The protective effect of soybean protein-derived peptides on apoptosis via the activation of PI3K-AKT and inhibition on apoptosis pathway

The SWGEDWGEIW from Soybean Peptides Reduces Insulin Resistance in 3T3-L1 Adipocytes by Activating p-Akt/GLUT4 Signaling Pathway

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with anti-diabetic properties. Notably, the protective mechanism of the single peptide SWGEDWGEIW (TSP) from soybean peptides (SBPs) on insulin resistance of adipocytes in an inflammatory state was investigated by detecting the lipolysis and glucose absorption and utilization of adipocytes. The results showed that different concentrations of TSP (5, 10, 20 µg/mL) intervention can reduce 3T3-L1 adipocytes’ insulin resistance induced by inflammatory factors in a dose-dependent manner and increase glucose utilization by 34.2 ± 4.6%, 74.5 ± 5.2%, and 86.7 ± 6.1%, respectively. Thus, TSP can significantly alleviate the lipolysis of adipocytes caused by inflammatory factors. Further mechanism analysis found that inflammatory factors significantly reduced the phosphorylation (p-Akt) of Akt, two critical proteins of glucose metabolism in adipocytes, and the expression of GLUT4 protein downstream, resulting in impaired glucose utilization, while TSP intervention significantly increased the expression of these two proteins. After pretreatment of adipocytes with PI3K inhibitor (LY294002), TSP failed to reduce the inhibition of p-Akt and GLUT4 expression in adipocytes. Meanwhile, the corresponding significant decrease in glucose absorption and the increase in the fat decomposition of adipocytes indicated that TSP reduced 3T3-L1 adipocytes’ insulin resistance by specifically activating the p-Akt/GLUT4 signal pathway. Therefore, TSP has the potential to prevent obesity-induced adipose inflammation and insulin resistance.

Tricholoma matsutake-Derived Peptides Ameliorate Inflammation and Mitochondrial Dysfunction in RAW264.7 Macrophages by Modulating the NF-κB/COX-2 Pathway

Tricholoma matsutake is an edible fungus that contains various bioactive substances, some of them with immunostimulatory properties. Presently, there is limited knowledge about the functional components of T. matsutake. Our aim was to evaluate the protective effects and molecular mechanisms of two T. matsutake-derived peptides, SDLKHFPF and SDIKHFPF, on lipopolysaccharide (LPS)-induced mitochondrial dysfunction and inflammation in RAW264.7 macrophages. Tricholoma matsutake peptides significantly ameliorated the production of inflammatory cytokines and inhibited the expression of COX-2, iNOS, IKKβ, p-IκB-α, and p-NF-κB. Immunofluorescence assays confirmed the inhibitory effect of T. matsutake peptides on NF-κB/p65 nuclear translocation. Furthermore, the treatment with T. matsutake peptides prevented the accumulation of reactive oxygen species, increased the Bcl-2/Bax ratio, reversed the loss of mitochondrial membrane potential, and rescued abnormalities in cellular energy metabolism. These findings indicate that T. matsutake peptides can effectively inhibit the activation of NF-κB/COX-2 and may confer an overall protective effect against LPS-induced cell damage.

Role of bioactive peptides derived from food proteins in programmed cell death to treat inflammatory diseases and cancer

Bioactive peptides are specific peptide which usually contains 2-20 amino acid residues and actively exerts various functions and biological activities and ultimately affect health. Programmed cell deaths are some styles of cell death discovered in recent years, which is the key to tissue development and balance, eliminating excess, damaged or aging cells. More importantly, programmed cell death is a potential way to treat inflammatory diseases and cancer. In this review, through screening references from 2015 to present, we introduce the effect of bioactive peptides derived from food proteins on inflammatory diseases or cancer through regulating programmed cell deaths, including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis. And this review also introduces the targets of these bioactive peptides to regulate programmed cell death. The purpose of this review is to help to expand the prospective applications of bioactive peptides in the field of inflammatory disease and cancer to provide some guidance.

The Inhibition Effect of the Seaweed Polyphenol, 7-Phloro-Eckol from Ecklonia Cava on Alcohol-Induced Oxidative Stress in HepG2/CYP2E1 Cells

The liver is vulnerable to oxidative stress-induced damage, which leads to many diseases, including alcoholic liver disease (ALD). Liver disease endanger people's health, and the incidence of ALD is increasing; therefore, prevention is very important. 7-phloro-eckol (7PE) is a seaweed polyphenol, which was isolated from Ecklonia cava in a previous study. In this study, the antioxidative stress effect of 7PE on HepG2/CYP2E1 cells was evaluated by alcohol-induced cytotoxicity, DNA damage, and expression of related inflammation and apoptosis proteins. The results showed that 7PE caused alcohol-induced cytotoxicity to abate, reduced the amount of reactive oxygen species (ROS) and nitric oxide (NO), and effectively inhibited DNA damage in HepG2/CYP2E1 cells. Additionally, the expression levels of glutathione (GSH), superoxide dismutase (SOD), B cell lymphoma 2 (Bcl-2), and Akt increased, while γ-glutamyltransferase (GGT), Bcl-2 related x (Bax), cleaved caspase-3, cleaved caspase-9, nuclear factor-κB (NF-κB), and JNK decreased. Finally, molecular docking proved that 7PE could bind to BCL-2 and GSH protein. These results indicate that 7PE can alleviate the alcohol-induced oxidative stress injury of HepG2 cells and that 7PE may have a potential application prospect in the future development of antioxidants.

Salvinorin A protects against methicillin resistant staphylococcus aureus-induced acute lung injury via Nrf2 pathway

Salvinorin A (SA), a neoclerodane diterpene, is isolated from the dried leaves ofSalvia divinorum. SA has traditionally been used treatments for chronic pain diseases. Recent research has demonstrated that SA possesses the anti-inflammatory property. The present study aim to explore the effects and potentialmechanisms ofSA in protection against Methicillin Resistant Staphylococcus aureus (MRSA)-induced acute lung injury (ALI). Here, we firstly found that verylowdosesof SA (50 μg/kg) could markedly decrease the infiltration of pulmonary neutrophils, mRNA expression of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) and then attenuated ALI cause by MRSA infection in mice. In vitro findings revealed that SA attenuated lipoteichoicacid-induced apoptosis, inflammation and oxidative stress in RAW264.7 cells. Mechanism research revealed that SA increased both mRNA levels and protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and up-regulated mRNA expression of its downstream genes (HO-1, Gclm, Trx-1, SOD1 and SOD2). Additionally, Nrf2 knockout mice abolished the inhibitory effect of SA on neutrophil accumulation and oxidative stress in MRSA-induced ALI. In conclusion, SA attenuates MRSA-induced ALI via Nrf2 signaling pathways.