Use of Nutraceuticals in Angiogenesis-Dependent Disorders

The term of angiogenesis refers to the growth of new vessels from pre-existing capillaries. The phenomenon is necessary for physiological growth, repair and functioning of our organs. When occurring in a not regulated manner, it concurs to pathological conditions as tumors, eye diseases, chronic degenerative disorders. On the contrary insufficient neovascularization or endothelial disfunction accompanies ischemic and metabolic disorders. In both the cases an inflammatory and oxidative condition exists in supporting angiogenesis deregulation and endothelial dysfunction. The use of nutraceuticals with antioxidant and anti-inflammatory activities can be a therapeutic option to maintain an adequate vascularization and endothelial cell proper functioning or to blunt aberrant angiogenesis. A revision of the updated literature reports on nutraceuticals to guide endothelial cell wellness and to restore physiological tissue vascularization is the objective of this paper. The critical aspects as well as lacking data for human use will be explored from a pharmacological perspective

Inhibition of cell cycle progression by the hydroxytyrosol-cetuximab combination yields enhanced chemotherapeutic efficacy in colon cancer cells

Hydroxytyrosol (HT), a polyphenol of olive oil, downregulates epidermal growth factor (EGFR) expression and inhibits cell proliferation in colon cancer (CC) cells, with mechanisms similar to that activated by the EGFR inhibitor, cetuximab. Here, we studied whether HT treatment would enhance the cetuximab inhibitory effects on cell growth in CC cells. HT-cetuximab combination showed greater efficacy in reducing cell growth in HT- 29 and WiDr cells at concentrations 10 times lower than when used as single agents. This reduction was clearly linked to cell cycle blockade, occurring at G2/M phase. The cell cycle arrest in response to combination treatment is related to cyclins B, D1, and E, and cyclin-dependent kinase (CDK) 2, CDK4, and CDK6 down-regulation, and to the concomitant over-expression of CDK inhibitors p21 and p27. HT and cetuximab stimulated a caspase-independent cell death cascade, promotedtranslocation of apoptosis-inducing factor (AIF) from mitochondria to nucleus and activated the autophagy process. Notably, normal colon cells and keratinocytes were less susceptible to comboinduced cell death and EGFR downregulation. These results suggest a potential role of diet, containing olive oil, during cetuximab chemotherapy of colon tumor. HT may be a competent therapeutic agent in CC enhancing the effects of EGFR inhibitors

Involvement of bradykinin B2 receptor in pathological vascularization in oxygen-induced retinopathy in mice and rabbit cornea

The identification of components of the kallikrein-kinin system in the vitreous from patients with microvascular retinal diseases suggests that bradykinin (BK) signaling may contribute to pathogenesis of retinal vascular complications. BK receptor 2 (B2R) signaling has been implicated in both pro-inflammatory and pro-angiogenic effects promoted by BK. Here, we investigated the role of BK/B2R signaling in the retinal neovascularization in the oxygen-induced retinopathy (OIR) model. Blockade of B2R signaling by the antagonist fasitibant delayed retinal vascularization in mouse pups, indicating that the retinal endothelium is a target of the BK/B2R system. In the rabbit cornea assay, a model of pathological neoangiogenesis, the B2 agonist kallidin induced vessel sprouting and promoted cornea opacity, a sign of edema and tissue inflammation. In agreement with these results, in the OIR model, a blockade of B2R signaling significantly reduced retinal neovascularization, as determined by the area of retinal tufts, and, in the retinal vessel, it also reduced vascular endothelial growth factor and fibroblast growth factor-2 expression. All together, these findings show that B2R blockade reduces retinal neovascularization and inhibits the expression of proangiogenic and pro-inflammatory cytokines, suggesting that targeting B2R signaling may be an effective strategy for treating ischemic retinopathy

Development of phenol-enriched olive oil with phenolic compounds extracted from wastewater produced by physical refining

While in the last few years the use of olive cake and mill wastewater as natural sources of phenolic compounds has been widely considered and several studies have focused on the development of new extraction methods and on the production of functional foods enriched with natural antioxidants, no data has been available on the production of a phenol-enriched refined olive oil with its own phenolic compounds extracted from wastewater produced during physical refining. In this study; we aimed to: (i) verify the effectiveness of a multi-step extraction process to recover the high-added-value phenolic compounds contained in wastewater derived from the preliminary washing degumming step of the physical refining of vegetal oils; (ii) evaluate their potential application for the stabilization of olive oil obtained with refined olive oils; and (iii) evaluate their antioxidant activity in an in vitro model of endothelial cells. The results obtained demonstrate the potential of using the refining wastewater as a source of bioactive compounds to improve the nutraceutical value as well as the antioxidant capacity of commercial olive oils. In the conditions adopted, the phenolic content significantly increased in the prototypes of phenol-enriched olive oils when compared with the control oil

Bradykinin B2 receptor contributes to inflammatory responses in human endothelial cells by the transactivation of the fibroblast growth factor receptor FGFR-1

Elevated levels of bradykinin (BK) and fibroblast growth factor-2 (FGF-2) have been implicated in the pathogenesis of inflammatory and angiogenic disorders. In angiogenesis, both stimuli induce a pro-inflammatory signature in endothelial cells, activating an autocrine/paracrine amplification loop that sustains the neovascularization process. Here we investigated the contribution of the FGF-2 pathway in the BK-mediated human endothelial cell permeability and migration, and the role of the B2 receptor (B2R) of BK in this cross-talk. BK (1 µM) upregulated the FGF-2 expression and promoted the FGF-2 signaling, both in human umbilical vein endothelial cells (HUVEC) and in retinal capillary endothelial cells (HREC) by the activation of Fibroblast growth factor receptor-1 (FGFR-1) and its downstream signaling (fibroblast growth factor receptor substrate: FRSα, extracellular signal–regulated kinases1/2: ERK1/2, and signal transducer and activator of transcription 3: STAT3 phosphorylation). FGFR-1 phosphorylation triggered by BK was c-Src mediated and independent from FGF-2 upregulation. Either HUVEC and HREC exposed to BK showed increased permeability, disassembly of adherens and tight-junction, and increased cell migration. B2R blockade by the selective antagonist, fasitibant, significantly inhibited FGF-2/FGFR-1 signaling, and in turn, BK-mediated endothelial cell permeability and migration. Similarly, the FGFR-1 inhibitor, SU5402, and the knock-down of the receptor prevented the BK/B2R inflammatory response in endothelial cells. In conclusion, this work demonstrates the existence of a BK/B2R/FGFR-1/FGF-2 axis in endothelial cells that might be implicated in propagation of angiogenic/inflammatory responses. A B2R blockade, by abolishing the initial BK stimulus, strongly attenuated FGFR-1-driven cell permeability and migration

Stemness marker ALDH1A1 promotes tumor angiogenesis via retinoic acid/HIF-1α/VEGF signalling in MCF-7 breast cancer cells

BackgroundAldehyde dehydrogenase 1A1 (ALDH1A1), a member of aldehyde dehydrogenase family, is a marker of stemness in breast cancer. During tumor progression cancer stem cells (CSCs) have been reported to secrete angiogenic factors to orchestrate the formation of pathological angiogenesis. This vasculature can represent the source of self-renewal of CSCs and the route for further tumor spreading. The aim of the present study has been to assess whether ALDH1A1 controls the output of angiogenic factors in breast cancer cells and regulates tumor angiogenesis in a panel of in vitro and in vivo models.MethodsStemness status of breast cancer cells was evaluated by the ability to form turmorspheres in vitro. A transwell system was used to assess the angiogenic features of human umbilical vein endothelial cells (HUVEC) when co-cultured with breast cancer cells MCF-7 harboring different levels of ALDH1A1. Under these conditions, we survey endothelial proliferation, migration, tube formation and permeability. Moreover, in vivo, MCF-7 xenografts in immunodeficient mice allow to evaluate blood flow, expression of angiogenic factors and microvascular density (MVD).ResultsIn MCF-7 we observed that ALDH1A1 activity conferred stemness property and its expression correlated with an activation of angiogenic factors. In particular we observed a significant upregulation of hypoxia inducible factor-1 (HIF-1) and proangiogenic factors, such as vascular endothelial growth factor (VEGF). High levels of ALDH1A1, through the retinoic acid pathway, were significantly associated with VEGF-mediated angiogenesis in vitro. Co-culture of HUVEC with ALDH1A1 expressing tumor cells promoted endothelial proliferation, migration, tube formation and permeability. Conversely, downregulation of ALDH1A1 in MCF-7 resulted in reduction of proangiogenic factor release/expression and impaired HUVEC angiogenic functions. In vivo, when subcutaneously implanted in immunodeficient mice, ALDH1A1 overexpressing breast tumor cells displayed a higher expression of VEGF and MVD.ConclusionIn breast tumors, ALDH1A1 expression primes a permissive microenvironment by promoting tumor angiogenesis via retinoic acid dependent mechanism. In conclusion, ALDH1A1 might be associated to progression and diffusion of breast cancer

Use of Nutraceuticals in Angiogenesis-Dependent Disorders

The term of angiogenesis refers to the growth of new vessels from pre-existing capillaries. The phenomenon is necessary for physiological growth, repair and functioning of our organs. When occurring in a not regulated manner, it concurs to pathological conditions as tumors, eye diseases, chronic degenerative disorders. On the contrary insufficient neovascularization or endothelial disfunction accompanies ischemic and metabolic disorders. In both the cases an inflammatory and oxidative condition exists in supporting angiogenesis deregulation and endothelial dysfunction. The use of nutraceuticals with antioxidant and anti-inflammatory activities can be a therapeutic option to maintain an adequate vascularization and endothelial cell proper functioning or to blunt aberrant angiogenesis. A revision of the updated literature reports on nutraceuticals to guide endothelial cell wellness and to restore physiological tissue vascularization is the objective of this paper. The critical aspects as well as lacking data for human use will be explored from a pharmacological perspective

Nitric oxide and PGE-2 cross-talk in EGFR-driven epithelial tumor cells

Nitric oxide (NO) exerts physiopathological effects based mainly on its concentration. Thus, it facilitates or inhibits cancer-promoting characteristics. This review discusses the role of NO and its network of partners in tumor progression and angiogenesis: prostaglandin E 2 (PGE-2) and its producing enzymes, cyclooxigenase 2 (COX-2) and microsomal PGE synthase 1 (mPGES-1), and epidermal growth factor receptor (EGFR) signaling. Understanding the molecular mechanisms and cross-talk modulating NO effects by PGE-2 and EGFR and vice versa allows us to develop better therapeutic strategies for cancer treatment

H2S dependent and independent anti-inflammatory activity of zofenoprilat in cells of the vascular wall

Cardiovascular diseases as atherosclerosis are associated to an inflammatory state of the vessel wall which is accompanied by endothelial dysfunction, and adherence and activation of circulating inflammatory cells. Hydrogen sulfide, a novel cardiovascular protective gaseous mediator, has been reported to exert anti-inflammatory activity. We have recently demonstrated that the SH containing ACE inhibitor zofenoprilat, the active metabolite of zofenopril, controls the angiogenic features of vascular endothelium through H2S enzymatic production by cystathionine gamma lyase (CSE). Based on H2S donor/generator property of zofenoprilat, the objective of this study was to evaluate whether zofenoprilat exerts anti-inflammatory activity in vascular cells through its ability to increase H2S availability. Here we found that zofenoprilat, in a CSE/H2S-mediated manner, abolished all the inflammatory features induced by interlukin-1beta (IL-1β) in human umbilical vein endothelial cells (HUVEC), especially the NF-κB/cyclooxygenase-2 (COX-2)/prostanoid biochemical pathway. The pre-incubation with zofenoprilat/CSE dependent H2S prevented IL-1β induced paracellular hyperpermeability through the control of expression and localization of cell-cell junctional markers ZO-1 and VE-cadherin. Moreover, zofenoprilat/CSE dependent H2S reduced the expression of the endothelial markers CD40 and CD31, involved in the recruitment of circulating mononuclear cells and platelets. Interestingly, this anti-inflammatory activity was also confirmed in vascular smooth muscle cells and fibroblasts as zofenoprilat reduced, in both cell lines, proliferation, migration and COX-2 expression induced by IL-1β, but independently from the SH moiety and H2S availability. These in vitro data document the anti-inflammatory activity of zofenoprilat on vascular cells, reinforcing the cardiovascular protective effect of this multitasking drug