Isosteviol prevents the development of isoprenaline‑induced myocardial hypertrophy

Flaxseed lignans alleviates isoproterenol-induced cardiac hypertrophy by regulating myocardial remodeling and oxidative stress

Cardiovascular diseases, the leading global cause of death, are usually associated with cardiac hypertrophy (CH). CH is an adaptive response of the heart against cardiac overloading, but continuous CH accelerates cardiac remodeling and results in heart failure. Available CH therapies delay the progress of heart failure, but they often fail to control symptoms or restore quality of life. Although flaxseed lignans have been shown to have significant anti-oxidant, anti-hypertensive, anti-inflammatory, and anti-fibrotic effects in various cardiovascular diseases, little is known about their effect on CH. Thus, this study evaluated the therapeutic effect of flaxseed lignans on CH, which was induced by subcutaneous injections with isoproterenol (5 mg/kg b.w) for 14 consecutive days. Flaxseed lignans (200 mg/kg) was given orally for 4 weeks. Cardiac pathological remodeling was evaluated by echocardiography, after which morphometric, biochemical, histological, and ultrastructural analyses were performed. Flaxseed lignans significantly ameliorated CH structural and functional alterations as shown by echocardiography. Lignans also reduced the relative heart weight, significantly decreased the elevated CK-MB and the lipid peroxidation marker malondialdehyde, augmented the myocardial total antioxidant capacity, and ameliorated the histopathological and ultrastructural changes in cardiac tissues and prevented interstitial collagen deposition. The results demonstrate promising anti-hypertrophic effect of flaxseed lignans against isoproterenol-induced cardiac hypertrophy, via regulating myocardial remodeling and oxidative stress. Therefore, lignans could be used as potential pharmacological intervention in the management of CH.

Cardioprotective potential of the antioxidant-rich bioactive fraction of Garcinia pedunculata Roxb. ex Buch.-Ham. against isoproterenol-induced myocardial infarction in Wistar rats

This Study aimed to characterise the phenolic compounds in Garcinia pedunculata extract and assess their potential antioxidant activity as well as its cardioprotective potential in isoproterenol-induced cardiac hypertrophy in an experimental animal model. In vitro antioxidant properties were determined using DPPH, ABTS, FRAP, PMD assays. In vitro lipid peroxidation experiment was also performed with heart tissues. Cardioprotective and cardiotoxicity effects were determined using the cell line studies. The cardioprotective effect of GP was assessed in a rat model of isoproterenol-(ISO-) induced cardiac hypertrophy by subcutaneous administration. Heart weight/tail length ratio and cardiac hypertrophy indicators were reduced after oral administration of GP. Additionally, GP reduced oxidative stress and heart inflammation brought on by ISO. In H9c2 cells, the antihypertrophic and anti-inflammatory effects of the extract of GP were seen in the presence of ISO, which were further supported by the in vivo observations. This study makes a compelling case for the possibility that supplementing with dried GP fruit can prevent heart hypertrophy by reducing oxidative stress and inflammation.

Isosteviol Sodium Ameliorates Dextran Sodium Sulfate-Induced Chronic Colitis through the Regulation of Metabolic Profiling, Macrophage Polarization, and NF-κB Pathway

Inflammatory bowel diseases (IBDs) constitute a group of chronic intestinal conditions prominently featuring deranged metabolism. Effective pharmacological treatments for IBDs are lacking. Isosteviol sodium (STV-Na) exhibits anti-inflammatory activity and may offer therapeutic benefits in chronic colitis. However, the associated mechanism remains unclear. This study is aimed at exploring the therapeutic effects of STV-Na against chronic colitis in terms of metabolic reprogramming and macrophage polarization. Results show that STV-Na attenuated weight loss and colonic pathological damage and restored the hematological and biochemical parameters in chronic colitis mice models. STV-Na also restored intestinal permeability by increasing the goblet cell numbers, which was accompanied by lowered plasma lipopolysaccharide and diamine oxidase levels. Metabolomic analysis highlighted 102 candidate biomarkers and 5 vital pathways that may be crucial in the potential pharmacological mechanism of STV-Na in regulating intestinal inflammation and oxidative stress. These pathways were glycerophospholipid metabolism, phenylalanine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, the pentose phosphate pathway, and phosphonate and phosphinate metabolism. Furthermore, STV-Na significantly decreased M1 macrophage polarization in the spleen and colon. The mRNA and protein levels of IL-1β, TNF-α, and NF-κB/p65 in colonic tissue from the colitis mice were decreased after the STV-Na treatment. Overall, STV-Na could alleviate chronic colitis by suppressing oxidative stress and inflammation levels, reprogramming the metabolic profile, inhibiting macrophage polarization, and suppressing the NF-κB/p65 signaling pathway. STV-Na remains a promising candidate drug for treating IBDs.

Isosteviol Sodium Exerts Anti-Colitic Effects on BALB/c Mice with Dextran Sodium Sulfate-Induced Colitis Through Metabolic Reprogramming and Immune Response Modulation

PURPOSE

Inflammatory bowel diseases (IBDs) are global health problems that are associated with immune regulation, but clinical IBDs treatment is currently inadequate. Effective preventive or therapeutic methods for immune disorders rely on controlling the function of immune cells. Isosteviol sodium (STV-Na) has antioxidant activity, but the therapeutic effect of STV-Na against IBD remain undocumented. Herein, we investigated the therapeutic effect of STV-Na in mice models with IBDs.

METHODS

Mice received 3.5% DSS for 7 days to establish IBD models. Intraperitoneal STV-Na was given 2 days before DSS and lasted for 9 days. Commercially available drugs used in treating IBDs (5-aminosalicylic acid, dexamethasone, and infliximab) were used as positive controls. Samples were collected 7 days after colitis induction. Histopathological score, biochemical parameters, molecular biology methods, and metabolomics were used for evaluating the therapeutic effect of STV-Na.

RESULTS

Our data revealed that STV-Na could significantly alleviate colon inflammation in mice with colitis. Specifically, STV-Na treatment improved body weight loss, increased colon length, decreased histology scores, and restored the hematological parameters of mice with colitis. The untargeted metabolomics analysis revealed that metabolic profiles were restored by STV-Na treatment. Furthermore, STV-Na therapy suppressed the number of CD68 macrophages and F4/80 cell infiltration. And STV-Na suppressed M1 and M2 macrophage numbers along with the mRNA expressions of proinflammatory cytokines. Moreover, STV-Na administration increased the number of regulatory T (Treg) cells while decreasing Th1/Th2/Th17 cell counts in the spleen. Additionally, STV-Na treatment restored intestinal barrier disruption in DSS-triggered colitis tissues by ameliorating the TJ proteins, increasing goblet cell proportions, and mucin protein production, and decreasing the permeability to FITC-dextran, which was accompanied by decreased plasma LPS and DAO contents.

CONCLUSION

These results indicate that STV-Na can ameliorate colitis by modulating immune responses along with metabolic reprogramming, and could therefore be a promising therapeutic strategy for IBDs.

Isosteviol improves cardiac function and promotes angiogenesis after myocardial infarction in rats

Isosteviol has been indicated as a cardiomyocyte protector. However, the underlying mechanism remains unclear. Thus, we sought to confirm the protective effect of isosteviol after myocardial infarction in a model of permanent coronary artery occlusion and investigate the potential proangiogenic activity in vitro and in vivo. A 4-week permanent coronary artery occlusion rat model was generated, and the protective effect of isosteviol was evaluated by echocardiographic imaging and hemodynamics assays. The coronary capillary density was tested by immunochemistry and micro-computed tomography (μCT) imaging. The effect of isosteviol on endothelial cells was determined in human umbilical vein endothelial cells (HUVECs) in vitro and Tg (kdrl: EGFP) zebrafish in vivo. We also examined the expression of related transcription factors by real-time polymerase chain reaction (RT-qPCR). Isosteviol increased ejection fraction (EF), fractional shortening (FS), cardiac systolic index (CI), maximum rate of increase of left ventricular pressure (Max dp/dt), and left ventricular systolic pressure (LVSP) by 32%, 40%, 25%, 26%, and 10%, respectively, in permanent coronary artery occlusion rats. Interestingly, it also promoted coronary capillary density by 2.5-fold. In addition, isosteviol promoted the proliferation and branching of HUVECs in vitro. It also rescued intersegmental vessel (ISV) development and improved endothelial cell proliferation by approximately fivefold (4-6) in zebrafish embryos in vivo. Isosteviol also upregulated the expression of hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGFA) in zebrafish by fourfold and 3.5-fold, respectively. Our findings suggest that isosteviol is a proangiogenic agent and that this activity is related to its protective effects against myocardial ischemia. After using the permanent coronary artery occlusion model, we demonstrated that isosteviol promotes angiogenesis directly and increases capillary density in myocardial ischemia rats. Isosteviol promotes angiogenesis in zebrafish in vivo and increases vascular endothelial cell proliferation in HUVECs and zebrafish. The angiogenesis activity of isosteviol may be correlated with VEGFA and HIF-1α signaling.

Isosteviol Protects H9c2 Cells Against Hypoxia-reoxygenation by Activating ERK1/2

AIMS

In the present study, we have investigated the cardioprotective properties of Isosteviol (STV) under conditions of hypoxia-reoxygenation and elucidated the underlying mechanism.

BACKGROUND

In our previous studies, we have determined that STV exhibits neuro- and cardio-protective properties. However, the mechanism underlying STV-induced cardioprotection has not yet been fully understood.

METHODS

All experiments were performed on rat heart embryonic H9c2 cell line. To induce hypoxia- reoxygenation, cells were exposed to 1% oxygen (in no glucose and no sodium pyruvate DMEM) following by reoxygenation (using fully supplemented MEM). Cells viability was tested by MTT assay, and protein levels were compared by Western blotting.

RESULTS

Treatment of heart embryonic H9c2 cells with STV (10 μM) significantly increased the survival of cells exposed to hypoxia-reoxygenation. STV (10 μM) activated ERK1/2 and DRP1 in hypoxia-reoxygenation, but did not have any effects on ERK1/2 or DRP1 in normoxia. STV (10 μM) did not regulate CAMKII, AKT or AMPK signaling pathways.

CONCLUSION

Taken all together, our findings demonstrate that 1) STV protects H9c2 cells against hypoxia-reoxygenation and that 2) this effect is mediated via ERK1/2. The property of STV that selectively activates ERK1/2 in cells exposed to stress, but not in cells under non-stress conditions, makes this compound a promising candidate-drug for therapy against myocardial ischemia-reperfusion in clinical practice.