Vascular anti-inflammatory effects of curcumin on HMGB1-mediated responses in vitro

High mobility group box 1 (HMGB1) protein up-regulates proinflammatory cytokines in several inflammatory diseases. Curcumin is a polyphenol responsible for the yellow color of the curry spice turmeric. It possesses diverse pharmacological properties such as anti-inflammatory, anti-oxidant, anti-proliferative and anti-angiogenic activities. However, the effects of curcumin on HMGB1-mediated proinflammatory responses have not been studied.

The anti-inflammatory activities of curcumin were determined by measuring solute flux, leukocyte adhesion and migration and activation of proinflammatory proteins in HMGB1-activated human umbilical vein endothelial cells.

Curcumin inhibited the release of HMGB1 by lipopolysaccharide (LPS)- and HMGB1-mediated barrier disruption, neutrophil adhesion and migration, and expression of cell adhesion molecules. Further studies revealed that curcumin down-regulated the cell surface receptor of HMGB1 in human endothelial cells.

These findings suggest that curcumin exerts anti-inflammatory effects in HMGB1-mediated proinflammatory responses, endorsing its usefulness as therapy for vascular inflammatory diseases.