Naringin is a bioactive compound found primarily in tomatoes, grapefruits, and other citrus fruits. It is classified as a flavonoid and has been shown in research to support many aspects of human health. Naringin may help support bone and cardiovascular health, healthy metabolism, cognitive and neural health, and the body’s response to oxidative stress and inflammation.
The inflammatory response is complex and involves many pathways and cell types. Naringin has been shown to influence the activity of nuclear factor-kappa B (NF-κB), interleukin-(IL)-6, IL-8, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-ɣ), and more. An animal study showed a reduction in signaling related to the pro-inflammatory cytokines, IL-6, IL-8, and TNF-α. It also reported changes in inducible nitric oxide synthase (iNOS) and nuclear factor erythroid 2-related factor 2 (Nrf2) in the presence of naringin. Nrf2 is a transcription factor that plays a role in cellular glutathione regulation. It also helps regulate NADPH regeneration, heme metabolism, and detoxification of reactive oxygen species.
A laboratory study published by Zhao and colleagues explored the role of naringin in endothelial cell protection in the context of atherosclerosis and inflammation. Endothelial cells were exposed to a simulation of atherosclerosis. Study measurements included inflammatory markers and incidence of apoptosis and endothelial damage. Results indicated that the presence of naringin prevented the endothelial injury and apoptosis typically expected in the atherosclerosis simulation. A reduced presence was also observed of the inflammatory cytokines, IL-1β, IL-6, and IL-18.
Naringin has also been shown to help support neuronal and cognitive health. A systematic review and meta-analysis by Viswanatha and colleagues explored this topic. Naringin has been shown to influence levels of brain-derived neurotrophic factor (BDNF). The BDNF is a protein that plays an important role in synaptic plasticity, nervous system modulation, memory formation, and the growth, maintenance, and survival of neurons. Altered levels of BDNF have been associated with several psychological and neurological disorders, including depression.
An animal study simulated Parkinson’s disease-like conditions and found that the presence of naringin prevented microglial activation in the substantia nigra. It also activated mTORC1, which may have a protective effect on dopamine neurons. Another animal study related to Huntington’s disease showed improvements in the presence of naringin. These improvements were attributed to the potential of naringin to decrease the expression of certain pro-inflammatory mediators and to activate Nrf2.
Research regarding the potential of naringin to support healthy inflammation is still primarily in the pre-clinical realm, and further conclusions about human health cannot be made without more evidence. However, research indicates that naringin may support the body in many ways, including a healthy response to inflammation.
By Colleen Ambrose, ND, MAT