Loading...
6 results
Search Results
Now showing 1 - 6 of 6
- Natural antioxidants in emulsions O/WPublication . EL-GEUNDOUZ, Soukaina; Azza, S.; Dandlen, Susana Anahi; MAJDOUB, Nesrine; Lyoussi, Badiaa; Raposo, Sara; Gomes, Vera; Bankova, Vassya; Popova, Milena; Antunes, Maria Dulce; Miguel, Maria GracaThis study compared the capacity of propolis extract (PE) and thyme waste extract (TWE) to prevent the oxidation of oil in water (O/W) emulsion, as well as their impact on emulsion apparent viscosity (AV) in the presence of wheat germ and almond oils as lipid phase. For this, central composite design (CCD) and principal component analysis (PCA) were performed. Oxidation process was monitored by evaluating the formation of primary and secondary lipid oxidation products, at the same time the AV behavior was determined evaluating consistency index and flow behavior index. The results revealed that the increase of PE% and TWE% decreases TBARS (Thiobarbituric Acid Reactive Substances) and hydroperoxides formation. Viscosity increases with the rise of TWE% over (0.04%), whereas lower concentrations of PE% decreases it. Those results have been confirmed in the PCA analysis. TWE showed higher resistance to oxidation, although PE was more effective as antioxidant than TWE.
- Toxicity and hepatoprotective effects of ZnO nanoparticles on normal and high-fat diet-fed rat livers: mechanism of actionPublication . Mirzaei, Fatemeh; Abbasi, Ebrahim; Mirzaei, Amir; Hosseini, Nashmin Fayazi; Naseri, Nima; Khodadadi, Iraj; Jalili, Cyrus; MAJDOUB, NesrineThis experiment aimed to evaluate the beneficial and toxic properties of synthetic zinc oxide nanoparticles (ZnO NPs) on the liver of normal and high-fat diet (HFD) fed-rats. The ZnO NPs were synthesized and, its characterizations were determined by different techniques. Effect of ZnO NP on cell viability, liver enzymes and lipid accumulation were measured in HepG2 cells after 24 h. After that, rats orally received various dosages of ZnO NPs for period of 4 weeks. Toxicity tests were done to determine the appropriate dose. In the subsequent step, the hepatoprotective effects of 5 mg/kg ZnO NPs were determined in HFD-fed rats (experiment 2). The oxidative stress, NLRP3 inflammasome, inflammatory, and apoptosis pathways were measured. Additionally, the activity of caspase 3, nitric oxide levels, antioxidant capacity, and various biochemical factors were measured. Morphological changes in the rat livers were also evaluated by hematoxylin and eosin (H & E) and Masson trichrome. Liver apoptosis rate was also approved by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Treatment of animals with 5 mg/ZnO NPs revealed potential hepatoprotective properties, while ZnO NPs at the doses of above 10 mg/kg showed toxic effects. Antioxidant enzyme gene expression and activity were significantly augmented, while apoptosis, NLRP3 inflammasome, and inflammation pathways were significantly reduced by 5 mg/kg ZnO NPs. Liver histopathological alterations were restored by 5 mg/kg ZnO NPs in HFD. Our study highlights the hepatoprotective effects of ZnO NPs against the HFD-induced liver damage, involving antioxidant, anti-inflammatory, and anti-apoptotic pathways, indicating their promising therapeutic potential.
- Effect of poplar-type propolis on oxidative stability and rheological properties of O/W emulsionsPublication . EL-GEUNDOUZ, Soukaina; AAZZA, Smail; Lyoussi, Badiaa; MAJDOUB, Nesrine; Bankova, Vassya; Popova, Milena; Raposo, Sara; Antunes, Maria Dulce; Miguel, MariaPropolis is known to possess antioxidant activity. However, there is no information on this activity in emulsions O/W. The protective effect of propolis on the oxidation and rheological properties of emulsions O/W containing wheat germ and almond oils was evaluated. Emulsions O/W were prepared with different concentration of propolis extract, almond oil and wheat germ oil. All emulsions physically stable without phase separation were stored at 37 °C for 9 weeks. Chemical composition of propolis was established by Gas chromatography coupled to mass spectrometry. Rheological characterization of different emulsions was performed evaluating consistency index and flow behavior index. The oxidation was monitored by measuring the lipid hydroperoxides and thiobarbituric acid-reactive substances (TBARS) methods. Flavonoids, phenolic acid esters, and aromatic acids were the main groups of compounds found in propolis. The results showed that popolis was good antioxidant in the concentration of 0.02 and 0.04% when lipid phase was constituted by almond oil. The rheological behavior is typical of a non-Newtonian fluid, being almond oil more adequate for having a higher stable O/W emulsion.
- Leaf mineral element content and soil characteristics on in vitro antioxidant and enzymatic inhibitory activities of aqueous fennel extractsPublication . MAJDOUB, Nesrine; EL-GEUNDOUZ, Soukaina; Carlier, Jorge; Clara Costa, Maria; Guerrero, Carlos; Duarte, João; Miguel, Mariahis study was conducted to evaluate the biochemical characterization of three harvested Foeniculum vulgare plants collected from two bioclimatic zones in order to investigate the soil growing conditions effect. The results showed a great variability of the phenolic amounts and biological properties of samples rely on localities. FvSEN contained the highest amounts of phenolic compounds. These amounts were accompanied by the greatest antioxidant ability through almost studied assays. FvSEN and FvZO were significantly different. In addition, the samples exhibited a significant and variable enzymatic inhibition activity with values ranging from 30 to 50 mu g/mL for lipoxygenase assay. But these extracts did not revealed significant differences on their tyrosinase abilities. On the other hand, the levels of mineral elements were also estimated. These contents varied depending on sample and locality. The growing soil conditions of samples in terms of different parameters is likely related to their antioxidant and enzyme inhibition potentialities added to their mineral composition which settled by Spearman's correlation. These data may confirm the interesting potential of F. vulgare as a valuable source for natural antioxidant molecules but the growing soil conditions can affect all the potentialities of these plants set for human consumption and other uses.
- Growth, photosynthetic pigments, phenolic content and biological activities of Foeniculum vulgare Mill., Anethum graveolens L. and Pimpinella anisum L. (Apiaceae) in response to zincPublication . MAJDOUB, Nesrine; EL-GEUNDOUZ, Soukaina; Rezgui, Marwa; Carlier, Jorge; Clara Costa, Maria; Ben Kaab, Leila Bettaieb; Miguel, Maria GracaThe effect of zinc (Zn) on phenols, antioxidant activities (free radicals' scavenging activities, inhibition of lipid peroxidation, chelating activity and reducing power), and enzyme inhibition activities of acetylcholinesterase, lipoxygenase and tyrosinase of anise, dill and two cultivars of fennel [Latina" (F-L) and "Doux de Florence" (F-DF)] aqueous extracts was evaluated for the first time. At the same time, growth and photosynthetic pigment contents were also estimated. A significant decrease in all growth parameters, such as plant height, fresh and dry weights of aerial parts and roots was statistically proved in the presence of 2 mM Zn. An enhancement of Zn accumulation was observed, particularly in aerial part. Exposure to 2 mM Zn induced quantitative changes in the phenols of all tested extracts. In fennel extracts, a decrease of phenol content was observed when treated with Zn, whereas an increase was found in dill and anise extracts submitted to Zn treatment. All samples, either in the presence or absence of Zn, showed antioxidant activity, independent on the tested assay, with the exception of the cultivar F-DF (treated and non-treated), which was unable to scavenge NO radicals. Zn-treated dill and anise presented usually higher antioxidant activity. Concerning inhibitory activities against acetylcholinesterase, lipoxygenase and tyrosinase enzymes, both treated and non-treated F-DF did not inhibit acetylcholinesterase activity. Zinc-treated F-DF was also unable to inhibit lipoxygenase activity. The remaining species presented capacity for inhibiting those enzymes and tyrosinase as well, but their abilities varied in response to Zn excess.
- Antioxidant activity of thyme waste extract in O/W emulsionsPublication . EL-GEUNDOUZ, Soukaina; AAZZA, Smail; Anahi Dandlen, Susana; MAJDOUB, Nesrine; Lyoussi, Badiaa; Raposo, Sara; Antunes, Maria Dulce; Gomes, Vera; Miguel, MariaThymus vulgaris (thyme) is an aromatic plant and its essential oil has been applied as antimicrobial and antioxidant due to the presence of phenolic compounds. However, after steam distillation, the deodorized plant material is rejected, despite the possible presence of bioactive compounds. Ethanolic thyme waste extract revealed the presence of benzoic acid, 4-hydroxybenzoic acid, ferulic acid, caffeic acid, and sinapic acid. This waste thyme extract had the capacity for preventing the formation of primary and secondary lipid oxidation products in emulsions O/W (oil in water), constituted by diverse proportions of wheat and almond oils, without interfering with the viscosity parameters, for 10 weeks, at 37 °C. The increasing proportion of almond oil (≥50%) in the emulsion increases its resistance to oxidation, which is improved with the presence of an optimal concentration of tested thyme waste extract (0.02% and 0.04%). The waste thyme extract can, therefore, be used as an antioxidant either in food or pharmaceutical emulsions O/W, replacing the synthetic antioxidants.