Anti-fatigue effects of fermented soybean protein peptides in mice.

BACKGROUND: Bioactive protein hydrolysates and peptides are believed to help counteract and ameliorate physical fatigue. Fermented soybean protein peptides (FSPPs) were prepared by protease hydrolysis and microbial fermentation. The present study aimed to evaluate the anti-fatigue properties of FSPPs. RESULTS: The forced swimming time in the FSPP group was 35.78% longer than the control group, the oxygen-resistant survival time of the FSPP group was significantly prolonged and the prolongation rate was 31.00%. In addition, FSPPs decreased the lactic acid (LD), blood urea nitrogen (BUN) and creatine kinase (CK) concentration by 27.47%, 25.93% and 21.70%, respectively, after treatment, while increasing the levels of liver glycogen and muscle glycogen by 93.35% and 67.31%, respectively. FSPPs can significantly increase gut microbiota diversity and regulate the species richness of gut microbiota. The results of real-time polymerase chain reaction (RT-PCR) and western blotting showed that FSPPs activate p-AMPK/PGC1-α and PI3K/Akt/mTOR signaling pathways. CONCLUSION: These results indicate that treatment with FSPPs induces anti-fatigue effects, which may be due to the mediating muscle protein synthesis and participation in skeletal muscle hypertrophy, providing energy for muscle cells. FSPPs may have potential applications in the food industry as functional material additives. © 2021 Society of Chemical Industry.

A Novel Combination of Wheat Peptides and Fucoidan Attenuates Ethanol-Induced Gastric Mucosal Damage through Anti-Oxidant, Anti-Inflammatory, and Pro-Survival Mechanisms.

Gastritis or peptic ulcer is believed to affect about half of people worldwide. Traditional medications can lead to adverse effects, therefore, alternative nutritional strategies are needed to prevent the development of gastric mucosal damage. A novel combination of two food-grade ingredients, wheat peptides and fucoidan (WPF), was prepared to treat male Sprague Dawley rats for 30 days before gastric mucosal damage was induced by oral administration of ethanol. The serum levels of biomarkers were determined by enzyme-linked immunosorbent assay. Biomarkers in stomach tissue were analyzed using immunohistochemistry. In addition, human gastric epithelial cell line (GES-1) was used to investigate protein expression by Western blot. WPF could attenuate ethanol-induced gastric mucosal damage in an inverse dose-dependent manner, with both ulcer index and pathological index improved. WPF increased superoxide dismutase level and decreased malondialdehyde level. WPF also decreased the levels of interleukin-8, platelet-activating factor, and Caspase 3, while increasing the levels of prostaglandin E-2, epidermal growth factor (EGF), and EGF receptor (EGFR). Furthermore, phosphorylation of EGFR and extracellular signal-regulated kinases was induced by WPF in GES-1 cells. In conclusion, the novel combination of wheat peptides and fucoidan attenuated ethanol-induced gastric mucosal damage in rats through anti-oxidant, anti-inflammatory, and pro-survival mechanisms.

EGAR, A Food Protein-Derived Tetrapeptide, Reduces Seizure Activity in Pentylenetetrazole-Induced Epilepsy Models Through α-Amino-3-Hydroxy-5-Methyl-4-Isoxazole Propionate Receptors.

A primary pathogeny of epilepsy is excessive activation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionate receptors (AMPARs). To find potential molecules to inhibit AMPARs, high-throughput screening was performed in a library of tetrapeptides in silico. Computational results suggest that some tetrapeptides bind stably to the AMPAR. We aligned these sequences of tetrapeptide candidates with those from in vitro digestion of the trout skin protein. Among salmon-derived products, Glu-Gly-Ala-Arg (EGAR) showed a high biological affinity toward AMPAR when tested in silico. Accordingly, natural EGAR was hypothesized to have anticonvulsant activity, and in vitro experiments showed that EGAR selectively inhibited AMPAR-mediated synaptic transmission without affecting the electrophysiological properties of hippocampal pyramidal neurons. In addition, EGAR reduced neuronal spiking in an in vitro seizure model. Moreover, the ability of EGAR to reduce seizures was evaluated in a rodent epilepsy model. Briefer and less severe seizures versus controls were shown after mice were treated with EGAR. In conclusion, the promising experimental results suggest that EGAR inhibitor against AMPARs may be a target for antiepilepsy pharmaceuticals. Epilepsy is a common brain disorder characterized by the occurrence of recurring, unprovoked seizures. Twenty to 30 % of persons with epilepsy do not achieve adequate seizure control with any drug. Here we provide a possibility in which a natural and edible tetrapeptide, EGAR, can act as an antiepileptic agent. We have combined computation with in vitro experiments to show how EGAR modulates epilepsy. We also used an animal model of epilepsy to prove that EGAR can inhibit seizures in vivo. This study suggests EGAR as a potential pharmaceutical for the treatment of epilepsy.

Protective effect of corn peptides against alcoholic liver injury in men with chronic alcohol consumption: a randomized double-blind placebo-controlled study.

BACKGROUND: Corn peptides (CPs) are a novel food prepared from corn gluten meal, which is a main by-product of the corn starch industry. Recently, significant beneficial effects of CPs on early alcoholic liver injury in rats and on acute alcoholic injury in mice were observed. To our knowledge, the present study is the first report showing that CPs supplementation has beneficial effects on lipid profile, oxidative stress and alcoholic liver injury in men with chronic alcohol consumption. METHODS: A 9-week, randomized, double-blind, placebo-controlled study was conducted between September 2011 and August 2012 to assess the hepatoprotective effect of CPs. A total of 161 men were randomized to receive CPs (n=53), whey protein (n=54), or corn starch placebo (n=54) at the same dose of 2 g twice daily. 146 participants completed the study. Serum lipid profile, serum markers of liver injury, oxidative stress and inflammation, and fatty liver based on the results of abdominal ultrasonography were assessed at the beginning and end of the intervention. RESULTS: CPs supplementation (4 g/d) for 9 weeks significantly lowered serum levels or activities of total cholesterol, triglyceride, alanine aminotransferase, aspartate aminotransferase, malondialdehyde and tumor necrosis factor-α, and significantly increased serum activities of superoxide dismutase and glutathione peroxidase, but the same dose of whey protein and corn starch (placebo) did not demonstrate these effects. CONCLUSIONS: Our results indicate that CPs may have protective effects on alcohol-induced liver damage via modulation of lipid metabolism and oxidative stress. CPs may potentially be used as a functional food for the management of alcoholic liver disease in subjects with chronic alcohol consumption.

[Effect of curcumin on antioxidant function in the mice with acute alcoholic liver injury].

OBJECTIVE: To study the effect of curcumin on antioxidant function in the mice with acute alcoholic liver injury. METHODS: 50 male KM mices were randomly divided into 5 groups according to the weight, i. e. the normal control group, model control group, and curcumin low-dose group, middle-dose group, high-dose group (50, 100 and 200 mg/kg BW). After a 14-day administration, the relative liver weight, the content of MDA, the activity of SOD, GSH-Px, T-AOC in the liver tissue and the content of serum AST, ALT were determined. RESULTS: Compared with the normal control group, all indexes of model control group were significantly different (P < 0.05). The content of serum AST and ALT at high-dose group were significantly decreased compared with model control group (P < 0.05). Meanwhile, the activity of SOD, GSH-Px and T-AOC in the liver tissue were increased significantly (P < 0.05), and the content of MDA decreased significantly (P < 0.05). CONCLUSION: Curcumin can improve the antioxidant activity of the mice with acute alcoholism, and has good protective effects on acute alcoholic liver injury in mice.

Protective effect of wheat peptides against indomethacin-induced oxidative stress in IEC-6 cells.

Recent studies have demonstrated that wheat peptides protected rats against non-steroidal anti-inflammatory drugs-induced small intestinal epithelial cells damage, but the mechanism of action is unclear. In the present study, an indomethacin-induced oxidative stress model was used to investigate the effect of wheat peptides on the nuclear factor-κB(NF-κB)-inducible nitric oxide synthase-nitric oxide signal pathway in intestinal epithelial cells-6 cells. IEC-6 cells were treated with wheat peptides (0, 125, 500 and 2000 mg/L) for 24 h, followed by 90 mg/L indomethacin for 12 h. Wheat peptides significantly attenuated the indomethacin-induced decrease in superoxide dismutase and glutathione peroxidase activity. Wheat peptides at 2000 mg/L markedly decreased the expression of the NF-κB in response to indomethacin-induced oxidative stress. This study demonstrated that the addition of wheat peptides to a culture medium significantly inhibited the indomethacin-induced release of malondialdehyde and nitrogen monoxide, and increased antioxidant enzyme activity in IEC-6 cells, thereby providing a possible explanation for the protective effect proposed for wheat peptides in the prevention of indomethacin-induced oxidative stress in small intestinal epithelial cells.

[Effect of wheat oligo-peptides on antioxidant function in aged mice].

OBJECTIVE: To study the effect of wheat oligo-peptides on antioxidant function in vitro and in vivo. METHODS: Male KM aged mice were randomly divided into 4 groups according to the serum MDA level, i. e. the negative control group, low-dose group, middle-dose group and high-dose group (0, 500, 1000, 2000 mg/kg BW of wheat oligo-peptides). After a 30-day administration of wheat oligo-peptides, the content of serum MDA, activity of SOD, GSH-Px and T-AOC were determined. The reducing power, DPPH radical and hydroxyl radical scavenging activity were also determined to evaluate the antioxidant activity in vitro. RESULTS: The wheat oligo-peptides were found a good reducing power in vitro (R=0.97), scavenging activity of DPPH radical and hydroxyl radical (RDPPH.=0.90, R.OH=0.91). In vivo experiment, the activity of serum SOD and GSH-Px, and the serum T-AOC of all treated groups was significantly increased compared with negative control group (P<0.05). CONCLUSION: The results from this study showed that wheat oligo-peptides have a good antioxidant activity both in vitro and in vivo.

[Changes of vitamins and mineral retention factors in potato cooked by different methods].

OBJECTIVE: To study the effect on the retention factors (RFs) of vitamin and mineral in potato cooked by different methods, to provide reference for evaluation of diet's nutrition and the RF decision of similar vegetables in our country. METHODS: Potato were selected and cooked by different methods, such as frying, braising, boiling deep frying and steaming, according to local tradition and custom. Meanwhile, weights of potato before and after cooking were recorded. Respectively vitamin and mineral contents in every sample were analyzed with the national standard methods. RESULTS: The RF value of vitamin C was higher during braising than that of during frying, boiling, deep frying and steaming. The RF values of thiamin, riboflavin, vitamin B6 and niacin were more loss during boiling and deep frying than those during other methods. The RFs of every minerals were more loss only during boiling. CONCLUSION: Cooking may change the contents of vitamins and minerals in potato. There could be for one nutrient different RFs during different cooking methods.