Oxocarotenoids can protect brain cell metabolism
What is it about?
Cognitive impairment may result from neuronal apoptosis in specific regions of the brain, a process that involves mitochondrial dysfunction. Population studies have shown that people with higher blood levels of lutein and zeaxanthin (oxocarotenoids enriched in vegetables) are less likely to have cognitive impairment. We wanted to understand whether oxocarotenoids protect neuronal mitochondria under stress. We used an n oxidised phospholipid, POVPC, that we had shown previously to be increased in the blood of people with Alzheimer’s disease, to stress SHSY-5Y neurones sin vitro. We determined concentrations of POVPC that did not cause neuronal death but did cause mitochondrial dysfunction. WE then looked at whether carotenoids could protect brain cell metabolism. Co-treatment of neurones with oxo carotenoids preserved mitochondrial function only when POVPC concentrations were low. At higher POVPC concentrations, oxo carotenoids did not protect mitochondrial ATP production. We showed for the first time that the oxo carotenoids lutein and zeaxanthin are taken up by neuronal cells and protect neuronal mitochondria from loss of function induced by low concentrations of POVPC.
Why is it important?
We have shown that low level mitochondrial dysfunction, without neuronal cell death, is reversible by oxocarotenoids. Our work has identified mitochondrial function in neurones as a new avenue to explore in our understanding about the correlation previously reported between oxocarotenoid concentration and cognition in epidemiological studies.