Pigmented Rice-Derived Phenolic Compounds Reduce Biomarkers of Oxidative Stress and Inflammation in Human Umbilical Vein Endothelial Cells.

Scope: Endothelial dysfunction pathogenesis is significantly associated with increased oxidative stress (OS) and inflammation. Rice-derived phenolic compounds have been demonstrated to have antioxidant and anti-inflammatory potential. This study aims to determine if phenolic extracts (PE) from pigmented rice varieties (Purple, Yunlu29-red, and Reiziq-brown) at varying concentrations modulate biomarkers of OS and inflammation in human umbilical vein endothelial cells under induced OS conditions.

Methods And Results: 2,7-dichlorofluorescein diacetate and superoxide dismutase-1 (SOD-1) enzyme-linked immuno-sorbent assay quantification demonstrate that Purple PE significantly decreases reactive oxygen species and increases SOD-1 by 27% and 226%, respectively. Yunlu29 PE (50 µg mL ) is the most effective in reducing (p < 0.0001) interleukin-8 (61%) and interleukin-6 (57.2%). Yunlu29 (50 µg mL ) reduces intracellular-adhesion molecule-1 (p < 0.0001) expression by 34%, followed by Reiziq (31.9%) and Purple (30.2%). Flow cytometric analysis demonstrates that vascular cell-adhesion molecule-1 expression is reduced (p < 0.0001) by 53.5% by Yunlu29 followed by Purple (46.8%) and Reiziq (46.7%). Yunlu29 is the most effective in reducing nuclear factor kappa-B expression by 50.1%, followed by purple (48.8%) and Reiziq (38.6%).

Conclusion: This study indicates that colored rice PE may potentially target OS and inflammatory pathways associated with the pathogenesis of endothelial dysfunction.