Capsules of insulin produced in genetically modified lettuce could hold the key to restoring the bodys ability to produce insulin and help millions of Americans who suffer from insulin-dependent diabetes, according to University of Central Florida biomedical researchers.

Professor Henry Daniells research team genetically engineered tobacco plants with the insulin gene and then administered freeze-dried plant cells to five-week-old diabetic mice as a powder for eight weeks. By the end of the study, the diabetic mice had normal blood and urine sugar levels, and their cells were producing normal levels of insulin.

Those results and prior research indicate that insulin capsules could someday be used to prevent diabetes before symptoms appear and treat the disease in its later stages, Daniell said. He has since proposed using lettuce instead of tobacco to produce the insulin because that crop can be produced cheaply and avoids the negative stigma associated with tobacco.

The National Institutes of Health provided $2 million to fund the UCF study. The findings are reported in the July issue of Plant Biotechnology Journal.

Insulin-dependent, or Type 1, diabetes is an autoimmune disease in which the bodys immune system attacks and destroys insulin and insulin-producing beta cells in the pancreas. Insulin is a hormone that is needed to convert sugar, starches and other food into energy.

Insulin typically is given through shots and not pills so the hormone can go straight into the bloodstream. In Daniells method, plant cell walls made of cellulose initially prevent insulin from degrading. When the plant cells containing insulin reach the intestine, bacteria living there begin to slowly break down the cell walls and gradually release insulin into the bloodstream.

Currently, the only relief for diabetes is a momentary relief, Daniell said. Diabetics still have to monitor their blood and urine sugar levels. They
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Contact: Chad Binette
cbinette@mail.ucf.edu
407-823-6312
University of Central Florida
30-Jul-2007