Search

Intestinal barrier is an important basis for intestinal function, which can strictly control the exchange of substances between the host and the external environment. An intact intestianl barrier is also the guardian of human health. In this study, the protective effect of corn protein hydrolysate with glutamine-rich peptides (APH) on intestinal epithelial cell barrier was evaluated in Caco-2 cell inflammatory damage model induced by lipopolysaccharide (LPS). Then, the sequences of glutamine peptides in APH were identified by Nano LC-MS/MS, and the structural characteristics of the identified glutamine peptides were analyzed. The results showed that the hydrolysate effectively alleviated LPS-induced cell damage and decreased the inflammatory response by down-regulating the levels of pro-inflammatory cytokines (TNF-α, IL-8, and IL-1β) and up-regulating the levels of anti-inflammatory cytokine (IL-10). Moreover, the hydrolysate also up-regulated the gene expression of three tight junction proteins (ZO-1, Occludin, Claudin-1) to maintain the integrity of the intestinal epithelial barrier. More importantly, the hydrolysate protected the intestinal barrier function via down-regulating the key genes expression (TLR4, MyD88, NF-κB) in the NF-κB signaling pathway and inhibiting the overexpression of MLCK gene in the MLCK signaling pathway. Finally, 374 corn glutamine peptides were identified from APH, and their structural characteristics showed that corn glutamine peptides had high affinity with membrane proteins. Taken together, these results indicated that APH has excellent potential to protect intestinal barrier function and can be developed into a functional health food.

More than 50% of the world population is infected with Helicobacter pylori (H. pylori). Potential anti-adhesive peptides from corn protein hydrolysate were developed using in vitro methodologies to prevent Helicobacter pylori infection. To obtain anti-adhesive peptides against Helicobacter pylori, corn gluten meal (CGM) was hydrolyzed by neutrase, and the hydrolysate (CPHN) was purified by using Superdex peptide gel filtration, Q anion exchange and Mono Q anion exchange. Then, sequences of peptides were identified by Nano-LC-MS/MS, and the structural and functional properties of the identified peptides were characterized. Three novel peptides Pro-Tyr-Ala-Glu-Tyr (PYAEY, PY5), Ile-Ile-Pro-Gln-Cys-Ser (IIPQCS, II6) and Thr-Ile-Ile-Pro-Gln (TIIPQ, TI5) were identified, respectively. PY5 exhibited the best anti-adhesive activity among the three novel peptides, and its anti-adhesive activity was 40.75 ± 0.72% at 4 mg/mL. Meanwhile, PY5 also possessed significant 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and excellent 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacity, with IC50 values of 1.650 ± 0.184 and 0.007 ± 0.001 mg/mL, respectively, suggesting that PY5 could alleviate stomach damage induced by Helicobacter pylori infection. In addition, molecular docking and dot blot results showed that PY5 could also conjugate with the Helicobacter pylori adhesins, SabA and BabA, through hydrophobic interactions and hydrogen bond inhibiting Helicobacter pylori adhesion. These results indicate that three novel peptides from corn protein hydrolysate have potential anti-adhesive and antioxidant effects and could serve as functional foods or drugs to prevent Helicobacter pylori infection.

Alcoholic liver disease is one of the most prevalent chronic diseases that causes high morbidity and mortality worldwide. This study demonstrated the protective potential of Alcalase-black soybean-derived peptides (BSPs) against alcohol-induced liver injury in mice. BSPs were rich in oligopeptides (80%, w/w, 0.05). All treatments significantly (P

Corn gluten meal (CGM) is a major by-product of corn wet milling. Pretreatments of CGM by Na2CO3, starch removal, and cooking reduced the total starch and fat by 93% and 78%, respectively. Higher antioxidant hydrolysate was prepared by using Alcalase, Protamex and Flavourzyme at a substrate concentration of 13.5% (w/w). The degree of hydrolysis reached 29.49% and 27.11%. The peptides in hydrolysate were in the range of 1200–250 Da. It increased the activities of superoxide dismutase, glutathione peroxidase, and reduced MDA equivalents of mice at a dose of 300 mg/kg. Therefore, corn gluten can be developed into an antioxidant supplement.