Wyniki wyszukiwania - Biblioteka Nauki

1

A comparative study of the antioxidant activity and phytochemical composition of leaves extract between three varieties of date palm tree

100%

Eddine L. S. , Ladjel S. , Mohamed O. M.

International Letters of Chemistry, Physics and Astronomy

|

2013

|

tom Vol. 9, iss. 2

162-171

EN

The date palm (Phoenyx dactylifera) consisted, for the people of southern Algeria, as tree of providence. Dates and their extracts are also used for many centuries as a medicine against allergy, inflammation, constipation and gastro-protective; they also have a high antibacterial and antioxidant activity. However, no studies are conducted to evaluate the extract from the leaves of date palm (Phoenyx dactylifera) in point of view of phytochemical composition, antimicrobial and the antioxidant activity. In this study, we have determined the phenolic compounds, antioxidant and antimicrobial activity of methanolic extracts from three varieties of leaves tree. According to the results the leaves extracts have very important values for polyphenols (215.24 to 156.46 mg GAE / g DW) and high antioxidant activity (324. 45 to 206.21 mg GAE / g DW), Diphenyl-1 picrylhydrazyl radical-scavenging activity (IC50 = 2.98 to 4.83 μg / ml); also the three extracts reveal a considerable antimicrobial potency and antifungal considerable activity, the diameter of inhibition is 35.2 to 39.5 mm (concentration 50 mg/ml) for Candida albicans ATCC 90026.

2

Antioxidant capacity of roasted health-promoting products

100%

Kosinska A. , Karamac M.

Polish Journal of Food and Nutrition Sciences

|

2006

|

tom 15/56

|

nr 2

EN

Roasted sesame seeds, pumpkin seeds, sunflower seeds, soy beans, and wheat germs were obtained from Ekoprodukt company (Częstochowa, Poland). Phenolic compounds were extracted with 80% aqueous methanol. The extract of roasted sunflower seeds was characterised by a higher content of total phenolics (158 mg/g). The Total Antioxidant Capacity was the highest in the extract of roasted sunflower seeds (0.478 mmol Trolox/g) followed by the extract of roasted wheat germs (0.066 mmol Trolox/g). The extracts of roasted sunflower seeds and wheat germs were strong scavengers of DPPH radical. Their reducing power was strong as well.

PL

Ekstrakty związków fenolowych uzyskano z prażonych nasion sezamu, dyni, słonecznika, soi oraz zarodków pszenicy – analizowany materiał pochodził z firmy Ekoprodukt. Związki fenolowe ekstrahowano 80% metanolem. Ekstrakt z prażonych nasion słonecznika charakteryzował się najwyższą zawartością fenoli ogółem (158 mg/g). Całkowita Pojemność Przeciwutleniająca ekstraktu z nasion słonecznika i zarodków pszenicy były najwyższe – odpowiednio 0.478 i 0.066 mmol Trolox/g. Obydwa wyżej wymienione ekstrakty były silnymi zmiataczami wolnego rodnika DPPH. Ich zdolność redukcyjna była również wysoka.

3

Antioxidant properties of leaf and root extract and oil from different types of horseradish (Armoracia rusticana Gaertn.)

84%

Majewska A. , Balasinska B. , Dabrowska B.

Folia Horticulturae

|

2004

|

tom 16

|

nr 1

15-22

4

Zmiany sily redukujacej i zdolnosci wygaszania wolnych rodnikow w wybranych olejach tloczonych na zimno w czasie ich przechowywania

67%

Bartkowiak-Fludra E. , Jasinska-Stepniak A. , Gogolewski M. , Delbowski B.

|

2006

|

tom 39

|

nr 2

127-133

5

Effects of rice blast fungus (Pyricularia grisea) on phenolics, flavonoids, antioxidant capacity in rice (Oryza sativa L.)

67%

Toan N. P. , Ha P. T. T. , Xuan T. D.

|

tom 61

EN

Rice blast fungus (Pyricularia grisea) is one of the most problematic pathogen to significantly reduce rice production worldwide. In this study, after being inoculated with P. grisea, changes in phenolic components and antioxidant capacity and correlation with the resistant level against rice blast fungus were investigated. Among screened rice cultivars, AV-3 was the strongest resistant, whereas BII-3 was the most susceptible. It was found that although total contents of phenolics and flavonoids, and antioxidant capacities varied among studied varieties, no significant coefficient with the resistance against P. grisea was observed. After rice was affected by rice blast fungus, total phenolics and flavonoids were markedly reduced, but in contrast, the DPPH scavenging activities of only the susceptible rice cultivars was reduced. Among the 11 phenolic acids detected, catechol was found only in the tolerant cultivar AV-3, whereas the amount of cinnamic acid was increased after infection. Quantity of vanillin was also promoted, except in the susceptible cultivar BII-3 that was significantly reduced. Findings of this study showed that the resistant level against P. grisea was proportionally correlated to the antioxidant capacity. Catechol, cinnamic acid, and vanillin may play a role but it needs further elaboration. Observations of this study suggested that the infection of blast disease by reducing amount of phenolics and flavonoids that may weaken the resistance of rice against this detrimental fungus.

6

Evaluation of antioxidant activity of in vitro propagated medicinal Ceratophyllum demersum L. extracts

67%

Emsen B. , Dogan M.

Acta Scientiarum Polonorum. Hortorum Cultus

|

2018

|

tom 17

|

nr 1

EN

Ceratophyllum demersum L. is a medical plant of the family Ceratophyllaceae that has been traditionally used for the treatment of diseases such as ulcer, diarrhoea, wounds and fever since ancient times. This study presents antioxidant activities of water and methanol extracts of in vitro propagated C. demersum. Shoot tip explants of C. demersum for in vitro plant regeneration were cultured on liquid Murashige and Skoog (MS) medium containing 0.25–1.25 mg/L 6-Benzylaminopurine (BAP) and 0.10 mg/L Thidiazuron (TDZ) combinations for eight weeks. Maximum number of plantlets per explant (110.67) was obtained on MS medium supplemented with 0.75 mg/L BAP + 0.10 mg/L TDZ. In order to determine antioxidant activities of C. demersum, antioxidant contents (β-carotene, flavonoid, lycopene and total phenols), metal chelating and reducing power capacities of methanol and water extracts obtained from C. demersum were investigated. It was detected that water extract was more effective in all activities. Total phenols (76.55 μg/mg) in water extract were measured as the highest antioxidant component. Based on the water extracts data, as IC50 value for chelating on ferrous ions was 9.24 mg/mL, EC50 value for reducing power activity was 8.23 mg/mL. It was also determined that the metal chelating and reducing power activities of the both extracts are increased depending on the concentration. Therefore, all these data suggest that both tested extracts of in vitro propagated C. demersum would exert beneficial effects by virtue of their antioxidant properties and may be utilized as a promising source of therapeutics.

7

Ciemnienie i moc redukcyjna roztworów aminokwasów z cukrami

67%

Markuze Z.

|

1959

|

tom 10

|

nr 1

8

Effect of various pH conditions simulated in vivo on the activity of lipophilic antioxidants isolated from selected spices

67%

Gawlik-Dziki U. , Swieca M.

Polish Journal of Food and Nutrition Sciences

|

2007

|

tom 57

|

nr 3[A]

EN

Extracts of rosemary (Rosemarinus officinalis), thyme (Thymus vulgaris) and marjoram (Origanum majorana) before and after simulated digestion were investigated for their antiradical activity, iron chelation, iron reduction and inhibition of lipid peroxidation. The changes of total phenolic compounds, phenolic acids, quercetin, kaempferol and luteolin contents were measured as well. Digestion in vitro caused a significant increase in the content of total phenolics in all samples. The rosemary extract showed the highest ability to scavenge free DPPH radicals (91.97%). The activities of marjoram and thyme samples were much lower (32.55 and 24%, respectively). Digestion in vitro caused a decrease of activity in all samples. The highest decrease (88.47%) occurred after rosemary extract digestion. The activity of thyme and marjoram extracts decreased about 71.05% and 29.24% respectively. The extracts obtained from marjoram and thyme showed significant chelating power (>76%), whereas the rosemary extract was less active (19.26%). No interchangeable effect of hydrolysis under variable pH conditions on the chelating power was noticed in the study. In vitro digestion had no significant effect on the ability of the rosemary extract to inhibit linoleic acid autooxidation, the activity of this sample was high (about 87%). In the case of the other samples a significant decrease in their activity was observed after the in vitro digestion. The highest losses of activity were observed in the case of the marjoram extract. Reducing power of thyme and marjoram extracts was lower than the activity of rosemary extract but the differences were not truly significant. After digestion the activity of all samples decreased dramatically. In the case of rosemary and marjoram extracts digestion caused about 83% decrease of their activity. The thyme extract after hydrolysis retained 12.26% of its reducing power.

PL

W ekstraktach z rozmarynu (Rosemarinus officinalis), tymianku (Thymus vulgaris), i majeranku (Origanum marjorana) przed i po symulowanym trawieniu określono aktywność przeciwrodnikową, zdolność do chelatowania jonów żelaza, zdolność do redukcji żelaza i inhibicji peroksydacji lipidów a także zmiany zawartości związków fenolowych ogółem, fenolokwasów, kwercetyny, kempferolu i luteoliny. Trawienie in vitro spowodowało znaczący wzrost zawartości związków fenolowych we wszystkich próbach. Najwyższą zdolnością do neutralizacji wolnych rodników DPPH charakteryzował się ekstrakt z rozmarynu (91,97%). Aktywność prób z rozmarynu i majeranku była znacznie niższa (odpowiednio 32,55 i 24%). Trawienie in vitro spowodowało spadek aktywności wszystkich prób. Najwyższy spadek aktywności (88,47%) nastąpił po trawieniu ekstraktu z rozmarynu. Aktywność ekstraktów z tymianku i majeranku spadła odpowiednio o 71,05% i 29,24% (rys. 1). Ekstrakty otrzymane z majeranku i tymianku wykazywały znaczącą zdolność do chelatowania (>76%), ekstrakt z rozmarynu był mniej aktywny (19,26%). Nie stwierdzono jednoznacznego wpływu hydrolizy w zmiennych warunkach pH na zdolność do chelatowania (rys. 2). Trawienie in vitro nie wpłynęło na zdolność do hamowania samoutleniania kwasu linolowego przez ekstrakt z rozmarynu; jego aktywność była wysoka i kształtowała się na poziomie około 87% (rys. 3). W przypadku pozostałych prób po trawieniu in vitro nastąpił znaczący spadek aktywności. Największe straty aktywności zaobserwowano w przypadku ekstraktu z majeranku. Siła redukcji ekstraktów z tymianku i majeranku była niższa niż aktywność ekstraktu z rozmarynu, ale różnice nie były znaczące (rys. 4). Po trawieniu aktywność wszystkich prób drastycznie zmalała. W przypadku ekstraktów z majeranku i tymianku trawienie spowodowało około 83% spadek aktywności. Ekstrakt z tymianku po hydrolizie zachował 12,26% zdolności do redukcji.

9

Okreslenie potencjalu antyoksydacyjnego ekstraktow z lisci morwy bialej

59%

Jeszka M. , Kobus J. , Flaczyk E.

Bromatologia i Chemia Toksykologiczna

|

2009

|

tom 42

|

nr 3

885-889

10

Influence of simulated digestion in various pH conditions on antioxidant activity and composition of extracts from selected spices

51%

Gawlik-Dziki U. , Swieca M.

Herba Polonica

|

2007

|

tom 53

|

nr 3

EN

Extracts of dried leaves of dill (Anethum graveolens) and parsley (Petroselinum crispum), black pepper fruits (Piper nigrum), and black cumin seeds (Nigella sativa) under and after simulated digestion were investigated for their antiradical activity, iron chelation, iron reduction and inhibition of lipid peroxidation. The changes of total phenolic compounds, phenolic acids, quercetin and kaempferol content were also measured. In vitro digestion caused significant increase of total phenolics content in all samples, except black pepper fruits extract. All samples showed low ability to scavenge DPPH radicals (below 18%). The highest activity was observed for parsley leaves extract, and the lowest in the case of black pepper fruits extract. Hydrolyzed extracts from black cumin seeds, parsley and dill leaves showed significantly better iron chelating capacity then non-hydrolyzed samples. After digestion this activity increased in all samples, except black pepper fruits extract. The highest ability to inhibition of lipid peroxidation was obtained for hydrolyzed black cumin seeds samples. Activity of all samples increased after digestion.

PL

W ekstraktach z suszonego ziela koperku (Anethum graveolens) i ziela pietruszki (Petroseli- num crispum), owoców czarnego pieprzu (Piper nigrum) i nasion czarnuszki (Nigella sativa) przed i po trawieniu in vitro określono aktywność przeciwrodnikową, zdolność do chela- towania, siłę redukcji i zdolność do hamowania peroksydacji lipidów. Określono także zmiany zawartości związków fenolowych oraz wybranych fenolokwasów, kwercetyny i kemp- ferolu. Trawienie in vitro spowodowało istotny wzrost zawartości związków fenolowych we wszystkich badanych próbach z wyjątkiem pieprzu. Wszystkie próby wykazały niską zdolność do neutralizacji wolnych rodników DPPH (poniżej 18%). Najwyższą aktywnością charakteryzował się ekstrakt z pietruszki, najniższą - z pieprzu. Hydrolizowane ekstrakty z nasion czarnuszki, ziela pietruszki i koperku wykazały lepszą zdolność do chelatowania niż przed hydrolizą. Po trawieniu aktywność ta wzrosła we wszystkich próbach z wyjątkiem ekstraktu z owoców pieprzu. Najwyższą zdolnością do hamowania peroksydacji lipidów charakteryzowała się hydrolizowana próba z nasion czarnuszki. Aktywność wszystkich badanych prób wzrosła po hydrolizie, podczas gdy zdolność do redukcji zmalała.