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Recently, biomolecules from natural products have paved the way for novel drug in the treatment of some diseases in vitro and in vivo models as diabetes, cancer and infertility. As such, we aimed to evaluate the capacity of Oleuropein (OLE), the major bio-phenol in olive leaf, to protect human sperm against bacterial lipopolysaccharide (LPS) inducing sperm oxidative stress and defective sperm functions. The toxic effect of OLE on human sperm was firstly investigated by evaluating sperm parameters after incubation during 60 minutes with different concentrations. Determined non-toxic concentration was then used to evaluate the capacity of OLE to protect sperm against LPS oxidative damages and sperm parameters alterations. Thus, sperms were consecutively incubated with LPS (10 µg/mL) and OLE (40 µg/mL) during 60 minutes, then submitted to sperm parameters analysis and oxidative stress assessment by measuring malondialdehyde (MDA), carbonyl groups (CG) levels and the activity of some antioxidant enzymes: superoxide dismutase (SOD) and catalase (CAT). A significant decrease of sperm parameters as well as a significant increase in MDA levels, CG levels, SOD and CAT activities was found after stimulation by LPS. However, a non-significant difference was shown comparing sperms treated by LPS and OLE with LPS-treated control sperms. Consequently, despite the high antioxidant and anti-inflammatory capacity of OLE reported in diverse cells, this phenolic compound seems to be not appropriate to protect human sperm in vitro against induced LPS oxidative stress and seems to have a "double-edged sword" behavior. [ABSTRACT FROM AUTHOR]

Abstract Background The aim of this study is to investigate the effect of quercetin in alleviating the cytotoxic effects of Dimethoate in human peripheral blood lymphocytes. Methods Lymphocytes were divided into too groups. The first group, lymphocytes were incubated for 4 h at 37°C with different concentrations (0, 40, 60 and 100 mM) of Dimethoate. The second group was preincubated with quercetin for 30 min and followed by Dim incubation for 4 h at 37°C. Results Following in vitro incubation, Dimethoate caused a significant increase in malondialdehyde levels, a significant decrease in thiol levels, as well as a significant increase in superoxide dismutase, and catalase activities in lymphocytes at different concentrations. Quercetin pretreated lymphocytes showed a significant protection against the cytotoxic effects inducted by Dimethoate on the studied parameters. Conclusion In conclusion, antioxidant quercetin could protect against Dimethoate-induced oxidative stress by decreasing lipid peroxidation, protein oxidation and increasing superoxide dismutase and catalase activities in human lymphocytes.

Abstract Background We investigated the oxidative modifications of lipids, proteins and DNA, potential molecular targets of oxidative stress, in two lymphoblastoid cell lines: B95-8 and Raji, after EBV lytic cycle induction. Conjugated dienes level was measured as biomarker of lipid peroxidation. Malondialdehyde adduct and protein carbonyl levels, as well as protein thiol levels were measured as biomarkers of protein oxidation. DNA fragmentation was evaluated as biomarker of DNA oxidation. Results After 48 h (peak of lytic cycle), a significant increase in conjugated dienes level was observed in B95-8 and Raji cell lines (p = 0.0001 and p = 0.019 respectively). Malondialdehyde adduct, protein carbonyl levels were increased in B95-8 and Raji cell lines after EBV lytic cycle induction as compared to controls (MDA-adduct: p = 0.008 and p = 0.006 respectively; Carbonyl: p = 0.003 and p = 0.0039 respectively). Proteins thiol levels were decreased by induction in B95-8 and Raji cell lines (p = 0.046; p = 0.002 respectively). DNA fragmentation was also detected in B95-8 and Raji cell lines after EBV lytic cycle induction as compared to controls. Conclusion The results of this study demonstrate the presence of increased combined oxidative modifications in lipids, proteins in B95-8 and Raji cells lines after EBV lytic cycle induction. These results suggest that lipid peroxidation, protein oxidation and DNA fragmentation are generally induced during EBV lytic cycle induction and probably contribute to the cytopathic effect of EBV.

Abstract Background The antioxidant potency of the hydroethanolic extract of Ormenis Africana (HEOA), Asteraceae was evaluated with regards to total polyphenol, flavonoid and anthocyanins content. Antioxidant activity has been assessed chemically and biologically. First, the free radical scavenging ability of HEOA was evaluated using two commonly in vitro tests: ABTS and DPPH radicals. Then, the protection effect of this extract against oxidative stress was conducted in HeLa cells treated with Fe2+ or H2O2. Oxidative stress was evaluated by measuring the lipid peroxidation levels (TBARs and DC) and the antioxidant enzymes activities (catalase and Superoxide dismutase). Cytotoxic effect of HEOA was prealably determined against HeLa cell line by MTT assay. Results HEOA contain considerable levels of antioxidant compound as evidenced by high amount of polyphenols (312.07 mg GAE/g dray matter), flavonoids (73.72 ± 1.98 mg QE/g dray matterl) and anthocyanins (0.28 ± 0.09 mg Cy-3-glu E/g dray matter). DPPH and ABTS assays showed a high antioxidant activity (IC50 = 24 μg/ml; TEAC = 2.137 mM) which was comparable to BHT. In biological system, HEOA exhibited a 50% cytotoxic concentration evaluated as 16.52 μg/ml. Incubation of HeLa cell line with no cytotoxic concentrations resulted in a remarkable protection from oxidative stress induced by Fe2+ or H2O2 which was evidenced by a decrease of MDA and CD levels as well as a diminution of antioxidant enzymes activities (Catalase and SOD) as compared to cells treated with Fe2+ or H2O2 alone. Conclusion The hydroethanolic extract of O. Africana could thus be considered as a source of potential antioxidants. The results of this study will promote the reasonable usage of this plant in food and pharmacy industries as well as in alternative medicine and natural therapy.

Background: During the last few decades, there has been a growing interest in the search for novel bioactive compounds from marine origins. Methods: The present study is the first to determine the molecular characterization which it was deposited in the genebank database, to investigate and evaluate the biological properties of sulfated polysaccharide from Cymodocea nodosa (CNSP) seagrass. Results: The results revealed that CNSP had high activity in total antioxidant assay (59.03 mg ascorbic acid equivalents/g extract), reducing power (OD = 0.3), DPPH radical scavenging (IC50 = 1.22 mg/ml) and ABTS radical scavenging (IC50 = 1.14 mg/ml). It was also noted to exhibit antimicrobial activity against a wide range of microorganisms, with important inhibition zones. The results revealed that CNSP was able to inhibit the proliferation of Hela cell lines with a dose-dependent manner. Conclusion: Overall, the results presented in this study demonstrate that CNSP has several attractive antioxidant, antimicrobial and antiproliferative properties with potential benefits towards health. [ABSTRACT FROM AUTHOR]

Pemphigus is an autoimmune disorder resulting from the interaction between autoantibodies and desmoglein. Oxidative stress seems to be responsible for the onset/aggravation of many human diseases. Actually, it is considered as one of the several factors for the etiopathogenesis of pemphigus. The present study aims to evaluate the oxidative state in the sera of pemphigus vulgaris and pemphigus foliaceus patients by assessing lipid peroxidation, proteins oxidation, and antioxidant enzyme activity. This study included 36 pemphigus vulgaris and 42 pemphigus foliaceus patients as well as a group of controls consisting of 78 healthy volunteers. Malondialdehyde levels ( p < 0.001) and catalase activity ( p < 0.001) are higher in both groups of patients than in the control group. The two groups of patients showed a nonsignificant decrease in the thiol groups compared with the healthy one. A nonsignificant difference was shown between pemphigus vulgaris and pemphigus foliaceus patients, except for the catalase which shows an increase in the pemphigus vulgaris group. We have also found significant correlations between serum oxidative stress marker levels and serum anti-desmoglein antibody levels in the two pemphigus groups. These findings underline the implication of oxidative stress in the physiopathology of pemphigus by the increase in the autoantibodies' reactivity. [ABSTRACT FROM AUTHOR]