LOS ANGELES, CA (Catholic online) - The experimental medication also didn't increase pain in the mice and showed no toxic effects. The medication also efficiently crossed the blood brain barrier, which protects the central nervous system from potentially harmful chemicals carried around in the rest of the bloodstream.

"This is a first to have a drug that can be taken orally to produce functional improvement with no toxicity in a rodent model," Professor Sung Ok Yoon of Ohio State University Columbus says.

"So far, in the spinal cord injury field with rodent models, effective treatments have included more than one therapy, often involving invasive means. Here, with a single agent, we were able to obtain functional improvement."

The small molecule in the study was tested for its ability to prevent the death of cells called oligodendrocytes, which surround and protect axons, long projections of a nerve cell, by wrapping them in a myelin sheath that protects the fibers.

The drug then preserved oligodendrocytes by inhibiting the activation of a protein called p75. Yoon's lab previously found p75 is linked to the death of these specialized cells after a spinal cord injury. When they die, axons that are supported by them degenerate.

"Because we know oligodendrocytes continue to die for a long period of time after an injury, we took the approach that if we could put a brake on that cell death, we could prevent continued degeneration of axons.

"Many researchers in the field are focusing on regeneration of neurons, but we specifically targeted a different type of cell because it allows a relatively long therapeutic window."

The current treatment for humans, methylprednisolone must be administered within eight but not after 24 hours after the injury to be effective at all.

An estimated 1.3 million people in the United States are living with spinal cord injuries, experiencing paralysis and complications that include bladder, bowel and sexual dysfunction and chronic pain.

Called LM11A-31, the experimental drug was developed by Professor Frank Longo, of Stanford University, California.

The researchers gave three different oral doses of LM11A-31 in addition to a placebo, to different groups of mice starting four hours after injury and then twice daily for a 42 day experimental period.

The scientists analyzed the compound's effectiveness at improving limb movement and preventing myelin loss.

The spinal cord injuries in mice mimicked those caused in humans by the application of extensive force and pressure, resulting in loss of hind limb and bladder function and difficulty in walking and swimming.

The researchers determined the mice did not experience more pain than the placebo group at all the doses tested, suggesting LM11A-31 does not worsen nerve pain after spinal cord injury.