Malaysian Tualang honey (TH) is a known therapeutic honey extracted from the honeycombs of the Tualang tree (Koompassia excelsa) and has been reported for its antioxidant, anti-inflammatory, antiproliferative, and wound healing properties. However, the possible vascular protective effect of TH against oxidative stress remains unclear. In this study, the effects of TH on hydrogen peroxide- (H2O2-) elicited vascular hyperpermeability in human umbilical vein endothelial cells (HUVECs) and Balb/c mice were evaluated. Our data showed that TH concentrations ranging from 0.01% to 1.00% showed no cytotoxic effect to HUVECs. Induction with 0.5 mM H2O2 was found to increase HUVEC permeability, but the effect was significantly reversed attenuated by TH (p < 0.05), of which the permeability with the highest inhibition peaked at 0.1%. In Balb/c mice, TH (0.5 g/kg-1.5 g/kg) significantly (p < 0.05) reduced H2O2 (0.3%)-induced albumin-bound Evans blue leak, in a dose-dependent manner. Immunofluorescence staining confirmed that TH reduced actin stress fiber formation while increasing cortical actin formation and colocalization of caveolin-1 and β-catenin in HUVECs. Signaling studies showed that HUVECs pretreated with TH significantly (p < 0.05) decreased intracellular calcium release, while sustaining the level of cAMP when challenged with H2O2. These results suggested that TH could inhibit H2O2-induced vascular hyperpermeability in vitro and in vivo by suppression of adherence junction protein redistribution via calcium and cAMP, which could have a therapeutic potential for diseases related to the increase of both oxidant and vascular permeability.
Matched MeSH terms: Human Umbilical Vein Endothelial Cells/pathology
Ardisia crispa Thunb. A. DC. (Primulaceae) has been used extensively as folk-lore medicine in South East Asia including China and Japan to treat various inflammatory related diseases. Ardisia crispa root hexane fraction (ACRH) has been thoroughly studied by our group and it has been shown to exhibit anti-inflammatory, anti-hyperalgesic, anti-arthritic, anti-ulcer, chemoprevention and suppression against inflammation-induced angiogenesis in various animal model. Nevertheless, its effect against human endothelial cells in vitro has not been reported yet. Hence, the aim of the study is to investigate the potential antiangiogenic property of ACRH in human umbilical vein endothelial cells (HUVECs) and zebrafish embryo model. ACRH was separated from the crude ethanolic extract of the plant's root in prior to experimental studies. MTT assay revealed that ACRH exerted a concentration-dependent antiproliferative effect on HUVEC with the IC50 of 2.49 ± 0.04 μg/mL. At higher concentration (10 μg/mL), apoptosis was induced without affecting the cell cycle distribution. Angiogenic properties including migration, invasion and differentiation of HUVECs, evaluated via wound healing, trans-well invasion and tube formation assay respectively, were significantly suppressed by ACRH in a concentration-dependent manner. Noteworthily, significant antiangiogenic effects were observed even at the lowest concentration used (0.1 μg/mL). Expression of proMMP-2, vascular endothelial growth factor (VEGF)-C, VEGF-D, Angiopoietin-2, fibroblast growth factor (FGF)-1, FGF-2, Follistatin, and hepatocyte growth factor (HGF) were significantly reduced in various degrees by ACRH. The ISV formation in zebrafish embryo was significantly suppressed by ACRH at the concentration of 5 μg/mL. These findings revealed the potential of ACRH as antiangiogenic agent by suppressing multiple proangiogenic proteins. Thus, it can be further verified via the transcription of these proteins from their respective DNA, in elucidating their exact pathways.
Matched MeSH terms: Human Umbilical Vein Endothelial Cells/pathology
Inflammatory injury of the endothelium leads to apoptosis and endothelial dysfunction. The current study explored the effect and mechanisms of paeonol in inflammation-induced apoptosis and endothelial dysfunction induced by lipopolysaccharides (LPSs). The effects of paeonol on LPS-induced inflammatory injury were assessed by Western blotting, flow cytometry and reactive oxygen species (ROS) measurement in human umbilical vein endothelial cells (HUVECs) and C57BL/6J mice. Vascular reactivity of isolated mouse aortae was examined using wire myographs. The exposure of HUVECs to LPS increased the protein presence of Toll-like receptor 4 (TLR4), bone morphogenic protein 4 (BMP4), BMP receptor type 1A, nicotinamide adenine dinucleotide phosphate oxidase subunit 2, mitogen-activated protein kinase (MAPK), inducible nitric oxide synthase (iNOS), and cleaved caspase 3, as well as decreased it in phosphorylated endothelial nitric oxide synthase; these effects were prevented by treatment with paeonol. Similarly, cotreatment with paeonol reversed BMP4-induced apoptosis in HUVECs. Relaxation in response to the endothelium-dependent vasodilator acetylcholine were impaired in mouse aortae after exposure to LPSs; this endothelial dysfunction was reversed by cotreatment with paeonol, noggin (a BMP4 inhibitor), TAK242 (TLR4 antagonist), apocynin (an ROS scavenger), MAPK inhibitors, and AG (an iNOS inhibitor). BMP4 small interfering RNAs (siRNAs) abolished LPS-induced upregulation of BMP4 and cleaved caspase 3 protein, but not in cells treated with TLR4 siRNA and vice versa. The silencing of TLR4 and BMP4 abolished the inhibitory effects of paeonol on LPS-induced activation of cleaved caspase 3. The present results demonstrate that paeonol reduces LPS-induced endothelial dysfunction and apoptosis by inhibiting TLR4 and BMP4 signaling independently.
Matched MeSH terms: Human Umbilical Vein Endothelial Cells/pathology