Pulmonary hypertension is a life-threatening, progressive disease that, to this day, is still incurable. Recently, a team of researchers turned to nature for answers, experimenting with extracting a protective enzyme from plant leaves that may hold the key to making a novel treatment work.
Lead author and assistant research scientist at the University of Florida, Gainesville, Vinayak Shenoy, Ph.D., said that among all the available therapies for PH, none target the root of the disease. This approach is more palliative than problem-solving, and does not lead to a better prognosis. He believes the answer could be from a natural source. This study was presented during the American Heart Association’s High Blood Pressure Research Scientific Sessions 2014.
PH has a long list of risk factors and associated causes. Shenoy’s study noted the relationship between the disease and the protein, angiotensin converting enzyme 2 (ACE2). Past studies using animal models showed that restoring ACE2 levels prevented PH.
Today, researchers are studying this protein’s potential as a treatment for pulmonary damage. However, because of its protein structure, one of its drawbacks is its sensitivity to stomach acids when administered orally. Shenoy and his fellow researchers believe they have found a workaround for this problem.
The study made use of plant cells’ protective features. By utilizing transplastomic techniques to genetically modify chloroplasts to carry a gene for ACE2, Shenoy and his team were able to cultivate plants with leaves containing significant amounts of the protein.
These genetically modified, ACE2-producing plants were then freeze dried and ground into powder in order to be fed to laboratory rats that had PH. The rats were given the powdered leaves for a total of 4 weeks. The results were impressive. There was a significant decrease in the rats’ pulmonary blood pressure, resulting in less obstructed blood flow; and right-sided cardiac function improved.
Shenoy believes this method is quite promising, and may be the lower-cost, safer solution to PH that science has been looking for. The team’s next step would be to test for the ACE2-producing plant’s safety in a phase I clinical trial.
Fundamental to finding a cure to any disease is to first understand cellular pathophysiology. Researchers from Yale School of Medicine studied the cells responsible for the development of excess smooth muscle mass in PH patients’ lungs.