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ABSTRACT The phytochemical study of Galium tunetanum Lam., Rubiaceae, leaves led to the isolation of 13 compounds from the chloroform-methanol and the methanol extracts, including six iridoid glycosides, one non-glycoside iridoid, two p-coumaroyl iridoid glycosides, two phenolic acids, and two flavonoid glycosides. The structural determination of the isolated compounds was performed by mono- and bidimensional NMR spectroscopic data, as well as ESI-MS experiments. All compounds were isolated from this species for the first time. The anti-angiogenic effects of the isolated iridoids were also reported on new blood vessels formation using the chick embryo chorioallantoic membrane as in vivo model. Results showed that among the isolated iridoids tested at the dose of 2 µg/egg, asperuloside (1), geniposidic acid (2), and iridoid V1 (3) reduced microvessel formation of the chorioallantoic membrane on morphological observations using a stereomicroscope. The anti-angiogenic effects of the active compounds, expressed as percentages of inhibition versus control, were 67% (1), 59% (2), and 54% (3), respectively. In addition, the active compounds were able to inhibit angiogenesis in the chorioallantoic membrane assay, in a dose-dependent manner (0.5-2 µg/egg) as compared to the standard retinoic acid.
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Objective To investigate the inhibitory effects of Tum5 on the angiogenesis of human umbilical vein endothelial cells (HUVECs) and alkali-induced corneal neovascularization.Methods HUVECs in logarithmic growth phase were divided into 4 groups,cells with untreated as normal control group,cells with the infection of rAdGFP virus as rAd-GFP group,cells with the infection of rAd-Tum5 virus as rAd-Tum5 group,and cells with the infection of rAd-Tum5 virus followed by VEGF treatment as rAd-Tum5 + VEGF group.Then cell proliferation,migration,and tube formation of HUVECs were examined by CCK-8,Transwell and Matrigel assays,respectively.Sixty-four healthy male SD rats were randomly divided into 4 groups (n =16) by using random number table,and they were normal control group,alkali-burn group,alkali-burn + rAd-GFP group,and alkali-burn + rAd-Tum5 group.The alkali-burn rat model was then established except normal control group,and the normal control group received no treatment,whereas the alkali-burn,alkali-burn + rAd-GFP,and alkali-burn + rAd-Tum5 groups received subconjunctival injection of equal volumes of sterilized saline,rAd-GFP virus,and rAd-Tum5 virus,respectively following the alkaline burn.The relative area of corneal neovascularization and the number of infiltrating inflammatory cells were recorded on day 1,7,and 14 after injection.Results The CCK-8 assay showed that the proliferative rate of rAd-Tum5 group was lower than that of the normal control group and rAd-GFP group (both P ＜0.01),while rAd-Tum5 + VEGF group exhibited a significantly greater cell proliferative capability than rAd-Tum5 group (P =0.004).There were no statistical differences between rAd-Tum5 + VEGF group,normal control group and rAdGFP group (all P ＞ 0.05).Transwell assay showed the significantly lower number of migrating cells in the rAd-Tum5 group than those in the normal control group and rAdGFP group (both P ＜ 0.01).The number of migrating cells in rAd-Tum5 + VEGF group was higher than those in rAd-Tum5 group (P =0.000);however,the migration capacity had not been restored to normal level,and rAd-Tum5 + VEGF group had significant difference with normal control group and rAd-Tum5 group (both P ＜0.05).Matrigel assay showed that the number of meshes in rAd-Tum5 group was lower than that in the normal control group and rAd-GFP group (both P ＜0.01);while the number of meshes in rAd-Tum5 + VEGF group was significantly increased compared with rAd-Tum5 group(P =0.001).The density and number of corneal neovascularization increased gradually from day 1 to day 14 after alkali burn,while the relative neovascularization area in the alkali-burn + rAd-Tum5 group was significantly reduced as compared to those in the alkali-burn group and alkali-burn + rAd-GFP group on day 7 and day 14,suggesting that Tum5 could reduce the growth rate and density of corneal neovascularization,so as to inhibit corneal neovascularization induced by alkali burn.On day 7 and 14 after alkali burn,in the normal control group,the corneas were intact,no infiltrating inflammatory cells and cells were arranged in an orderly manner.On day 7 after alkali burn,there were disordered epithelial structure,corneal edema and infiltrating inflammatory cells in alkali-burn group and alkali-burn + rAd-GFP group.The number of infiltrating inflammatory cells in alkaliburn + rAd-Tum5 group was significantly lower than that in alkali-burn group and alkali-burn + rAd-GFP group (both P ＜0.01).On day 14 after alkali burn,the number of infiltrating inflammatory cells in alkali-bum,alkali-burn + rAd-GFP and alkali-burn + rAd-Tum5 group were significantly lower than those on day 7,while the corneal epitheliums were intact and dropsy was alleviated,while the number of inflammatory cells was significantly lower than that in alkali burn group and alkali-burn + rAd-GFP group,with significant difference (both P ＜ 0.01).Conelusion Tum5 can inhibit the angiogenic capability of HUVECs by VEGF pathway,as well as suppress the alkali-burn-induced corneal neovascularization and inflammatory cell infiltration in rats.
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Objective: To study the chemical constituents from Ampelopsis cantoniensis and their anti-angiogenic activities. Methods: The compounds were isolated and purified by various chromatographic techniques and their structures were elucidated by spectral analysis. The anti-angiogenic activities of the compounds isolated were evaluated using a zebrafish model. Results: Fifteen compounds were obtained from the ethyl acetate fraction in the 90% ethanol extract of A. cantoniensis and their structures were identified as cantonienol (1), nootkatone (2), aromadendrane-4β, 10β-diol (3), abscisic acid (4), 12-oxo-hardwickiic acid (5), betulinic acid (6), platanic acid (7), vanillic acid (8), resveratrol (9), nectandrin B (10), nectandrin A (11), 3, 5, 7-trihydroxychromone (12), 5, 7, 3', 4', 5'-pentahydroxyflavanone (13), taxifolin (14), and myricitrin (15). Conclusion: Compound 1 is a new sesquiterpene named cantonienol. Compounds 2-7 and 10-12 are isolated from the plants of Ampelopsis Michaux for the first time, and the other compounds are firstly reported in this plant. Compounds 9, 11, and 12 exhibit the weak anti-angiogenic activity when evaluated using a zebrafish model.