目的 探讨葛根素通过磷脂酰肌醇3-激酶（PI3K）/蛋白激酶B（Akt）信号通路，改善肌少症小鼠骨骼肌细胞衰老及线粒体功能障碍的作用机制。方法 40只C57BL/6J雄性小鼠随机分为对照组，模型组及葛根素低、中、高剂量(50、100、200 mg·kg^-1)组。以D-半乳糖诱导骨骼肌衰老，建立小鼠肌少症模型。测定小鼠体质量、握力；通过苏木素-伊红（HE）染色及天狼猩红染色观察骨骼肌病理变化及纤维化程度；运用免疫荧光（IF）和免疫组化（IHC）技术检测周期蛋白依赖性激酶抑制剂1（p21）、过氧化物酶体增殖物激活受体γ共激活因子-1α（PGC-1α）蛋白质在细胞或组织中的定位和表达水平；采用蛋白免疫印迹法（Western blotting）及实时荧光定量聚合酶链式反应（qTR-PCR）检测PI3K、Akt、PGC-1α、动力蛋白相关蛋白（DRP）1、p21、p53蛋白与mRNA表达水平。结果 对照组相比，模型组小鼠体质量降低（P<0.05、0.01）；握力显著下降（P<0.01）；肌纤维断裂萎缩、组织结构受损，胶原纤维增生明显、纤维化程度升高；PI3K、Akt、PGC-1α蛋白和mRNA表达水平显著降低（P<0.01）,p21、p53、DRP1的蛋白及mRNA表达水平显著升高（P<0.01）。与模型组比较，葛根素高剂量组小鼠体质量有所回升，中、高剂量组握力显著提高（P<0.05、0.01）；肌纤维排列逐渐整齐、组织结构趋于完整，胶原纤维增生被抑制、纤维化程度降低；PGC-1α、PI3K、Akt的蛋白及mRNA表达水平显著升高（P<0.01）,p21、p53、DRP1的蛋白及mRNA表达水平显著降低（P<0.01），且上述效应呈剂量相关性。结论 葛根素可能通过上调PI3K/Akt信号通路，抑制DRP1和p53/p21通路激活，改善线粒体稳态、逆转骨骼肌细胞衰老，进而发挥骨骼肌保护作用。

Objective To explore the mechanism by which puerarin improves sarcopenia in mice through the phosphatidylinositol 3-kinase（PI3K）/protein kinase B（Akt） signaling pathway, and to investigate its effects on skeletal muscle cell senescence and mitochondrial dysfunction. Methods Forty male C57 BL/6J mice were randomly divided into a control group, a model group, and puerarin low-, medium-, high dose(50, 100, and 200 mg·kg^-1) groups. Sarcopenia was induced in mice by D-galactose. Body weight and grip strength were measured. Skeletal muscle pathological changes and fibrosis were observed by hematoxylin-eosin（HE） staining and sirius red staining. The localization and expression levels of cyclin-dependent kinase inhibitor 1（p21） and peroxisome proliferatoractivated receptor γ coactivator-1α（PGC-1α） proteins in cells or tissues were detected by immunofluorescence（IF） and immunohistochemistry（IHC） techniques. The expression levels of PI3K, Akt, PGC-1α, dynamin-related protein（DRP） 1, p21, and p53 proteins and mRNAs were detected by Western blotting and real-time fluorescence quantitative polymerase chain reaction（qTRPCR）. Results Compared with the control group, the model group showed decreased body weight（P ＜0.05, 0.01）, significantly reduced grip strength（P ＜0.01）, muscle fiber fragmentation and atrophy, damaged tissue structure, increased collagen fiber proliferation, and elevated fibrosis degree. The expression levels of PI3K, Akt, and PGC-1α proteins and mRNAs were significantly decreased（P ＜0.01）, while the expression levels of p21, p53, and DRP1 proteins and mRNAs were significantly increased（P ＜0.01）. Compared with the model group, the body weight of mice in high dose puerarin groups increased, and the grip strength of the medium and high-dose groups significantly improved（P ＜0.05, 0.01）. The arrangement of muscle fibers gradually became orderly, the tissue structure tended to be complete, collagen fiber proliferation was inhibited, and the degree of fibrosis decreased. The expression levels of PGC-1α, PI3K, and Akt proteins and mRNAs were significantly increased（P ＜0.01）, while the expression levels of p21, p53, and DRP1 proteins and mRNAs were significantly decreased（P ＜0.01）, and these effects were dose-dependent. Conclusion Puerarin may protect skeletal muscle by up-regulating the PI3K/Akt signaling pathway, inhibiting the activation of the DRP1 and p53/p21 pathways, improving mitochondrial homeostasis, and reversing skeletal muscle cell senescence.

R285;R592

湖北省重点研发计划资助项目(2024BCB035); 湖北省中医药管理局重点项目(ZY2025D007); 湖北省自然科学基金创新发展联合基金资助项目(2024AFD332,2025AFD519); 湖北省时珍人才工程科研项目(P-20250923-1556)