The two diseases are caused by the deterioration of neurons, highly specialized cells in the brain and central nervous system.

Advanced Alzheimer`s disease results in the loss of memory, erratic behavior and death. Parkinson`s disease is not necessarily fatal, but results in disrupted motor skills, extreme tremors and loss of balance.

Scientists were able to destroy two different chemicals in the brains of fruit flies that reversed the symptoms of the two diseases. The chemicals are known as kynurenine pathway (KP) enzymes and are named kynurenine-3-monooxygenase (KMO) and tryptophan-2,3-dioxygenase (TDO).

The team hopes that the discovery will lead to a breakthrough in the treatment of humans. While human brains are obviously much larger, they actually share many of the same genes as fruit flies.

The research was published Monday in the journal Proceedings of the National Academy of Sciences. Researchers were based at the University of Maryland School of Medicine and the University of Leicester in the United Kingdom. Funding came from the United States government through the National Institutes of Health.

"Our work strongly supports targeting of the KP as a potential treatment strategy for several major neurodegenerative disorders and suggests that alterations in the levels of neuroactive KP metabolites could underlie several therapeutic benefits," according to the study.

Alzheimer`s Disease International, a global non-profit, estimates that almost 44 million people across the planet have Alzheimer`s in 2016, but only a quarter of sufferers are diagnosed. Patient support non-profit Parkinson`s Disease Foundation believes 10 million people are living with Parkinson`s worldwide.

Scientists believe the study could also lead to a cure for Huntington`s disease -- a much less common degenerative brain disorder that effects behavior, movement and cognition skills.

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