A plant-based, oral delivery of insulin regulates blood sugar levels similar to natural insulin

Recent clinical studies show that injection via insulin pens can cause insulin to reach the bloodstream so quickly that hypoglycemia, or blood sugar levels that dip below the healthy range, may result. Automated insulin pumps can deliver precise insulin and minimize this risk but are expensive and available only to a small portion of diabetes patients around the world.

Now, a plant-based, oral delivery of proinsulin could address these drawbacks, according to a new study published in the journal Biomaterials.

The Daniell lab created a plant-based insulin that contains all three peptides and can be ingested orally. The strength of plant cell walls protects insulin from acids and enzymes in a patient’s stomach before the material is broken down by gut microbes. Then, the released insulin is delivered to the liver via the gut-liver axis.

Using diabetic mice, Daniell, and his team found that their plant-based insulin-regulated blood sugar within 15 minutes of ingestion very similarly to naturally secreted insulin. In comparison, mice treated with traditional insulin injections experienced rapidly decreased blood glucose levels leading to transient hypoglycemia.

To produce plant-based insulin, scientists identified human insulin genes and then used what Daniell calls a “gene gun” to blast the genes through the tough plant cell walls. The insulin genes are then integrated into the plant’s genome, in this case the lettuce genome. The resulting seeds permanently retained insulin genes, and subsequently grown lettuce was freeze-dried, ground, and prepared for oral delivery following6 FDA regulatory guidelines.

Reference: Affordable oral proinsulin bio encapsulated in plant cells regulates blood sugar levels similar to natural insulin, Biomaterials, DOI 10.1016/j.biomaterials.2023.122142