Betanin, a natural pigment found in the sugar beet (Beta vulgaris), could eventually help slow the accumulation of misfolded proteins in the brain, a process that is associated with Alzheimer’s disease.
“Betanin shows some promise as an inhibitor of certain chemical reactions in the brain that are involved in the progression of Alzheimer’s disease,” said study co-author Professor Li-June Ming, from the University of South Florida.
“This is just a first step, but we hope that our findings will encourage other scientists to look for structures similar to betanin that could be used to synthesize drugs that could make life a bit easier for those who suffer from this disease.”
Alzheimer’s disease affected up to 5 million Americans in 2013 and is expected to grow to 14 million by 2050.
Scientists are still trying to figure out what causes this progressive and irreversible brain disorder. But one prime suspect is beta-amyloid, a peptide that accumulates in the brain, disrupting communication between brain cells called neurons.
“Much of this damage occurs when beta-amyloid attaches itself to metals such as iron or copper,” Dr. Ming said.
“These metals can cause beta-amyloid peptides to misfold and bind together in clumps that can promote inflammation and oxidation — a process similar to rusting — in nearby neurons, eventually killing them.”
A previous study suggests that beetroot juice can improve oxygen flow to the aging brain and possibly improve cognitive performance.
Building on that work, Professor Ming and his colleague, Darrell Cole Cerrato from the University of South Florida, wanted to find out if betanin could block the effects of copper on beta-amyloid and, in turn, prevent the misfolding of these peptides and the oxidation of neurons.
They conducted a series of experiments involving 3,5 di-tert-butylcatechol (DTBC), a compound that is used as a model substance for tracking the chemistry of oxidation.
Using visible spectrophotometry, the team measured the oxidative reaction of DTBC when exposed to beta-amyloid only, beta-amyloid bound to copper, and copper-bound beta-amyloid in a mixture containing betanin.
On its own, beta-amyloid caused little or no oxidation of DTBC. However, as expected, beta-amyloid bound to copper induced substantial DTBC oxidation.
But when betanin was added to the copper-bound beta-amyloid mixture, the study authors found oxidation dropped by as much as 90%, suggesting that misfolding of the peptides was potentially suppressed.
“We can’t say that betanin stops the misfolding completely, but we can say that it reduces oxidation,” Cerrato said.
“Less oxidation could prevent misfolding to a certain degree, perhaps even to the point that it slows the aggregation of beta-amyloid peptides, which is believed to be the ultimate cause of Alzheimer’s.”
The researchers presented their results today at the 255th National Meeting & Exposition of the American Chemical Society in New Orleans, LA.
Darrell Cole Cerrato & Li-June Ming. 2018. ‘Beeting’ Alzheimer’s: Inhibition of Cu2+-β-amyloid mediated oxidation and peroxidation by betanin from sugar beets. 255th ACS National Meeting & Exposition, abstract # INOR 926