Chronic mouth dryness caused by inflammation of the salivary glands is a condition that can negatively affect a person’s general health, the health of their teeth and gums, and their ability to taste, chew and swallow food. It can be caused by various medical conditions, treatment regimes and medications, or may simply occur as part of the aging process. Scientists at the University of South Alabama (UA) in the US have discovered – albeit accidentally – a drug that may reduce the inflammation and prevent excessive dryness in the mouth.

Using a drug known as roflumilast to inhibit the activity of inflammation-causing phosphodiesterase-4 (PDE4) enzymes in the infected lungs of mice, the scientists were surprised to discover roflumilast caused increased salivation in the animals. Further analysis revealed that this was due to the inhibition of PDE4 in the salivary glands and in the autonomic nervous system, the latter of which regulates involuntary body processes.

Additional experiments showed that PDE4 inhibition also increased salivation in mice with cystic fibrosis, a disease in which inflammation not only affects patients’ ability to breath, but also frequently gives them a dry mouth.

According to UA doctoral candidate Abigail Boyd, saliva is “indispensable for oral health and overall well-being.” Boyd also admitted that new ways to treat dry mouth is much needed as current treatment options are limited. The scientist and her colleagues thus hope to conduct human trials with roflumilast as soon as possible.