University of California Los Angeles (UCLA) researchers have genetically engineered tomatoes to produce a peptide, a compound containing two or more amino acids linked in a chain, that causes the tomato to imitate the actions of good cholesterol when eaten.
A study was published in the Journal of Lipid Research that proved the peptide in tomatoes actually worked, after they fed them to a group of mice and found that they had less inflammation and plaque build-up in their arteries. The tomatoes were fed to the mice ground up and freeze-dried.
"This is one of the first examples of a peptide that acts like the main protein in good cholesterol, and can be delivered by simply eating the plant," said senior author Dr. Alan M. Fogelman, executive chair of the department of medicine and director of the atherosclerosis research unit at the David Geffen School of Medicine at UCLA. "There was no need to isolate or purify the peptide - it was fully active after the plant was eaten."
What the researchers didn't expect was to find the peptide to be active in the small intestine before degrading to natural amino acids before absorbing into the blood. Stated in the press release, this suggests that by possibly "targeting" the small intestine, they might be able to find a new strategy to "prevent diet-induced atherosclerosis, the plaque-based disease of the arteries that can lead to heart attacks and strokes."
To see results, the team had to genetically engineer tomatoes to produce "6F," a tiny peptide that "mimics" the action of "apoA-1," the chief protein in high-density lipoprotein, known simply as HDL or what scientists call "good" cholesterol. The scientists fed these tomatoes to mice that lacked the ability to remove "bad" cholesterol from their blood, causing them to develop inflammation and atherosclerosis if consuming a diet high in fat. Hours after the mice had their share of genitically modified, freeze-dried tomatoes, the "intact" peptide was found in the small intestine, but none was found in the blood.
"It seems likely that the mechanism of action of the peptide-enhanced tomatoes involves altering lipid metabolism in the intestine, which positively impacts cholesterol," said the study's corresponding author, Srinavasa T. Reddy, a UCLA professor of medicine and of molecular and medical pharmacology.
