Abstract

This study aimed to investigate effects of apple polyphenols (APPs) on myofiber-type transformation in longissimus dorsi muscle of finishing pigs and its mechanism. In this study, 36 healthy castrated Duroc × Landrace × Yorkshire pigs with an average body weight of 71.25 ± 2.40 kg were randomly divided into three treatment groups (control, 0.04% APPs, 0.08% APPs). The experiment lasted for 49 days. Results showed that dietary APP supplementation increased the protein expression of MyHC I and the activities of succinic dehydrogenase and malate dehydrogenase, as well as decreased the protein expression of MyHC IIb and the activity of lactate dehydrogenase, suggesting that APPs promoted muscle fiber-type transformation from fast-twitch to slow-twitch in finishing pigs. We also showed that dietary 0.08% APP supplementation increased the expressions of mitochondrial biogenesis and function-related proteins PGC-1α, Sirt1 and Cytc. In addition, dietary supplementation with 0.08% APPs increased the activities of T-SOD, GSH-PX and CAT and decreased the MDA content. Together, we provided the first evidence that APP promotes muscle fiber-type transformation from fast-twitch to slow-twitch in finishing pigs, which may be achieved by improving the mitochondrial biogenesis and function and increasing the antioxidant capacity of skeletal muscle.

摘要

本研究旨在研究苹果多酚（APPs）对背最长肌肌纤维型转化的影响。育肥猪肌肉及其作用机制. 本研究将36头平均体重71.25±2.40 kg的健康去势杜洛克×长白×约克夏猪随机分为三个治疗组（对照组，0.04% APPs，0.08% APPs）。实验持续了49天。结果表明，日粮添加APP增加了MyHC I的蛋白表达和琥珀酸脱氢酶和苹果酸脱氢酶的活性，同时降低了MyHC IIb的蛋白表达和乳酸脱氢酶的活性，表明APP促进了肌纤维型转化。育肥猪从快肌到慢肌。我们还表明，饮食中添加 0.08% APP 会增加线粒体生物发生和功能相关蛋白 PGC-1α、Sirt1 和 Cytc 的表达。此外，饮食中添加 0.08% APPs 增加了 T-SOD、GSH-PX 和 CAT 的活性并降低了 MDA 含量。总之，我们提供了第一个证据，表明APP促进肥育猪的肌纤维类型从快肌纤维转变为慢肌纤维，这可能通过改善线粒体生物发生和功能以及增加骨骼肌的抗氧化能力来实现。