Inexpensive Antibiotic Could Transform Stroke Therapy Management

The use of minocycline--a commonly used antibiotic--immediately after a stroke has the potential of reducing the destruction of brain cells by as much as two thirds, according to a new study.

Researchers at the University of South Florida (Tampa, FL, USA), Nagoya City University Medical School (Japan), and other institutions examined the direct protective effects of minocycline on neurons and astrocytes, while at the same time determining minocycline's toxicity profile in both in vitro and in vivo models of stroke. The researchers succeeded in demonstrating that minocycline attenuates both in vitro (oxygen glucose deprivation) and in vivo (middle cerebral artery occlusion) experimentally induced ischemic deficits by direct inhibition of apoptotic-like neuronal cell death. The researchers found that this anti-apoptotic effect of minocycline is seen in neurons, but not apparent in astrocytes.

The researchers found that injecting the antibiotic after a stroke and for several days afterwards reduces swelling and guards the neuron cells from the havoc caused by stroke. Up to 80% percent of nerve cells survived a stroke in the lab and in animal tests, twice the rate of survival in cases left untreated. The researcher's laboratory tests further indicate that the neuroprotection is dose-dependent, in that only low dose minocycline inhibits neuronal cell death cascades at the acute stroke phase, whereas the high dose exacerbates the ischemic injury. The study was published ahead of print in the October 6, 2009, issue of BMC Neuroscience, a publication of BioMed Central.

"The safety and therapeutic efficacy of low dose minocycline and its robust neuroprotective effects during acute ischemic stroke make it an appealing drug candidate for stroke therapy,” said lead author Cesar Borlongan, Ph.D. "An on-going Phase I clinical study funded by the National Institutes of Health is exploring the use of intravenous minocycline to treat acute ischemic stroke.”

Minocycline hydrochloride is a second generation tetracycline antibiotic, and has a broader spectrum than the other members of the group. Because of its long half-life, it generally has serum levels 2-4 times that of most other tetracyclines. It is primarily used to treat acne and other skin infections, as well as Lyme disease. Current research is examining the possible neuroprotective and anti-inflammatory effects of minocycline against progression of a group of neurodegenerative disorders, including multiple sclerosis (MS), rheumatoid arthritis (RA), amyotrophic lateral sclerosis (ALS), Huntington's disease, and Parkinsons disease, among others neurodegenerative diseases.

Related Links:
University of South Florida
Nagoya City University Medical School