Publications by authors named "Anne-Marie Mariotte"

Antioxidant activity of isorhamnetin 3-O neohesperidoside (I3ON), isolated from the leaves of Acacia salicina, was determined by the ability of this compound to inhibit lipid peroxidation and to protect against hydroxyl radical-induced DNA damage in pKS plasmid DNA and Escherichia coli cultures. Antigenotoxic activity was assessed by using the comet assay. The IC(50) value of the inhibitory activity toward lipid peroxidation by I3ON is 0.

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A Total Oligomers Flavonoids (TOFs) and ethyl acetate extracts of Cyperus rotundus were analyzed, in vitro, for their antioxidant activity using several biochemical assays: the xanthine (X)/xanthine oxidase (XO), the lipid peroxidation induced by H(2)O(2) in K562 human chronic myelogenous leukemia cells and the DNA damage in pKS plasmid DNA assay induced by H(2)O(2)/UV-photolysis and for their apoptotic effect. TOF and ethyl acetate extracts were found to be efficient in inhibiting xanthine oxidase with IC(50) values of 240 and 185 microg/ml and superoxide anion with IC(50) values of 150 and 215 microg/ml, respectively. Also, all the extracts tested were effective in reducing the production of thiobarbituric acid reactive substances (TBARS) and were able to protect against H(2)O(2)/UV-photolysis induced DNA damage.

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The total oligomers flavonoids (TOF), chloroform, petroleum ether and aqueous extracts from Acacia salicina, were investigated for the antioxidative, cytotoxic, antimutagenic and antigenotoxic activities. The viability of K562 cells were affected by all extracts after 48 h exposure. Our results showed that A.

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Antioxidant activity of myricetin-3-o-galactoside and myricetin-3-o-rhamnoside, isolated from the leaves of Myrtus communis, was determined by the ability of each compound to inhibit xanthine oxidase activity, lipid peroxidation and to scavenge the free radical 1,1-diphenyl-2-picrylhydrazyl. Antimutagenic activity was assessed using the SOS chromotest and the Comet assay. The IC50 values of lipid peroxidation by myricetin-3-o-galactoside and myricetin-3-o-rhamnoside are respectively 160 microg/ml and 220 microg/ml.

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The ability of three Rhamnus alaternus leaves extracts on antigenotoxic and gene expression level effects was respectively investigated in a bacterial assay system, i.e. the SOS chromotest with Escherichia coli PQ37 and in human K562 lymphoblast cell line.

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As part of an ongoing project to identify plant natural products as efflux pump inhibitors (EPIs), bioassay-guided fractionation of the methanolic extract of Mirabilis jalapa Linn. (Nyctaginaceae) led to the isolation of an active polyphenolic amide: N-trans-feruloyl 4'-O-methyldopamine. This compound showed moderate activity as an EPI against multidrug-resistant (MDR) Staphylococcus aureus overexpressing the multidrug efflux transporter NorA, causing an 8-fold reduction of norfloxacin MIC at 292 microM (100 microg/mL).

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In vitro antioxidant and antimutagenic activities of two polyphenols isolated from the fruits of Pistacia lentiscus was assessed. Antioxidant activity was determined by the ability of each compound to scavenge the free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH*), to inhibit xanthine oxidase and to inhibit the lipid peroxidation induced by H(2)O(2) in K562 cell line. Antimutagenic activity was assayed with SOS chromotest using Escherichia coli PQ37 as tester strain and Comet assay using K562 cell line.

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From aerial parts of Swertia longifolia Boiss., which grows in the north of Iran, five xanthones, two of which in diglycosidic form, were isolated. The structures were confirmed by means of their spectral data as isobellidifolin, bellidin, gentisein, 1,5-dihydroxy-3-methoxy-6-O-primeverosyl xanthone, and 8-hydroxy-3,5-dimethoxy-1-O-primeverosyl xanthone, the latter two of which were new derivatives in the plant kingdom.

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Melanin play a major role in human skin protection and their biosynthesis is vital. Due to their color, they contribute to the skin pigmentation. Tyrosinase is a key enzyme involved in the first stage of melanin synthesis, catalyzing the transformation of tyrosine to l-dopaquinone.

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Tyrosinase is a copper-dependent enzyme which converts l- tyrosine to dopaquinone and is involved in different biological processes such as melanogenesis and skin hyperpigmentation. The purpose of this study was to investigate naturally occurring aurones (Z-benzylidenebenzofuran-3(2H)-one) and analogues as human tyrosinase inhibitors. Several aurones bearing hydroxyl groups on A-ring and different substituents on B-ring were synthesized and evaluated as inhibitors of human melanocyte-tyrosinase by an assay which measures tyrosinase-catalyzed l-Dopa oxidation.

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2-Alkyl-5-hydroxychromones (2-alkyl-5-hydroxy-4-oxo-4H-1-benzopyran) and 3-alkoyl-2-alkyl-5-hydroxychromones (3-alkoyl-2-alkyl-5-hydroxy-4-oxo-4H-1-benzopyran) were prepared in one-step and one pot reaction by condensation of 2',6'-dihydroxyacetophenone with an alkoyl chloride in the presence of K2CO3.

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Flavonoid derivatives were synthesized and tested for their ability to modulate P-glycoprotein (Pgp)-mediated multidrug resistance (MDR) in vitro. These compounds belong to various flavonoid subclasses, namely: chromones, azaisoflavones, and aurones. Among the investigated compounds, three showed potent reversing activity.

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From leaves of Leea guineense (Leeaceae) three hydrophilic flavonoids were isolated and identified as quercetin-3'-sulphate-3-O-alpha-L-rhamnopyranoside, quercetin-3,3'-disulphate and a new flavonoid sulphate, quercetin-3,3',4'-trisulphate, together with kaempferol, quercetin, quercitrin, mearnsitrin, gallic acid and ethyl gallate. The structures were established by spectroscopic analysis (UV, MS, (1)H-NMR, (13)C-NMR and 2D-NMR). Their antioxidant effect on free radical scavenging was evaluated in the DPPH assay.

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A series of 4-hydroxy-6-methoxyaurones and 4,6-dimethoxyaurones has been synthesised and tested for their binding affinity toward the nucleotide-binding domain of P-glycoprotein, an ABC (ATP-Binding Cassette) transporter which mediates the resistance of cancer cells to chemotherapy. These compounds differ from each other by the nature of the substituent on the aurone B-ring. The binding affinity seems to be linked to the nature of the substituent, as well as to the presence or the absence of a hydroxy group at position 4.

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