Rice Bioactive Peptide Binding with TLR4 To Overcome H2O2-Induced Injury in Human Umbilical Vein Endothelial Cells through NF-κB Signaling.

Reactive oxygen species-induced vessel endothelium injury is crucial in cardiovascular diseases progression. Rice-derived bran bioactive peptides (RBAP) might exert antioxidant effect through unknown mechanisms. Herein, we validated the antioxidant effect and mechanism of RBAP on H2O2-induced oxidative injury in human umbilical vein endothelial cells (HUVECs). Here, HUVECs were treated with RBAP under H2O2 stimulation; the effects of RBAP on HUVECs oxidative injury were evaluated. H2O2 injury-induced cell morphology changes were ameliorated by RBAP. The effect of H2O2- on HUVEC apoptosis (percentage of apoptotic cell: 38.00 ± 2.00 in H2O2 group vs 21.07 ± 2.06 in RBAP + H2O2 group, P = 0.0013 compared to H2O2 group), the protein levels of cleaved caspase-3 (relative protein expression: 2.90 ± 0.10 in H2O2 group vs 1.82 ± 0.09 in RBAP + H2O2 group, P < 0.0001 compared to H2O2 group) and p-p65 (relative protein expression: 1.86 ± 0.09 in H2O2 group vs 1.35 ± 0.08 in RBAP + H2O2 group, P < 0.0001 compared to H2O2 group) could be attenuated by RBAP. RBAP exerts its protective function through binding with Toll-like receptor 4 (TLR4). Taken together, RBAP protects HUVECs against H2O2-induced oxidant injury, which provided the theoretical basis for the molecular mechanism of rice deep processing and exploitation of functional peptides.