Cellular Biochemistry Division, DRDO Defence Institute of Physiology and Allied Sciences, Delhi, India.
IUBMB Life. 2021 Feb;73(2):375-389. doi: 10.1002/iub.2435. Epub 2020 Dec 24.
Hypobaric hypoxic stress leads to oxidative stress, inflammation, and disturbance in protein turnover rate. Aggregately, this imbalance in redox homeostasis is responsible for skeletal muscle protein loss and a decline in physical performance. Hence, an urgent medical need is required to ameliorate skeletal muscle protein loss. The present study investigated the efficacy of ursolic acid (UA), a pentacyclic triterpene acid to ameliorate hypobaric hypoxia (HH)-induced muscle protein loss. UA is a naturally occurring pentacyclic triterpene acid present in several edible herbs and fruits such as apples. It contains skeletal muscle hypertrophy activity; still its potential against HH-induced muscle protein loss is unexplored. To address this issue, an in vivo study was planned to examine the beneficial effect of UA supplementation on HH-induced skeletal muscle loss. Male Sprague Dawley rats were exposed to HH with and without UA supplementation (20 mg/kg; oral) for 3 continuous days. The results described the beneficial role of UA as supplementation of UA with HH exposure attenuated reactive oxygen species production and oxidative protein damage, which indicate the potent antioxidant activity. Furthermore, UA supplementation enhanced Akt, pAkt, and p70S6kinase activity (Akt pathway) and lowered the pro-inflammatory cytokines in HH exposed rats. UA has potent antioxidant and anti-inflammatory activity, and it enhanced the protein content via upregulation of Akt pathway-related proteins against HH exposure. These three biological activities of UA make it a novel candidate for amelioration of HH-induced skeletal muscle damage and protein loss.
低氧减压应激会导致氧化应激、炎症和蛋白质周转率紊乱。总的来说,这种氧化还原平衡的失衡是导致骨骼肌蛋白损失和身体机能下降的原因。因此,迫切需要改善骨骼肌蛋白损失。本研究探讨了熊果酸(UA)作为一种五环三萜酸改善低氧减压(HH)诱导的肌肉蛋白损失的功效。UA 是一种天然存在的五环三萜酸,存在于几种食用草药和水果中,如苹果。它具有促进骨骼肌肥大的作用;但其对 HH 诱导的肌肉蛋白损失的潜在作用尚未得到探索。为了解决这个问题,计划进行一项体内研究,以检验 UA 补充对 HH 诱导的骨骼肌损失的有益影响。雄性 Sprague Dawley 大鼠在 HH 环境下暴露于 UA 补充(20mg/kg;口服),持续 3 天。结果表明,UA 具有有益作用,因为 HH 暴露与 UA 补充联合应用可减弱活性氧的产生和氧化蛋白损伤,这表明其具有很强的抗氧化活性。此外,UA 补充可增强 HH 暴露大鼠的 Akt、pAkt 和 p70S6kinase 活性(Akt 通路),并降低促炎细胞因子的水平。UA 具有很强的抗氧化和抗炎活性,通过上调 Akt 通路相关蛋白来增强蛋白质含量,从而对抗 HH 暴露。UA 的这三种生物学活性使其成为改善 HH 诱导的骨骼肌损伤和蛋白损失的新型候选药物。