The antibiotic tetracycline may help prevent the brain damage associated with several animal and human diseases, including a form of Creutzfeldt-Jakob disease in people, mad cow disease and chronic wasting disease in deer and elk, according to a new study.

Those diseases are caused by rouge proteins called prions, which convert natural proteins into more prions and eventually build up in the brain, causing damage. Prions are normally resistant to enzyme digestion, but a group of Italian and British scientists found that when they treated infected brain tissue with tetracycline, prions became more susceptible to breakdown.

Hamsters injected with antibiotic-treated prions also stayed healthy longer than those injected with untreated prions, the researchers found. Their work is published in today's issue of the Proceedings of the National Academy of Sciences.