Our aim was to determine whether a Vaccinium myrtillus (bilberry) anthocyanoside (VMA) and/or its main anthocyanidin constituents (cyanidin, delphinidin, and malvidin) can protect retinal ganglion cells (RGCs) against retinal damage in vitro and in vivo. In RGC cultures (RGC-5, a rat ganglion cell-line transformed using E1A virus) in vitro, cell damage and radical activation were induced by 3-(4-morpholinyl) sydnonimine hydrochloride (SIN-1, a peroxynitrite donor). Cell viability was measured using a water-soluble tetrazolium salt assay. Intracellular radical activation within RGC-5 cells was evaluated using 5-(and-6)-chloromethyl-2,7-dichlorodihydrofluorescein diacetate acetyl ester (CM-H(2)DCFDA). Lipid peroxidation was assessed using the supernatant fraction of mouse forebrain homogenates. In mice in vivo, we evaluated the effects of VMA on N-methyl-D-aspartic acid (NMDA)-induced retinal damage using hematoxylin-eosin and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) stainings. VMA and all three anthocyanidins (i) significantly inhibited SIN-1-induced neurotoxicity and radical activation in RGC-5, (ii) concentration-dependently inhibited lipid peroxidation in mouse forebrain homogenates. Intravitreously injected VMA significantly inhibited the NMDA-induced morphological retinal damage and increase in TUNEL-positive cells in the ganglion cell layer. Thus, VMA and its anthocyanidins have neuroprotective effects (exerted at least in part via an anti-oxidation mechanism) in these in vitro and in vivo models of retinal diseases.

Vaccinium myrtillus (Bilberry) extracts (VME) were tested for effects on angiogenesis in vitro and in vivo. VME (0.3–30 µg ml−1) and GM6001 (0.1–100 µM; a matrix metalloproteinase inhibitor) concentration-dependently inhibited both tube formation and migration of human umbilical vein endothelial cells (HUVECs) induced by vascular endothelial growth factor-A (VEGF-A). In addition, VME inhibited VEGF-A-induced proliferation of HUVECs. VME inhibited VEGF-A-induced phosphorylations of extracellular signal-regulated kinase 1/2 (ERK 1/2) and serine/threonine protein kinase family protein kinase B (Akt), but not that of phospholipase Cγ (PLCγ). In an in vivo assay, intravitreal administration of VME inhibited the formation of neovascular tufts during oxygen-induced retinopathy in mice. Thus, VME inhibited angiogenesis both in vitro and in vivo, presumably by inhibiting the phosphorylations of ERK 1/2 and Akt. These findings indicate that VME may be effective against retinal diseases involving angiogenesis, providing it can reach the retina after its administration. Further investigations will be needed to clarify the major angiogenesis-modulating constituent(s) of VME.

The aim of this study was to examine the antiangiogenic properties and antioxidant activities (a) of the main anthocyanidins (delphinidin, cyanidin and malvidin) found as constituents in Vaccinium myrtillus (bilberry) anthocyanosides (VMA) and (b) of N-acetyl-L-cysteine (NAC). Each of these anthocyanidins concentration-dependently inhibited vascular endothelial growth factor (VEGF)-induced tube formation in a co-culture of human umbilical vein endothelial cells (HUVECs) and fibroblasts, the effect of each anthocyanidin being significant at 3 and/or 10 microM, while NAC significantly inhibited such tube formation at 1 microM (the only concentration tested). Moreover, each anthocyanidin (0.3-10 microM) and NAC (1-1000 microM) concentration-dependently scavenged the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. The inhibitory effects against angiogenesis were similar among the anthocyanidins, as were those against the DPPH radical. Moreover, their radical-scavenging effects were induced by concentrations that were at or below those that induced their antiangiogenic effects. These findings indicate that the inhibitory effect of VMA on angiogenesis may depend on those of its main constituent anthocyanidins (delphinidin, cyanidin and malvidin), presumably via antioxidant effects.

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