Researchers from the University of Cambridge report that a drug traditionally used to treat glaucoma, which lowers intraocular pressure, may help guard the brain against the toxic protein build up linked to Alzheimer’s disease. The discovery comes from animal experiments published in Nature Chemical Biology this year.
To test the potential anti tau effects, the team screened more than 1,400 medicinal compounds in zebrafish. These tiny fish were genetically engineered to mimic tauopathies, a group of diseases marked by clumps of tau protein in the brain, a signature feature of Alzheimer’s disease.
Several carbonic anhydrase inhibitors showed protective effects against tau aggregates and improved disease-related symptoms in both zebrafish and mouse models. One drug in this class, methazolamide, is already approved for lowering eye pressure in glaucoma.
All of these drugs work by blocking carbonic anhydrase, an enzyme that helps regulate cellular acidity. Inhibiting this enzyme appears to shift lysosomal activity, guiding lysosomes toward the cell surface where they fuse with the membrane and help dispose of tau protein.
Cambridge researchers chose zebrafish because they mature quickly and support high throughput studies. While the results are encouraging, they remain preclinical and have not yet been tested in larger animals or in humans.
Beyond methazolamide, several drugs in the carbonic anhydrase inhibitor family have known safety profiles in humans, which could accelerate future work. However, many compounds fail to translate across species, and extensive testing in mammals and eventually in people will be required before any clinical use can be considered.
These findings point to a potential path for drug repurposing aimed at tauopathies, including Alzheimer’s disease. The approach targets how cells handle tau and may complement other strategies aimed at reducing toxic tau species.
Overall, the Cambridge study adds to a growing body of evidence that manipulating cellular waste pathways can influence neurodegenerative disease progression. While promising, the work stresses the need for careful, rigorous testing in mammalian models and clinical trials to determine safety and efficacy in humans.