Borrowing a technique from plants, researchers at the University of Pennsylvania’s dental school have infused lettuce with the three proteins that make up insulin, the drug that controls symptoms of diabetes.

Unlike animals, plant cells have sturdy walls.

In the insulin-laden lettuce, those tough walls allow the cells to survive their journey through the stomach intact and only break down when they reach the intestine.

There, they release their proteins, which are then sent directly to the liver to do their work.

In tests using diabetic mice, the insulin-bearing lettuce evened out blood sugar levels within 15 minutes. Mice receiving insulin by injections sometimes experienced blood sugar crashes, known as hypoglycemia.

“The risk of hypoglycemia is one of the biggest disadvantages of the current delivery system [for insulin] and can even result in a coma,” lead researcher Henry Daniell told Science magazine. 

“Our insulin, given orally, has all three proteins [needed to make insulin] and is delivered right to the liver. It works just like natural insulin, which minimizes the risk of hypoglycemia,” he noted.

The mouse tests showed no adverse effects in the mice or other genetic alterations in the lettuce.

The special lettuce was created with a “gene gun” that shot human insulin cells through the lettuce’s cell walls into the cells’ interiors. The genes then were incorporated into the cells’ genomes.

Previously, Daniell had developed his expertise with gene guns at the University of Florida, where he shot medicinal genes into tobacco leaves.

TRENDPOST: Insulin injections can lead to hypoglycemia. Delivering insulin through an implanted pump costs around $6,500 just to buy the device, which wears out after three or four years.

In contrast, the insulin-carrying lettuce can be simply freeze-dried, ground, and stored. 

Human trials are being planned.

More broadly, Daniell’s lettuce advances the field of nutraceuticals—foods engineered to contain enhanced versions of natural substances that can be used in place of synthetic drugs but have the same beneficial effects.

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