Tangerines, Tomatoes, and Neuroinflammation! Oh My!

While we are still in the midst of the flu season, we all try to stay as healthy as possible by consuming large quantities of Vitamin C.  Whether it’s chewable tablets, a powder to mix in your drink, or just plain orange juice, we have all learned the immune-boosting benefits of Vitamin C.  Interestingly, new evidence from citruses and tomatoes show that they may do more than fight the flu.  They can also prevent neuronal loss.

To understand this new study, let’s understand how the immune system works.  Waging a cellular and molecular war begins with pro-inflammatory markers secreted by the body’s immune cells.  These warn other nearby non-immune and immune cells that our bodies are under attack.  These immune cells begin to gear up for battle and kill cancer cells, bacteria or viruses.  To wage these specific wars, our body has pre-designed “footmen,” “militia,” and “tanks” to carry out the deed.  Unfortunately, our brains do not have such a multi-tiered army.  Instead, our brains have the “secret service” of immune cells called microglia, which respond to any neuropathological attack.

Although pro-inflammatory markers are beneficial to other immune cells, too much of these markers make these immune cells go rogue and damage other surrounding cells.  If this cellular and molecular immune war persists longer than it should, then our body’s resilient immune system starts to injure itself.  This same process seems to occur in our brains when one develops Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative disorders.  In other words, microglia, the brain’s special immune cells, hold the potential to harm neurons when there is an abundance of these pro-inflammatory markers.  This leads to neuronal cell death, which causes memory loss and other deficiencies in brain function.

Neuroinflamation to Prevent Neuronal Loss by Knowing Neurons

Two very recent studies demonstrated that a specific active compound in citrus fruits, called Tangeretin, and a different one in tomatoes, called Lycopene, could tune down pro-inflammatory markers.  How did they show this?  First, the researchers isolated microglia from mice and rats and added LPS (lipopolysaccharide) to invoke an immune response from microglia.  As expected, the microglia produced pro-inflammatory markers.  Then, the researchers added increasing concentrations of Tangeretin or Lycopene to the microglia.  They found a proportional decline in the concentration of pro-inflammatory markers.  In other words, as they added more Tangeretin or Lycopene to activated microgila, there was a decrease in the concentration of these pro-inflammatory markers.  From these results, these researchers concluded that both Tangeretin and Lycopene have the therapeutic potential to mitigate or delay neuron loss.  With this in mind, let’s eat a few more citrus fruits and drink more tomato juice to fight through this flu season and prevent neuron loss!

Tangerines, Tomatoes, and Neuroinflammation! Oh My! Knowing Neurons


Written by Brian Leung



Lin H.Y., Huang B.R., Yeh W.L., Lee C.H., Huang S.S., Lai C.H., Lin H. & Lu D.Y. (2014). Antineuroinflammatory effects of lycopene via activation of adenosine monophosphate-activated protein kinase-α1/heme oxygenase-1 pathways, Neurobiology of Aging, 35 (1) 191-202. DOI:

Shu Z., Yang B., Zhao H., Xu B., Jiao W., Wang Q., Wang Z. & Kuang H. (2014). Tangeretin exerts anti-neuroinflammatory effects via NF-κB modulation in lipopolysaccharide-stimulated microglial cells, International Immunopharmacology, 19 (2) 275-282. DOI:

Images by Jooyeun Lee.


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