The study, “Vitamin B12 inhibits α-synuclein fibrillogenesis and protects against amyloid-induced cytotoxicity,” was published in the journal Food & Function.
When the brain produces an excess of alpha-synuclein, this protein starts to form aggregates and toxic deposits called Lewy bodies. This process is closely associated with the onset and progression of Parkinson’s disease.
As a result, developing new therapies that inhibit alpha-synuclein aggregation is seen “as an attractive therapeutic strategy to ameliorate Parkinson’s disease,” the researchers wrote.
However, developing such therapies is challenging since most of the compounds that inhibit alpha-synuclein aggregation cause adverse side effects such as liver failure, or cannot cross the blood-brain barrier — a semipermeable membrane that protects the brain against the external environment, and is a major obstacle for the efficient delivery of certain therapeutics that need to reach the brain and central nervous system.
“Vitamins are dietary components that are indispensable for life in addition to proteins, carbohydrates, fats and minerals,” the researchers wrote.
Previous studies have shown that vitamins of the B-complex are essential to the development of neurons, the detoxification of the body, and the function of the immune and inflammatory response. Vitamin B12 is widely used as a food supplement, can cross the blood-brain barrier, and has shown positive effects on the cognitive function of animals models and people with dementia.
Here, a team of Chinese researchers used different techniques to assess whether vitamin B12 affected the formation of alpha-synuclein aggregates and whether the vitamin could make alpha-synuclein less toxic to brain nerve cells grown in the lab.
They found that vitamin B12 delayed the formation of clumps of alpha-synuclein, and that the aggregates that formed in the presence of the vitamin were smaller than those created in its absence; these smaller aggregates were less toxic to the nerve cells.
Vitamin B12 was able to do this by directly interacting with alpha-synuclein and preventing it from taking a form that is prone to aggregation. It also destroyed preformed aggregates of alpha-synuclein.
“[Vitamin B12] destabilized and disassembled the preexisting mature [aggregates] into less toxic pieces. In summary, VB12 can efficiently disassemble mature [alpha-synuclein] fibrils and protect [nerve] cells from [alpha-synuclein]-induced toxicity,” the researchers wrote.
“[Vitamin B12] appears to have great potential to develop as an [alpha-synuclein] aggregation inhibitor and functional food ingredient for therapeutic interventions in [Parkinson’s disease],” they added.
These results identify vitamin B12 as a valuable nutrient source that “possesses great potential to be developed as a new functional food ingredient to help alleviate [Parkinson’s disease],” the study concluded.