Identifying chondroprotective diet-derived bioactives and investigating their synergism

Osteoarthritis (OA) is a multifactorial disease and nutrition is a modifiable factor that may contribute to disease onset or progression. A detailed understanding of mechanisms through which diet-derived bioactive molecules function and interact in OA is needed. We profiled 96 diet-derived, mainly plant-based bioactives using an in vitro model in chondrocytes, selecting four candidates for further study. We aimed to determine synergistic interactions between bioactives that affected the expression of key genes in OA. Selected bioactives, sulforaphane, apigenin, isoliquiritigenin and luteolin, inhibited one or more interleukin-1-induced metalloproteinases implicated in OA (MMP1, MMP13, ADAMTS4, ADAMTS5). Isoliquiritigenin and luteolin showed reactive oxygen species scavenging activity in chondrocytes whereas sulforaphane had no effect and apigenin showed only a weak trend. Sulforaphane inhibited the IL-1/NFκB and Wnt3a/TCF/Lef pathways and increased TGFβ/Smad2/3 and BMP6/Smad1/5/8 signalling. Apigenin showed potent inhibition of the IL-1/NFκB and TGFβ/Smad2/3 pathways, whereas luteolin showed only weak inhibition of the IL-1/NFκB pathway. All four bioactives inhibited cytokine-induced aggrecan loss from cartilage tissue explants. The combination of sulforaphane and isoliquiritigenin was synergistic for inhibiting MMP13 gene expression in chondrocytes. We conclude that dietary-derived bioactives may be important modulators of cartilage homeostasis and synergistic relationships between bioactives may have an anti-inflammatory and chondroprotective role

A simple and efficient method for poly-3-hydroxybutyrate quantification in diazotrophic bacteria within 5 minutes using flow cytometry

The conventional method for quantification of polyhydroxyalkanoates based on whole-cell methanolysis and gas chromatography (GC) is laborious and time-consuming. In this work, a method based on flow cytometry of Nile red stained bacterial cells was established to quantify poly-3-hydroxybutyrate (PHB) production by the diazotrophic and plant-associated bacteria, Herbaspirillum seropedicae and Azospirillum brasilense. The method consists of three steps: i) cell permeabilization, ii) Nile red staining, and iii) analysis by flow cytometry. The method was optimized step-by-step and can be carried out in less than 5 min. The final results indicated a high correlation coefficient (R2=0.99) compared to a standard method based on methanolysis and GC. This method was successfully applied to the quantification of PHB in epiphytic bacteria isolated from rice roots

Effects of Decavanadate Salts with Organic and Inorganic Cations on Escherichia coli, Giardia intestinalis, and Vero Cells

Decavanadate salts with nicotinamide (3-pyridinecarboxamide, 3-pca) and isonicotinamide (4-pyridinecarboxamide, 4-pca) in both neutral and protonated forms, (3-Hpca) 4 [H 2 V 10 O 28 ]·2H 2 O·2(3-pca) (complex I) and (4-Hpca) 4 [H 2 V 10 O 28 ]·2(4-pca) (complex II), have been synthesized and characterized by vibrational spectroscopy (infrared and Raman), thermogravimetric analysis (TGA), 51 V NMR, and single-crystal X-ray diffraction analysis. The effects of sodium decavanadate (henceforth called NaV 10 ) and compounds I and II on Escherichia coli, Giardia intestinalis, and Vero (African green monkey epithelial kidney) cells were evaluated. Enhanced growth inhibitory activity against E. coli cultures was observed upon treatment with products I and II when compared to that with NaV 10 (GI 50 values of 2.8, 4.0, and 11 mmol L -1 , respectively), as well as lower cell viability as measured by the intake of propidium iodide (PI). Exposure of Giardia trophozoites to NaV 10 and II revealed reduction in trophozoite viability (GI 50 values of ca. 10 μmol L -1 ) and affected the parasite adherence to both polystyrene culture tubes and a monolayer of Vero cells, even at low concentrations. A lesser effect on Giardia was shown for I. Furthermore, all three compounds were significantly less toxic to Vero cells than the reference drug, albendazole, employed in the treatment of giardiasis. Toxicity reports of oxidovanadium compounds toward Giardia are unprecedented and open a path to the development of new therapeutic agents

Targeting the multidrug ABCG2 transporter with flavonoidic inhibitors: in vitro optimization and in vivo validation.

International audienceThis review describes the breast cancer resistance protein ABCG2 through its structure, functional roles and involvement in cell multidrug resistance, especially in cancer cells resistance to chemotherapeutics. The different types of known inhibitors are described, some being non-selective, since they also bind to other targets, and others being quite specific such as flavonoids. The different classes of active flavonoids and other polyphenols are described, some as plant natural compounds, but most of them being prepared and derivatized through medicinal chemistry. Quantitative structure-activity relationships of the ability of flavones, chalcones, xanthones, acridones and various benzopyrane/benzofurane derivatives to inhibit ABCG2-mediated drug efflux have led to pharmacophores and molecular models allowing to optimize the available hit compounds and to design new-generation lead compounds. Interestingly, inhibitory flavonoids are quite specific for ABCG2 versus ABCB1 and ABCC1, and appear either non-competitive or partially competitive towards mitoxantrone efflux. Most compounds do not inhibit ATPase activity, and are assumed not to be transported themselves by the transporter. Some acridones, firstly optimized in vitro as potent inhibitors, are indeed efficient in vivo, against human xenografts in SCID mice, more efficiently than gefitinib taken as a control. Future developments should open the way to more efficient/targeted modulators including (i) the potential interest of bimodulation by combining two different inhibitors, (ii) computer-assisted ligand-based drug design for getting more potent and more specific inhibitors, (iii) structure-based drug design from ABCG2 molecular models allowing in silico screening and docking of new inhibitors

Phenolic indeno[1,2-b]indoles as ABCG2-selective potent and non-toxic inhibitors stimulating basal ATPase activity

Gustavo Jabor Gozzi,1,2 Zouhair Bouaziz,3 Evelyn Winter,1,4 Nathalia Daflon-Yunes,1 Mylène Honorat,1 Nathalie Guragossian,3 Christelle Marminon,3 Glaucio Valdameri,1,2 Andre Bollacke,5 Jean Guillon,6 Noël Pinaud,7 Mathieu Marchivie,8 Silvia M Cadena,2 Joachim Jose,5 Marc Le Borgne,3 Attilio Di Pietro11Equipe Labellisée Ligue 2014, BMSSI UMR5086 CNRS/Lyon I University, IBCP, Lyon, France; 2Department of Biochemistry and Molecular Biology, Federal University of Paraná, Curitiba, Paraná, Brazil; 3Faculty of Pharmacy – ISPB, EA 4446 Biomolecules, Cancer and Chemoresistance, Health SFR of East Lyon CNRS UMS3453 - INSERM US7, University of Lyon, Lyon I University, Lyon Cedex 8, France; 4Department of Pharmaceutical Sciences, PGFAR, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil; 5Institute of Pharmaceutical and Medicinal Chemistry, University of Münster, Münster, Germany; 6ARNA Laboratory, Pharmaceutical Sciences UFR, INSERM U869, University of Bordeaux, Bordeaux Cedex, France; 7ISM – CNRS UMR 5255, University of Bordeaux Cedex, France; 8ICMCB CNRS-UPR 9048, University of Bordeaux, Pessac Cedex, FranceAbstract: Ketonic indeno[1,2-b]indole-9,10-dione derivatives, initially designed as human casein kinase II (CK2) inhibitors, were recently shown to be converted into efficient inhibitors of drug efflux by the breast cancer resistance protein ABCG2 upon suited substitutions including a N5-phenethyl on C-ring and hydrophobic groups on D-ring. A series of ten phenolic and seven p-quinonic derivatives were synthesized and screened for inhibition of both CK2 and ABCG2 activities. The best phenolic inhibitors were about threefold more potent against ABCG2 than the corresponding ketonic derivatives, and showed low cytotoxicity. They were selective for ABCG2 over both P-glycoprotein and MRP1 (multidrug resistance protein 1), whereas the ketonic derivatives also interacted with MRP1, and they additionally displayed a lower interaction with CK2. Quite interestingly, they strongly stimulated ABCG2 ATPase activity, in contrast to ketonic derivatives, suggesting distinct binding sites. In contrast, the p-quinonic indenoindoles were cytotoxic and poor ABCG2 inhibitors, whereas a partial inhibition recovery could be reached upon hydrophobic substitutions on D-ring, similarly to the ketonic derivatives.Keywords: multidrug resistance, cancer cells, ABCG2/BCRP, indenoindole inhibitors, structure–activity relationships, ATPase activit

Azaindole derivatives are inhibitors of microtubule dynamics, with anti-cancer and anti-angiogenic activities

International audienceBackground and Purpose Drugs targeting microtubules are commonly used for cancer treatment. However, the potency of microtubule inhibitors used clinically is limited by the emergence of resistance. We thus designed a strategy to find new cell-permeable microtubule-targeting agents. Experimental Approach Using a cell-based assay designed to probe for microtubule polymerization status, we screened a chemical library and identified two azaindole derivatives, CM01 and CM02, as cell-permeable microtubule-depolymerizing agents. The mechanism of the anti-tumour effects of these two compounds was further investigated both in vivo and in vitro. Key Results CM01 and CM02 induced G2/M cell cycle arrest and exerted potent cytostatic effects on several cancer cell lines including multidrug-resistant (MDR) cell lines. In vitro experiments revealed that the azaindole derivatives inhibited tubulin polymerization and competed with colchicines for this effect, strongly indicating that tubulin is the cellular target of these azaindole derivatives. In vivo experiments, using a chicken chorioallantoic xenograft tumour assay, established that these compounds exert a potent anti-tumour effect. Furthermore, an assay probing the growth of vessels out of endothelial cell spheroids showed that CM01 and CM02 exert anti-angiogenic activities. Conclusions and Implications CM01 and CM02 are reversible microtubule-depolymerizing agents that exert potent cytostatic effects on human cancer cells of diverse origins, including MDR cells. They were also shown to inhibit angiogenesis and tumour growth in chorioallantoic breast cancer xenografts. Hence, these azaindole derivatives are attractive candidates for further preclinical investigations