World’s oldest blood pressure drug may help treat aggressive brain tumour, study finds

A drug that has been sitting in medicine cabinets for over 70 years may have a surprising second act! Hydralazine, one of the world’s oldest blood pressure drugs, used especially during pregnancy, has shown promise in halting the growth of aggressive brain tumours.

No one knew its mechanism of action, especially how it works at a molecular level. Now, scientists at the University of Pennsylvania say they have finally uncovered how it works, and their findings could open a new door to treating aggressive cancers. The findings of the research are published in Science Advances.

Decades-old drug gets a new purpose

Hydralazine has been used to treat life-threatening high blood pressure, especially during pregnancy, yet doctors never fully understood its mechanism.

“Hydralazine is one of the earliest vasodilators ever developed, and it is still a first-line treatment for pre-eclampsia—a hypertensive disorder that accounts for 5–15% of maternal deaths worldwide,” Kyosuke Shishikura, a physician-scientist at the University of Pennsylvania, said. “It came from a ‘pre-target’ era of drug discovery, when researchers relied on what they saw in patients first and only later tried to explain the biology behind it.”

The scientists unveiled the action of hydralazine and thereby found an unexpected biological link between hypertensive disorders and brain cancer.

“Pre-eclampsia has affected generations of women in my own family and continues to disproportionately impact Black mothers in the United States. Understanding how hydralazine works at the molecular level offers a path towards safer, more selective treatments for pregnancy-related hypertension—potentially improving outcomes for patients who are at greatest risk,” Meghan Matthews, Assistant Professor of Chemistry at Penn, added.

Pre-eclampsia is a condition that affects some pregnant women, usually during the second half of pregnancy (from 20 weeks) or soon after their baby is delivered, according to the NHS. It is characterised by high blood pressure (hypertension) and protein in the urine (proteinuria).

How the blood pressure drug fights cancer

The research team found that hydralazine directly targets a tiny but critical enzyme called 2-aminoethanethiol dioxygenase, or ADO, which is a molecular switch that tells blood vessels when to tighten.

“ADO is like an alarm bell that rings the moment oxygen starts to fall. Most systems in the body take time; they have to copy DNA, make RNA, and build new proteins. ADO skips all that. It flips a biochemical switch in seconds,” Matthews said. They found that the medication binds to ADO and shuts it down—effectively silencing the alarm that helps cancer cells stay alive.

The findings of the study could pave the way for designing a safer medication that is more effective in treating brain cancer. “It is rare that an old cardiovascular drug ends up teaching us something new about the brain, but that is exactly what we are hoping to find more of—unusual links that could spell new solutions,” Matthews added.

Note: The information provided in this article is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare professional before starting any new medication or treatment, or before changing your diet or supplement regimen.