An experimental compound that can help regenerate nerve cells shows promise in animal tests and this could pave way for a new therapy that can restore movements in individuals paralyzed because of spinal cord injuries.

In laboratory tests, the newly developed chemical compound known as intracellular sigma peptide (ISP) helped up to 80 percent of experimental animals with severe spinal injury restore their ability to urinate or move.

Although more work is still needed before the compound can be tested in human trials, scientists behind the drug said that the findings boosted hopes that millions of people could someday regain muscle functions they lost due to spinal cord injuries.

Injuries damage never fibers that transmit messages between the body and the brain as well as enable muscle movement and function. Nerve communication can be blocked as a result of scarring around the injury site. Build-up of proteins known as proteoglycans in the scar tissue reacts with enzymes found in the nerve tissues and then blocks off the nerve signal. ISP works by blocking this enzyme and thus makes nerve communication possible across what had been an impenetrable barrier.

For the animal tests described in a study published in the journal Nature on Dec. 3, neuroscientist Jerry Silver, from the Case Western Reserve University School of Medicine, and colleagues injected 26 rats with severe spinal cord injury with ISP every day for a period of seven weeks.

During this period, the researchers assessed the animals' ability to walk and balance, as well as their ability to control bladder movement. Of these animals, 21 showed improvements in muscle function after they were injected with the ISP. Some even regained all of the ability to walk, balance and control when and how much they urinate.

"This recovery is unprecedented," Silver said. "Each of the 21 animals got something back in terms of function. For any spinal cord-injured patient today, it would be considered extraordinary to regain even one of these functions, especially bladder function."

The researchers said that if ISP is successfully developed into a drug, it could be either used as a standalone treatment or in combination with other therapies to give the best chances of recovery to spinal-injured individuals.

Silver likewise said that ISP can also potentially treat other diseases characterized by the body producing damaging scarring such as peripheral nerve injury, heart attack and multiple sclerosis (MS).