Compound in essential oils could help treat Parkinson’s disease
A chemical widely used in perfumery and a component of many essential oils, farnesol, has just been found to help preserve dopamine-producing neurons (nerves) in the brains of sufferers of Parkinson’s disease (PD). A progressive loss of dopamine neurons causes the difficulties with movement and cognition that is associated with PD. Although drugs can be prescribed to improve nerve signaling and alleviate motor signaling, there is no proven treatment to delay or prevent the progression of PD.
Scientists from South Korea’s Sungkyunkwan University School of Medicine and American Johns Hopkins University School of Medicine found that farnesol was able to prevent the death of dopamine neurons in a mouse model of PD – the findings could herald a huge change in treatment.
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The scientists began their study by screening a large library of drugs to find a compound that inhibits a protein called PARIS; PARIS slows down the manufacture of another antioxidant protein, PGC-1 alpha, which shields brain cells from highly reactive oxygen molecules which would eventually kill the cells.
The screening process identified farnesol as a potent inhibitor of PARIS. Farnesol chemically alters PARIS in a process known as farnesylation – reduced farnesylation of PARIS contributes to the death of dopamine neurons.
To be sure of the protective properties of farnesol, the scientists studied the brains and behaviours of mice fed either a diet supplemented with farnesol or a normal diet alone for one week. The scientists had later injected fibrils of a misfolded protein called alpha-synuclein into the animal’s brain to mimic conditions of PD.
The mice that had eaten the farnesol-supplemented diet went on to perform twice as well on standard tests of strength and coordination compared with the mice that ate an ordinary diet; the mice on the farnesol diet also had twice as many healthy dopamine neurons in their brains, while the brains of the mice that ate a normal diet contained about 55% less of the protective protein PGC-1 alpha.
The scientists noted that farnesol could be taken orally, as it was able to cross the blood-brain barrier to protect brain cells. They are planning a clinical trial of farnesol in patients with PD.
“Parkinson’s is what happens when dopamine-producing cells in the brain die, so this study is important as it highlights a new pathway that could target and protect these brain cells in a person with Parkinson’s,” said Professor David Dexter, Associate director of research at Parkinson’s UK.
“Designing more potent drugs replicating the action of this natural compound — farnesol — would be the next steps for researchers to progress this into clinical trials and potentially hold the key for a groundbreaking new treatment.”
