Plant extract that gives perfumes their floral scent may help cure Parkinson’s disease

BALTIMORE, Md. — A plant extract that gives perfumes their floral scent may hold the key to curing Parkinson’s disease, according to new research. Scientists from Johns Hopkins University say experiments using the compound farnesol reversed the devastating neurological disorder.

In nature, farnesol comes from berries, peaches, and tomatoes, as well as herbs and essential oils. The fruit compound may hold the key to treating and even preventing Parkinson’s, which affects around 200,000 Americans every year.

The compound boosts neurons that make dopamine, which the brain uses to send messages which control movement. A shortage of the key chemical triggers the hallmark symptoms of stiffness, slowness, tremors, confusion, and cognitive decline.

“Our experiments showed that farnesol both significantly prevented the loss of dopamine neurons and reversed behavioral deficits in mice, indicating its promise as a potential drug treatment to prevent Parkinson’s disease,” says study lead author Professor Ted Dawson in a media release.

How does farnesol defend against Parkinson’s?

Parkinson’s is the second most prevalent neuro-degenerative disease after Alzheimer’s, affecting more than six million people worldwide. It’s believed to be fueled by a rogue protein called PARIS. Farnesol, which is also an ingredient in food flavorings, blocks its activity.

The discovery opens the door to therapies that specifically target the molecule, researchers add. In the brains of patients, a build up of proteins puts the brakes on the manufacturing of the protective protein PGC-1alpha. That protective screen shields neurons from the accumulation of damaging free radicals formed from oxygen.

An illustration of PARIS with the crystal structure of Farnesyltransferase, the enzyme that enables farnesylation. (CREDIT:
Johns Hopkins Medicine)

Without PGC-1alpha, dopamine neurons die off, leading to the cognitive and physical decline caused by Parkinson’s. The study, published in the journal Science Translational Medicine, identified farnesol’s potential by screening a large library of drugs.

The team fed mice a diet either laced with farnesol or regular food and drink for a week. Scientists then injected the animals with a protein called alpha-synuclein that kills dopamine cells to model the effects of Parkinson’s. Those mice eating a farnesol diet performed twice as well on strength and coordination tests that detect the advancement of symptoms.

Analysis of brain tissue later showed the farnesol group had twice as many healthy dopamine neurons than their untreated peers. They also had about 55 percent more of the protective protein PGC-1alpha in their brains.

The results show that farnesol binds to PARIS, changing the protein’s shape so it can no longer interfere with PGC-1alpha production. Farnesol is naturally produced in a range of fruits and herbs, including lemongrass and thyme. Synthetic versions are common in manufacturing, but the amounts people get through diet is unclear.

Farnesol may go from cosmetic to cure-all

Scientists have not determined what the safe dose for humans is as of yet. Only carefully controlled clinical trials can do so, the researchers add. Prof. Dawson and his colleagues hope farnesol will help create treatments that prevent or reverse brain damage due to Parkinson’s.

Farnesol has a long and varied history, spanning from perfumes to medicine. The scent has been described as “reminiscent of lily of the valley.”

It’s one of the 26 specific fragrance ingredients that have to be declared on cosmetics labels according to cosmetic directives. It’s also used in anti-aging skin creams, deodorants, and even as an additive in cigarettes. Previous work suggests it could also combat drug-resistant superbugs and cancer — by dowsing inflammation.

South West News Service writer Mark Waghorn contributed to this report.