Endothelial dysfunction caused by reactive oxygen species (ROS) has been implicated in numerous cardiovascular diseases. Astragalus polysaccharide (APS), an important bioactive component extracted from the Chinese herb Astragalus membranaceus, has been widely used for the treatment of cardiovascular disease. The present study aimed to investigate the effects of APS on hydrogen peroxide (H2O2)-induced human umbilical vein endothelial cell (HUVEC) injury. Following treatment with 400 µM H2O2 for 24 h, cell viability was decreased and apoptosis was increased. However, pretreatment with APS for 1 h significantly attenuated H2O2-induced injury in HUVECs. In addition, APS decreased intracellular ROS levels, increased the protein expression of endothelial nitric oxide synthase and copper-zinc superoxide dismutase, elevated intracellular cyclic guanosine monophosphate (an activity marker for nitric oxide) levels and restored the mitochondrial membrane potential, compared with cells treated with H2O2 only. In conclusion, the results of the present study suggested that APS may protect HUVECs from injury induced by H2O2 via increasing the cell antioxidant capacity and nitric oxide (NO) bioavailability, which may contribute to the improvement of the imbalance between ROS and NO levels.
We report a new synthetic strategy
of combining N-carboxyanhydride (NCA) chemistry and
photonic crystals for the fabrication
of polypeptide structural color films. Driven by surface-initiated
ring-opening polymerization, the di-NCA derivative of l-cystine
(Cys) is introduced to replicate the functionalized colloidal crystal
templates and construct freestanding P(Cys) films with tunable structural
color. Furthermore, the feasibility of preparing patterned polypeptide
photonic films is demonstrated via template microfabrication. Because
of the incorporation of l-glutamate (Glu) components, the
P(Cys-co-Glu) co-polypeptide films are endowed with
a visual color responsiveness toward pH changes. Additionally, the
polypeptide photonic films show on-demand degradability. Given the
large family of amino acid building blocks, this powerful and versatile
approach paves the way for chemical derivatization of multifunctional
peptide-based optical platforms.
Ginsenoside Rg1 (Rg1), a protopanaxadiol saponin extracted from Chinese medicine Panax ginseng C.A. Meyer, has been demonstrated to inhibit the cardiac hypertrophy. However, the molecular mechanisms underlying the inhibition remain poorly understood. Activation of nuclear factor-kappa B (NF-κB) mediated by tumor necrosis factor α (TNF-α) gets involved in the cardiac hypertrophy. This study is designed to investigate the effects and the potential mechanism of Rg1 on the abdominal aorta coarctation (AAC)-induced cardiac hypertrophy with focus on TNF-α/NF-κB signaling pathway. The results showed that oral administration of Rg1 dose-dependently improved the pathological changes, decreased the ratios of left ventricular weight/body weight (LVW/BW) and heart weight/BW (HW/BW), corrected the dysfunction of the cardiac hemodynamics by decreasing the left ventricular systolic pressure and left ventricular end-diastolic pressure and increasing the maximal rate of left ventricular systolic and diastolic pressure (±dp/dtmax) compared with the AAC alone. Rg1 also downregulated the atrial natriuretic peptide mRNA expression and decreased the mRNA and protein expression of TNF-α in the heart tissue of rats compared with the AAC alone. In addition, Rg1 and BAY, the specific inhibitor of NF-κB, decreased the protein content and downregulated the mRNA expression of atrial natriuretic peptide in neonatal rat ventricular myocytes treated with TNF-α. Furthermore, Rg1 increased the protein expression of p65, the subunit of NF-κB, in cytoplasm and decreased the expression p65 in nucleus of the heart tissue of rats undergoing the AAC and of neonatal rat ventricular myocytes treated with TNF-α. The results suggested that Rg1 attenuates the AAC-induced cardiac hypertrophy through inhibition of TNF-α/NF-κB signaling pathway.
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