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−1) is the most effective in reducing (p < 0.0001) interleukin-8 (61%) and interleukin-6 (57.2%). Yunlu29 (50 µg mL−1) 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. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim