摘要Astragali Radix(AR)and Notoginseng Radix et Rhizoma(NR)are frequently employed in car-diovascular disease treatment.However,the efficacy of the AR-NR medicine pair(AN)in im-proving cardiac remodeling and its underlying mechanism remains unclear.This study aimed to evaluate AN's cardioprotective effect and potential mechanism on cardiac remodeling us-ing transverse aortic constriction(TAC)in mice and angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat cardiomyocytes(NRCMs)and fibroblasts in vitro.High-performance liquid chromato-graphy-quadrupole-time of flight tandem mass spectrometry(HPLC-Q-TOF-MS/MS)charac-terized 23 main components of AN.AN significantly improved cardiac function in the TAC-in-duced mice.Furthermore,AN considerably reduced the serum levels of N-terminal pro-B-type natriuretic peptide(NT-proBNP),cardiac troponin T(CTn-T),and interleukin-6(IL-6)and mitigated inflammatory cell infiltration.Post-AN treatment,TAC-induced heart size ap-proached normal.AN decreased cardiomyocyte cross-sectional area and attenuated the up-regulation of cardiac hypertrophy marker genes(ANP,BNP,and MYH7)in vivo and in vitro.Concurrently,AN alleviated collagen deposition in TAC-induced mice.AN also reduced the ex-pression of fibrosis-related indicators(COL1A1 and COL3A1)and inhibited the activation of the transforming growth factor-β1(TGF-β1)/mothers against decapentaplegic homolog 3(Smad3)pathway.Thus,AN improved TAC-induced cardiac remodeling.Moreover,AN down-regulated p-dynamin-related protein(Drp1)(Ser616)expression and upregulated mitogen 2(MFN-2)and optic atrophy 1(OPA1)expression in vivo and in vitro,thereby restoring mito-chondrial fusion and fission balance.In conclusion,AN improves cardiac remodeling by regu-lating mitochondrial dynamic balance,providing experimental data for the rational applica-tion of Chinese medicine prescriptions with AN as the main component in clinical practice.