Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi, 110054, India.
Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi, 110054, India.
Biochimie. 2019 Jan;156:138-147. doi: 10.1016/j.biochi.2018.10.012. Epub 2018 Oct 19.
Chronic hypobaric hypoxia induced muscle atrophy results in decreased physical performance at high altitude. Curcumin has been shown to have muscle sparing effects under cachectic conditions. However, the protective effects of curcumin under chronic hypobaric hypoxia have not been studied till now. Therefore, the present study aims at evaluating the effects of curcumin administration on muscle atrophy under chronic hypobaric hypoxia. Male Sprague Dawley rats were divided into four groups: Control (C)-normoxia exposed, Control Treated (CT)-normoxia exposed and administered with curcumin at a dose of 100 mg/kg body weight for 14 days, Hypoxia (H)-exposed to hypobaric hypoxia for 14 days and Hypoxia Treated (HT)-exposed to hypobaric hypoxia and administered with curcumin for 14 days. Oxidative stress, muscle protein degradation, proteolytic pathways, myosin heavy chain (MHC), CPK activity and muscle histology were performed in gastrocnemius muscle samples of the exposed rats. In addition, fatigue time on treadmill running was also evaluated to observe the effects of curcumin administration on physical performance of the rats. As previously shown, hypobaric hypoxia increased muscle protein degradation via upregulated calpain and ubiquitin-proteolytic pathways. An enhanced oxidative stress has been linked to upregulation of these pathways under hypoxic conditions. Curcumin administration resulted in reduced oxidative stress as well as reduced activity of the proteolytic pathways in HT group as compared to H group thereby resulting in reduced muscle protein degradation under hypobaric hypoxia. Histology of rat muscle revealed an increased number of muscle fibres in HT as compared to H group. Thus, increased number of muscle fibres and decreased muscle proteolysis following curcumin administration, lead to enhanced muscle mass under hypobaric hypoxia resulting in improved physical performance of the rats.
慢性低氧诱导的肌肉萎缩导致高原地区体力下降。姜黄素已被证明在恶病质条件下具有肌肉保护作用。然而，姜黄素在慢性低氧下的保护作用尚未得到研究。因此，本研究旨在评估姜黄素给药对慢性低氧下肌肉萎缩的影响。雄性 Sprague Dawley 大鼠分为四组：对照组（C）-暴露于常氧环境，对照治疗组（CT）-暴露于常氧环境并给予 100mg/kg 体重的姜黄素 14 天，低氧组（H）-暴露于低氧 14 天，低氧治疗组（HT）-暴露于低氧并给予姜黄素 14 天。在暴露大鼠的腓肠肌样本中进行氧化应激、肌肉蛋白降解、蛋白水解途径、肌球蛋白重链（MHC）、CPK 活性和肌肉组织学检测。此外，还评估了跑步机跑步的疲劳时间，以观察姜黄素给药对大鼠体力的影响。如前所述，低氧增加了肌肉蛋白降解，通过上调钙蛋白酶和泛素蛋白水解途径。在缺氧条件下，氧化应激的增强与这些途径的上调有关。与 H 组相比，HT 组姜黄素给药导致氧化应激减少以及蛋白水解途径活性降低，从而导致低氧下肌肉蛋白降解减少。大鼠肌肉组织学显示 HT 组的肌纤维数量增加。因此，姜黄素给药后肌肉纤维数量增加和肌肉蛋白水解减少导致低氧下肌肉质量增加，从而提高大鼠的体力。
