Total flavonoids from Plumula Nelumbinis suppress angiotensin II-induced fractalkine production by inhibiting the ROS/NF-κB pathway in human umbilical vein endothelial cells

Peptides from Harpadon nehereus Bone Ameliorate Angiotensin II-Induced HUVEC Injury and Dysfunction through Activation of the AKT/eNOS and Nrf2 Pathway

Angiotensin II (Ang II)-induced vascular endothelial cell injury and dysfunction are important pathophysiological factors in the occurrence and development of hypertension. In this study, the amelioration effects of two peptides KA-8 (KLHDEEVA) and PG-7 (PSRILYG) from Harpadon nehereus bone on Ang II-induced damage and dysfunction in human umbilical vein endothelial cells (HUVECs) were investigated. The results showed that they could significantly decrease the reactive oxygen species (ROS) level and increase the activity of antioxidant enzymes in Ang II-induced HUVEC. Two peptides, especially PG-7, significantly upregulated the expression of nuclear factor erythroid 2-related factor 2 (Nrf2). In addition, PG-7 significantly reduced the level of expression of endothelin-1(ET-1) and increased the phosphorylation level of phosphoinositide 3-kinase (PI3K), serine/threonine kinase (AKT), and nitric oxide synthase (eNOS). These results indicated that the two peptides, especially PG-7, can ameliorate angiotensin II-induced HUVEC injury and dysfunction through activation of the AKT/eNOS and Nrf2 pathway. Furthermore, PG-7 showed a stronger affinity with angiotensin-converting enzyme (ACE) and ACE inhibitory than KA-8. In conclusion, peptide PG-7 reveals potential in the prevention and treatment of hypertension.

Physicochemical Properties of Collagen from the Bone of Harpadon nehereus and Its Protective Effects against Angiotensin II-Induced Injury in Human Umbilical Vein Endothelial Cells

The physicochemical characterization of a new collagen from the bone of Harpadon nehereus (HNBC) and its protective effects against Ang II-induced injury of human umbilical vein endothelial cells (HUVEC) were investigated. The triple helix of HNBC analyzed by SDS-PAGE was formed as (α₁)₂α₂, belonging to type I collagen. UV spectra showed that HNBC had a maximum absorbance at 230 nm. FTIR spectra indicated the triple helical structure and activity of HNBC. The high solubility of HNBC was observed in the low pH ranges (≤4) and NaCl concentrations (≤2%, w/v). The maximum transition (T _m) of HNBC was determined to be 48.5 °C. The amino acid composition analysis showed that glycine, glutamic acid, proline, and alanine were the abundant amino acids available in HNBC. HNBC showed free radical (DPPH and OH·) scavenging activities in the tested concentrations (0.5-6 mg/mL). In addition, HNBC could effectively protect against Ang II-induced injury of HUVEC by increasing the activities of antioxidant enzymes, such as CAT, SOD, and GSH-Px. Overall, collagen from the bone of H. nehereus has promising prospects in functional food and biomedical industries.

In Vitro Vascular-Protective Effects of a Tilapia By-Product Oligopeptide on Angiotensin II-Induced Hypertensive Endothelial Injury in HUVEC by Nrf2/NF-κB Pathways

Angiotensin II (Ang II) is closely involved in endothelial injury during the development of hypertension. In this study, the protective effects of the tilapia by-product oligopeptide Leu-Ser-Gly-Tyr-Gly-Pro (LSGYGP) on oxidative stress and endothelial injury in Angiotensin II (Ang II)-stimulated human umbilical vein endothelial cells (HUVEC) were evaluated. LSGYGP dose-dependently suppressed the fluorescence intensities of nitric oxide (NO) and reactive oxygen species (ROS), inhibited the nuclear factor-kappa B (NF-κB) pathway, and reduced inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and endothelin-1 (ET-1) expression, as shown by western blot. In addition, it attenuated the expression of gamma-glutamyltransferase (GGT) and heme oxygenase 1 (HO-1), as well as increasing superoxide dismutase (SOD) and glutathione (GSH) expression through the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Other experiments revealed that LSGYGP increased the apoptotic inhibition ratio between cleaved-caspase-3/procaspase-3, reduced expressions of pro-apoptotic ratio between Bcl-2/Bax, inhibited phosphorylation of mitogen-activated protein kinases (MAPK), and increased phosphorylation of the serine/threonine kinase (Akt) pathway. Furthermore, LSGYGP significantly decreased Ang II-induced DNA damage in a comet assay, and molecular docking results showed that the steady interaction between LSGYGP with NF-κB may be attributed to hydrogen bonds. These results suggest that this oligopeptide is effective in protecting against Ang II-induced HUVEC injury through the reduction of oxidative stress and alleviating endothelial damage. Thus, it has the potential for the therapeutic treatment of hypertension-associated diseases.

Apigenin and its methylglyoxal-adduct inhibit advanced glycation end products-induced oxidative stress and inflammation in endothelial cells

Protein glycation in the body can lead to malfunction of intracellular and extracellular proteins. Reactive carbonyl species (RCS) have been identified to be key intermediates in the reactions. The reaction products, generally termed as advanced glycation end products (AGEs), have been implicated in the development of diabetic complications. In this study, the activity of apigenin (API), a natural flavone in scavenging RCS and the molecular mechanism involved in its protective effect against AGEs-induced oxidative stress and inflammation were examined in vitro. Results showed that API could directly trap methylglyoxal (MGO) to form API-MGO adducts, thus inhibiting AGEs formation. API and di-apigenin adduct (DMA) were found to inhibit AGEs-induced oxidative stress and inflammation in human umbilical vein endothelial cells (HUVECs) by significantly suppressing reactive oxygen species (ROS) production (30% relative to control) and decreasing the protein expression of pro-inflammatory cytokines and adhesion molecules by 30-70%. Further mechanistic investigation revealed that the protective effect was likely mediated via suppression of the extracellular-signal-regulated kinase 1/2 (ERK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway initiated by AGEs-RAGE (receptor for AGEs) interaction and induction of ERK/nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway with subsequent up-regulation of antioxidant defense molecules. In summary, our results suggest that API possesses great potential to protect against AGEs-associated health disorders by modulating cellular inflammatory and antioxidant defense signaling pathways.

New Naphthalene Derivatives from the Bulbs of Eleutherine americana with Their Protective Effect on the Injury of HUVECs

Five new naphthalene derivatives, named Eleutherols A–C (1–3) and Eleuthinones B–C (4,5), together with three known compounds were isolated from the bulbs of Eleutherine americana. Their structures were elucidated on the basis of spectroscopic analysis including HR-ESI-MS, 1D and 2D NMR techniques. These compounds exhibited a potent effect against the injury of human umbilical vein endothelial cell (HUVECs) induced by high concentrations of glucose in vitro.

Cucumis sativus Aqueous Fraction Inhibits Angiotensin II-Induced Inflammation and Oxidative Stress In Vitro

Inflammation and oxidative stress play major roles in endothelial dysfunction, and are key factors in the progression of cardiovascular diseases. The aim of this study was to evaluate in vitro the effect of three subfractions (SFs) from the Cucumis sativus aqueous fraction to reduce inflammatory factors and oxidative stress induced by angiotensin II (Ang II) in human microvascular endothelial cells-1 (HMEC-1) cells. The cells were cultured with different concentrations of Ang II and 0.08 or 10 μg/mL of SF1, SF2, or SF3, or 10 μmol of losartan as a control. IL-6 (Interleukin 6) concentration was quantified. To identify the most effective SF combinations, HMEC-1 cells were cultured as described above in the presence of four combinations of SF1 and SF3. Then, the effects of the most effective combination on the expression of adhesion molecules, the production of reactive oxygen species (ROS), and the bioavailability of nitric oxide (NO) were evaluated. Finally, a mass spectrometry analysis was performed. Both SF1 and SF3 subfractions decreased the induction of IL-6 by Ang II, and C4 (SF1 and SF3, 10 μg/mL each) was the most effective combination to inhibit the production of IL-6. Additionally, C4 prevented the expression of adhesion molecules, reduced the production of ROS, and increased the bioavailability of NO. Glycine, arginine, asparagine, lysine, and aspartic acid were the main components of both subfractions. These results demonstrate that C4 has anti-inflammatory and antioxidant effects.

Characterization of polysaccharides and their antioxidant properties from Plumula nelumbinis

Two novel polysaccharides, Plumula nelumbinis (P. nelumbinis) polysaccharide I (LNP I) and P. nelumbinis polysaccharide II (LNP II), were extracted and purified from P. nelumbinis, and a sulfated polysaccharide, P. nelumbinis polysaccharide III (LNP III), with a substitution degree of 0.62 was prepared from LNPI. The structures of the LNPs were preliminarily characterized using high performance size exclusion chromatography (HPSEC), gas chromatography-mass spectrometry (GC–MS), Fourier transformed infrared spectrometry (FT-IR), and nuclear magnetic resonance (NMR) spectrometry. In addition, evaluation of the antioxidant activity of the LNPs showed that they could significantly increase the proliferation of RAW264.7 macrophages (P < 0.05) and improve the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) based on cell model of H₂O_2-induced oxidative damage. This suggested that these LNPs may be used as potential antioxidants.

Cyanidin-3-glucoside attenuates angiotensin II-induced oxidative stress and inflammation in vascular endothelial cells

Angiotensin II (Ang II) causes oxidative stress and vascular inflammation, leading to vascular endothelial cell dysfunction, and is associated with the development of inflammatory cardiovascular diseases such as atherosclerosis. Therefore, interventions of oxidative stress and inflammation may contribute to the reduction of cardiovascular diseases. Cyanidin-3-glucoside (C3G) plays a role in the prevention of oxidative damage in several diseases. Here, we investigated the effect of C3G on Ang II-induced oxidative stress and vascular inflammation in human endothelial cells (EA.hy926). C3G dose-dependently suppressed the free radicals and inhibited the nuclear factor-kappa B (NF-κB) signaling pathway by protecting the degradation of inhibitor of kappa B-alpha (IκB-α), inhibiting the expression and translocation of NF-κB into the nucleus through the down-regulation of NF-κB p65 and reducing the expression of inducible nitric oxide synthase (iNOS). Pretreatment with C3G not only prohibited the NF-κB signaling pathway but also promoted the activity of the nuclear erythroid-related factor 2 (Nrf2) signaling pathway through the upregulation of endogenous antioxidant enzymes. Particularly, we observed that C3G significantly enhanced the production of superoxide dismutase (SOD) and induced the expression of heme oxygenase (HO-1). Our findings confirm that C3G can protect against vascular endothelial cell inflammation induced by AngII. C3G may represent a promising dietary supplement for the prevention of inflammation, thereby decreasing the risk for the development of atherosclerosis.

Involvenflavones A-F, six new flavonoids with 3'-aryl substituent from Selaginella involven

Six new flavonoids, involvenflavones A-F (1-6), were isolated from Selaginella involven. Their structures were elucidated based on UV, IR, 1D and 2D NMR as well as HR-ESI-MS techniques. All compounds belong to apigenin derivatives with 3'-aryl substituent. This is the first report of the apigenin derivatives with 3'-aryl substituent from nature resources. These compounds also exhibited a potent effect against the injury of human umbilical vein endothelial cell (HUVECs) induced by high concentrations of glucose in vitro.

Relaxant action of plumula nelumbinis extract on mouse airway smooth muscle

The traditional herb Plumula Nelumbinis is widely used in the world because it has many biological activities, such as anti-inflammation, antioxidant, antihypertension, and butyrylcholinesterase inhibition. However, the action of Plumula Nelumbinis on airway smooth muscle (ASM) relaxation has not been investigated. A chloroform extract of Plumula Nelumbinis (CEPN) was prepared, which completely inhibited precontraction induced by high K⁺ in a concentration-dependent manner in mouse tracheal rings, but it had no effect on resting tension. CEPN also blocked voltage-dependent L-type Ca²⁺ channel- (VDCC-) mediated currents. In addition, ACh-induced precontraction was also completely blocked by CEPN and partially inhibited by nifedipine or pyrazole 3. Besides, CEPN partially reduced ACh-activated nonselective cation channel (NSCC) currents. Taken together, our data demonstrate that CEPN blocked VDCC and NSCC to inhibit Ca²⁺ influx, resulting in relaxation of precontracted ASM. This finding indicates that CEPN would be a candidate of new potent bronchodilators.

A key mediator, PTX3, of IKK/IκB/NF-κB exacerbates human umbilical vein endothelial cell injury and dysfunction

OBJECTIVE

This study was performed to investigate PTX3-mediated iNOS expression and IKK/IκB/NF-κB activation in PA-induced atherosclerotic HUVECs injury model.

METHODS

The cell viability was detected by the CCK8 assay. The cell apoptosis was assessed by annexin V-PI double-labeling staining. Expression of genes and proteins were analyzed by real-time PCR and western blotting respectively. Cells were transfected with siRNAs as a gene silencing methods.

RESULTS

PA induced cell apoptosis in human umbilical vein endothelial cells in a time and dose-dependent manner. PA also induced upregulation expression of PTX3. TPCA-1, an inhibitor of IKK-2, could suppress the expression of PTX3 and phospho-IκB-α in PA-induced endothelial dysfunction cell model. We also found that transfection of cells with PTX3 siRNA reduced the expression of iNOS and NO, and protected PA-induced cell apoptosis in HUVECs.

CONCLUSIONS

PTX3 could exacerbate endothelial dysfunction, at least partially, through IKK/IκB/NF-κB activation and overexpression of iNOS and NO, and advance the development of atherosclerosis.