A research team at Seoul National University Hospital has found that direct administration of coenzyme Q10, an antioxidant agent, into the brain enhances neuroprotection for Parkinson's disease patients.

Parkinson's disease is a degenerative neurological disease that occurs and worsens due to the loss of dopamine neurons in the middle brain. It is a common degenerative brain disease with dementia. Symptoms of the disease include tremors, stiffness, postural anxiety, and gait disturbances.

Coenzyme Q10, an antioxidant, is necessary for many metabolic activities. As some studies have shown that coenzyme Q10 can inhibit Parkinson's disease progression, some patients with Parkinson's disease have taken coenzyme Q10 orally. However, orally administered coenzyme Q10 has a very low absorption rate in the body.

Because of the blood-brain barrier that protects the brain from the blood, it is also difficult for drugs to reach the deep areas of the brain, resulting in poor treatment efficiency. Such limitations have made patients take more than necessary, even though there was little efficacy.

The research team, led by Professors Paek Sun-ha and Choy Young-bin at the hospital, hypothesized that if researchers can deliver coenzyme Q10 directly to the brain where drugs are needed, they could prevent dopamine neuron damage at very low doses. Professor Park Chun-gwon at Sungkyunkwan University also participated in the study.

As a result of the experiment, mice that received a tiny amount of coenzyme Q10 directly in the brain deeper showed better progress in behavioral disorders, changes in inflammation levels, and damage to dopamine neurons compared to mice that received a high dose of coenzyme Q10 orally.

The research team divided experimental mice with Parkinson's disease into five groups and checked differences -- they consisted of a group that received no treatment, a group that received an oral dose of high-concentration coenzyme Q10, a group with physiological saline deep infusion, a group with lowest-concentration coenzyme Q10 infusion, and a group with low-concentration coenzyme Q10 infusion.

Afterward, the team observed the brain's tyrosine hydroxylase response in each group. Tyrosine hydroxylase is a major factor regulating dopamine synthesis.

On this account, researchers found that the more severe the symptom of Parkinson's disease, the less tyrosine hydroxylase. Actually, the tyrosine hydroxylase reaction is active in all groups when intact, while less tyrosine hydroxylase reaction is observed in the lesion sites.

A consequent observation found that the group injected directly with coenzyme Q10 showed relatively more tyrosine hydroxylase reaction than the group that did not receive treatment or took the coenzyme 10 orally.

"If we add the ability to deliver small amounts of coenzyme Q10 to existing medical devices that can inject drugs deeply in the brain, we expect to see synergies in the treatment of Parkinson's disease," Professor Choy said.

Professor Paek also said, “If this research methodology is applied to various drug treatments, it could be helpful for degenerative brain diseases other than Parkinson's disease."

Scientific Reports published the results of the study.