
Researchers from Ruhr University Bochum in Germany recently identified a plant substance that may reduce or reverse the effects of pulmonary hypertension (PH). Professor Daniela Wenzel, PhD, and Alexander Seidinger, PhD, led the team in testing the active ingredient FR900359 (referred to as FR) found in the common houseplant Ardisia crenata.
The study, which was published in EMBO Molecular Medicine, was part of Dr. Seidinger’s doctoral thesis focused on finding new treatment options for PH. Current drugs are based on blocking individual receptors or signaling pathways that transmit the signal to constrict the pulmonary vessels.
“There are many of these so-called vasoconstrictors, and each one has its own receptor,” said Dr. Seidinger, first author of the study. “A single blockade is therefore not very effective.”
FR differs from previously used active substances in that it targets a different point in the signaling pathway that leads to PH. As a result, it simultaneously inhibits numerous factors that lead to vasoconstriction in the lungs.
Daniela Wenzel, Michaela Matthey and Alexander Seidinger (from left) tested the effect of the substance FR on pulmonary hypertension.© RUB, Marquard
Previous studies had shown that FR influences Gq proteins. Therefore, the researchers hoped to use FR to inhibit many different vasoconstrictors equally.
“Within the cells, there are only a few pathways through which the signal for vasoconstriction is passed on,” said Dr. Seidinger. “So-called Gq proteins are involved in many of these pathways. This makes them a good target for intervention.”
Initially, the team tested the substance on isolated pulmonary vessels from mice and demonstrated its ability to increase vascular relaxation. Subsequent tests on tissue from pigs and human samples confirmed this effect. In experiments on mice suffering from pulmonary hypertension, the researchers eventually showed that treatment with FR alleviated the symptoms and greatly improved the animals’ state of health.
“The thickness of the muscle layer around the pulmonary vessels decreased — or didn’t even increase in the first place,” Dr. Seidinger said.
The researchers only observed minor side effects, primarily of blood pressure dropping slightly throughout the body. They noted this could be beneficial in the treatment of PH.
“FR could, therefore, be a promising drug candidate for the treatment of the disease,” Dr. Seidinger said in conclusion. “However, it will certainly take many years of intensive research before it can be used in clinical practice.”