Is there a new hormone therapy on the horizon for women with MS?

A recent study found that administering estriol, a pregnancy hormone, in a mouse model of multiple sclerosis (MS) reduced disease severity and promoted myelin repair in the cortex, a part of the brain usually affected by MS.

Researchers at the University of California, in Los Angeles, said it is the first study to identify a possible treatment to remyelinate in the brain’s cortex.

Estriol has already been used in the medical world as a therapy to help symptoms of the menopause for years and is generally very safe. This makes it an attractive therapeutic option.

It is a form of oestrogen made by the foetus and placenta during pregnancy. It’s thought to be one of the reasons women with MS experience less disease activity whilst pregnant.

All the mice in the study were female. “We expect that estriol-treated male mice would exhibit similar effects to estriol-treated female mice,” the researchers said. But they didn’t test males because, “as a potential therapy for MS, estriol treatment may lead to unwanted side-effects in male patients.”

Mice treated shortly after disease onset had significantly less severe movement problems than mice given a placebo. They also had less shrinkage of the cortex – which is linked to worsening permanent disability.

The researchers found that starting estriol treatment shortly after disease onset resulted in significantly less-severe movement problems, compared with a placebo.

Estriol-treated mice also showed significantly less atrophy, or shrinkage, of the cortex, a brain region whose shrinkage in MS is linked to permanent disability worsening, than animals given a placebo.

Treated mice had lower activation of the brain’s immune cells that are thought to contribute to myelin loss, called microglia, plus more oligodendrocytes, which are the cells responsible for repairing and making myelin.

Researchers said that based on these good results, there should be more studies to discover if this hormone treatment for women with MS is viable.