New findings suggest that a combination of these natural extracts could pave the way for affordable supplements to combat muscle wasting and enhance athletic performance.
Study: Synergistic effects of Korean mistletoe and apple peel extracts on muscle strength and endurance. Image credit: rsooll/Shutterstock.com
In a recent study published in Nutrientsresearchers investigated the role of mistletoe and apple peel extracts in improving muscle health and increasing endurance.
Their findings have implications for the development of cost-effective and natural supplements for muscle growth, with applications in sports that address age-related muscle decline and muscle growth in children.
Background
Muscular strength and endurance are important components of fitness and essential for maintaining quality of life. However, skeletal muscle mass declines by 3-8% per decade after a person turns 30, and this decline accelerates after age 60.
Physical activity helps maintain muscle mass, but activity levels have declined with modern technology and automation.
Studies show that in 2016, less than 30% of adults worldwide failed to meet weekly physical activity guidelines, increasing the risk of chronic disease. In Europe, insufficient physical activity may contribute to more deaths than obesity.
In addition to physical activity, natural plant products such as curcumin (found in turmeric), catechin (found in tea), and resveratrol (found in red grapes) may also improve muscle health. Extracts from mistletoe, which is rich in bioactive compounds, have been shown to enhance muscle strength and endurance, even surpassing resveratrol.
However, mistletoe can be difficult to harvest, making it expensive, and high doses can cause adverse effects. To address these issues, researchers are investigating supplementing mistletoe extract with apple peel extracts, which are safe, nutrient-rich, and affordable while containing beneficial polyphenols.
About the study
The researchers prepared mistletoe extract by mashing and blending the fruits, stems, and leaves before blending them for 16 hours, centrifuging the mixture, filtering it, and freeze-drying it. Apple peel extract was prepared by blending the dried apple peels before using ethanol for extraction before filtration and freeze drying. The levels of polyphenols and flavonoids in the extracts were measured.
Animal experiments were conducted, with male mice divided into six groups. Mice were treated with different doses of creatine, mistletoe and apple peel extracts for four weeks. Their grip strength and treadmill endurance were measured after treatment.
Grip strength was assessed using a force meter with five trials per mouse, and treadmill endurance tests were performed at increasing speeds until mice reached exhaustion.
The researchers then analyzed the muscle tissue to understand the genetic mechanisms involved in muscle function and analyzed protein levels in the tissue.
Findings
The researchers found that apple peel extraction techniques are poorly developed compared to mistletoe, with the best extraction results achieved using 60% ethanol for 12 hours.
Analysis of the extracts showed that the apple peel extract contained 1.08 mg/mL polyphenols and 0.65 mg/mL flavonoids. The combination of apple peel and mistletoe extract yielded higher polyphenol levels (2.21 mg/mL) and flavonoid levels (0.98 mg/mL).
Mice treated with apple peel, mistletoe or combined extracts for four weeks showed no significant difference in calorie intake or body weight between groups.
However, the combined extract groups showed significant improvements in muscle strength compared to the control groups. They also showed a 233-258% increase in running time compared to control groups in endurance tests.
Further analysis showed that mice given the combined extracts also showed an increase in muscle fiber size.
The combined extracts also significantly decrease genes associated with protein degradation while increasing genes associated with protein synthesis and muscle growth. Certain proteins linked to muscle growth were activated at higher rates in the combined groups.
The combined extracts also resulted in a significant increase in mitochondrial content and gene expression related to mitochondrial biogenesis. Genes related to mitochondrial fission were decreased, while genes related to fusion were increased.
Regarding effects on muscle fibers, mice treated with mistletoe and combined extracts showed an increase in fibers important for endurance. Mice given the combined extracts at half the concentration also showed improvements in muscle fibers compared to those in the control groups.
conclusions
The study investigated whether the combination of mistletoe extract and apple peel extract could improve muscle strength and endurance more effectively than using each extract alone.
The researchers found that both extracts are high in polyphenols, but the apple peel contains more flavonoids. The combination of mistletoe and apple peel extracts showed synergistic effects – boosting muscle strength and endurance better than either extract alone.
The combined group observed larger muscle fiber cross-sections and higher mitochondrial density, associated with increased muscle protein synthesis and decreased protein degradation.
The phenolic acids in the mistletoe and the flavonoids in the apple peel likely contributed to the observed effects. Compounds like quercetin (in apple peel) and chlorogenic acid (in mistletoe) have been noted to boost muscle strength and reduce inflammation.
Although these findings are promising, longer study durations are needed to provide more evidence. Human trials are necessary to determine the efficacy, optimal dosage, and safety of these extracts for improving muscle function.
