scholarly journals A Leaf Disc Assay for Evaluating the Response of Tea (Camellia sinensis) to PEG-Induced Osmotic Stress and Protective Effects of Azoxystrobin against Drought

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 546
Author(s):  
Yu-Chieh Chiu ◽  
Bo-Jen Chen ◽  
Yen-Shuo Su ◽  
Wen-Dar Huang ◽  
Chang-Chang Chen

Tea (Camellia sinensis), a globally cultivated beverage crop, is sensitive to drought, which can have an adverse effect on the yield and quality of tea. Azoxystrobin (AZ) is one kind of fungicide considered as an agent to relieve damage caused by stress. Initially, the response of tea plant to osmotic-gradient stress was evaluated using leaf disc assays with PEG-induced osmotic stress. The decline of the maximum quantum yield of PSII (Fv/Fm), actual photosynthetic efficiency of PS II (Y(II)), total chlorophylls, carotenoids, DPPH radical scavenging capacity, reducing power, total phenols, and the increase in MDA was observed in leaf discs treated with a gradient of PEG solutions (22.8, 33.2, 41.1% PEG, and blank). These results revealed that efficiency of photosystem II (PSII), photosynthetic pigments, and antioxidant ability in leaf discs were inhibited with an aggravated lipid peroxidation under PEG-induced osmotic stress, and indicated leaf disc assay with moderate PEG iso-osmotic condition would reflect a portion of tea plant response to drought stress. Therefore, the protective effect of AZ (0.125 and 1.25 g a.i. L−1) on tea plants suffering from drought was evaluated using leaf disc assays with 22.8% PEG iso-osmotic condition. Pretreatment of AZ (0.125 a.i. g L−1) reversed Fv/Fm, Y(II), DPPH radical scavenging capacity, and reducing power with reduced MDA in PEG-treated leaf discs, but photosynthetic pigments, total phenols, and ascorbate peroxidase activity were irresponsive to AZ. An Alleviated physiological damage in tea leaf with AZ applying was preliminarily revealed in this study. A Rapid screening of agents for tea plants against drought was developed to assist in the selection of protective agents.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Song Yu ◽  
Xuetian Zhu ◽  
Helin Yang ◽  
Lihe Yu ◽  
Yifei Zhang

AbstractSeed deterioration, coupled with a decrease in nutrients, is unavoidable following long-term storage, and these seeds are therefore used as livestock fodder. Here, we developed a simple, rapid and efficient method of producing high amounts of antioxidants from deteriorated seeds via melatonin-induced germination. Legume seeds were subjected to high humidity at 55 °C for 12–36 h to obtain aged seeds with a 40% germination rate and severely reduced antioxidant nutrition (total phenolics content, ferric reducing power and 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging capacity). Aged seeds were then treated with 0.1 mM melatonin, resulting in the production of sprouts with a higher total phenolics content (fivefold), greater ferric reducing power (sevenfold) and greater DPPH radical scavenging capacity (twofold) compared to the aged seeds. These findings suggest that melatonin treatment efficiently converted aged seed reserve residues into antioxidant nutrients, providing an alternative use for deteriorated seeds in food production.


Author(s):  
Fei-Hong Zhai ◽  
Yan-Fei Chen ◽  
Yong Zhang ◽  
Wen-Jing Zhao ◽  
Jian-Rong Han

Abstract Solid-state fermentation with Agaricus brasiliensis and Agaricus bisporus on whole grain wheat was carried out. Phenolic compounds and antioxidant properties of fermented wheat were determined. The results showed that the maximum values of polyphenols contents in wheat fermented with A. brasiliensis and A. bisporus reached respectively (3.16 ± 0.21) and (3.93 ± 0.23) mg GAE/g, which were 2.90 and 3.61 times of unfermented control. By employing ultra performance liquid chromatography coupled to mass spectrometry (UPLC-MS), 18 kinds of phenolic compounds were identified from fermented wheat. Compared with control, only 4-hydroxy-benzaldehyde was the same compound. It indicated that fermentation with the two fungi changed polyphenols contents and phenolic compounds composition in wheat to a great extent. Among these phenolic compounds, except for 4-hydroxy-benzaldehyde, 4-hydroxy-benzoic acid and β-N-(γ-glutamyl)-4-formylphenylhydrazine, other 15 kinds of phenolic compounds were first identified from mushroom samples (including fruit bodies, mycelia and fermentation products). DPPH radical scavenging capacity, reducing power, ferrous ion chelating ability and inhibition of lipid peroxidation of fermented wheat were significantly stronger than control (P < 0.05).


2014 ◽  
Vol 3 (2) ◽  
pp. 52-57
Author(s):  
Jelena Stojanovic ◽  
Nada Nikolic ◽  
Miodrag Lazic ◽  
Ivana Karabegovic ◽  
Jasna Mastilovic ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Nur Sumirah Mohd Dom ◽  
Nurshieren Yahaya ◽  
Zainah Adam ◽  
Nik Mohd Afizan Nik Abd. Rahman ◽  
Muhajir Hamid

The present study aimed to evaluate the potential of standardized methanolic extracts from seven Ficus deltoidea varieties in inhibiting the formation of AGEs, protein oxidation, and their antioxidant effects. The antiglycation activity was analyzed based on the inhibition of AGEs, fructosamine, and thiol groups level followed by the inhibition of protein carbonyl formation. The antioxidant activity (DPPH radical scavenging activity and reducing power assay) and total phenolic contents were evaluated. After 28 days of induction, all varieties of Ficus deltoidea extracts significantly restrained the formation of fluorescence AGEs by 4.55–5.14 fold. The extracts also reduced the fructosamine levels by 47.0–86.5%, increased the thiol group levels by 64.3–83.7%, and inhibited the formation of protein carbonyl by 1.36–1.76 fold. DPPH radical scavenging activity showed an IC50 value of 66.81–288.04 μg/ml and reducing power activity depicted at 0.02–0.24 μg/ml. The extent of phenolic compounds present in the extracts ranged from 70.90 to 299.78 mg·GAE/g. Apart from that, correlation studies between the activities were observed. This study revealed that seven varieties of Ficus deltoidea have the potential to inhibit AGEs formation and possess antioxidant activity that might be attributed to the presence of phenolic compounds.


BIBECHANA ◽  
2021 ◽  
Vol 18 (2) ◽  
pp. 143-153
Author(s):  
Richa K. Gupta ◽  
Ganesh M. S. Thakuri ◽  
Gan B Bajracharya ◽  
Ram Narayan Jha

Antioxidant and antibacterial activities of natural anthraquinones namely chrysophanol (1) and emodin (2), and synthesized anthraquinones viz. 2-methylanthraquinone (3), anthraquinone (4), 2-bromoanthraquinone (5), rubiadin (6), chrysophanol diacetate (7), rubiadin diacetate (8) and 1,8-dimethoxy-3-methylanthraquinone (9) were investigated. Anthraquinones 9, 3, 6, 5 and 2 exhibited a high DPPH• radical scavenging capacity (IC50 = <500 μg/mL) showing their therapeutic potentiality for the treatment of cancers. These anthraquinones 1-9 have also displayed a weak to moderate antibacterial activity against Bacillus subtilis. Chrysophanol diacetate (7) including emodin (2) have been appeared as the valuable antibacterials. BIBECHANA 18 (2) (2021) 143-153


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Chai-Hyeon Lee ◽  
Ye-Na Park ◽  
Hyeung-Rak Kim ◽  
Sang Gil Lee ◽  
Bohkyung Kim

Abstract Objectives It has been a long time since seaweeds have been used for food ingredients in Asian countries. Recently, a body of research has revealed the health benefits of bioactive compounds in seaweeds, especially their antioxidant capacities. Although numerous seaweeds inhabit in the ocean, only a small percentage has been explored for functional food. Therefore, the purpose of this study was to analyze the antioxidant capacities of various seaweeds grown off the Korean coast to screen for the potential functional food sources. Methods Ten ethanol extracts of Korean seaweeds were provided by the National Marine Biodiversity Institute of Korea, which included Scytosiphon gracilis, Scytosiphon lomentaria, Sargassum muticum, Sargassum confusum, Petrospongium rugosum, Sargassum fusiforme, Petalonia fascia, Sargassum nigrifolium, Ishige foliacea, and Myelophycus simplex. Hundred mg/L of samples in 80% methanol was used to measure their ABTS, DPPH, and superoxide radical scavenging activities. Mg vitamin C equivalent antioxidant capacity (VCEAC)/100 mg was used to express the ABTS and DPPH radical scavenging capacities. For the superoxide radical scavenging capacity, inhibition rate of superoxide radical generation (%) was calculated. Results Among the ten seaweeds, S. nigrifolium and I. foliacea exhibited the most significant radical scavenging capacities. DPPH radical scavenging capacities of I. foliacea and S. nigrifolium were 122.4 mg VCEAC/100 mg and 95.8 mg VCEAC/100 mg, respectively. For ABTS radical scavenging capacity, I. foliacea exhibited 178.5 mg VCEAC/100 mg, followed by S. nigrifolium as 80.9 mg VCEAC/100 mg. I. foliacea inhibited about 68% of superoxide radical generation followed by S. nigrifolium (40.6%) while vitamin C as positive control inhibited about 28.9% of superoxide radical generation. The antioxidant capacities measured by the three assays were positively correlated with each other. Conclusions The current study explored total antioxidant capacities of various Korean seaweeds and found I. foliacea and S. nigrifolium as the most potential antioxidant-rich food resources. Further research would be warranted to investigate bioactive compounds from S. nigrifolium and I. foliacea. Funding Sources This work was supported by the Pukyong National University Research Fund in 2018.


2012 ◽  
Vol 7 (2) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Laura Giamperi ◽  
Anahi Bucchini ◽  
Angela Bisio ◽  
Emanuela Giacomelli ◽  
Giovanni Romussi ◽  
...  

The total phenolic content and antioxidant activity of 6 Salvia spp. exudates were measured to find new potential sources of natural antioxidants. Total phenolic content was assessed by a modified Prussian blue method, and the antioxidant activity by two methods: 1,1- diphenyl-2-picryl- hydrazyl (DPPH) radical scavenging capacity assay and lipoxygenase inhibitory assay. The total phenolic content ranged between 1.3 μg/mg DW ( S. fallax) and 74.0 μg/mg DW ( S. cacaliaefolia). In the DPPH test, S. cacaliaefolia was more effective than BHT, while in the inhibition of lipid peroxidation all the extracts presented good antioxidant capacity.


2019 ◽  
Vol 78 ◽  
pp. 02008
Author(s):  
Hong-li Zhou ◽  
Bing Li ◽  
Mei-fu Wu ◽  
Ye Liu

To determine the effect of different harvesting time on antioxidant capacity in Jerusalem artichoke polysaccharides (inulin), the Jerusalem artichoke before and after overwintering were collected from the same region, and then evaluate their antioxidant capacity in vitro by reducing power assay, DPPH radical-scavenging assay and hydroxyl radical-scavenging assay. Ascorbic acid at similar mass concentration was served as positive control. The results showed no significant difference were observed in reducing power when the absorbance values were about 0.3. When the mass concentrations before and after overwintering were 0.9 mg/mL and 1.7 mg/mL, the DPPH radical-scavenging rate both reached at 50%. And when the mass concentrations were both 10 mg/mL, the hydroxyl radical-scavengings were 35.8% and 27.9%, respectively. Thus, it could be concluded that the antioxidant capacity in Jerusalem artichoke polysaccharides before overwintering was higher than that after overwintering, and showed a good dose-dependent manner with its mass concentration.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1654
Author(s):  
Bo Kim ◽  
Seung Park ◽  
Geum-Joung Youn ◽  
Yeon Kwak ◽  
Mi Kim

The purpose of this study was to develop a formulation of Sunsik with improved health benefits by adding germinated wheat (GW) and herbal plant extract (HPE) using a response surface methodology (RSM). The central composite experimental design (CCD) was used to evaluate the effects of Sunsik with added HPE (2–4%) and GW (10–20%) on total phenolic content (TPC), total flavonoid content (TFC), Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, gamma butyric acid (GABA) content, total color changes (△E), browning index (BI), water absorption index (WAI), and water solubility index (WSI). As a result of the CCD, the independent and dependent variables were fitted by the second-order polynomial equation, and the lack of fit for response surface models was not significant except in relation to WSI. The GABA content, TPC, and TEAC were more adequate for a linear model than for a quadratic model, and they might be affected by GW rather than HPE. Alternatively, the TFC, DPPH radical scavenging capacity, WAI, WSI, △E, and BI were fitted with quadratic models. The optimum formulation that could improve antioxidant and physicochemical properties was Sunsik with 3.5% and 20% added HPE and GW, respectively.


Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 584
Author(s):  
Hong Chen ◽  
Zhuoyun Chen ◽  
Yuanfang Fu ◽  
Jiao Liu ◽  
Siying Lin ◽  
...  

Different methods of isolating arabinoxylans (AXs) from triticale were performed to investigate the extraction methods’ effects on the physiological functions of the AXs. Structural, antioxidant, and hypoglycemic activities were determined. The molecular weights (MWs) of enzyme- or water-extracted AXs were lower than those of alkali-extracted AXs. Opposite trends were shown by the arabinose–xylose ratio. Enzyme-extracted AXs exhibited higher glucose adsorption capacity and hydroxyl radical-scavenging efficiency than alkali-extracted AXs. The α-amylase inhibition ability, DPPH radical-scavenging capacity, and metal-chelating activity of alkali-extracted AXs were higher than those of enzyme-extracted AXs. Water-extracted AXs had the highest glucose dialysis retardation index. In conclusion, extraction methods can influence the physiological function of AXs through their structural features. AXs with higher MWs and esterified ferulic acid (FA) levels had higher antioxidant ability, whereas AXs with higher solubility and free FA level exhibited higher hypoglycemic activity.


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