It's a frustrating situation. There are already stem cells in the nervous system that are capable of repairing the damage done by multiple sclerosis, but getting them to do so has proven very difficult. Now, however, a multi-institutional team led by Case Western Reserve University's Prof. Paul Tesar may have found the answer – and it involves using medications that were designed to treat athlete's foot and eczema.

Multiple sclerosis causes the immune system to attack myelin, which is the protective coating that surrounds nerve fibers in the spinal cord, brain and optic nerve. With that insulating layer gone or compromised, electrical signals can't travel down the nerves properly. As a result, MS sufferers can lose partial to complete control of their legs or arms, or the use of their eyes – along with experiencing other problems.

While other studies have looked at introducing stem cells that could produce new myelin, Tesar and colleagues have instead turned to oligodendrocyte progenitor cells, or OPCs. These are stem cells that are already present in the nervous system. Although they had previously been difficult to study, the scientists devised a method of producing billions of them for lab analysis.

A total of 727 existing drugs were then tested on these lab-grown OPCs, to see which ones might cause them to form new myelinating cells. As it turned out, the two best-performing medications were miconazole (for treating fungal infections such as athlete's foot) and clobetasol (for skin conditions like eczema and dermatitis).

When administered to mice afflicted with an MS-like condition, the two drugs each caused the native OPCs to regenerate new myelin, drastically reversing the effects of the disease. They had a similar effect on the cultured human OPCs.

Before optimized versions of the drugs can enter clinical trials, however, the scientists still need to establish a safe means of administering them internally, along with further assessing their potential side effects and long-term efficacy.

A paper on the research was published this week in the journal Nature.