Scientists identify the first approved drugs that show anti-prion activity

Scripps Research Institute scientists recently identified the first drugs already approved for human use that show anti-prion activity, which may be useful for treating prion diseases.

Misfolded proteins, known as prions, cause incurable diseases in the human body such as dementia, personality changes, hallucinations and vertigo-like symptoms. One of the most well-known diseases prions cause is Creutzfeldt-Jakob disease, or the human equivalent of mad cow disease.

The surface of a protein becomes distorted by prion diseases. Two drugs, tacrolimus and astemizole, were proven to reduce the surface of the prion cell by 70 percent.

Tacrolimus is an immune suppressant whose use is currently being debated, since it may produce neurotoxicity. Astemizole, however, is an antihistamine that is safe in small doses and crosses the blood-brain barrier, and is currently considered the more promising anti-prion drug.

TSRI Professor Corinne Lasmézas, who lead the study, noted that astemizole may stimulate autophagy, a process in which cells dispose of unwanted components.

"Autophagy is involved in several protein misfolding neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's diseases," Lasmézas said. "Future studies on the mode of action of astemizole may uncover potentially new therapeutic targets for prion diseases and similar disorders."