A Potential Benefit of Quercetin in Preserving Tight Junction Integrity

ABSTRACT

Disruption of tight junction (TJ) integrity can occur from loss of TJ protein expression and/or disorganization. Consequently, epithelial/endothelial barriers lose their barrier functions in the control over paracellular transport, leading to the compromised defense mechanism of the organ. The TJ disruption has been related to multiple signal transduction pathways including mitogen-activated protein kinases (MAPK). Quercetin is one of the most widely studied flavonoids with broad spectrum of pharmacological activities. In addition to antioxidant capability, quercetin may exert its actions via the alteration of protein kinase activities and the sequential signaling processes. This may enable quercetin to prevent the disintegration of TJ structure and to enhance the expression, localization and interaction of TJ proteins. This review presents the information to corroborate the potential benefit of quercetin in preserving integrity and function of TJ complexes. The involvement of protein kinase C (PKC) and MAPK signaling pathway is emphasized.