Bioflavonoids are natural antioxidants formed by plants. Three such compounds, hesperidin, hesperetin and neohesperidin, are found in citrus fruit. Research that appeared in the Journal of Agricultural and Food Chemistry (published on line Jan, 2008, ahead of print) showed that bioflavonoids protect cells from damage. The researchers injected cells with the different concentrations of the bioflavonoids and then injected the cells with hydrogen peroxide (to create oxidative stress and cell destruction). They found that all three of the bioflavonoids acted to protect the cells, reducing cell loss and preventing membrane damage from the peroxide. They also increased the activity of the antioxidant enzyme, catalase.

The activity of citrus bioflavonoids may act to protect the nervous system. More researchers are considering the idea that Alzheimer’s disease if from a build up of beta amyloid plaques, which are associated with an increase in cell damage and death from oxidative stress.