Antioxidant, Immunomodulatory and Potential Anticancer Capacity of Polysaccharides (Glucans) from Euglena gracilis G.A. Klebs

The present study was carried out to determine the bioactivity of polysaccharides extracted from Euglena gracilis (EgPs). These were characterized by FT-IR and GC-MS. Cytotoxicity analyses (MTT) were performed on healthy human gingival fibroblast cell lines (HGF-1), obtaining an IC50 of 228.66 µg mL-1, and cell lines with anticancer activity for colon cancer (HCT-116), breast cancer (MCF-7), human leukemia (U-937, HL-60) and lung cancer (NCl-H460), showing that EgPs have anticancer activity, mainly in HTC-116 cells (IC50 = 26.1 µg mL-1). The immunological assay determined the immunomodulatory capacity of polysaccharides for the production of proinflammatory cytokines IL-6 and TNF-α in murine macrophages (RAW 264.7) and TNF-α in human monocytes (THP-1). It was observed that the EgPs had a stimulating capacity in the synthesis of these interleukins. The antioxidant capacity of polysaccharides and their biomass were analyzed using the ABTS method (18.30 ± 0.14% and (5.40 ± 0.56%, respectively, and the DPPH method for biomass (17.79 ± 0.57%). We quantitatively profiled HGF-1 proteins by liquid chromatography-tandem mass spectrometry analysis, coupled with 2-plex tandem mass tag labelling, in normal cells. In total, 1346 proteins were identified and quantified with high confidence, of which five were considered to be overexpressed. The data is available through ProteomeXchange, under identifier PXD029076.

The strigolactone analog GR-24 inhibits angiogenesis in vivo and in vitro by a mechanism involving cytoskeletal reorganization and VEGFR2 signalling.

Phytohormones have shown great potential as natural anticancer compounds, being interesting in cancer prevention and therapy. Strigolactones are a class of plant hormones involved in the inhibition of root branching and sprouting. The antiproliferative capacity of the synthetic strigolactone analog GR-24 has been described against breast cancer cell lines in vitro. In this study, we show for the first time that GR-24 is a potent antiangiogenic compound in vivo and in vitro. In the in vivo tests, GR-24 shows a great inhibitory effect on vasculature formation in the chicken chorioallantoic membrane and in two different zebrafish models. Our in vitro results show that GR-24 inhibits the growth of endothelial cells and different cancer cell lines with a micromolar range of half inhibitory concentration (IC50) values. In addition, GR-24 inhibits key steps of the angiogenic process in vitro, such as tubulogenesis, invasion, extracellular matrix remodeling capacity, migration and adhesion of endothelial cells at non-cytotoxic concentrations. Our data point to an effect of GR-24 on cytoskeleton organization in endothelial cells, in addition to a decrease in focal adhesion kinase (FAK) presence in these cells. All these data, together with the observed increase in surface expression of vascular endothelial-cadherin (VE-cadherin) and platelet and endothelial cell adhesion molecule 1 (PECAM-1), suggest that GR-24 prevents angiogenesis by maintaining the quiescent phenotype in endothelial cells. The proposed mechanism of action underlying the antiangiogenic activity of GR-24 involves the inhibition of VEGFR2 phosphorylation, and the downstream reduction in activation of FAK, a key regulator protein implicated in angiogenesis. Our results suggest that GR-24 may be a promising new compound for antiangiogenic therapy of cancer and other angiogenesis-dependent diseases.

Exploring the Antiangiogenic Potential of Solomonamide A Bioactive Precursors: In Vitro and in Vivo Evidences of the Inhibitory Activity of Solo F-OH During Angiogenesis.

Marine sponges are a prolific source of bioactive compounds. In this work, the putative antiangiogenic potential of a series of synthetic precursors of Solomonamide A, a cyclic peptide isolated from a marine sponge, was evaluated. By means of an in vitro screening, based on the inhibitory activity of endothelial tube formation, the compound Solo F-OH was selected for a deeper characterization of its antiangiogenic potential. Our results indicate that Solo F-OH is able to inhibit some key steps of the angiogenic process, including the proliferation, migration, and invasion of endothelial cells, as well as diminish their capability to degrade the extracellular matrix proteins. The antiangiogenic potential of Solo F-OH was confirmed by means of two different in vivo models: the chorioallantoic membrane (CAM) and the zebrafish yolk membrane (ZFYM) assays. The reduction in ERK1/2 and Akt phosphorylation in endothelial cells treated with Solo F-OH denotes that this compound could target the upstream components that are common to both pathways. Taken together, our results show a new and interesting biological activity of Solo F-OH as an inhibitor of the persistent and deregulated angiogenesis that characterizes cancer and other pathologies.

Exploring the Ring-Closing Metathesis for the Construction of the Solomonamide Macrocyclic Core: Identification of Bioactive Precursors.

New synthetic strategies directed toward the novel cyclopeptides solomonamides have been explored utilizing an olefin metathesis as the key reaction. In the various strategies investigated, we worked on minimally oxidized systems, and the olefin metathesis reaction demonstrated efficiency and validity for the construction of the macrocyclic core. The described synthetic strategies toward the solomonamides are well suited for the subsequent access to the natural products and represent flexible and diversity-oriented routes that allow for the generation of a variety of analogues via oxidative transformations. In addition, preliminary biological evaluations of the generated solomonamide precursors revealed antitumor activity against various tumor cell lines.

Copper-containing mesoporous bioactive glass promotes angiogenesis in an in vivo zebrafish model.

The osteogenic and angiogenic responses of organisms to the ionic products of degradation of bioactive glasses (BGs) are being intensively investigated. The promotion of angiogenesis by copper (Cu) has been known for more than three decades. This element can be incorporated to delivery carriers, such as BGs, and the materials used in biological assays. In this work, Cu-containing mesoporous bioactive glass (MBG) in the SiO2-CaO-P2O5 compositional system was prepared incorporating 5% mol Cu (MBG-5Cu) by replacement of the corresponding amount of Ca. The biological effects of the ionic products of MBG biodegradation were evaluated on a well-known endothelial cell line, the bovine aorta endothelial cells (BAEC), as well as in an in vivo zebrafish (Danio rerio) embryo assay. The results suggest that ionic products of both MBG (Cu free) and MBG-5Cu materials promote angiogenesis. In vitro cell cultures show that the ionic dissolution products of these materials are not toxic and promote BAEC viability and migration. In addition, the in vivo assay indicates that both exposition and microinjection of zebrafish embryos with Cu free MBG material increase vessel number and thickness of the subintestinal venous plexus (SIVP), whereas assays using MBG-5Cu enhance this effect. STATEMENT OF SIGNIFICANCE: Mesoporous bioactive glasses (MBGs) with high specific surface area, well-ordered pores, large pore volumes and controllable amount of ions are interesting to develop controlled drug delivery systems for bone tissue regeneration. Copper (Cu) incorporation to the basic SiO2-CaO-P2O5 composition has attracted high interest due to its multifunctional biological properties. Promotion of angiogenesis is one of these properties, which can be integrated to the biomaterial with lower cost and higher stability when compared with growth factors. This work reports the synthesis and characterization of Cu-containing MBG evaluating its angiogenic properties in the subintestinal vessel zebrafish assay. This transgenic in vivo assay is merging as an alternative model providing short-time consuming protocols and facilities during pro-angiogenic drug screenings. The report shows that the ionic products of this MBG material delivered to the zebrafish incubation media significantly enhance angiogenesis in comparison with control groups. Besides, results indicate Cu ions may exhibit a synergic effect with Si, Ca, and P ions in angiogenesis stimulation both in vitro and in vivo. To our knowledge, this is the first time that zebrafish in vivo assays are used to evaluate angiogenic activity of ionic dissolution products from MBG materials.

Effects of partner smoking status and gender on long term abstinence rates of patients receiving smoking cessation treatment.

AIMS: To assess the effect of partner smoking status on the success of a cessation program. DESIGN: Prospective cohort. SETTING: Smoking Cessation Unit in Hospital of Bellvitge (Hospitalet de Llobregat, Barcelona). PARTICIPANTS: A total of 1516 smokers of 10 or more cigarettes who started a smoking cessation program between January 1995 and December 2001 were included. MEASUREMENTS: All patients gave information about smoking history and smoking partner status. Abstinence was determined by carbon monoxide exhaled. FINDINGS: Significant differences were found in the abstinence rates at 12 months by smoking partner status: abstinence was achieved by 28.3% of patients with smoking partner, and by 46.5% of patients without smoking partner (p<0.001). Subjects whose partner was smoking at the beginning of the program appear to be more likely to relapse than subjects without smoking partners (p<0.001) and this is more pronounced in women than in men. However no significant gender differences were found in any group of smoking partner status. CONCLUSIONS: Having a smoking partner is a determinant of relapse 1 year after the beginning of the cessation program. Interacting not just with the smoker, but also with his or her partner, could neutralize interpersonal influences making smokers more accessible to behavioural and pharmacological techniques.