Getting bitten by a snake hardly sounds like a relaxing experience, but a peptide found in one species' venom could help relieve hypertension and some forms of congestive heart failure. A bite from the South American pit viper in question, Bothrops jararaca, causes swelling, bleeding of the gums, hemorrhage, and, in some cases, death.

During the early 1970s, a group of researchers in Brazil led by Sergio Henrique Ferreira discovered a family of peptides in the pit viper's venom that increased the activity of bradykinin, a peptide that lowers blood pressure by causing blood vessels to dilate. This peptide family, which became known collectively as the bradykinin potentiating factor (BPF), was also found to block the conversion of angiotensin I to angiotensin II, a process that causes blood pressure to rise.

The peptides were later used by researchers at Bristol-Myers Squibb to develop the first group of angiotensin-converting enzyme (ACE) inhibitors. The resulting drug, named captopril, is now commonly used to treat hypertension and certain cardiac diseases.