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

Abstract

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.

Buffalo Milk Can Rescue Fatigue in Young Mice, Alleviate Oxidative Stress and Boost Learning and Memory in Aging Mice

“…Many cross-sectional studies have demonstrated that females have a greater capacity to resist fatigue than males [27]. Forced swimming time and biomarkers such as hepatic glycogen, BUN, and LDH concentration are often used as indicators to evaluate anti-fatigue [29,30]. In the present study, we found that PBM rescued fatigue more signi cantly in female than male mice.…”

“…1a). Forced swimming time and biomarkers such as hepatic glycogen, blood urea nitrogen (BUN), and lactate dehydrogenase (LDH) concentration were used as indicators to evaluate anti-fatigue capacity [29,30]. There was no signi cant difference in forced swimming time among the four groups of male mice (P > 0.05) (Fig.…”

The Preventive Effects of Pterostilbene on the Exercise Intolerance and Circadian Misalignment of Mice Subjected to Sleep Restriction

“…The weight‐loaded FST is a valid experimental protocol widely used for reflecting exercise endurance and fatigue and screening the anti‐fatigue activities of certain agents. [ 28,29,31 ] Our results of the weight‐loaded FST demonstrated that PTE treatment remarkably prolonged the exhaustive swimming time and ameliorated the biochemical parameters of exercise fatigue in SR mice, indicating that PTE prolonged exercise endurance of SR mice and possessed an anti‐fatigue effect. Lagouge et al.…”

“…Several biochemical parameters were used to evaluate the extent of muscle fatigue and muscle damage, including BUN, LDH, and CK. [ 31–33 ] The concentration of LDH and CK were significantly increased in SR mice compared with mice in CON group, while PTE treatment remarkably reduced them both (Figure 2B,C). The level of BUN increased significantly in SR mice, but there was no significant difference between mice of SR group and SR+PTE group (Figure 2D).…”

Bioactive Peptides from Walnut Residue Protein

“…In addition, many literatures reported that walnut peptides with high antioxidant activity also have excellent anti-tumor activity [22,24], improve memory activity [43,48,53,54], enhance immunity and anti-fatigue activity [54], etc. Wang et al found that the mixed solution of low molecular weight walnut peptide improved the memory deficit behavior induced by sleep deprivation in rats (666 mg/kg peptide daily recommended).…”