Nakazato Koichi, Song Hongsun, Waga Toshiaki
Department of Exercise Physiology, Graduate School of Health and Sport Sciences, Nippon Sport Science University, Tokyo, Japan.
Med Sci Sports Exerc. 2007 Jun;39(6):934-40. doi: 10.1249/mss.0b013e31803df4bc.
Green tea polyphenols have been reported to improve muscle function in dystrophic mice. The chemical structure of apple polyphenols (APP) is similar to that of tea polyphenols; however, their effects on muscle function have not been examined previously. We examined the effects of dietary intake of APP on gastrocnemius function in Wistar rats.
Sixteen male rats (11 wk old) were divided into two groups: the 4.8% APP diet group and the control group (N=8 in each group). Before and after 3 wk of treatment, right-leg tetanic ankle torques were measured. Successive twitch torques (four sessions per minute for 2 min) were also measured to test indications of fatigue. Contralateral (left) legs were used for wet weight measurement and examination of mRNA expression.
Total-body and muscle weights were similar in both the groups. The adipose tissue weight of the APP group was significantly lower than that of the control group (P<0.05). The isometric torque of the APP group was significantly higher than that of the control group (P<0.05). During the 2-min experimental period, the relative twitch torques (compared with the initial value) of the APP group were larger than those of the control group. Statistical significance was observed at 90, 105, and 120 s (P<0.05). Expression of peroxisome proliferator-activated receptors alpha and delta--positive regulators of lipid oxidation--were significantly higher in the APP group than in the control group (P<0.05).
We conclude that dietary APP enhance normal muscle function in Wistar rats. Alteration of lipid metabolism might be one of the mechanisms of this phenomenon.
据报道，绿茶多酚可改善营养不良小鼠的肌肉功能。苹果多酚（APP）的化学结构与茶多酚相似；然而，此前尚未研究过它们对肌肉功能的影响。我们研究了饮食摄入APP对Wistar大鼠腓肠肌功能的影响。
将16只雄性大鼠（11周龄）分为两组：4.8%APP饮食组和对照组（每组n = 8）。在治疗3周前后，测量右下肢强直踝关节扭矩。还测量了连续抽搐扭矩（每分钟4次，共2分钟）以测试疲劳指标。对侧（左）腿用于湿重测量和mRNA表达检测。
两组的总体重和肌肉重量相似。APP组的脂肪组织重量显著低于对照组（P < 0.05）。APP组的等长扭矩显著高于对照组（P < 0.05）。在2分钟的实验期间，APP组的相对抽搐扭矩（与初始值相比）大于对照组。在90、105和120秒时观察到统计学显著性（P < 0.05）。APP组中过氧化物酶体增殖物激活受体α和δ（脂质氧化的阳性调节因子）的表达显著高于对照组（P < 0.05）。
我们得出结论，饮食中的APP可增强Wistar大鼠的正常肌肉功能。脂质代谢的改变可能是这一现象的机制之一。
