Walnut extract exhibits anti-fatigue action via improvement of exercise tolerance in mice

Walnut Oligopeptide Delayed Improved Aging-Related Learning and Memory Impairment in SAMP8 Mice

Aging-related learning and memory decline are hallmarks of aging and pose a significant health burden. The effects of walnut oligopeptides (WOPs) on learning and memory were evaluated in this study. Sixty SAMP8 mice were randomly divided into four groups (15 mice/group), including one SAMP8 age-control group and three WOP-treated groups. SAMR1 mice (n = 15) that show a normal senescence rate were used as controls. The SAMP8 and SAMR1 controls were administered ordinary sterilized water, while the WOP-intervention groups were administered 110, 220, and 440 mg/kg·bw of WOPs in water, respectively. The whole intervention period was six months. The remaining 15 SAMP8 (4-month-old) mice were used as the young control group. The results showed that WOPs significantly improved the decline in aging-related learning/memory ability. WOPs significantly increased the expression of BDNF and PSD95 and decreased the level of APP and Aβ1-42 in the brain. The mechanism of action may be related to an increase in the activity of antioxidant enzymes (SOD and GSH-Px), a reduction in the expression of inflammatory factors (TNF-α and IL-1β) in the brain and a reduction in oxidative stress injury (MDA). Furthermore, the expression of AMPK, SIRT-1, and PGC-1α was upregulated and the mitochondrial DNA content was increased in brain. These results indicated that WOPs improved aging-related learning and memory impairment. WOP supplementation may be a potential and effective method for the elderly.

An overview of walnuts application as a plant-based

The plant-based refers to plant-based raw materials or products that are available as the source of protein and fat. Utilization and development of walnuts as a plant-based, resulting in a high-quality protein-rich walnut plant-based product: walnut protein powder and walnut peptides. Progress in research on the application of walnuts as a plant-based has been advanced, solving the problem of wasted resources and environmental pollution caused by the fact that walnut residue, a product of walnuts after oil extraction, is often thrown away as waste, or becomes animal feed or compost. This paper reviews and summarizes the research and reports on walnut plant-based at home and abroad, focusing on the application of walnut plant-based in the preparation process (enzymatic and fermentation methods) and the biological activity of the walnut protein and walnut peptide, to provide a theoretical basis for the further processing of walnuts as a walnut plant-based. It can make full use of walnut resources and play its nutritional and health care value, develop and build a series of walnut plant-based products, improve the competitiveness of walnut peptide products, turn them into treasure, and provide more powerful guidance for the development of food and medicine health industry in Yunnan.

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-1β 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.

Short-Term Mediterranean Diet Improves Endurance Exercise Performance: A Randomized-Sequence Crossover Trial

Objective: Healthful dietary patterns have constituents that are known to improve exercise performance, such as antioxidants, nitrates, and alkalizing effects. However, ergogenic effects of such diets have not been evaluated. We hypothesized that a short-term Mediterranean diet results in better exercise performance, as compared to a typical Western diet. Methods: Eleven recreationally active women (n = 7) and men (n = 4) (body mass index, 24.6 ± 3.2 kg/m²; age 28 ± 3 years) were studied in a randomized-sequence crossover study, in which they underwent exercise performance testing on one occasion after 4 days of a Mediterranean diet and on another occasion after 4 days of a Western diet. A 9- to 16-day washout period separated the two trials. Endurance exercise performance was evaluated with a 5-km treadmill time trial. Anaerobic exercise performance tests included a Wingate cycle test, a vertical jump test, and hand grip dynamometry. Results: Five-kilometer run time was 6% ± 3% shorter (faster) in the Mediterranean diet trial than in the Western diet trial (27.09 ± 3.55 vs 28.59 ± 3.21 minutes; p = 0.030) despite similar heart rates (160 ± 5 vs 160 ± 4 beats/min; p = 0.941) and ratings of perceived exertion (14.6 ± 0.5 vs 15.0 ± 0.5; p = 0.356). No differences between the diet conditions were observed for anaerobic exercise tests, including peak and mean power from the Wingate test (both p ≥ 0.05), the vertical jump test (p = 0.19), and the hand grip strength test (p = 0.69). Conclusions: Our findings extend existing evidence of the health benefits of the Mediterranean diet by showing that this diet is also effective for improving endurance exercise performance in as little as 4 days. Further studies are warranted to determine whether a longer-term Mediterranean diet provides greater benefits and whether it might also be beneficial for anaerobic exercise performance and muscle strength and power.

Small Molecule Oligopeptides Isolated from Walnut (Juglans regia L.) and Their Anti-Fatigue Effects in Mice

Walnut (Juglans regia L.) is unique for its extensive biological activities and pharmaceutical properties. There are few studies on walnut oligopeptides (WOPs), which are small molecule peptides extracted from walnuts. This study aimed to evaluate the anti-fatigue effects of WOPs on ICR mice and explore the possible underlying mechanism. Mice were randomly divided into four experimental sets and each set of mice were then randomly divided into four groups. The vehicle group was administered distilled water, and the three WOP intervention groups were orally administered WOP solution at a dose of 110, 220, and 440 mg/kg of body weight, respectively. After 30 days of WOP intervention, the anti-fatigue activity of WOPs were evaluated using the weight-loaded swimming test and by measuring the change of biochemical parameters, glycogen storage and energy metabolism enzymes, anti-oxidative capacity and mitochondrial function. It was observed that WOPs could significantly prolong the swimming time, decrease the accumulation of lactate dehydrogenase (LDH), creatine kinase (CK), blood urea nitrogen (BUN) and blood lactic acid (BLA), and increased the glycogen storage of liver and gastrocnemius muscle. WOPs also markedly inhibited fatigue induced oxidative stress by increasing the activity of superoxide dismutase (SOD), glutathione peroxidase (GPX) and decreasing the content malondialdehyde (MDA). Notably, WOPs improved the activity of pyruvate kinase (PK), succinate dehydrogenase (SDH), Na+-K+-ATPase, and enhanced the mRNA expression of mitochondrial biogenesis factors and mitochondrial DNA content in skeletal muscles of mice. These results suggest that WOPs have beneficial anti-fatigue effects, which may be attributed to their positive effects on increasing glycogen storage, improving energy metabolism, inhibiting oxidative stress, enhancing mitochondrial function in skeletal muscle, and ameliorating the cell damage and the muscular injury.

Voluntary Exercise Prevents Oxidative Stress in the Brain of Phenylketonuria Mice

BACKGROUND

High phenylalanine levels in phenylketonuria (PKU) have been associated with brain oxidative stress and amino acid imbalance. Exercise has been shown to improve brain function in hyperphenylalaninemia and neurodegenerative diseases. This study aimed to verify the effects of exercise on coordination and balance, plasma and brain amino acid levels, and brain oxidative stress markers in PKU mice.

METHODS

Twenty wild-type (WT) and 20 PAH(enu2) (PKU) C57BL/6 mice were placed in cages with (exercise, Exe) or without (sedentary, Sed) running wheels during 53 days. At day 43, a balance beam test was performed. Plasma and brain were collected for analyses of amino acid levels and the oxidative stress parameters superoxide dismutase (SOD) activity, sulfhydryl and reduced glutathione (GSH) contents, total radical-trapping antioxidant potential (TRAP), and total antioxidant reactivity (TAR).

RESULTS

SedPKU showed poor coordination (p < 0.001) and balance (p < 0.001), higher plasma and brain phenylalanine (p < 0.001), and increased brain oxidative stress (p < 0.05) in comparison to SedWT. ExePKU animals ran less than ExeWT (p = 0.018). Although no improvement was seen in motor coordination and balance, exercise in PKU restored SOD, sulfhydryl content, and TRAP levels to controls. TAR levels were increased in ExePKU in comparison to SedPKU (p = 0.012). Exercise decreased plasma and brain glucogenic amino acids in ExePKU, but did not change plasma and brain phenylalanine in both WT and PKU.

CONCLUSIONS

Exercise prevents oxidative stress in the brain of PKU mice without modifying phenylalanine levels. Hence, exercise positively affects the brain, demonstrating its value as an intervention to improve brain quality in PKU.

The traditional drug Gongjin-Dan ameliorates chronic fatigue in a forced-stress mouse exercise model

ETHNOPHARMACOLOGICAL RELEVANCE

Gongjin-Dan is a representative traditional Oriental medicine herbal drug that has been used to treat chronic fatigue symptoms for several hundred years. We evaluated the anti-fatigue effects of Gongjin-Dan and the underlying mechanisms in a chronic forced exercise mouse model.

METHODS AND MATERIALS

Balb/C male mice underwent an extreme treadmill-based running stress (1-h, 5 days/week), and daily oral administration of distilled water, Gongjin-Dan (100, 200, or 400 mg/kg), or ascorbic acid (100 mg/kg) for 28 days. The anti-fatigue effects of Gongjin-Dan were evaluated with behavioral tests (exercise tolerance and swimming tests), and the corresponding mechanisms were investigated based on oxidative stress and inflammatory cytokine and stress hormone levels in skeletal muscle, sera, and brain tissue.

RESULTS

Gongjin-Dan significantly increased exercise tolerance and latency times but reduced the number of electric shocks and immobilization time on the treadmill running and swimming tests, compared with the control group. Gongjin-Dan also significantly ameliorated alterations in oxidative stress-related biomarkers (reactive oxygen species and malondialdehyde), inflammatory cytokines (tumor necrosis factor-α, interleukin-1 beta, interleukin-6, and interferon-γ) and glycogen and L-lactate levels in skeletal muscle, compared with those in the control group. Moreover, Gongjin-Dan considerably normalized the forced running stress-induced changes in serum corticosterone and adrenaline levels, as well as brain serotonin level. These antioxidant and anti-stress effects of Gongjin-Dan were supported by the results of Western blotting (4-hydroxynonenal and heme oxygenase-1) and the gene expression levels (serotonin receptor and serotonin transporter).

CONCLUSION

These results support the clinical relevance of Gongjin-Dan regarding anti-chronic fatigue properties. The underlying mechanisms involve attenuation of oxidative and inflammatory reactions in muscle and regulation of the stress response through the hypothalmo-pituitary-adrenal axis.