Comparative study of leaf antioxidant activity as a possible mechanism for frost tolerance in ‘Hass’ and ‘Ettinger’ avocado cultivars

2019 ◽  
Vol 157 (04) ◽  
pp. 342-349
Author(s):  
A. Weil ◽  
C. Sofer-Arad ◽  
Y. Bar-Noy ◽  
O. Liran ◽  
L. Rubinovich

AbstractA major drawback of avocado (Persea americanaMill.) is susceptibility to frosts, which reduces yields and limits its geographic distribution and market growth. Whereas the frost-susceptible cultivar ‘Hass’ leads the global avocado market, cv. ‘Ettinger’, although commercially less important, is considered frost-tolerant. The mechanism behind the greater frost tolerance of ‘Ettinger’ has not yet been elucidated; therefore, the aim of the current study was to evaluate the differences between the frost responses of the two cultivars. The results showed that detached ‘Ettinger’ branches had greater tolerance than ‘Hass’ to controlled frost stress. Tissue browning caused by methyl viologen oxidative cell damage, superoxide accumulation in leaf discs following wounding and browning of cut surfaces in branches were much lower in ‘Ettinger’ than in ‘Hass’, suggesting greater antioxidant activity (AA) in the former. In leaf extracts, AA was significantly higher in ‘Ettinger’ than in ‘Hass’, but osmolarity was similar in the two cultivars. Total phenolics content was significantly higher in ‘Ettinger’ but addition of a protein mask did not significantly reduce AA in either cultivar. Interestingly, following the freezing treatment, AA increased in ‘Ettinger’ and remained almost unchanged in ‘Hass’, while osmolarity was unaffected in either cultivar. These results suggest that the greater frost-tolerance of ‘Ettinger’ than ‘Hass’ is due largely to its greater AA, which springs mainly from a non-enzymatic source, i.e. accumulation of phenolic compounds. Based on the current study, future applications may be developed to minimize frost damage in avocado orchards.

Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 173 ◽  
Author(s):  
Cecilia Castro-López ◽  
Israel Bautista-Hernández ◽  
María D. González-Hernández ◽  
Guillermo C. G. Martínez-Ávila ◽  
Romeo Rojas ◽  
...  

Persea americana (avocado) is a fruit consumed worldwide; however, since avocado leaves are apparently a natural ingredient that can be used as a traditional medicine, they can be a potential source of bioactive compounds. This study aimed to analyze the antioxidant activity of seven Mexican avocado leaf extracts by DPPH•, ABTS•+, and lipid peroxidation (LPO), and to identify the compound profile by liquid chromatography coupled to mass spectrometry/electron spray ionization. The highest free radical-scavenging activity was observed for Platano Delgado and Criollo 6 avocado cultivars havin IC50 values of 271.86 ± 13.69 and 269.56 ± 6.53 for DPPH• and ABTS•+ radicals, respectively, while the best result for lipid oxidation inhibition was registered in Criollo 6 cultivar extract. In this study forty-one compounds were detected in avocado leaves of the the seven cultivars analyzed, and of these compounds, eighteen phenolics were identified for first time in such plant material. The present study demonstrated that Mexican cultivars of Persea americana possess diverse polyphenolic compounds with strong antioxidant activity, which might be useful in the food and pharmaceutical industries.


2019 ◽  
Vol 20 (5) ◽  
pp. 433-444 ◽  
Author(s):  
Jhonatas Emílio Ribeiro da Cruz ◽  
Joyce Ferreira da Costa Guerra ◽  
Marcos de Souza Gomes ◽  
Guilherme Ramos Oliveira e Freitas ◽  
Enyara Rezende Morais

Background: Currently, the treatment of infectious diseases has not always been successful due to the emergence of microbial resistance worldwide. Objective: This study aimed to evaluate the antioxidant activity, content of total phenolic compounds and flavonoids, antifungal potential and antibacterial action of six medicinal plants found in the Cerrado, leaf extracts of Boldo (Peumus boldus), Goiaba (Psidium guajava), Assa-Peixe (Vernonia polysphaera), Abacate (Persea americana), Eucalipto (Eucalyptus citriodora) and raw sap of Bálsamo (Jatropha multifida). Methods: The antioxidant activity was also determined through the DPPH, ABTS and phosphomolybdenum assays. In addition, the total phenolic content and flavonoid dosage were analyzed using the Folin- Ciocalteu method and the aluminum chloride test, respectively. Results: All extracts, except from Assa-Peixe, showed promising values against Staphylococcus aureus, with halos varying from 13-20 mm. Analysis of the minimum inhibitory concentration (MIC) values of the six medicinal plants revealed inhibitory activity of S. aureus, with concentrations varying from 3.12-12.5 mg/mL, which is a significant result considering that S. aureus is one of the main causes of hospital infections. Conclusion: In the analysis of the phytochemical profile, Goiaba contained the best yield of phenolic compounds and total flavonoids, as well as higher antioxidant activity by DPPH and phosphomolybdenum, demonstrating that this species contains antioxidant components that can sequester free radicals under in vitro conditions. Therefore, the crude extracts investigated are promising and their antibacterial and antioxidant actions should be thoroughly studied.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1325
Author(s):  
Mohamed Z. M. Salem ◽  
Abeer A. Mohamed ◽  
Hayssam M. Ali ◽  
Dunia A. Al Al Farraj

Background: Trees are good sources of bioactive compounds as antifungal and antioxidant activities. Methods: Management of six molecularly identified Fusarium oxysporum isolates (F. oxy 1, F. oxy 2, F. oxy 3, F. oxy 4, F. oxy 5 and F. oxy 6, under the accession numbers MW854648, MW854649, MW854650, MW854651, and MW854652, respectively) was assayed using four extracts from Conium maculatum leaves, Acacia saligna bark, Schinus terebinthifolius wood and Ficus eriobotryoides leaves. All the extracts were analyzed using HPLC-VWD for phenolic and flavonoid compounds and the antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene-linoleic acid (BCB) bleaching assays. Results: In mg/kg extract, the highest amounts of polyphenolic compounds p-hydroxy benzoic, benzoic, gallic, and rosmarinic acids, with 444.37, 342.16, 311.32 and 117.87, respectively, were observed in C. maculatum leaf extract; gallic and benzoic acids with 2551.02, 1580.32, respectively, in A. saligna bark extract; quinol, naringenin, rutin, catechol, and benzoic acid with 2530.22, 1224.904, 798.29, 732.28, and 697.73, respectively, in S. terebinthifolius wood extract; and rutin, o-coumaric acid, p-hydroxy benzoic acid, resveratrol, and rosmarinic acid with 9168.03, 2016.93, 1009.20, 1156.99, and 574.907, respectively, in F. eriobotryoides leaf extract. At the extract concentration of 1250 mg/L, the antifungal activity against the growth of F. oxysporum strains showed that A. saligna bark followed by C. maculatum leaf extracts had the highest inhibition percentage of fungal growth (IPFG%) against F. oxy 1 with 80% and 79.5%, F. oxy 2 with 86.44% and 78.9%, F. oxy 3 with 86.4% and 84.2%, F. oxy 4 with 84.2, and 82.1%, F. oxy 5 with 88.4% and 86.9%, and F. oxy 6 with 88.9, and 87.1%, respectively. For the antioxidant activity, ethanolic extract from C. maculatum leaves showed the lowest concentration that inhibited 50% of DPPH free radical (3.4 μg/mL). Additionally, the same extract observed the lowest concentration (4.5 μg/mL) that inhibited BCB bleaching. Conclusions: Extracts from A. saligna bark and C. maculatum leaves are considered potential candidates against the growth of F. oxysporum isolates—a wilt pathogen—and C. maculatum leaf as a potent antioxidant agent.


2018 ◽  
Vol 10 (1) ◽  
pp. 407
Author(s):  
Dewi Kumala Putri ◽  
Berna Elya ◽  
Nuraini Puspitasari

Objective: To assess the antioxidant activity from another part of the plant, in this study, leaf extracts in n-hexane were fractionated.Methods: Ten fractions were obtained and tested in vitro for antioxidant activity using two methods, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferricreducing antioxidant power (FRAP), to identify the most active fraction.Results: The IC50 of the most active fraction was 36.24 μg/mL using the DPPH method, and the EC50 was 39.54 μg/mL using the FRAP method. Themost active fraction was also shown to contain terpenoids.Conclusion: The most active fraction of an n-hexane extract of the leaves of Gacinia bancana Miq., which was tested by both DPPH and FRAP methodshad antioxidant activities with IC50 and EC50 values of 36.2482 μg/mL and 39.5442 μg/mL, respectively. Phytochemical screening showed that activefraction contains terpenoids.


2012 ◽  
Vol 24 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Jerzy Lisek

Winter frost injury of buds on one-year-old grapevine shoots ofVitis viniferacultivars and interspecific hybrids in PolandFollowing the winter of 2009/2010, an assessment of frost damage was carried out on the vines of 40 wine cultivars and 32 table grape cultivars grown in central Poland (Skierniewice, latitude 51° 57' N, longitude 20° 08' E). The minimum winter temperature of -28.1°C was recorded on 26 January 2010. Cultivars were assigned to five classes of different frost tolerance, according to information on the percentage of frozen buds: very resistant (below 1.9%), resistant (2 - 24.9%), medium susceptible (25 - 74.9%), susceptible (75 - 95.9%) and very susceptible (above 96%). The numbers of wine and table cultivars in each class were as follows: very resistant - 5 (wine) and 3 (table), resistant - 2 and 5, medium susceptible - 15 and 10, susceptible - 13 and 9 and very susceptible - 5 and 5. The most tolerant were the ‘Alwood’, ‘Delaware’, ‘Fredonia’ and ‘Zilga’ interspecific hybrids of theVitis labruscanagroup; the ‘Aurore’, ‘Marechal Foch’ and ‘Leon Millot’ hybrids originating fromV. vinifera, V. rupestris, V. ripariaandV. lincecumiiand ‘Sibera’ originating fromV. viniferaandV. amurensis.More than 96% of buds froze on the vines of some interspecific hybrids (‘Arkadia’, ‘Fanny’, ‘Kodrianka’ and ‘Lilla’). ‘Ortega’, ‘Nektar’, ‘Cserszegi Fueszeres’, ‘Riesling’ and ‘Chasselas Dore’ from theV. viniferacultivars showed the best tolerance to frost damage (42.5-62% of frozen buds). The buds of theV. viniferacultivars ‘Acolon’, ‘Dakapo’ and ‘Favorit’ all froze. Plant parts covered with soil and snow were not exposed to significant damage, even in the case of susceptible cultivars.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 212
Author(s):  
Yeimi Cecilia Vega-Ruiz ◽  
Corina Hayano-Kanashiro ◽  
Nohemí Gámez-Meza ◽  
Luis Angel Medina-Juárez

Jatropha species have been shown to be an important source of secondary metabolites with different biological effects. Jatropha cinerea (Ortega) Müll. Arg and Jatropha cordata (Ortega) Müll. Arg are distributed in the Northwestern region of Mexico, are adapted to extreme weather conditions and are widely used (stems, leaves, and sap) in traditional medicine. The aim of the present study was to carry out the phytochemical characterization and the evaluation of the antioxidant activity in methanolic extracts of stems and leaves from J. cinerea and J. cordata. The compounds present in the extracts of both species were characterized by ESI-IT-MS/MS and quantified by HPLC-DAD. The results showed that the stem extracts of both species are rich in phenolic acids, while the leaf extracts are rich in flavonoids. Some of the main compounds found were gallic acid, gentisic acid, 3,4-Dihydroxybenzoic acid, vitexin, isovitexin, and catechol. Both species showed high concentrations of phenols and total flavonoids and antioxidant activity. J. cordata showed the highest antioxidant capacity and the highest concentration of phenolic compounds. Overall, both Jatropha species are a natural source of antioxidant compounds with potential biotechnological uses.


2011 ◽  
Vol 137 (1) ◽  
pp. 669-680 ◽  
Author(s):  
Hsin-Ling Yang ◽  
Ssu-Ching Chen ◽  
Kai-Yuan Lin ◽  
Mei-Tsun Wang ◽  
Yu-Chang Chen ◽  
...  

2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Wojciech Koch ◽  
Tomasz Baj ◽  
Wirginia Kukula-Koch ◽  
Zbigniew Marzec

AbstractThe determination of phenolic acids’ and flavonoids’ content in daily food rations (DFRs) of a selected group of male and female students and the development of chromatographic conditions is the primary goal of the study. The presence of 7 phenolic components were confirmed in the prepared extracts from all diets reconstructed within a period of 3 years. The highest concentrations were determined for hesperidin (124 and 55.6 mg for women and men, respectively), naringin (47.6 mg in female and 37 mg in male diets) and chlorogenic acid (19.7 and 19.8 mg for women and men). The antioxidant potential of the daily food rations, measured with a DPPH test, was higher for women (range 47.1‒78.8%) than for men (range 34.5‒78.0%) and was found to strongly correlate with the total phenolics content of the samples (Folin-Ciocalteu test) (correlation coefficient 0.90).


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