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Brown seaweeds produce useful bioactive substances with high cosmetic and pharmacological values due to the presence of antioxidant derivatives, mainly phlorotannins (PHT), which are of particular interest. A central composite rotatable design (CCRD) with three variables (extraction time, dry material-to-solvent ratio and ethanol concentration) and two responses was performed to optimize the microwave-assisted extraction (MAE) of phlorotannins from Cystoseira sedoides using response surface methodology (RSM). Results showed that the independent variables significantly affected both phlorotannin content and the scavenging capacity. The optimum operating conditions were extraction time, 101.74 sec; dry material-to-solvent ratio, 1:10 g/mL; and ethanol extraction, 50%. Under these conditions, the predicted values of PHT content and radical scavenging activity-IC50 were close to the observed values and were 383.887 µg PGE/g Dm and 18.353 µg/mL, respectively. Characterization of the phlorotannin-rich fraction was conducted by high-performance liquid chromatography and Fourier transform infrared spectroscopy. The evaluation of the anticancer activity against MCF-7 breast cancer cell line showed a potent activity to trigger apoptotic death in more than a half of the MCF-7 cells, with an estimated IC50 value of 78 μg/mL. In addition, this fraction induced a notable growth regression effect on 3D spheroids model in a concentration-dependent manner, with a growth rate of about 1.17, at 200 µg/mL.

Abbreviations: CCRD: Central composite rotatable design; Dm: Dry material; DMBA: 2,4-dimethoxy benzaldehyde; DMSO: Dimethyl sulfoxide; DPPH: 1,1-diphenyl-2-picrylhydrazyl; EDTA: Ethylene diamine tetraacetic acid; FBS: Fetal bovine serum; FT-IR: Fourier transform infrared; HPLC: High-performance liquid chromatography; IC50: Half-maximal inhibitory concentration; MAE: Microwave-assisted extraction; Min: minutes; PBS: Phosphate buffered saline; PGE: Phloroglucinol equivalent; PHT: Phlorotannins; PHT-SED: phlorotannins derived from Cystoseira sedoides; PI: Propidium iodide; RSA: Radical scavenging activity; RSM: Response surface methodology; Sec: seconds  相似文献   
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Exopolysaccharide (EPS) from marine microalgae are promising sources of a new generation of drugs. However, lot of them remain to be discovered and tested. In this study, EPS produced by Porphyridium marinum and its oligomers prepared by High Pressure Homogenizer have been tested for different biological activities, i.e., antibacterial, anti-fungal and antibiofilm activities on Candida albicans, as well as for their effects on the viability of murine breast cancer cells. Results have shown that all EPS samples present some biological activity. For antibacterial and antibiofilm activities, the native EPS exhibited a better efficiency with Minimum Inhibitory Concentration (MIC) from 62.5 µg/mL to 1000 µg/mL depending on the bacterial strain. For Candida albicans, the biofilm formation was reduced by about 90% by using only a 31.3 µg/mL concentration. Concerning breast cancer cells, lower molar masses fractions appeared to be more efficient, with a reduction of viability of up to 55%. Finally, analyses of polymers composition and viscosity measurements were conducted on all samples, in order to propose hypotheses involving the activities caused by the intrinsic properties of polymers.  相似文献   
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Salmon byproducts (Salmo salar) generated by the food chain represent a source of long-chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA): 20:5n-3; docosahexaenoic acid (DHA): 22:6n-3) and peptides that can be used as supplements in food for nutraceutical or health applications, such as in the prevention of certain pathologies (e.g., Alzheimer’s and cardiovascular diseases). The extraction of polar lipids naturally rich in PUFAs by enzymatic processes without organic solvent (controlled by pH-Stat method), coupled with the production of 1 kDa salmon peptides by membrane filtration, allowed the formulation of nanocarriers. The physicochemical properties of the nanoliposomes (size ranging from 120 to 140 nm, PDI of 0.27, zeta potential between −32 and −46 mV and encapsulation efficiency) were measured, and the bioactivity of salmon hydrolysate peptides was assessed (antioxidant and antiradical activity: ABTS, ORAC, DPPH; iron metal chelation). Salmon peptides exhibited good angiotensin-conversion-enzyme (ACE) inhibition activity, with an IC50 value of 413.43 ± 13.12 µg/mL. Cytotoxicity, metabolic activity and proliferation experiments demonstrated the harmlessness of the nanostructures in these experimental conditions.  相似文献   
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Antidepressant drugs and psychotherapy combined are more effective in treating mood disorders than either treatment alone, but the neurobiological basis of this interaction is unknown. To investigate how antidepressants influence the response of mood-related systems to behavioral experience, we used a fear-conditioning and extinction paradigm in mice. Combining extinction training with chronic fluoxetine, but neither treatment alone, induced an enduring loss of conditioned fear memory in adult animals. Fluoxetine treatment increased synaptic plasticity, converted the fear memory circuitry to a more immature state, and acted through local brain-derived neurotrophic factor. Fluoxetine-induced plasticity may allow fear erasure by extinction-guided remodeling of the memory circuitry. Thus, the pharmacological effects of antidepressants need to be combined with psychological rehabilitation to reorganize networks rendered more plastic by the drug treatment.  相似文献   
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  • ? At present, the production of wood composites mainly relies on the petrochemical-based and formaldehyde-based adhesives such as phenol-formaldehyde (PF) resins and urea-formaldehyde (UF) resins, which are non-renewable and therefore ultimately limited in supply.
  • ? This paper concerns the decay resistance of wood products bonded with a new, environment-friendly adhesive derived from abundant and renewable cornstarch and tannin. To improve the total resistance of the composite against both Coriolus versicolor and Coniophora puteana rot fungi, borax (di-sodium tetraborate) was added in proportions of 0.5%, 1% and 2% (w/w) to the cornstarch-tannin adhesives.
  • ? The results show that increasing the concentration of borax in the adhesive decreased the mechanical properties of the composite. The best way to avoid this problem was to use wood impregnated with borax.
  • ? Biodegradation studies were conducted on new composites, first without any treatment, followed by borax at 0.5% aqueous solution treatment. The results show that wood impregnated with borax, in the presence of tannin and sodium hydroxide in the adhesive improves the total resistance of the wood composite against both Coriolus versicolor and Coniophora puteana rot fungi.
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    Journal of Plant Diseases and Protection - The present investigation aimed to throw light on the effect of Bacillus subtilis SPB1 biosurfactant on the third larval instars of the Mediterranean...  相似文献   
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