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GLP-1 Drug Exendin-4 Restores Saliva Production in Aging Rats with Dry Mouth

RPEP-153952026Jung, Jae-Eun; Park, Su-Bin; Yu, Hwa Young; Yoon, Su-Bin; Kim, Junghyun
evidence
The takeaway

The GLP-1 RA exendin-4 ameliorated D-galactose-induced dry mouth (hyposalivation) in aging rats, suggesting GLP-1 drugs may treat age-related salivary gland dysfunction.

Saliva restored

A GLP-1 drug restored saliva production in aging rats — an unexpected benefit for the 20% of elderly people who suffer from dry mouth

What the researchers found

Exendin-4 ameliorated D-galactose-induced hyposalivation in aging rats, likely through GLP-1R-mediated anti-inflammatory and anti-apoptotic protection of salivary gland tissue.

Why it matters

Dry mouth affects 20% of elderly people with no effective treatment. A GLP-1 drug that restores saliva production could dramatically improve quality of life.

How the study worked

D-galactose accelerated aging rat model with exendin-4 treatment, salivary flow measurement, and salivary gland histology/mechanism analysis.

What this study cannot tell us

Rat aging model. D-galactose model doesn't perfectly replicate human aging. Saliva composition changes not fully characterized.

How to read the evidence

Preclinical aging model. Novel finding for GLP-1 drug repurposing.

When this study was published

Published in 2025.

The bigger picture

GLP-1 receptors are expressed in salivary glands. Activating them with GLP-1 drugs protects against age-related gland deterioration.

Questions still open

  • Do GLP-1 drug users have less dry mouth?
  • Could GLP-1 drugs be used specifically for Sjögren's syndrome dry mouth?
  • Would local GLP-1 delivery to salivary glands be more effective?

Common questions

Could GLP-1 drugs help dry mouth?
In aging rats, the GLP-1 drug exendin-4 restored saliva production. If this translates to humans, it could help the millions of elderly people who suffer from dry mouth.
Why would a diabetes drug affect saliva?
Salivary glands have GLP-1 receptors. The drug's anti-inflammatory and cell-protective effects preserved salivary gland function during aging.

Read the original research

Amelioration of D-galactose-induced hyposalivation in aging rats by the GLP-1 receptor agonist Exendin-4.

European journal of pharmacology, 1011, 178445

View on PubMed ↗Publisher’s paper ↗

Citation

Jung, Jae-Eun; Park, Su-Bin; Yu, Hwa Young; Yoon, Su-Bin; Kim, Junghyun. (2026). Amelioration of D-galactose-induced hyposalivation in aging rats by the GLP-1 receptor agonist Exendin-4.. European journal of pharmacology, 1011, 178445. https://doi.org/10.1016/j.ejphar.2025.178445