Beneficial Effects of Walnut Oligopeptides on Muscle Loss in Senescence-Accelerated Mouse Prone-8 (SAMP8) Mice: Focusing on Mitochondrial Function

Abstract

Aging-related muscle loss is a hallmark of aging and is the cause of some negative outcomes. An optimized diet and supplements have a positive effect in slowing down the process of muscle loss. This study was designed to evaluate the beneficial effects of walnut oligopeptides (WOPs) on aging-related muscle loss and explore the possible underlying mechanism in Senescence-Accelerated Mouse Prone 8 (SAMP8) Mice. SAMP8 mice were randomly divided into four groups (n = 15/group), including one group which was the SAMP8 age control group and three groups those were WOP intervention groups. Meanwhile, Senescence Accelerated Resistant Mouse 1 (SAMR1) mice (n = 12), which had normal senescence rates, were used as model controls. During the six-month intervention period, the age control and normal control groups were given sterilized water, while the three WOP intervention groups were given WOP solution with low (110 mg/kg·bw), medium (220 mg/kg·bw) and high concentrations (440 mg/kg·bw), respectively. The results showed that WOPs could significantly increase muscle mass and improve physical performance (wire hang and catwalk behavioral tests) in aging mice. Moreover, WOPs could significantly reduce the levels of IL-1β, IL-6 and TNF-α in serum and gastrocnemius tissues and increase the mitochondrial DNA content, as well as the expression levels of AMPK, PGC-1α, NRF-1 and TFAM in the gastrocnemius muscle of aging mice, which was speculated to be the specific mechanism related to mitochondrial function improvement and inflammation reduction. These results indicate that WOPs can improve aging-related muscle loss, in term of both muscle mass and physical performance, and WOP supplements seems to be potentially effective in elderly individuals.

Sarcopenia phenotype and impaired muscle function in male mice with fast-twitch muscle-specific knockout of the androgen receptor

“…Each mouse was placed on top of a wire mesh cage, which was then gently inverted to encourage the mouse to grip the wire; thereafter, the latency to fall (s) was measured. The maximum time to fall among three sequential trials was selected and holding impulse (Ns) was calculated by the following formula: mouse weight (g) × latency to fall (s) × 0.00980665 (gravitational force, N/g) ( 53 , 54 ).…”

Sea cucumber (Acaudina leucoprocta) peptides extended the lifespan and enhanced antioxidant capacity via DAF-16/DAF-2/SOD-3/OLD-1/PEPT-1 in Caenorhabditis elegans

“…Anti-aging product research is exploding, and biologically active peptides to slow down the aging process has become a hot topic. Bioactive peptides are effective and have been well studied, such as the rice bran peptide KF-8 improves the health span of Caenorhabditis elegans ( 30 ) and the walnut protein exhibited an excellent anti-photoaging effect ( 31 ). As examples of animal peptide sources, chicken bone collagen peptides have been shown to dramatically reduce the signs of skin aging ( 32 ), and the crimson snapper scales peptides effectively extended the lifespan and improved the motor ability of both male and female Drosophila ( 33 ).…”

Targeting mitochondrial quality control in muscle aging: Natural dietary products as potential interventions

“…In addition to the above exogenous components, a few specific polysaccharides, peptides, polyunsaturated fatty acids, and extracts also target the MQC network and exert antimuscle aging effects, as shown in Table 3. Alginate oligosaccharides from brown algae and walnut oligopeptides from walnuts delayed cardiac and skeletal muscle aging by increasing the level of mitochondrial biogenesis, respectively (Fan et al., 2022; Feng et al., 2021). Eicosapentaenoic acid (EPA), an omega‐3 fatty acid, enhanced muscle mitochondrial function and reduced mitochondrial protein carbonylation while increasing the muscle protein quality in naturally aged mice (Johnson et al., 2015).…”