Neferine ameliorates hypertensive vascular remodeling modulating multiple signaling pathways in spontaneously hypertensive rats

Impact of inhibition of the renin-angiotensin system on early cardiac and renal abnormalities in Sprague Dawley rats fed short-term high fructose plus high salt diet

Introduction

The combination of a high fructose and high salt diet typical of western diet induces high blood pressure, aortic stiffening, left ventricular (LV) diastolic dysfunction and impaired renal function in rodents. Despite an activated renin-angiotensin system (RAS) in rats fed high fructose and high salt, acute inhibition of the RAS pathway does not improve cardiac and vascular parameters. It may well be that longer term treatment is required to permit remodeling and improve cardiovascular function. Thus, we hypothesized that chronic RAS inhibition fructose+high salt-fed rats to restore blood pressure (BP) to levels similar to glucose plus normal salt-fed controls will improve cardiorenal function and histopathology.

Methods

Male and female Sprague Dawley rats monitored by hemodynamic telemetry were fed 0.4% NaCl chow during baseline, then changed to chow containing either 20% glucose+0.4% NaCl (G) or 20% fructose+4% NaCl (F) and treated with vehicle, enalapril (Enal, 4 mg/kg/d) or losartan (Los, 8 mg/kg/d) by osmotic minipump for 25-26 days.

Results

BP was elevated in the fructose+high salt groups of both sexes (P < 0.05) and restored to control levels by Enal or Los. Pulse wave velocity (PWV) was lower in female F+Los rats and cardiac output higher in female F+Enal rats. GFR was not changed by diet or treatment. Fructose+high salt groups of both sexes displayed higher albuminuria that was decreased by Enal in male rats. Cardiac fibrosis and mesangial hypercellularity were greater in fructose+high salt-fed rats of both sexes and improved with either Los or Enal.

Discussion

Thus, inhibition of the RAS improves early changes in cardiac and renal histopathology in both sexes and albuminuria in male rats fed high fructose and high salt diet. Functional improvements in cardiorenal parameters may require longer treatment.

Nrf2 activation by neferine mitigates microglial neuroinflammation after subarachnoid hemorrhage through inhibiting TAK1-NF-κB signaling

Oxidative stress and neuroinflammation are two major causes leading to early brain injury after subarachnoid hemorrhage (SAH). Nuclear factor E2-related factor 2 (Nrf2) is a critical transcription factor that contributes to antioxidant responses. Additionally, Nrf2 could inhibit transforming growth factor beta-activated kinase 1 (TAK1), which plays a vital role in microglial activation-mediated neuroinflammation. Neferine (NE) exhibits considerable protective effects in diverse disease models. However, the detailed effect and mechanism of NE on SAH remain unknown. Our data showed that NE treatment significantly reduced behavior and cognitive impairment, and brain edema in the early period after SAH. In addition, NE mitigated SAH-induced oxidative damage, neuroinflammation, and neural death. Moreover, NE inhibited M1 microglial polarization and enhanced M2 phenotype microglia both in vivo and in vitro. Further investigations revealed that NE enhanced the Nrf2-antioxidant response element (ARE) signaling pathway and suppressed TAK1-NF-κB signaling. In contrast, depletion of Nrf2 by ML385 suppressed Nrf2-ARE signaling, induced TAK1-NF-κB activation, and further promoted M1 microglial polarization. Additionally, ML385 abated the neuroprotective effects of NE against SAH. Notably, LPS also aggravated TAK1-NF-κB activation and reversed the beneficial effects of NE after SAH. In summary, NE provides protection after SAH by inhibiting oxidative stress and modulating microglial polarization through Nrf2 activation and TAK1-NF-κB suppression.

Neferine Pretreatment Attenuates Isoproterenol-Induced Cardiac Injury Through Modulation of Oxidative Stress, Inflammation, and Apoptosis in Rats

Heart attacks, also known as myocardial infarctions (MIs), are one of the main reasons people die from cardiovascular diseases (CVDs) worldwide. Neferine, an alkaloid derived from Nelumbo nucifera seeds, has garnered interest due to its purported medicinal effects. In the current research, we induced MI in rats using the β-adrenergic agonist isoproterenol to investigate whether neferine can improve cardiac dysfunction. The rats were separated into four groups: control, isoproterenol (ISO), and two treatment groups received neferine at doses of 10 or 20 mg/kg once daily for 28 days. On days 27 and 28, the groups undergoing treatment were administered with an ISO injection. Results showed that pretreatment with neferine strongly protected against changes in lipid profiles and cardiac functional markers in ISO-administered rats. Neferine attenuated histopathologic changes, collagen deposition, and myocardial fibrosis in rats administered ISO. Neferine pretreatment significantly inhibited the oxidative stress, inflammatory, and apoptotic markers in the heart of ISO-injected rats. This was achieved through Nrf2/Keap1/ARE signaling stimulation, TLR4/NF-κB/MAPK-mediated signaling inhibition, and activation of the intrinsic apoptotic pathway. Using CB-Dock-2, researchers determined that neferine has a high binding affinity with protein receptors that are pivotal in several biological processes. In conclusion, the study provides strong evidence that pretreatment with neferine protects rats from ISO-induced heart damage.

The Role of mTOR in Doxorubicin-Altered Cardiac Metabolism: A Promising Therapeutic Target of Natural Compounds

Doxorubicin (DOX) is commonly used for the treatment of various types of cancer, however can cause serious side effects, including cardiotoxicity. The mechanisms involved in DOX-induced cardiac damage are complex and not yet fully understood. One mechanism is the disruption of cardiac metabolism, which can impair cardiac function. The mammalian target of rapamycin (mTOR) is a key regulator of cardiac energy metabolism, and dysregulation of mTOR signaling has been implicated in DOX-induced cardiac dysfunction. Natural compounds (NCs) have been shown to improve cardiac function in vivo and in vitro models of DOX-induced cardiotoxicity. This review article explores the protective effects of NCs against DOX-induced cardiac injury, with a focus on their regulation of mTOR signaling pathways. Generally, the modulation of mTOR signaling by NCs represents a promising strategy for decreasing the cardiotoxic effects of DOX.

Qingda granule ameliorates vascular remodeling and phenotypic transformation of adventitial fibroblasts via suppressing the TGF-β1/Smad2/3 pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Qingda granule (QDG) exhibits significant therapeutic effects on high blood pressure, vascular dysfunction, and elevated proliferation of vascular smooth muscle cells by inhibiting multiple pathways. However, the effects and underlying mechanisms of QDG treatment on hypertensive vascular remodeling are unclear.

AIM OF THE STUDY

The aim of this study was to determine the role of QDG treatment in hypertensive vascular remodeling in vivo and in vitro.

MATERIALS AND METHODS

An ACQUITY UPLC I-Class system coupled with a Xevo XS quadrupole time of flight mass spectrometer was used to characterize the chemical components of QDG. Twenty-five spontaneously hypertensive rats (SHR) were randomly divided into five groups, including SHR (equal volume of double distilled water, ddH₂O), SHR + QDG-L (0.45 g/kg/day), SHR + QDG-M (0.9 g/kg/day), SHR + QDG-H (1.8 g/kg/day), and SHR + Valsartan (7.2 mg/kg/day) groups. QDG, Valsartan, and ddH₂O were administered intragastrically once a day for 10 weeks. For the control group, ddH₂O was intragastrically administered to five Wistar Kyoto rats (WKY group). Vascular function, pathological changes, and collagen deposition in the abdominal aorta were evaluated using animal ultrasound, hematoxylin and eosin and Masson staining, and immunohistochemistry. Isobaric tags for relative and absolute quantification (iTRAQ) was performed to identify differentially expressed proteins (DEPs) in the abdominal aorta, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Cell Counting Kit-8 assays, phalloidin staining, transwell assays, and western-blotting were performed to explore the underlying mechanisms in primary isolated adventitial fibroblasts (AFs) stimulated with transforming growth factor-β 1 (TGF-β1) with or without QDG treatment.

RESULTS

Twelve compounds were identified from the total ion chromatogram fingerprint of QDG. In the SHR group, QDG treatment significantly attenuated the increased pulse wave velocity, aortic wall thickening, and abdominal aorta pathological changes and decreased Collagen I, Collagen III, and Fibronectin expression. The iTRAQ analysis identified 306 DEPs between SHR and WKY and 147 DEPs between QDG and SHR. GO and KEGG pathway analyses of the DEPs identified multiple pathways and functional processes involving vascular remodeling, including the TGF-β receptor signaling pathway. QDG treatment significantly attenuated the increased cell migration, actin cytoskeleton remodeling, and Collagen I, Collagen III, and Fibronectin expression in AFs stimulated with TGF-β1. QDG treatment significantly decreased TGF-β1 protein expression in abdominal aortic tissues in the SHR group and p-Smad2 and p-Smad3 protein expression in TGF-β1-stimulated AFs.

CONCLUSIONS

QDG treatment attenuated hypertension-induced vascular remodeling of the abdominal aorta and phenotypic transformation of adventitial fibroblasts, at least partly by suppressing TGF-β1/Smad2/3 signaling.