the onset of diabetes.
One such study conducted at the Tulane University School of Public Health and Tropical Medicine in New Orleans found increased intake of green leafy vegetables may reduce the risk of women developing type-2 diabetes.
Published in the journal Diabetes Care, the epidemiological study of 71,346 female nurses found for every additional serving of green leafy vegetables, the risk of developing diabetes may be reduced by almost 10 per cent.
The study followed the women, none of whom had diabetes, heart disease or cancer at the start of the study, for 18 years.
An estimated 19 million people are affected by diabetes in the EU 25, equal to four per cent of the total population. This figure is projected to increase to 26 million by 2030.
In the US, there are over 20 million people with diabetes, equal to seven per cent of the population. The total costs are thought to be as much as $132 billion, with $92 billion being direct costs from medication, according to 2002 American Diabetes Association figures.
Published online August 4, 2008, as db06-1003
"Activation of NF-E2-related factor-2 reverses biochemical dysfunction of endothelial cells induced by hyperglycemia linked to vascular disease"
Authors: Mingzhan Xue, Qingwen Qian, Adaikalakoteswari Antonysunil, Naila Rabbani, Roya Babaei-Jadidi, and Paul J. Thornalley