Effects of Light and Temperature on Antioxidant Activity and Peroxidase Expression at Different Growth Stages of the Chinese Red Radish

2009 ◽  
Vol 52 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Lan Wang
2016 ◽  
Vol 7 ◽  
Author(s):  
Ivette González-Palma ◽  
Héctor B. Escalona-Buendía ◽  
Edith Ponce-Alquicira ◽  
Maura Téllez-Téllez ◽  
Vijai K. Gupta ◽  
...  

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 926
Author(s):  
Victoria Chepel ◽  
Valery Lisun ◽  
Liubov Skrypnik

Heather (Calluna vulgaris (L.) Hull.) is noted for a diverse chemical composition and a broad range of biological activity. The current study was aimed at monitoring changes in the accumulation of certain groups of phenolic compounds in various organs of heather (leaves, stems, roots, rhizomes, flowers, and seeds) at different growth stages (vegetative, floral budding, flowering, and seed ripening) as well as studying antioxidant (employing the DPPH and FRAP assays) and antibacterial activity of its extracts. The highest total amount of phenolic compounds, tannins, flavonoids, hydroxycinnamic acids, and proanthocyanidins was detected in leaves and roots at all growth stages, except for the flowering stage. At the flowering stage, the highest content of some groups of phenolic compounds (flavonoids, proanthocyanidins, and anthocyanins) was observed in flowers. Highest antioxidant activity was recorded for the flower extracts (about 500 mg of ascorbic acid equivalents per gram according to the DPPH assay) and for the leaf extract at the ripening stage (about 350 mg of ascorbic acid equivalents per gram according to the FRAP assay). Strong correlation was noted between antioxidant activity (DPPH) and the content of anthocyanins (r = 0.75, p ≤ 0.01) as well as between antioxidant activity (FRAP) and the total content of phenolic compounds (r = 0.77, p ≤ 0.01). Leaf extracts and stem extracts turned out to perform antibacterial action against both gram-negative and gram-positive bacteria, whereas root extracts appeared to be active only against B. subtilis, and rhizome extracts against E. coli.


Author(s):  
Elham Ghafiyehsanj ◽  
Kamaladdin Dilmaghani ◽  
Nader Chaparzade ◽  
Sara Saadatmand

In order to investigate the antioxidant activity of Salvia nemorosa L. collected from Ahar and Urmia regions in Iran at different growth stages, aerial parts of sage after collecting were dried, and for measurement, the ability of scavenge DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) radical in different concentrations (0.025, 0.05, 0.07, 0.1, 0.2, 0.04 and 0.6) of methanolic extracts were prepared. The result showed that the ability to scavenge DPPH radical and amount of inhibition percent of vegetative stage leaves, flowering stage leaves, and flowers increased with increasing concentrations of methanolic extracts from 0.25 to 0.6 mg/ml. In the region of Urmia, the highest amount of DPPH inhibition there was in vegetative stage leaves, and the lowest amount of DPPH inhibition was seen in flowers. In Ahar regions, unlike the Urmia region, the highest amount of DPPH inhibition there was in flowers, but the lowest of DPPH inhibition was seen in flowering stage leaves. Also, the content of inhibition of DPPH in Ahar and Urmia regions similarly increased between two phenological stages (vegetative stage leaves, flowering stage leaves, and flowers) in 0.4 mg/ml and 0.6 mg/ml concentrations


Foods ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 494 ◽  
Author(s):  
Behzad Nezhadasad Aghbash ◽  
Mohammad Pouresmaeil ◽  
Gholamreza Dehghan ◽  
Mohsen Sabzi Nojadeh ◽  
Haedeh Mobaiyen ◽  
...  

Essential oils (EOs) from medicinal and aromatic plants are interesting products to be used as natural food preservatives. The EOs from the genus Satureja are reported to inhibit foodborne pathogens being worthy of use as food preservatives. Satureja macrantha is found in Western and Northwest Iran and commonly used as a food flavoring agent and for the treatment of urinary diseases. The objective of the present study was to identify the chemical composition of S. macrantha EOs at different growth stages (vegetative, flowering and fruiting stages) and to evaluate their biological activities. Chemical compositions were analyzed using GC-FID and GC-MS. The antibacterial activity was evaluated using the broth microdilution method against the foodborne pathogenic bacteria Staphylococcus aureus (ATCC23922), Enterococcus faecalis (ATCC29212) (Gram-positive), Enterobacter aerogenes (ATCC13046) and Escherichia coli. The antioxidant activity was estimated using the DPPH, ABTS and reducing power assays. The yields of S. macrantha EOs were in the range of 1.4–1.8%, thus scalable for the manufacture of food preservatives on an industrial level. The main compounds of EOs were carvacrol (42.7–48.2%), thymol (0.2–16.5%), p-cymene (10.1–14.7%) and γ-terpinene (7.9–9.1%) in all phenological stages examined. The strongest antibacterial activity (MICs = 5–20 µg/mL) of the EOs was recorded in samples obtained during the flowering stage where carvacrol (42.7%) and thymol (16.5) were present both at high percentages. On the other hand, the antioxidant activity was found to be slightly higher in the other stages. As the EO obtained at flowering showed the best inhibitory properties against foodborne pathogenic bacteria, it is suggested that plants at this stage can be selected as main sources of food preservative agents.


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