Fairytale Insulin Substitute
People with type I diabetes could one day be prescribed an extract from pumpkins that will drastically cut their reliance on daily insulin injections. The extract has been demonstrated to promote regeneration of damaged pancreatic cells in rats with diabetes, boosting levels of insulin-producing beta cells and insulin in the blood, according to researchers in China.
Tao Xia and colleagues at the East China Normal University found that diabetic rats fed the extract had only 5% less plasma insulin and 8% fewer insulin-positive (beta) cells compared to normal healthy rats.
Globally, diabetes affects more than 230 million people, almost 1 in every 17 people, the World Diabetes Foundation reports. The study looked only at rats representing type I diabetes sufferers, but the researchers believe the pumpkin extract may also play a role in type II diabetes.
The protective effect of the pumpkin extract is thought to be due to the presence of antioxidants and D-chiro-inositol, a molecule that mediates insulin activity. Boosting insulin levels has the effect of lowering blood sugar levels, which reduces levels of oxidative oxygen species that damage beta-cell membranes, preventing further damage and allowing for some regeneration. Beta cells levels in the diabetic rats are, however, unlikely ever to reach that of controls, because some of the cells will have been damaged beyond repair.
"Pumpkin extract is potentially a very good product for pre-diabetic persons," Xia explains, "as well as those who have already developed diabetes." He adds that insulin injections will almost certainly always be needed by those with diabetes; pumpkin extract could help reduce the amount of insulin they need to take.
David Bender of the Royal Free and University College Medical School, London, adds, "This research is very exciting, the main finding is that feeding pumpkin extract prevents the progressive destruction of pancreatic beta-cells... but it is impossible to say whether pumpkin extract would promote regeneration in humans." He points out that if the research proves efficacious in people too, then it would be a useful medication that could be taken by mouth.
J Sci Food Agric, 2007, 87, 1753-1757