title: A combination of Korean mistletoe extract and resistance exercise retarded the decline in muscle mass and strength in the elderly: A randomized controlled trial.
abstract: Given the increased concerns about the degenerative decline in the physical performance of the elderly, there is a need for developing effective strategies to suppress the age-related loss of skeletal muscle mass and functional capacity through a lifestyle intervention. This randomized controlled trial examined whether a combination of Korean mistletoe extract (KME) supplement and exercise affected muscle mass, muscle function, and targeted molecular expressions. Sixty-seven subjects aged 55-75years were assigned to placebo, low-dose (1g/d), or high-dose (2g/d) of KME for 12weeks. The body composition was significantly changed in the high-dose group during the intervention period as determined by skeletal muscle mass (P=0.040), fat free mass (P=0.042), soft lean mass (P=0.023), skeletal muscle index (P=0.041), fat-free mass index (P=0.030), percent body fat (P=0.044), and fat mass to lean mass ratio (P=0.030). Knee strength was measured by Cybex, demonstrating a significant effect in the KME groups compared to the placebo group (P=0.026 for peak torque and P=0.057 for set total work), which was more pronounced after adjusting for age, gender, protein, and energy intake (P=0.009 for peak torque and P=0.033 for set total work). The dynamic balance ability was remarkably improved in the high-dose group over a 12-week period as determined by Timed "Up and Go" (P=0.005 for fast walk test and P=0.024 for ordinary walk test). Consistent with these results, RT-PCR, multiplex analyses, and immunocytofluorescence staining revealed that a high-dose KME supplementation was effective for suppressing intracellular pathways related to muscle protein degradation, but stimulating those related to myogenesis. In particular, significant differences were found in atrogin-1 mRNA (P=0.002 at a single administration and P=0.001 at a 12-week administration), myogenin mRNA (P<0.0001 at a single administration and P=0.040 at a 12-week administration), and insulin growth factor 1 receptor phosphorylation (P=0.002 at a 12-week administration). These results suggest that KME supplementation together with resistance exercise may be useful in suppressing the age-related loss of muscle mass and strength in the elderly.
authors.affiliation: Department of Nutritional Science and Food Management, Ewha Womans University, Seoul 03760, Republic of Korea.
authors.forename: Nam Ju
authors.initials: NJ
authors.lastname: Lim
authors.affiliation: Department of Rehabilitation Medicine, Ewha Womans University School of Medicine, Seoul 07985, Republic of Korea.
authors.forename: Jun Ho
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Department of Kinesiology and Sports Studies, College of Science and Industry Convergence, Ewha Womans University, Seoul 03760, Republic of Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Nutritional Science and Food Management, Ewha Womans University, Seoul 03760, Republic of Korea.
authors.forename: Yeni
authors.initials: Y
authors.lastname: Lim
authors.affiliation: Department of Food Science & Technology, Seoul National University of Science & Technology, Seoul, Republic of Korea.
authors.forename: Ji Yeon
authors.initials: JY
authors.lastname: Kim
authors.affiliation: Department of Kinesiology and Sports Studies, College of Science and Industry Convergence, Ewha Womans University, Seoul 03760, Republic of Korea.
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: Department of Rehabilitation Medicine, Ewha Womans University School of Medicine, Seoul 07985, Republic of Korea. Electronic address: ocrystal@ewha.ac.kr.
authors.forename: Soo Jeong
authors.initials: SJ
authors.lastname: Han
authors.affiliation: Department of Nutritional Science and Food Management, Ewha Womans University, Seoul 03760, Republic of Korea. Electronic address: orank@ewha.ac.kr.
authors.forename: Oran
authors.initials: O
authors.lastname: Kwon
mesh_terms: D000368:Aged; D000375:Aging / Q000187:drug effects*; D001823:Body Composition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D014784:Mistletoe / Q000737:chemistry*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D053580:Muscle Strength / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology*; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology*; D012333:RNA, Messenger / Q000032:analysis; D017526:Receptor, IGF Type 1; D017451:Receptors, Somatomedin / Q000235:genetics / Q000378:metabolism; D056910:Republic of Korea; D044843:SKP Cullin F-Box Protein Ligases / Q000235:genetics / Q000378:metabolism; D055948:Sarcopenia / Q000188:drug therapy*
chemical_list: C000597236:IGF1R protein, human; D009124:Muscle Proteins; D010936:Plant Extracts; D012333:RNA, Messenger; D017451:Receptors, Somatomedin; C440907:FBXO32 protein, human; D044843:SKP Cullin F-Box Protein Ligases; D017526:Receptor, IGF Type 1
keywords: Elderly; Mistletoe; Muscle biopsy; Muscle function; Muscle mass; Targeted gene analysis