Neuroprotective effects of flavone luteolin in neuroinflammation and neurotrauma

Abstract

Neuroinflammation leads to neurodegeneration, cognitive defects, and neurodegenerative disorders. Neurotrauma/traumatic brain injury (TBI) can cause activation of glial cells, neurons, and neuroimmune cells in the brain to release neuroinflammatory mediators. Neurotrauma leads to immediate primary brain damage (direct damage), neuroinflammatory responses, neuroinflammation, and late secondary brain damage (indirect) through neuroinflammatory mechanism. Secondary brain damage leads to chronic inflammation and the onset and progression of neurodegenerative diseases. Currently, there are no effective and specific therapeutic options to treat these brain damages or neurodegenerative diseases. Flavone luteolin is an important natural polyphenol present in several plants that show anti-inflammatory, antioxidant, anticancer, cytoprotective, and macrophage polarization effects. In this short review article, we have reviewed the neuroprotective effects of luteolin in neurotrauma and neurodegenerative disorders and pathways involved in this mechanism. We have collected data for this study from publications in the PubMed using the keywords luteolin and mast cells, neuroinflammation, neurodegenerative diseases, and TBI. Recent reports suggest that luteolin suppresses systemic and neuroinflammatory responses in Coronavirus disease 2019 . Studies have shown that luteolin exhibits neuroprotective effects through various mechanisms, including suppressing immune cell activation, such as mast cells, and inflammatory mediators released from these cells. In addition, luteolin can suppress neuroinflammatory response, activation of microglia and astrocytes,

Protection against Alzheimer's disease by luteolin: Role of brain glucose regulation, anti‐inflammatory activity, and the gut microbiota‐liver‐brain axis

“…82 Luteolin is known to suppress the activation of mast cells, which may be responsible for its effects in suppressing the activation of other glial cells. 83 Interestingly, mast cells have been shown to also protect against severe coronavirus-induced inflammation, which may suggest a role for luteolin in suppressing the long-term neurological disorders associated with coronavirus disease 2019 (COVID-19) infection. 84 Microglial cells are specialized macrophages that are specific to the brain and account for 10%-15% of the cells of the brain.…”

“…Brain resident mast cells are the first responders to brain injury and can act within seconds to release factors such as histamine, corticotropin‐releasing hormone, and pro‐inflammatory cytokines such as IL‐1β, TNF‐α, IL‐6, and more, which in turn can activate microglial cells and astrocytes 82 . Luteolin is known to suppress the activation of mast cells, which may be responsible for its effects in suppressing the activation of other glial cells 83 . Interestingly, mast cells have been shown to also protect against severe coronavirus‐induced inflammation, which may suggest a role for luteolin in suppressing the long‐term neurological disorders associated with coronavirus disease 2019 (COVID‐19) infection 84 .…”

Increased Stress Resistance and Lifespan in Chaenorhabditis elegans Wildtype and Knockout Mutants—Implications for Depression Treatment by Medicinal Herbs

“…Maslinic acid, which was found in Campsis grandiflora , also possesses antioxidant activity [ 86 ]. The flavone luteolin acts in a neuroprotective and antioxidant manner [ 87 , 88 ]. Alpha-linolenic acid, a constituent of Houttuynia cordata , is also neuroprotective [ 89 ].…”

Long‐COVID syndrome‐associated brain fog and chemofog: Luteolin to the rescue

“…Both flavonoids have broad anti-viral properties, inhibit entry of the virus into host cells, 108,147,148 inhibit neuroinflammation, 149 and reduce cognitive decline. 150 Furthermore, luteolin better penetrates into the brain, inhibits both microglia 151,152 and mast cells, 153,154 and has been reported to reduce neuroinflammation 145,155,156 and cognitive dysfunction, 157,158 including Alzheimer's disease in humans 159,160 and in animal models. 161 Luteolin and quercetin are difficult to absorb after oral administration, 162 but their pharmacokinetics are greatly improved in liposomal preparations using olive pomace oil.…”