目的 基于沉默信息调节因子 1（SIRT1）/叉头框蛋白 O3A（FOXO3A）信号通路调控线粒体自噬探究仙鹤 草对小鼠心肌纤维化（MF）的作用及机制。方法 将雄性昆明小鼠随机分为正常组、模型组、普萘洛尔组 （40 mg·kg-1 ）及仙鹤草低、中、高剂量组（生药量 0.78、1.56、3.12 g·kg-1 ），每组 10 只。采用皮下注射异丙肾 上腺素（ISO，15 mg·kg-1 ）14 d 复制 MF 小鼠模型。造模同时各给药组灌胃给予相应药物（给药体积为 10 mL·kg-1 ）， 每日 1 次，连续 14 d。采用超声心动图检测小鼠心功能，记录左心室射血分数（EF）、左心室缩短分数（FS）、 左室收缩末期内径（LVESD）、左室舒张末期内径（LVEDD）等心功能指标；生化法及 ELISA 法检测血清心肌酶 ［肌酸激酶（CK）、肌酸激酶同工酶 MB（CK-MB）、乳酸脱氢酶（LDH）］ 及胶原代谢物 ［Ⅰ型前胶原 C 端前肽 （PICP）、Ⅰ型胶原羧基端末肽（ICTP）］ 水平；HE 及天狼星红染色法观察心脏组织病理形态与胶原沉积情况； 流式细胞术检测心肌细胞线粒体膜电位；免疫荧光、免疫组化及 Western Blot 法检测心肌组织 SIRT1/FOXO3A 信号通路及自噬相关蛋白的表达情况。结果 与正常组比较，模型组小鼠的 EF、FS 显著降低（P＜0.01）， LVESD、LVEDD 显著升高（P＜0.01）；血清 CK、CK-MB、LDH、ICTP 及 PICP 含量或活性均显著升高（P＜ 0.01）；心肌纤维断裂，伴有部分炎性细胞浸润，胶原沉积显著增多（P＜0.01）；心肌细胞线粒体膜电位显著降 低（P＜0.01）；心脏组织中 LC3B 与 COXIV蛋白共定位表达显著增加（P＜0.01）；心脏组织 FOXO3A 在核内表达 增加，SIRT1、FOXO3A、BNIP3、LC3B、Beclin1、collagenⅠ、collagenⅢ蛋白表达显著上调（P＜0.01），p62 蛋 白表达显著下调（P＜0.01）。与模型组比较，仙鹤草各剂量组小鼠的 EF、FS 显著升高（P＜0.01），LVESD、 LVEDD 显著降低（P＜0.01）；血清 CK、CK-MB、LDH、ICTP 及 PICP 含量或活性均显著降低（P＜0.01）；心肌 纤维化有所改善，炎性细胞浸润明显减轻，胶原沉积显著减少（P＜0.01）；心脏组织中 LC3B 与 COXIV蛋白的 共定位表达显著减弱（P＜0.05，P＜0.01）；心脏组织 FOXO3A 在核内表达减少，SIRT1、FOXO3A、BNIP3、 LC3B、Beclin1、collagenⅠ、collagenⅢ蛋白表达显著下调（P＜0.05，P＜0.01）。与模型组比较，仙鹤草中、高 剂量组小鼠心脏组织 p62 蛋白表达显著上调（P＜0.05，P＜0.01），心肌细胞线粒体膜电位显著升高（P＜0.05， P＜0.01）。结论 仙鹤草可以改善 MF 小鼠的心功能和心肌损伤，减少心肌胶原沉积，改善纤维化，其作用机 制可能与抑制 SIRT1/FOXO3A 信号通路，调节线粒体自噬有关。

Objective To investigate the effect and mechanism of Agrimoniae Herba on myocardial fibrosis （MF） in mice based on the regulation of mitophagy via the silent information regulator 1（SIRT1）/forkhead box protein O3A （FOXO3A） signaling pathway. Methods Male Kunming mice were randomly divided into a normal group， model group，propranolol group （40 mg·kg-1 ），and low-，medium-，and high-dose Agrimoniae Herba groups （0.78，1.56， 3.12 g·kg-1 crude drug），with 10 mice in each group. The MF mouse model was established by subcutaneous injection of isoproterenol （ISO， 15 mg·kg-1 ） for 14 days. Concurrent with modeling， each administration group received the corresponding drugs by gavage （administration volume of 10 mL·kg-1 ） once daily for 14 consecutive days. Cardiac function was assessed using echocardiography，recording parameters including left ventricular ejection fraction （EF）， left ventricular fractional shortening （FS），left ventricular end-systolic diameter （LVESD），and left ventricular enddiastolic diameter （LVEDD）. Serum levels of cardiac enzymes [creatine kinase （CK），creatine kinase isoenzyme MB （CK-MB）， lactate dehydrogenase （LDH）] and collagen metabolites [procollagen type Ⅰ C-terminal propeptide （PICP），type I collagen carboxy-terminal telopeptide （ICTP）] were measured using biochemical methods and ELISA. Histopathological morphology and collagen deposition in cardiac tissue were observed using HE and Sirius red staining. Mitochondrial membrane potential in cardiomyocytes was detected by flow cytometry. The expression of SIRT1/FOXO3A signaling pathway and autophagy-related proteins in cardiac tissue was assessed using immunofluorescence， immunohistochemistry， and Western Blot. Results Compared with the normal group， the model group showed significantly decreased EF and FS （P＜0.01），and significantly increased LVESD and LVEDD （P＜0.01）；serum levels or activities of CK，CK-MB，LDH，ICTP，and PICP were significantly elevated （P＜0.01）；myocardial fibers were disrupted with some inflammatory cell infiltration，and collagen deposition was significantly increased （P＜0.01）； mitochondrial membrane potential in cardiomyocytes was significantly reduced （P＜0.01）； the co-localization expression of LC3B and COXIV proteins in cardiac tissue was significantly increased （P＜0.01）； the nuclear expression of FOXO3A in cardiac tissue was increased， and the protein expression of SIRT1， FOXO3A， BNIP3， LC3B，Beclin1，collagenⅠ，and collagen Ⅲ was significantly upregulated （P＜0.01），while p62 protein expression was significantly downregulated （P＜0.01）. Compared with the model group， each Agrimoniae Herba dose group exhibited significantly increased EF and FS （P＜0.01），and significantly decreased LVESD and LVEDD （P＜0.01）； serum levels or activities of CK，CK-MB，LDH，ICTP，and PICP were significantly reduced （P＜0.01）；myocardial fibrosis was ameliorated，inflammatory cell infiltration was notably reduced，and collagen deposition was significantly decreased （P＜0.01）；the co-localization expression of LC3B and COXIV proteins in cardiac tissue was significantly weakened （P＜0.05，P＜0.01）；the nuclear expression of FOXO3A in cardiac tissue was reduced，and the protein expression of SIRT1， FOXO3A， BNIP3， LC3B， Beclin1， collagen Ⅰ ， and collagen Ⅲ was significantly downregulated （P＜0.05，P＜0.01）. Compared with the model group，the medium- and high-dose Agrimoniae Herba groups showed significantly upregulated p62 protein expression in cardiac tissue （P＜0.05，P＜0.01） and significantly increased mitochondrial membrane potential in cardiomyocytes （P＜0.05，P＜0.01）. Conclusion Agrimoniae Herba can improve cardiac function and myocardial injury，reduce myocardial collagen deposition，and ameliorate fibrosis in MF mice. Its mechanism of action may be related to inhibiting the SIRT1/FOXO3A signaling pathway and regulating mitophagy.

R285.5

国家自然科学基金项目（82505547）；河北省中医药管理局科研计划项目（2021051）。