Evaluation and Exploration of Potentially Bioactive Peptides in Casein Hydrolysates against Liver Oxidative Damage in STZ/HFD-Induced Diabetic Rats

Abstract

Hyperglycemia-induced oxidative stress can cause liver damage in diabetes, and protein hydrolysates with antidiabetic and antioxidant properties are emerging as a potential therapy. In this study, protective effects of casein hydrolysates against live oxidative damage in streptozotocin/high-fat-induced diabetic rats were studied and potentially bioactive peptides were explored by an integrated approach of differential peptide and in silico analysis. Results showed that different casein hydrolysates significantly alleviated liver oxidative damage (p < 0.05) via different mechanisms. Particularly, casein hydrolyzed by a papain–flavourzyme combination (P-FCH) treatment significantly improved liver antioxidant enzyme activities by enhancing nuclear factor erythroid 2-related factor 2 (Nrf2) transcription (p < 0.05). Furthermore, 18 peptides were screened as potential bioactive peptides by analyzing differential peptides among different hydrolysates combined with in silico prediction. Among them, the dipeptide WM might directly inhibit the Kelch-like ECH-associated protein 1 (Keap1)–Nrf2 interaction as potential Nrf2 activators. These results suggested that P-FCH might be an alternative way to treat liver damage in diabetes.

Protective effects of bioactive peptides in foxtail millet protein hydrolysates against experimental colitis in mice

“…28 Low MW peptides (<3 kDa) have been found to be the most potential bioactive peptides in many studies, and polypeptides with higher hydrophobicity have been shown to penetrate the cell membrane more easily to reach the target location. 29 In our study, 60.7% of the peptides in FMPH had a molecular weight less than 3 kDa, and over 50% of the amino acids were hydrophobic, suggesting their potential biological activities.…”

Identification and Screening of Potential Bioactive Peptides with Sleep-Enhancing Effects in Bovine Milk Casein Hydrolysate

“…However, commonly used sedative drugs such as morphine and phenobarbital had serious side effects such as dizzy feeling, excessive sedation, and even addiction . Recently, bioactive peptides and hydrolysates were used to be a supportive therapy, such as for insomnia, diabetes, and memory deficits problems. − For instance, several natural proteins were found to contain encrypted peptides with anxiolytic and sleep-enhancing effects in their sequences, such as casein-derived decapeptide α-casozepine (YLGYLEQLLR, α-CZP) and undecapeptide (FLSSTEAQQSY) from soy β-conglycinin. , The αS1-casein tryptic hydrolysate (CTH) containing α-CZP was proven to alleviate anxiety and insomnia that was related with GABA A R in many studies, including intraperitoneal (i.p.) or oral administration (p.o.)…”

Synergistic Effects of Combined Anthocyanin and Metformin Treatment for Hyperglycemia In Vitro and In Vivo

“…T2DM is often accompanied by insulin resistance, which can lead to reduced glycogen synthesis and storage. 40,41 Therefore, this study measured liver glycogen content and found that the model group had less glycogen synthesis. Following intervention with different metformin and anthocyanin treatments, glycogen synthesis tended to match control values.…”