Anti-Inflammatory Effects of Polyphenols in Brain Microvascular Endothelial Cells Stimulated with TNF-α

The blood–brain barrier (BBB) is a structure that regulates the exchange of substances between the peripheral circulation and the central nervous system (CNS), thereby protecting this environment. An increase in BBB permeability may lead to the influx of inflammatory cells, resulting in neuroinflammation and neurodegeneration. The integrity of the BBB is maintained due to the specific properties of brain endothelial cells. Considering the importance of brain endothelial cells in the BBB during inflammatory processes, these cells may be a target for anti-inflammatory agents. Polyphenols are substances exhibiting the ability to decrease inflammation; therefore, in our research, we aimed to examine their effectiveness in a brain endothelial cell culture stimulated with the pro-inflammatory cytokine TNF-α. The tested polyphenols were myricetin, chrysin, resveratrol, and curcumin. ELISA tests revealed that myricetin and chrysin decreased the concentrations of the pro-inflammatory cytokines IL-1ß, IL-6, and IL-8 secreted by brain endothelial cells. The results of flow cytometry indicate that chrysin and resveratrol are the most potent in downregulating the expression of VCAM-1 on the surface of brain endothelial cells. The obtained results confirm the anti-inflammatory potential of polyphenols in brain endothelial cells. The selected polyphenols also contribute to increasing brain endothelial cell viability and act as antioxidants.