Old Blood Pressure Drug Hydralazine Shows Promise in Reducing Brain Tumour and Cancer Risk

A new scientific study has brought fresh attention to hydralazine, one of the oldest and most trusted medicines used to control high blood pressure. For more than 70 years, doctors have used it to help patients with severe hypertension, especially pregnant women dealing with dangerous conditions like pre-eclampsia. But researchers now say this medicine may be far more powerful than anyone expected. Their findings suggest that hydralazine could help reduce the risk of aggressive brain tumours and may even become a part of future cancer treatments.

Hydralazine has long been used because of its ability to relax and widen blood vessels, which helps lower blood pressure quickly. Doctors often rely on it for pregnant women with extremely high blood pressure, as it works fast and has been considered safe for decades. However, the way it works at a deeper biological level was not clearly understood until now. Scientists at the University of Pennsylvania have discovered how the drug influences certain processes in the body, and these results have opened new possibilities in medical research.

The study, published in Science Advances, found a surprising link between high blood pressure in pregnancy and the biology of brain tumours. Dr Kyosuke Shishikura, one of the researchers, described hydralazine as “one of the earliest vasodilators ever developed.” Neurosurgeon Dr Satnam Singh Chhabra explained that pre-eclampsia is a dangerous condition where pregnant women experience very high blood pressure. It is a major cause of complications and can even lead to maternal deaths if not treated quickly. Because of this, hydralazine continues to be an important medicine in maternity care.

Pre-eclampsia usually appears in the later months of pregnancy. Women may experience swelling, headaches, and high blood pressure, and doctors often detect protein in the urine. Both the mother and the baby face health risks, so proper treatment is essential. The new findings about hydralazine’s role could help improve treatment plans. Meghan Matthews, a chemistry professor at Penn, said that better understanding the drug’s action could help create safer and more effective medicines, especially for women from communities who face higher health risks.

The most surprising part of the study relates to cancer. Researchers discovered that hydralazine affects an enzyme in the body called ADO (2-aminoethanethiol dioxygenase). This enzyme works like an internal alarm system. When oxygen levels fall, ADO signals blood vessels to tighten. Matthews explains that ADO reacts “the moment oxygen starts to fall,” helping the body adjust quickly. However, in cancer cells—especially brain tumour cells—this fast reaction can help the tumour survive and grow.

The researchers found that hydralazine attaches itself to ADO and switches off this alarm. When this happens, the cancer cells lose one of their key survival signals. This makes them weaker and less capable of growing. In aggressive brain tumours, this could be a major breakthrough because these tumours often spread quickly and resist many treatments. By targeting ADO, hydralazine may help slow down or stop the tumour’s growth.

This discovery also shows how older medicines can still teach scientists new lessons. As Matthews says, “An old cardiovascular drug rarely ends up teaching us something new about the brain.” This unexpected connection has opened a new path for cancer research. Scientists now believe that medicines like hydralazine may inspire a new group of safer, more effective treatments for brain tumours. It may also help doctors create better medicines for pregnant women with high blood pressure.

While more research is needed, the study has given hope to doctors, scientists, and patients. A drug that has been trusted for more than half a century may now play a role in solving one of the world’s toughest medical challenges: fighting aggressive brain cancer. This discovery is a reminder that even old medicines can bring new possibilities—and sometimes, the answers to big problems come from places we least expect.