Walnut (Juglans regia L.) Oligopeptides Alleviate Alcohol-Induced Acute Liver Injury through the Inhibition of Inflammation and Oxidative Stress in Rats.

The study was aimed at investigating the effects of walnut oligopeptides (WOPs) on alcohol-induced acute liver injury and its underlying mechanisms. Male Sprague Dawley (SD) rats were randomly assigned to six groups: normal control, alcohol control, whey protein (440 mg/kg.bw), and three WOPs (220 mg/kg.bw, 440 mg/kg.bw, 880 mg/kg.bw) groups. After 30 days of gavage, ethanol with a volume fraction of 50%, administered at a dose of 7 g/kg.bw., caused acute liver injury. A righting reflex experiment and a blood ethanol concentration evaluation were then performed. Serum biochemical parameters, inflammatory cytokines, liver alcohol metabolism enzymes, oxidative stress biomarkers, liver nuclear factor-κB (NF-κB p65), and cytochrome P4502E1 expression were determined. The results revealed that the intervention of 440 mg/kg and 880 mg/kg WOPs could alleviate the degree of intoxication, decrease blood ethanol concentration, alleviate alcohol-induced hepatic steatosis, enhance the activity of hepatic ethanol metabolizing enzymes and antioxidant capacity, reduce lipid oxidation products and pro-inflammatory factor contents, and inhibit the expression of NF-κBp65 in the livers of rats. The outcomes of the study suggest that WOPs have beneficial effects on liver damage caused by acute ethanol binge drinking, with the high-dose WOPs (880 mg/kg.bw) exerting the most pronounced hepatoprotective effect.

The Effects of Peanut Oligopeptides on Exercise-Induced Fatigue in Mice and Its Underlying Mechanism.

The aim of this study was to clarify the anti-fatigue effect of peanut oligopeptides (POPs) in mice and to investigate its possible underlying mechanism. A total of 150 male ICR mice were randomly assigned into five groups: control, whey protein (0.50 g/kg·bw), and three peanut peptide groups (0.25, 0.50, and 1.00 g/kg·bw). All the mice were treated with intra-gastric administration for 30 days. Following the intervention, a weight-loaded swimming test, blood lactate concentration, glycogen content, the activities of antioxidant factors and energy metabolism enzymes, and the function of mitochondria in the skeletal muscle were examined. The results show that POP intervention significantly prolonged the exhaustive swimming time, decreased blood lactate concentration levels, regulated the process of energy metabolism, and increased the level of antioxidant enzymes, muscle glycogen, and expressions of mtTFA and NRF-1 in the mitochondria of the gastrocnemius muscle. The results suggest that POPs produce an anti-fatigue effect in the animals, and they may exert this effect through the mechanism of improving the animals' antioxidant capacity to reduce oxidative damage levels and regulating the process of energy metabolism.

Radioprotective Effect of Whey Hydrolysate Peptides against γ-Radiation-Induced Oxidative Stress in BALB/c Mice.

Radiation therapy is widely used in the treatment of tumor diseases, but it can also cause serious damage to the body, so it is necessary to find effective nutritional supplements. The main purpose of this study is to evaluate the protective effect of whey hydrolysate peptides (WHPs) against 60Coγ radiation damage in mice and explore the mechanism. BALB/c mice were given WHPs by oral gavage administration for 14 days. Then, some mice underwent a 30-day survival test after 8 Gy radiation, and other mice received 3.5 Gy radiation to analyze the changes in body weight, hematology and bone marrow DNA after three and 14 days. In addition, through further analysis of the level of oxidative stress and intestinal barrier function, the possible mechanism of the radioprotective effect of WHPs was explored. The study found WHPs can prolong survival time, restore body weight, and increase the number of peripheral blood white blood cells and bone marrow DNA content in irradiated mice. In addition, WHPs can significantly improve the antioxidant capacity, inhibit pro-inflammatory cytokines and protect the intestinal barrier. These results indicate that WHPs have a certain radioprotective effect in mice, and the main mechanism is related to reducing oxidative damage.

Jackfruit (Artocarpus heterophyllus Lam.) oligopeptides regulate immune responses via Th cell stimulation, cytokine secretion and antibody production.

This study aimed to observe the immunomodulatory effects of oligopeptides derived from jackfruit (Artocarpus heterophyllus Lam.) (JOPs). 200 female BALB/c mice in five groups were respectively given deionized water (control), whey protein (0.20 g per kg body weight (BW)) and JOPs at doses of 0.20, 0.40, and 0.80 g per kg BW by intragastric administration on a daily basis. 7 tests were conducted to determine the immunomodulatory effects of JOPs on immune organ indexes, cellular and humoral immune responses, macrophage phagocytosis, and natural killer (NK) cell activity. Spleen T lymphocyte sub-populations and serum cytokine and immunoglobulin levels were tested to study how JOPs improved the immune system. We found that JOPs could significantly enhance innate and adaptive immune responses in mice by the improvement of cell-mediated and humoral immunity, macrophage phagocytosis capacity and NK cell activity. The immunomodulatory effects may be based on increased T and Th cell percentages, serum interleukin (IL)-1α, IL-10, tumor necrosis factor (TNF)-α, production of immunoglobulin (Ig) M, IgG, and IgA, and depressed interferon (IFN)-γ secretion. These results suggest that dietary JOPs could be valuable as potential immunomodulators.

The Gastroprotective Effect of Small Molecule Oligopeptides Isolated from Walnut (Juglans regia L.) against Ethanol-Induced Gastric Mucosal Injury in Rats.

The study investigated the protective effect of walnut oligopeptides (WOPs) against ethanol-induced gastric injury using Sprague-Dawley (SD) rats. Rats were randomly divided into seven groups based on body weight (10/group), normal group, ethanol group, whey protein group (220 mg/kg body weight), omeprazole group (20 mg/kg body weight), and three WOPs groups (220, 440, 880 mg/kg body weight). After 30 days of treatment with WOPs, rats were given 5 ml/kg absolute ethanol by gavage to induce gastric mucosal injury. Gastric ulcer index (GUI) were determined and the following measured; gastric content pH, gastric mucin, endogenous pepsinogens (PG), prostaglandin E2 (PGE2), inflammatory cytokines, oxidative stress indicators, and the expression of apoptosis-related proteins were measured to evaluate the gastroprotective effect of WOPs. The results showed that the administration with WOPs markedly mitigated the hemorrhagic gastric lesions caused by ethanol in rats, and decreased the GUI, the gastric content pH, PG1, PG2, and NO levels, enhanced mucin and PGE2. Also, WOPs repressed gastric inflammation through the reduction of TNF-α, IL-6, IL-1ß and increase IL-10 levels, and revealed antioxidant properties with the enhancement of superoxide dismutase, glutathione, and catalase activity, while reduction of malondialdehyde. Moreover, WOPs treatment significantly down-regulated Bax, caspase-3 and nuclear factor-κB p65 (NF-κB p65) expression, while up-regulating the expression of Bcl-2 and inhibitor kappa Bα (IκBα) protein. These results indicated that WOPs have protective effects against ethanol-induced gastric mucosal injury in rats through anti-inflammatory, anti-oxidation, and anti-apoptosis mechanisms.

Radioprotective Effect of Walnut Oligopeptides Against Gamma Radiation-Induced Splenocyte Apoptosis and Intestinal Injury in Mice.

Walnut oligopeptides (WOPs) intake is associated with the augment of the antioxidant defense system and immune system. The chief object of this study is to evaluate the radioprotective effect of walnut oligopeptides extracted from walnut seed protein against 60Coγ-irradiation induced damage in mice. Female BALB/c mice were administered WOPs through drinking water for 14 days until a single dose of whole-body 60Coγ-irradiation. The 30-day survival test was carried out in the first group (8 Gy), and the other two groups (3.5 Gy) were sacrificed at 3 days and 14 days post-irradiation. Blood and organ samples of mice in the three groups were collected, the histopathological analysis and immunohistochemistry were conducted. The number of peripheral blood leukocytes, bone marrow DNA content, inflammatory cytokines, antioxidant capacity, and intestinal permeability were measured. We found that the administration of WOPs augmented antioxidant defense system, accelerated hematopoietic recovery and showed the significant trend toward higher survival rate and less weight loss compared with non-administrated control mice. In addition, WOPs administration appeared to be important to limit IR-induced splenocyte apoptosis and inflammatory cascade as well as reduce intestine epithelial barrier dysfunction and promote epithelial integrity. These results suggest that pre and post-treatment of WOPs may help to ameliorate acute damage, which is induced by ionizing radiation in mice and accelerate its recovery.