Current therapies for type 1 diabetes involve delivering insulin to the bloodstream. This can be done in a variety of ways. Patients can inject themselves with insulin, inhale the insulin or wear a pump that delivers the insulin to the bloodstream. The insulin does not cure the problem; it is only a momentary fix. Patients must continue to take insulin for the rest of their lives.
CAN LETTUCE HELP? Henry Daniell, Ph.D., a molecular biologist at the University of Central Florida in Orlando, Fla., has been experimenting with a new way to deliver insulin. He and his team inject the human gene for insulin into leafs of lettuce. The lettuce can be ground up and made into a powdered capsule. "This is genetically-modified lettuce," Dr. Daniell explained to Ivanhoe. "Every single cell in the lettuce leaf contains 10,000 copies of this insulin gene." He gave the lettuce powder to mice with diabetes once a week and the results were shocking. After just eight weeks of treatment, all the diabetic mice had normal blood sugar levels and their cells were producing normal levels of insulin. The researchers did not observe any adverse side effects in the mice. These 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.
HOW IT WORKS: In Dr. Daniell's method, the lettuce plant cells help the insulin reach the intestine. Once the plant cells get there, bacteria slowly break down the cell walls and gradually release insulin into the bloodstream. This creates an immune response in the body and teaches it to release its own insulin. "It is the same insulin that is injected, but here what we are doing is instead of injecting it in the blood system, we are presenting it to the immune cells and then asking the immune cells to see that this is your own protein," Dr. Daniell said. "What we have done is to teach the body how to cure this disorder. This is a totally new concept, a new platform to use this oral delivery system to fix this immune disorder."
Dr. Daniell says because this is a plant-based therapy, it would only cost pennies to produce. "You don't need to purify this," he noted. "You don't need to inject this, so all of these expenses, which are associated with human therapeutic delivery, are eliminated using this."
HUMAN TRIALS: The next step is to test the lettuce capsules in humans. Dr. Daniell says his research team already has offers from formal partners, and the University of Central Florida is negotiating with them to start a phase 1 clinical trial for human patients with type 1 diabetes. "We are anticipating the same result as we found in the animal model," Dr. Daniell remarked. He says his research may one day also help patients with type 2 diabetes, multiple sclerosis and some forms of arthritis.
FOR MORE INFORMATION, PLEASE CONTACT:
Henry Daniell, PhD
University of Central Florida, College of Medicine