With the rising incidence of diabetes， diabetic kidney disease （DKD） has become a significant global health burden. Although current prevention and treatment strategies can partially delay the progression of DKD， the risk of patients advancing to end-stage renal disease remains high. Since the concept of the "gut-kidney axis" was first introduced at the International Congress on Dialysis in 2011， research on the role of gut microbiota in the pathogenesis of DKD has received increasing attention. This review summarizes the current research on gut microbiota， explores the mechanisms through which it contributes to DKD development， and outlines clinical approaches for DKD prevention and treatment based on the "gut-kidney axis" theory. Evidence indicates that dietary interventions， intake of probiotics or prebiotics， use of metformin and novel antidiabetic drugs， and application of traditional Chinese medicine （TCM） compound formulas can effectively improve gut microbiota composition， influence metabolite production， and restore the intestinal mucosal barrier. These interventions can further regulate intestinal innate immunity and inflammatory responses， thereby modulating the progression of DKD. Despite challenges posed by the traditional oral administration of water-decocted TCM compound formulas and the complexity of their ingredients， increasing evidence suggests that TCM may indirectly affect the occurrence and development of DKD by modulating gut microbiota. This finding provides a new perspective on the potential mechanisms of TCM in DKD treatment and may offer novel strategies for DKD prevention and therapy.

ObjectiveTo investigate the mechanisms by which Mahuang Lianqiao Chixiaodoutang （MLC） improves obesity-type polycystic ovary syndrome （PCOS） through the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway. MethodsThirty-six female Sprague-Dawley （SD） rats were randomly divided into a blank control group （Con） and an obesity-type PCOS model preparation group. The model was induced by gavage with letrozole （1 mg·kg^-1） combined with a high-fat diet （HFD）. After model establishment， the obesity-type PCOS model preparation group was further divided into the model group （Mod， normal saline）， metformin group （Met， 0.3 g·kg^-1）， low-dose MLC group （MLC-L， 4.3 g·kg^-1）， medium-dose MLC group （MLC-M， 8.6 g·kg^-1）， and high-dose MLC group （MLC-H， 17.2 g·kg^-1）. Active components of MLC and targets of obesity-type PCOS were screened from databases， a protein-protein interaction （PPI） network was constructed， and gene ontology（GO）and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis was performed. The gut microbiota structure was analyzed based on 16S rRNA sequencing and correlated with network pharmacology pathways. Body weight and estrous cycle were dynamically monitored. Ovarian morphology was observed by hematoxylin-eosin （HE） staining. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL）. Enzyme-linked immunosorbent assay （ELISA） was used to detect levels of follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， anti-Müllerian hormone （AMH）， testosterone （T）， and estradiol （E₂）. Western blot was used to detect the protein expression levels of phosphorylated PI3K/PI3K （p-PI3K/PI3K）， phosphorylated Akt/Akt （p-Akt/Akt）， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax）. ResultsNetwork pharmacology screening identified 124 active components of MLC and 408 overlapping targets between the herbal formula and the disease. Core targets such as Akt1 and Bcl-2 were revealed. As indicated by 16S rRNA sequencing， the abundances of Lachnospiraceae， Lachnoclostridium， and Dorea were increased in the MLC groups （P<0.05）， while the abundance of Veillonella was decreased （P<0.05）. KEGG correlation analysis integrating network pharmacology and gut microbiota data showed significant enrichment of the PI3K/Akt signaling pathway. Animal experiments showed that， compared with the Mod group， body weight decreased to normal levels in the Met， MLC-M， and MLC-H groups. The estrous cycle became regular. The number of corpora lutea increased and cystic follicles decreased. Serum levels of T， FSH， and LH/FSH were reduced （P<0.05， P<0.01）， while the E₂ level was increased （P<0.01）. Ovarian cell apoptosis was reduced （P<0.01）， and the protein expression levels of p-PI3K/PI3K， p-Akt/Akt， and Bcl-2 in ovarian tissue were significantly increased， whereas Bax protein expression was significantly decreased （P<0.05， P<0.01）. ConclusionMLC can regulate gut microbiota structure， effectively improve ovarian pathology in rats with obesity-type PCOS， and inhibit ovarian granulosa cell apoptosis. The mechanism may be associated with upregulation of the PI3K/Akt signaling pathway.

ObjectiveTo investigate the mechanisms by which Mahuang Lianqiao Chixiaodoutang （MLC） improves obesity-type polycystic ovary syndrome （PCOS） through the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway. MethodsThirty-six female Sprague-Dawley （SD） rats were randomly divided into a blank control group （Con） and an obesity-type PCOS model preparation group. The model was induced by gavage with letrozole （1 mg·kg^-1） combined with a high-fat diet （HFD）. After model establishment， the obesity-type PCOS model preparation group was further divided into the model group （Mod， normal saline）， metformin group （Met， 0.3 g·kg^-1）， low-dose MLC group （MLC-L， 4.3 g·kg^-1）， medium-dose MLC group （MLC-M， 8.6 g·kg^-1）， and high-dose MLC group （MLC-H， 17.2 g·kg^-1）. Active components of MLC and targets of obesity-type PCOS were screened from databases， a protein-protein interaction （PPI） network was constructed， and gene ontology（GO）and Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway enrichment analysis was performed. The gut microbiota structure was analyzed based on 16S rRNA sequencing and correlated with network pharmacology pathways. Body weight and estrous cycle were dynamically monitored. Ovarian morphology was observed by hematoxylin-eosin （HE） staining. Cell apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL）. Enzyme-linked immunosorbent assay （ELISA） was used to detect levels of follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， anti-Müllerian hormone （AMH）， testosterone （T）， and estradiol （E₂）. Western blot was used to detect the protein expression levels of phosphorylated PI3K/PI3K （p-PI3K/PI3K）， phosphorylated Akt/Akt （p-Akt/Akt）， B-cell lymphoma-2 （Bcl-2）， and Bcl-2-associated X protein （Bax）. ResultsNetwork pharmacology screening identified 124 active components of MLC and 408 overlapping targets between the herbal formula and the disease. Core targets such as Akt1 and Bcl-2 were revealed. As indicated by 16S rRNA sequencing， the abundances of Lachnospiraceae， Lachnoclostridium， and Dorea were increased in the MLC groups （P<0.05）， while the abundance of Veillonella was decreased （P<0.05）. KEGG correlation analysis integrating network pharmacology and gut microbiota data showed significant enrichment of the PI3K/Akt signaling pathway. Animal experiments showed that， compared with the Mod group， body weight decreased to normal levels in the Met， MLC-M， and MLC-H groups. The estrous cycle became regular. The number of corpora lutea increased and cystic follicles decreased. Serum levels of T， FSH， and LH/FSH were reduced （P<0.05， P<0.01）， while the E₂ level was increased （P<0.01）. Ovarian cell apoptosis was reduced （P<0.01）， and the protein expression levels of p-PI3K/PI3K， p-Akt/Akt， and Bcl-2 in ovarian tissue were significantly increased， whereas Bax protein expression was significantly decreased （P<0.05， P<0.01）. ConclusionMLC can regulate gut microbiota structure， effectively improve ovarian pathology in rats with obesity-type PCOS， and inhibit ovarian granulosa cell apoptosis. The mechanism may be associated with upregulation of the PI3K/Akt signaling pathway.

ObjectiveTo investigate the clinical efficacy and mechanisms of Qigui Didang decoction in the treatment of kidney collateral stasis syndrome in patients with stage Ⅲ-Ⅳ diabetic kidney disease （DKD） in a real-world setting. MethodsPatients with stage Ⅲ-Ⅳ DKD with kidney collateral stasis syndrome admitted to Beijing Aerospace General Hospital from January 2022 to December 2024 were selected for clinical study. According to treatment methods， patients were divided into the Qigui Didang decoction group （Qigui Didang decoction + conventional treatment） and the control group （conventional treatment alone）. A 1∶1 propensity score matching （PSM） method was used to reduce bias caused by confounding factors. Clinical efficacy， traditional Chinese medicine （TCM） symptom scores， renal function indicators， mRNA expression related to pathway mechanisms， glycolipid metabolism indices， and adverse reactions were compared between the two groups. ResultsA total of 120 patients with stage Ⅲ-Ⅳ DKD with kidney collateral stasis syndrome were included， including 62 cases in the Qigui Didang Decoction group and 58 cases in the control group. Before matching， there were statistically significant differences between the two groups in DKD stage， baseline urinary albumin-to-creatinine ratio （UACR）， 24-hour urine total protein （24 h-UTP）， and estimated glomerular filtration rate （eGFR） （P<0.05）. After matching， 47 cases were included in each group， and there was no statistically significant difference in baseline data between the two groups. After matching， the total clinical effective rate of the Qigui Didang decoction group was significantly higher than that of the control group （χ²=4.681， P<0.05）. Compared with data before treatment， the scores of primary and secondary TCM symptoms in the Qigui Didang decoction group were significantly decreased （P<0.05）. Compared with data before treatment， serum creatinine （SCr）， 24 h-UTP， and UACR levels were significantly decreased， while eGFR was significantly increased in the Qigui Didang decoction group （P<0.05）. Compared with data before treatment， the mRNA expression of silent information regulator 1 （Sirt1） was significantly upregulated， while the mRNA expression of nuclear factor-kappa B （NF-κB） and tumor suppressor protein p53 （p53） was significantly downregulated in the Qigui Didang decoction group （P<0.05）. Compared with data before treatment， fasting plasma glucose （FPG）， 2-hour postprandial plasma glucose （2 hPG）， glycated hemoglobin A1c （HbA1c）， total cholesterol （TC）， triglycerides （TG）， and low-density lipoprotein cholesterol （LDL-C） levels were decreased， while high-density lipoprotein cholesterol （HDL-C） levels were increased （P<0.05）. There was no statistically significant difference in adverse reactions between the two groups. ConclusionQigui Didang decoction combined with conventional treatment can significantly improve renal function， glycolipid metabolism， and TCM syndromes in patients with stage Ⅲ-Ⅳ DKD with kidney collateral stasis syndrome， with good safety. The mechanism may be related to the regulation of the Sirt1/NF-κB/p53 signaling pathway.

ObjectiveTo investigate the clinical efficacy and mechanisms of Qigui Didang decoction in the treatment of kidney collateral stasis syndrome in patients with stage Ⅲ-Ⅳ diabetic kidney disease （DKD） in a real-world setting. MethodsPatients with stage Ⅲ-Ⅳ DKD with kidney collateral stasis syndrome admitted to Beijing Aerospace General Hospital from January 2022 to December 2024 were selected for clinical study. According to treatment methods， patients were divided into the Qigui Didang decoction group （Qigui Didang decoction + conventional treatment） and the control group （conventional treatment alone）. A 1∶1 propensity score matching （PSM） method was used to reduce bias caused by confounding factors. Clinical efficacy， traditional Chinese medicine （TCM） symptom scores， renal function indicators， mRNA expression related to pathway mechanisms， glycolipid metabolism indices， and adverse reactions were compared between the two groups. ResultsA total of 120 patients with stage Ⅲ-Ⅳ DKD with kidney collateral stasis syndrome were included， including 62 cases in the Qigui Didang Decoction group and 58 cases in the control group. Before matching， there were statistically significant differences between the two groups in DKD stage， baseline urinary albumin-to-creatinine ratio （UACR）， 24-hour urine total protein （24 h-UTP）， and estimated glomerular filtration rate （eGFR） （P<0.05）. After matching， 47 cases were included in each group， and there was no statistically significant difference in baseline data between the two groups. After matching， the total clinical effective rate of the Qigui Didang decoction group was significantly higher than that of the control group （χ²=4.681， P<0.05）. Compared with data before treatment， the scores of primary and secondary TCM symptoms in the Qigui Didang decoction group were significantly decreased （P<0.05）. Compared with data before treatment， serum creatinine （SCr）， 24 h-UTP， and UACR levels were significantly decreased， while eGFR was significantly increased in the Qigui Didang decoction group （P<0.05）. Compared with data before treatment， the mRNA expression of silent information regulator 1 （Sirt1） was significantly upregulated， while the mRNA expression of nuclear factor-kappa B （NF-κB） and tumor suppressor protein p53 （p53） was significantly downregulated in the Qigui Didang decoction group （P<0.05）. Compared with data before treatment， fasting plasma glucose （FPG）， 2-hour postprandial plasma glucose （2 hPG）， glycated hemoglobin A1c （HbA1c）， total cholesterol （TC）， triglycerides （TG）， and low-density lipoprotein cholesterol （LDL-C） levels were decreased， while high-density lipoprotein cholesterol （HDL-C） levels were increased （P<0.05）. There was no statistically significant difference in adverse reactions between the two groups. ConclusionQigui Didang decoction combined with conventional treatment can significantly improve renal function， glycolipid metabolism， and TCM syndromes in patients with stage Ⅲ-Ⅳ DKD with kidney collateral stasis syndrome， with good safety. The mechanism may be related to the regulation of the Sirt1/NF-κB/p53 signaling pathway.

This study aims to explore the mechanism through which Yishen Jiangtang Decoction(YSJTD) regulates endoplasmic reticulum stress(ERS)-mediated NOD-like receptor thermal protein domain associated protein 3(NLRP3) inflammasome to improve diabetic nephropathy(DN) in db/db mice. Thirty db/db mice were randomly divided into the model group, YSJTD group, ERS inhibitor 4-phenylbutyric acid(4-PBA) group, with 10 mice in each group. Additionally, 10 db/m mice were selected as the control group. The YSJTD group was orally administered YSJTD at a dose of 0.01 mL·g~(-1), the 4-PBA group was orally administered 4-PBA at a dose of 0.5 mg·g~(-1), and the control and model groups were given an equal volume of carboxylmethyl cellulose sodium. The treatments were administered once daily for 8 weeks. Food intake, water consumption, and body weight were recorded every 2 weeks. After the intervention, fasting blood glucose(FBG), glycosylated hemoglobin(HbA1c), urine microalbumin(U-mALB), 24-hour urine volume, serum creatinine(Scr), and blood urea nitrogen(BUN) were measured. Inflammatory markers interleukin-1β(IL-1β) and interleukin-18(IL-18) were detected using the enzyme-linked immunosorbent assay(ELISA). Renal pathology was assessed through hematoxylin-eosin(HE), periodic acid-Schiff(PAS), and Masson staining, and transmission electron microscopy(TEM). Western blot was used to detect the expression levels of glucose-regulated protein 78(GRP78), C/EBP homologous protein(CHOP), NLRP3, apoptosis-associated speck-like protein containing CARD(ASC), cysteinyl aspartate-specific proteinase(caspase-1), and gasdermin D(GSDMD) in kidney tissues. The results showed that compared to the control group, the model group exhibited poor general condition, increased weight and food and water intake, and significantly higher levels of FBG, HbA1c, U-mALB, kidney index, 24-hour urine volume, IL-1β, and IL-18. Compared to the model group, the YSJTD and 4-PBA groups showed improved general condition, increased body weight, decreased food intake, and lower levels of FBG, U-mALB, kidney index, 24-hour urine volume, and IL-1β. Specifically, the YSJTD group showed a significant reduction in IL-18 levels compared to the model group, while the 4-PBA group exhibited decreased water intake and HbA1c levels compared to the model group. Although there was a decreasing trend in water intake and HbA1c in the YSJTD group, the differences were not statistically significant. No significant differences were observed in BUN, Scr, and kidney weight among the groups. Renal pathology revealed that the model group exhibited more severe renal damage compared to the control group. Kidney sections from the model group showed diffuse mesangial proliferation in the glomeruli, tubular edema, tubular dilation, significant inflammatory cell infiltration in the interstitium, and increased glycogen staining and blue collagen deposition in the basement membrane. In contrast, the YSJTD and 4-PBA groups showed varying degrees of improvement in renal damage, glycogen staining, and collagen deposition, with the YSJTD group showing more significant improvements. TEM analysis indicated that the model group had extensive cytoplasmic edema, homogeneous thickening of the basement membrane, fewer foot processes, and widening of fused foot processes. In the YSJTD and 4-PBA groups, cytoplasmic swelling of renal tissues was reduced, the basement membrane remained intact and uniform, and foot process fusion improved.Western blot results indicated that compared to the control group, the model group showed upregulation of GRP78, CHOP, GSDMD, NLRP3, ASC, and caspase-1 expression. In contrast, both the YSJTD and 4-PBA groups showed downregulation of these markers compared to the model group. These findings suggest that YSJTD exerts a protective effect against DN by alleviating NLRP3 inflammasome activation through the inhibition of ERS, thereby improving the inflammatory response in db/db DN mice.
Animals ; Endoplasmic Reticulum Stress/drug effects* ; Diabetic Nephropathies/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/genetics* ; Drugs, Chinese Herbal/administration & dosage* ; Mice ; Inflammasomes/drug effects* ; Male ; Kidney/pathology* ; Endoplasmic Reticulum Chaperone BiP ; Humans ; Interleukin-18/genetics* ; Mice, Inbred C57BL

Objective To investigate the intervention effect of sacubitril/valsartan(Sac/Val)on doxorubicin-induced heart failure(HF)in rabbits and its regulative effect on the transforming growth factor β1(TGF-β1)/SMAD family member 3(Smad3)/connective tissue growth factor(CTGF)signaling pathway.Methods Thirty-eight male New Zealand rabbits were subjected,and 8 of them were randomly assigned into a control group.The other 30 rabbits were injected with doxorubicin to establish a rabbit HF model,and finally,there were 6 rabbits in a model group,7 in a valsartan group,and 7 in a Sac/Val group.After 8 weeks of intervention,echocardiography[left ventricular ejection fraction(LVEF),left ventricular fractional shortening(LVFS),left ventricular end-diastolic diameter(LVEDD),left ventricular end-systolic diameter(LVESD)],and myocardial histopathologic observation(HE staining,Masson staining)were performed,and collogen volume fraction(CVF)was calculated.The levels of N-terminal pro-B-type natriuretic peptide(NT-proBNP),soluble growth stimulation expressed gene 2(sST2),galectin-3(Gal-3)were detected.Activities of renin-angiotensin-aldosterone system(RAAS)and levels of atrial natriuretic peptide,B-type brain natriuretic peptide(BNP),cyclic guanosine monophosphate(cGMP)and protein kinase G(PKG)were measured.The expression of α-smooth muscle actin(α-SMA),typeⅠ collagen,TGF-β1,Smad3,recombinant SMAD family member 7(Smad7)and CTGF in the myocardial tissues were detected.Results Compared with the control group,the model group exhibited significantly lower LVEF and LVFS and decreased expression of Smad7,higher LVEDD and LVESD(P＜0.01).The CVF of each group was(7.15±0.82)％、(43.20±5.09)％、(29.53±4.05)％、(22.48±2.93)％.Valsartan and Sac/Val treatment resulted in obvious increases in LVEF and LVFS,up-regulation of Smad7,decreased in LVEDD,LVESD and CVF,reduced levels of NT-proBNP,sST2,Gal-3,AngⅡ,aldosterone,atrial natriuretic peptide,BNP,cGMP and PKG,and down-regulation of α-SMA,collagen I,TGF-β1,Smad3 and CTGF when compared with the model group(P＜0.01).Sac/Val treatment showed better effects in above indicators than simple valsartan treatment(P＜0.01).Conclusion Sac/Val can reduce myocardial fibrosis and improve cardiac function in doxorubicin-induced HF rabbits,which may be related to the dual inhibition of TGF-β1/Smad3/CTGF signaling pathway by upregulating atrial natriuretic peptide and BNP levels and blocking RAAS activation.

ObjectiveTo investigate the triglyceride-glucose (TyG) index and the level of serum homocysteine (Hcy) in association with the incidence of stroke in type 2 diabetes mellitus (T2DM) patients. MethodsBased on the chronic disease risk factor surveillance cohort in Pudong New Area, Shanghai, excluding those with stroke in baseline survey, T2DM patients who joined the cohort from January 2016 to October 2020 were selected as the research subjects. During the follow-up period, a total of 318 new-onset ischemic stroke patients were selected as the case group, and a total of 318 individuals matched by gender without stroke were selected as the control group. The Cox proportional hazards regression model was used to adjust for confounding factors and explore the serum TyG index and the Hcy biochemical indicator in association with the risk of stroke. ResultsThe Cox proportional hazards regression results showed that after adjusting for confounding factors, the risk of stroke in T2DM patients with 10 μmol·L⁻¹-¹ and Hcy>15 μmol·L⁻¹ was 1.532 times (95%CI: 1.017‒2.309 times, P=0.041) and 1.738 times (95%CI: 1.119‒2.699 times, P=0.014) higher respectively, compared to T2DM patients with Hcy≤10 μmol·L⁻¹. T2DM patients with TyG>9.074 had 1.396 times higher risk of stroke (95%CI: 1.091‒1.787, P=0.008) compared to those with TyG≤9.074. The study found that urea and α1-antitrypsin (α1-AT) were independent risk factors for the incidence of stroke in T2DM patients. For every unit increase in urea andα1-AT, the risk of stroke in T2DM patients increased by 233.6% (HR=3.336, 95%CI: 1.588‒7.009, P=0.001) and 11.3% (HR=1.113, 95%CI: 1.028‒1.205, P=0.008), respectively. Cumulative risk curves showed that Hcy>10 μmol·L⁻¹ and TyG>9.074 accelerated the time to stroke occurrence in T2DM patients. ConclusionElevated levels of Hcy>10 μmol·L⁻¹ and a higher TyG index are risk factors for stroke in T2DM patients. Effective interventions for Hcy and TyG should be conducted for diabetic patients to reduce the incidence of stroke.

Ovarian cancer is the most lethal malignancy affecting the female reproductive system. Pharmacological inhibitors targeting CDK4/6 have demonstrated promising efficacy across various cancer types. However, their clinical benefits in ovarian cancer patients fall short of expectations, with only a subset of patients experiencing these advantageous effects. This study aims to provide further clinical and biological evidence for antineoplastic effects of a CDK4/6 inhibitor (TQB4616) in ovarian cancer and explore underlying mechanisms involved. Patient-derived ovarian cancer organoid models were established to evaluate the effectiveness of TQB3616. Potential key genes related to TQB3616 sensitivity were identified through RNA-seq analysis, and TRIM4 was selected as a candidate gene for further investigation. Subsequently, co-immunoprecipitation and GST pull-down assays confirmed that TRIM4 binds to hnRNPDL and promotes its ubiquitination through RING and B-box domains. RIP assay demonstrated that hnRNPDL binded to CDKN2C isoform 2 and suppressed its expression by alternative splicing. Finally, in vivo studies confirmed that the addition of siTRIM4 significantly improved the effectiveness of TQB3616. Overall, our findings suggest that TRIM4 modulates ubiquitin-mediated degradation of hnRNPDL and weakens sensitivity to CDK4/6 inhibitors in ovarian cancer treatment. TRIM4 may serve as a valuable biomarker for predicting sensitivity to CDK4/6 inhibitors in ovarian cancer.
Humans ; Female ; Ovarian Neoplasms/pathology* ; Animals ; Tripartite Motif Proteins/genetics* ; Mice ; Cyclin-Dependent Kinase 4/antagonists & inhibitors* ; Cell Line, Tumor ; Cyclin-Dependent Kinase 6/antagonists & inhibitors* ; Protein Kinase Inhibitors/pharmacology* ; Ubiquitin/metabolism* ; Xenograft Model Antitumor Assays ; Ubiquitination ; Antineoplastic Agents/pharmacology*

Objective To study the protective effects and mechanism of sacubitril(Sac)/valsartan(Val)on cardiomyocytes of rabbits with heart failure induced by doxorubicin(DOX).Methods Thirty New Zealand rabbits were selected to establish DOX-induced heart failure rabbit model.Twenty-five rabbits with successful modeling were randomly assigned to model group(DOX group,n=9),DOX+Val group(n=8),and DOX+Sac/Val group(n=8);and another 8 New Zealand rabbits were selected as blank group.The DOX+Val group was gavaged with 4.65 mg/kg Val suspension each time,the DOX+Sac/Val group was gavaged with 9.3 mg/kg Sac/Val suspension each time,and the blank group and DOX group were gavaged with equal volume of distilled water each time.Each group was gavaged twice a day for 8 weeks.After 8 weeks of administration,echocardiography was used to measure left ventricular end-diastolic diameter(LVDD),left ventricular end-systolic diameter(LVSD),left ventricular ejection fraction(LVEF),and left ventricular fractional shortening(LVFS).The heart mass index(HMI)and left ventricular mass index(LVMI)were calculated.The pathological morphology and myocardial fibrosis of myocardial tissue were observed by hematoxylin-eosin(H-E)and Masson staining.The ultrastructure of cardiomyocytes was observed by transmission electron microscope.Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL)staining was used to observe cardiomyocytes apoptosis and apoptosis rate was calculated.Enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of N-terminal pro-brain natriuretic peptide(NT-proBNP),high-sensitivity cardiac troponin I(Hs-cTNI),angiotensin Ⅱ(Ang Ⅱ),aldosterone(ALD),atrial natriuretic peptide(ANP),brain natriuretic peptide(BNP),cyclic guanosine monophosphate(cGMP),and protein kinase G(PKG)in serum.Quantitative polymerase chain reaction(qPCR)was used to detect the expression of natriuretic peptide receptor A(NPR-A),cGMP-specific phosphodiesterase 5A(PDE5A[cGMP]),PKG,B-cell lymphoma 2(Bcl-2),Bcl-2 associated X protein(Bax),and cysteine aspartate protease 3(caspase 3)mRNA in myocardial tissue.Western blotting was used to detect the expression of phosphorylated cAMP response element-binding protein(p-CREB),phosphorylated Bcl-2 related death promoting factor(p-Bad),Bcl-2,Bax,and caspase 3 proteins in myocardial tissue.Results Compared with the blank group,the LVDD and LVSD in the DOX group were increased(both P<0.01),the LVEF and LVFS were decreased(both P<0.01)and the HMI and LVMI were increased(both P<0.01);the apoptosis and apoptosis rate of cardiomyocytes were increased(P<0.01);the levels of NT-proBNP,Hs-cTNI,Ang Ⅱ,ALD,ANP,BNP,cGMP and PKG and the expression of NPR-A,PDE5A(cGMP),PKG,p-CREB,Bax and caspase 3 were all increased(all P<0.01),while the expression of Bcl-2 was decreased(P<0.01),and the expression of p-Bad had no significant difference(P>0.05).Compared with the DOX group,the LVDD and LVSD of the DOX+Sac/Val group and DOX+Val group were decreased(all P<0.01),the LVEF and LVFS were increased(all P<0.01)and the HMI and the LVMI were decreased(all P<0.01);the apoptosis and apoptosis rate of cardiomyocytes were decreased(all P<0.01);the levels of NT-proBNP,Hs-cTNI,Ang Ⅱ,ALD,ANP,BNP,cGMP and PKG and the expression of NPR-A,PDE5A(cGMP),PKG,Bax and caspase 3 were all decreased(all P<0.01),while the expression of Bcl-2 was increased(P<0.01);and the expression of p-CREB and p-Bad was increased in the DOX+Sac/Val group(both P<0.01),but there was no significant difference in the DOX+Val group(both P>0.05).Compared with the DOX+Val group,the DOX+Sac/Val group showed a decrease in all indicators except for LVEF,LVFS,NPR-A,ANP,BNP,cGMP,PDE5A(cGMP),PKG,p-CREB,p-Bad,and Bcl-2,which were all elevated(all P<0.05).Myocardial pathology and transmission electron microscopy showed that Sac/Val effectively protected cardiomyocytes,reduced cardiomyocytes apoptosis and myocardial fibrosis,and these effects were significantly better than those of Val.Conclusion Sac/Val can effectively reduce cardiomyocytes apoptosis,improve cardiac function and reduce myocardial fibrosis in rabbits with heart failure,and these effects are superior to Val.Its mechanism may be related to activating the NPR-A/cGMP/PKG signaling pathway and inhibiting renin-angiotensin-aldosterone system.