Browsing by Subject "Free radical scavenging"

Now showing 1 - 4 of 4
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    Antioxidant activity in gilthead Seabream (Sparus aurata L.) fed with diet supplemented with moringa
    (MDPI, 2021-09-07) Jiménez-Monreal, Antonia María; Murcia Tomás, María Antonia; Martínez-Tomé, Magdalena; Esteban Abad, María de los Ángeles; Guardiola Abellán, Francisco Antonio; Tecnología de Alimentos, Nutrición y Bromatología
    Gilthead seabream is bred mainly in fish farms in the Mediterranean Sea. One important factor responsible for the deterioration of fish quality is lipid oxidation. Moringa oleifera leaves have been described as having high antioxidant content. This work investigates the effect of dietary supplementation with Moringa leaves on the antioxidant activity of seabream. Gilthead seabream specimens were divided into four groups, the control group (fed a commercial diet) and three other groups fed diets enriched with Moringa (5%, 10% and 15%). The antioxidant capacity was measured by assays of free radical scavenging (OH , H2O2, lipoperoxyl and ABTS), Rancimat test and linoleic acid system in muscle and skin of gilthead seabream, commercial diet, enriched diet and Moringa. Finally, the polyphenol content of Moringa and the fatty acid composition of seabream fed diets with and without Moringa were determined. Results showed an increase in antioxidant activity in gilthead seabream fed with diets enriched with a higher percentage of Moringa; therefore, Moringa could be considered a functional ingredient in diets for fish bred in fish farms and. The antioxidant potential of Moringa leaves could be mainly attributed to the presence of polyphenolic compounds.
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    Comparison of the antioxidant and pro-oxidant activities of broccoli amino acids with those of common food additives
    (Wiley, Society of Chemical Industry, 2001-08) Martínez Tomé, Magdalena; Murcia Tomás, María Antonia; García Carmona, Francisco
    The antioxidant and pro-oxidant activities of broccoli amino acids were compared with those of common food additives. In decreasing order, the data showed that Asp, SMC, GABA, Glu, Gln, Pro, Phe, Leu, Lys, Arg, Asn, Val, Ile, His, Ser, Gly, Orn and Ala, when dissolved in water at concentrations of 0.5 and 0.05 mM, partially inhibited damage to deoxyribose in the presence of ferric-EDTA and H2O2. In contrast, Tyr and Thr acted as pro-oxidants in this system. The amino acids present in broccoli had no hydrogen peroxide-scavenging effect. When dissolved in water, methanol or ethanol, SMC, Glu, Thr, Gln, Ser, GABA, Pro, Ala, Ile, Phe, Asp, Orn and Tyr inhibited lipid peroxidation. However, Asn, Val, Arg, Leu, Lys, His and Gly were not effective in decreasing peroxidation at concentrations of 0.5 and 0.05 mM. Asp > SMC > Ala > Phe > Hys > Orn > Gln = Ser > Lys > Leu = GABA = Gly > Tyr > Arg = Thr > Val > Asn > Pro > Ile > Glu (p < 0.025) showed scavenging activity towards hypochlorous acid protecting al-antiproteinase against inactivation. In this paper it has been established that some amino acids premixed with propyl gallate increase its hypochlorous acid-scavenging capacity, while other amino acids have an additive effect with propyl gallate, permitting smaller quantities of propyl gallate to be used as food additives in some products which contain these amino acids.
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    Increasing the Applications of Crocus sativus Flowers as Natural Antioxidants
    (Wiley, 2012-10-11) Serrano Díaz, Jessica; Sánchez, Ana María; Maggi, Luana; Martinez Tomé, Magdalena; García Diz, Luis; Murcia, M. Antonia; Alonso Díaz-Marta, Gonzalo L.; Tecnología de Alimentos, Nutrición y Bromatología
    Large amounts of floral bio-residues (92.6 g per 100 g of flowers) are generated and wasted in the production of saffron (Crocus sativus) spice. Progress in mechanization of saffron crop offer the opportunity to expand the uses of C. sativus flowers, beyond the spice (dried stigmas). The antioxidant potential of flowers of saffron, their separate parts (tepals, stamens, styles, and stigmas) and floral bio-residues were evaluated by 4 in vitro assays: lipid peroxidation, deoxyribose assay, Rancimat test, and Trolox equivalent antioxidant capacity. Phenolic content and crocetin ester composition were also determined. All the samples studied showed to be potential antioxidants. The highest phenolic, flavonoid, and anthocyanin contents were observed in tepals. Stamens showed lower phenolic, flavonoid, and anthocyanin contents than those of whole flowers, tepals, and floral bio-residues. Crocetin esters were not found in tepals or stamens. Stamens exhibited the most potent LOO• and OH• radicals scavenging activity, being higher than those of food antioxidant propyl gallate. Flowers of saffron, tepals, stamens, styles, and floral bio-residues showed LOO•, OH•, and ABTS•− radicals scavenging activity, while stigmas showed LOO• and ABTS•− radicals scavenging activity. All samples studied improved the oxidative stability of sunflower oil in Rancimat test. These antioxidant properties could suggest the application of this floral material as functional ingredients with the subsequent added value.
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    Intrinsically synthesized melatonin in mitochondria and factors controlling its production
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Reiter, Russel J.; Sharma, Ramaswamy N; Almieda Chuffa, Luiz Gustavo de; Silva, Danilo Grunig Humberto da Silva; Rosales Corral, Sergio
    The percentage of the total amount of melatonin produced in vertebrates that comes from the pineal is small (likely <5%) but, nevertheless, functionally highly noteworthy. The significance of pineal melatonin is that it is secreted cyclically such that it has a critical function in influencing not only the suprachiasmatic nucleus but clock genes that reside in perhaps every cell throughout the organism. Extrapineal melatonin, which may be synthesized in the mitochondria of all other cells in much larger amounts than that in the pineal gland has a different function than that derived from the pineal gland. Its synthesis is not circadian and it is not directly impacted by the photoperiodic environment. Also, melatonin from the extrapineal sites is not normally secreted into the blood stream; rather, it acts locally in its cell of synthesis or, possibly via paracrine mechanisms, on immediately adjacent cells. The functions of extrapineal melatonin include central roles in maintaining molecular and redox homeostasis and actions in resisting pathological processes due to its ability to directly or indirectly detoxify free radicals. The vast majority of organisms that exist on Earth lack a pineal gland so pineal-derived melatonin is unique to vertebrates. Evidence suggests that all invertebrates, protists and plants synthesized melatonin and they have no pineal homolog; thus, the production of melatonin by extrapineal cells in vertebrates should not be unexpected. While the factors that control pineal melatonin synthesis are well documented, the processes that regulate extrapineal melatonin production are undefined.