Absorption and Metabolism of Peptide WDHHAPQLR Derived from Rapeseed Protein and Inhibition of HUVEC Apoptosis under Oxidative Stress

Abstract

WDHHAPQLR (RAP) is an antioxidative peptide derived from rapeseed protein. Although the health benefits from RAP, due to its antioxidant activities, have been determined by chemical methods, a systematic assessment regarding the absorption, metabolism, and antioxidation processes of RAP is still lacking attention. Hence, Caco-2 cell monolayer models and animal experiments were used to evaluate the absorption and bioavailability of RAP. As expected, RAP could be absorbed by intestinal epithelial cells, and the Papp was 0.82 ± 0.19 × 10 cm/s. Three main fragments, RAP, DHHAPQLR, and WDHHAP were transported by the paracellular pathway, and QLR was transported by PepT1. An important modified product of RAP (EGDHHAPQLR) was found to contribute to the elimination of intracellular reactive oxygen species. The absolute bioavailability of RAP was 3.56%, and three degradation products of RAP were also detected in rat serum. More importantly, RAP exerts its antioxidant activity by inhibiting the apoptosis of oxidative stress cells. RAP could downregulate the expression of Bax and caspase-3 and upregulate the expression of Bcl-2 in HO-induced HUVECs (human umbilical vein endothelial cells). In general, using in vitro and in vivo experimental models, the in vivo absorption and transformation processes of RAP and its antioxidative molecular mechanisms by inhibiting apoptosis of cells were revealed.

Current understanding of transport and bioavailability of bioactive peptides derived from dairy proteins: a review

“…For example, rapeseed protein‐derived antioxidative peptide Trp‐Asp‐His‐His‐Ala‐Pro‐Gln‐Leu‐Arg (WDHHAPQLR) and its fragments (DHHAPQLR and WDHHAP) could be transported across Caco‐2 monolayers by paracellular route, and QLR was transported by PepT1. These four peptides were also detected in rat serum as illustrated in Table 5 (Xu et al ., ). Egg ovotransferrin‐derived antihypertensive peptide Ile‐Arg‐Trp could be transported across Caco‐2 monolayers via paracellular route and PepT1 (Bejjani & Wu, ).…”

Advances on Food-Derived Peptidic Antioxidants—A Review

“…Different model cells were selected according to the application purpose of the antioxidants, so as to evaluate the capacity of antioxidants to inhibit a specific oxidative stress response in the organism [205]. Currently, Erythrocytes, Human hepatoma (HepG2) cells, Caco-2 cell monolayer, Pheochromocytoma (PC-12) cells, Human colon adenocarcinoma (HT-29) cells, Human hepatocyte-derived (C3A) cells, Human leukemia T (Jurkat) cells, Human umbilical vein endothelial cells (HUVECs), etc., have been used in the evaluation of various antioxidants [206,207]. The evaluation indicators of PAs in cell models mainly include the promotion of endogenous enzymes and non-enzymatic antioxidants (SOD, catalase (CAT), GSH-Px and GSH) and the inhibition of oxidation products (ROS, MDA, oxidized glutathione (GSSG)) ( Table 3).…”

Characterization and analysis of an oil‐in‐water emulsion stabilized by rapeseed protein isolate under pH and ionic stress

“…Napin, a strongly basic protein (pI ∼11), is composed of a 4.5 kDa (40 amino acids) chain and a 9.5 kDa (90 amino acids) chain with a molecular mass approximately 12-14.5 kDa. 5 In the past, research on RPI was focused on the function development of its polypeptide extract, 6,7 but its emulsification function was not paid attention to. However, the soybean protein isolate (SPI), which is also oil crop protein, has been found to have good emulsification stability.…”