Wang Teng, Sun Xiaohui, Zhang Yidi, Wang Qingyan, Cheng Wenhui, Gao Yuhui, Shi Xin'e, Jin Jianjun
Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi 712100, China.
J Agric Food Chem. 2025 Mar 19;73(11):6878-6889. doi: 10.1021/acs.jafc.5c00300. Epub 2025 Mar 6.
Skeletal muscle is the major tissue for metabolic activity in the body and performs a variety of physiological functions. Among these, muscle fiber types are decisive in muscle function and meat quality. Numerous studies have shown that natural products can affect the development of skeletal muscle, regulate the formation of muscle fibers, and impact muscle function under physiological or pathological conditions. Baicalin, a natural flavonoid compound mainly derived from the dried roots of , has been reported to affect glucose metabolism and insulin resistance in skeletal muscle. However, the role of baicalin in the conversion of skeletal muscle fiber types and its underlying mechanisms remain unclear. This study aimed to explore the effects of baicalin on skeletal muscle fiber conversion in vitro and in vivo. The in vitro experiment used C2C12 cells as a model, with a baicalin treatment concentration of 125 μM; the in vivo experiment used C57BL/6J mice and weaned piglets as the models. The results showed that baicalin could participate in the remodeling of skeletal muscle fibers, promoting the conversion from glycolytic fibers to oxidative fibers in mice and pigs. This was evidenced by increased protein and mRNA expression levels of genes related to oxidative fibers, upregulated SDH enzyme activity, and mitochondrial complex expression in vivo and in vitro, while the protein and mRNA expression levels of genes related to glycolytic fibers were decreased, and LDH enzyme activity was downregulated. Mechanistic studies revealed that baicalin, as a small molecule, could target and bind to the p38 MAPK protein, increase its expression and phosphorylation levels, and activate the p38 MAPK/PGC-1α signaling pathway. Collectively, these data showed that baicalin induced a shift in skeletal muscle fiber composition from glycolytic to oxidative myofibers by activating the p38 MAPK/PGC-1α signaling pathway, thereby affecting the meat quality.
骨骼肌是体内代谢活动的主要组织，具有多种生理功能。其中，肌纤维类型对肌肉功能和肉质起决定性作用。大量研究表明，天然产物可影响骨骼肌的发育，调节肌纤维的形成，并在生理或病理条件下影响肌肉功能。黄芩苷是一种主要从黄芩干燥根中提取的天然黄酮类化合物，据报道其可影响骨骼肌中的葡萄糖代谢和胰岛素抵抗。然而，黄芩苷在骨骼肌纤维类型转换中的作用及其潜在机制仍不清楚。本研究旨在探讨黄芩苷在体外和体内对骨骼肌纤维转换的影响。体外实验以C2C12细胞为模型，黄芩苷处理浓度为125μM；体内实验以C57BL/6J小鼠和断奶仔猪为模型。结果表明，黄芩苷可参与骨骼肌纤维的重塑，促进小鼠和猪的糖酵解纤维向氧化纤维的转换。体内和体外实验中，氧化纤维相关基因的蛋白质和mRNA表达水平增加、SDH酶活性上调以及线粒体复合物表达增加，而糖酵解纤维相关基因的蛋白质和mRNA表达水平降低以及LDH酶活性下调，均证明了这一点。机制研究表明，黄芩苷作为一种小分子，可靶向并结合p38 MAPK蛋白，增加其表达和磷酸化水平，并激活p38 MAPK/PGC-1α信号通路。总体而言，这些数据表明黄芩苷通过激活p38 MAPK/PGC-1α信号通路诱导骨骼肌纤维组成从糖酵解型向氧化型肌纤维转变，从而影响肉质。
