Structural Adaptation and Antioxidant Response of Guarianthe bowringiana (O’Brien) Dressler & W. E. Higgins (Orchidaceae Juss.) Seedlings During Ex Vitro Acclimatization

2021 ◽  
Vol 74 ◽  
Author(s):  
Lyudmyla Buyun ◽  
Roman Ivannikov ◽  
Lyudmila Batsmanova ◽  
Nataliya Taran ◽  
Lyudmyla Kovalska ◽  
...  

Abstract Guarianthe bowringiana is one of the oldest samples cultivated at NBG’s orchid unit glasshouses since 1970s. An efficient protocol for asymbiotic in vitro seed germination of G. bowringiana has previously been established. Given that acclimatization is a crucial step in micropropagation, this study assesses the structural adaptation and antioxidant response of G. bowringiana seedlings during ex vitro acclimatization to ex vitro conditions. The leaf surface micromorphology of the G. bowringiana juvenile plants propagated in vitro from seeds as well as the leaves of adult plants cultivated in glasshouse were analyzed using scanning electron microscopy. The levels of lipid peroxidation (TBARS level), superoxide dismutase (SOD) activity, and the photosynthetic activity were monitored for seven days from the transfer of seedlings from the in vitro cultivation vessels as they are markers indicating the response of the leaves of in vitro propagated G. bowringiana plants to oxidative stress during the early stages of acclimatization to ex vitro conditions. During the initial 2 days of the monitored acclimatization period (0–7 days), the level of photosynthetic pigments (chlorophyll a , b , and carotenoid content) increased, followed by an insignificant increase during the successive period (by the seventh day) of acclimatization. At the same time, the level of the tested antioxidant enzyme (SOD) exhibited an increasing trend throughout the acclimatization period. The SOD activities in the leaves of G. bowringiana seedlings were significantly affected when they were transferred from in vitro to ex vitro conditions due to drought stress. Thus, it was revealed that in the early stages of acclimatizing to the altered environments, G. bowringiana seedlings exhibited a rapid increase in photosynthetic pigments, superoxide dismutase activity, and lipid peroxidation levels after being transferred to ex vitro conditions. Comparison of the leaf micromorphologies of G. bowringiana plants grown under in vitro and those grown under ex vitro conditions revealed that leaf development had undergone significant changes during acclimatization to the altered conditions. In vitro to ex vitro transfer leads to a transient decrease in photosynthetic parameters.

Author(s):  
I. Khomenko ◽  
O. Kosyk ◽  
N. Taran

Due to the aim the effect of pre-sowing treatment with a nonionic colloidal solution of the mix of copper, zinc, manganese and iron nanoparticles, cadmium ions and their combined action on the physiological and biochemical indices: the content of lipid peroxidation products and balance of photosynthetic pigments in green Lolo and red Lolo Ross varieties of Lactuca sativa L. was investigated. Spectrophotometric methods of investigating the content of peroxides, thiobarbiturate-active products (with use of the modified Kumar and Knowles method), as well as the content of the main photosynthetic pigments (chlorophyll a, b, a/b ratio, and the carotenoid content) with the Wintermans, de Mots calculations application were used. Due to the results, a decrease in the content of peroxides and growth of malonic dialdehyde was observed for most treatment variants of Lolo. The opposite tendency was observed for the Ross variety (the initial growth of these parameters under the nanoparticles influence decreased to the control during the fourteen-day exposure). The decrease of chlorophyll content was observed In the Lolo variety under the essential metal nanoparticles influence, in contrast to the action of cadmium.For the Ross variety, a significant reduction of both chlorophyll and carotenoid contents in all treatment types during exposure was calculated.The a/b-index for Lolo plants has significantly increased in variants of cadmium influence, for Ross plants the divergence of the influence of all treatment variants has been marked. As a result, the treatment with a mixture of essential nanometals showed additive stress-loading functions. It was observed in a growth of the level of lipid peroxidation products and the reduction of the photosynthetic pigment biomarkers in both varieties during the 0,1 mM cadmium exposure. The Lolo Ross variety showed a higher variability of results under different treatment, compared to the Lolo variety.


Author(s):  
Udedi Stanley Chidi ◽  
Ani Onuabuchi Nnenna ◽  
Asogwa Kingsley Kelechi ◽  
Maduji Fitzcharles Chijindu ◽  
Okafor Clinton Nebolisa

This study investigated the in-vitro antioxidant activity of ethanol leaf extract of Justicia carnea and its effect on antioxidant status of alloxan-induced diabetic albino rats. The in-vitro antioxidant activity was assayed by determining the total phenol, flavonoids, ascorbic acid, β-carotene and lycopene contents and by using 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, reducing antioxidant power and inhibition of lipid peroxidation antioxidant systems. Oxidative stress was produced in rats by single intraperitoneal injection of 150 mg/kg alloxan and serum concentration of malonaldehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were determined. Five experimental groups of rats (n=6) were used for the study. Two groups of diabetic rats received oral daily doses of 100 and 200 mg/kg Justicia carnea leaf extract respectively while gilbenclamide (5 mg/ml); a standard diabetic drug was also given to a specific group for 14 days. From the result, the leaf extract contained a higher concentration of flavonoids followed byphenols, ascorbic acid, lycopene and β-carotene. The extract displayed more potent reducing power ability with EC50 of 40 µg/ml compared to BHA (EC50 of 400µg/ml). The percentage DPPH radical scavenging activity of the extract was also higher with EC50 of 200µg/ml and increased with increase in concentration while BHA had EC50of 320µg/ml. The inhibition of lipid peroxidation also increased with increase in concentration with EC50 of 58µg/ml and comparable with BHA (EC50=60µg/ml). The effect of the plant extract on antioxidant enzyme activities was concentration-dependent. Administration of 100mg/kg of the plant extract resulted in a significant decrease (p<0.05) in serum MDA concentration, while 200 mg/kg of the extract caused a significant (p˂0.05) increase in superoxide dismutase (SOD) and catalase activities with a non-significant increase (p>0.05) in the serum level of MDA when compared with the diabetic untreated group. These findings suggest that ethanol leaf extract of Justicia carnea have antioxidant properties and could handle diabetes-induced oxidative stress.


2022 ◽  
Vol 46 (1) ◽  
Author(s):  
Patrick Chukwuyenum Ichipi-Ifukor ◽  
Samuel Ogheneovo Asagba ◽  
Chibueze Nwose ◽  
Joseph Chukwufumnanya Mordi ◽  
John Chukwuma Oyem

Abstract Background The probable mechanism of an earlier reported capacity of palm oil extracts to confer protection against high dose cadmium poisoning in rats was reported in this study. Similar experimental design earlier reported by us was retained. Rats therefore were sacrificed at intervals of twelve; twenty four and forty eight hours post CdCl2 insult. Results Oxidative stress and antioxidant status (malondialdehyde, superoxide dismutase, catalase and glutathione) were assessed in tissues (liver, kidney, heart, brain, muscle) and serum. Oxidative stress indicators showed a significantly (p < 0.05) increased lipid peroxidation and alterations in antioxidant defence systems occasioned by drop in catalase and superoxide dismutase enzymes (serum, liver, heart, brain and kidneys) of the rats. Also observed were significant (p < 0.05) reduction in the non-enzymatic antioxidant reduced glutathione over time. Pre-administration of rats with the crude palm oil and its extracts modulated cadmium mediated depletion of the antioxidant capacities of rats acutely exposed to cadmium and rising lipid peroxidation profile. Conclusions Regulation of stress and antioxidant response was the underlying mechanism by which the extracts conferred protection against high dose cadmium insult thus suggesting its potential as a viable therapeutic target against its deleterious effects. Graphical Abstract


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1440
Author(s):  
Amal F. M. Zein El Din ◽  
Mohamed F. M. Ibrahim ◽  
Reham Farag ◽  
Hany G. Abd El-Gawad ◽  
Ahmed El-Banhawy ◽  
...  

Few reports explain the mechanism of PEG action on stomatal behavior and anatomical structure and analyze the photosynthetic pigments of in vitro date palm plantlets for better tolerance to ex vitro exposure. The main challenge for in vitro micropropagation of date palm techniques remains restricted to high survival rates and vigorous growth after ex vitro transplantation. In vitro hardening is induced by Polyethylene glycol PEG (0.0, 10, 20, 30 g L−1) for 4 weeks. Leaf anatomy, stomatal behavior, water loss %, photosynthetic pigments, and reducing sugars were examined in date palm plantlets (Phoenix dactylifera L.) cv. (Sewi) after 4 weeks from in vitro PEG treatment and after 4 weeks from ex vitro transplanting to the greenhouse. Leaf anatomy and the surface ultrastructure of in vitro untreated leaves showed a thin cuticle layer, wide opened malfunctioning stomata, and abnormal leaf anatomy. Furthermore, addition of PEG resulted in increasing cuticle thickness, epicuticular wax depositions, and plastids density, improving the stomatal ability to close and decreasing the stomatal aperture length while reducing the substomatal chambers and intercellular spaces in the mesophyll. As a result, a significant reduction in water loss % was observed in both in vitro and ex vitro PEG treated leaves as compared to untreated ones, which exhibited rapid wilting when exposed to low humidity for 4 h. PEG application significantly increased Chlorophylls a, b and carotenoids concentrations, especially 10, 20 g L−1 treatments, which were sequentially reflected in increasing the reducing sugar concentration. However, leaves of plantlets treated with PEG at 30 g L−1 became yellow and had necrosis ends with death. In vitro hardening by 20 g L−1 PEG increased the survival rate of plantlets to 90% after ex vitro transfer compared to 63% recorded for the untreated plantlets. Therefore, this application provides normal date palm plantlets developed faster and enhances survival after ex vitro transfer.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Garry Duthie ◽  
Philip Morrice

Flavonoids are polyphenolic compounds with potential antioxidant activity via multiple reduction capacities. Oxidation of cellular lipids has been implicated in many diseases. Consequently, this study has assessed the ability of several dietary flavonoid aglycones to suppress lipid peroxidation of hepatic microsomes derived from rats deficient in the major lipid soluble antioxidant, dα-tocopherol. Antioxidant effectiveness was galangin > quercetin > kaempferol > fisetin > myricetin > morin > catechin > apigenin. However, none of the flavonoids were as effective as dα-tocopherol, particularly at the lowest concentrations used. In addition, there appears to be an important distinction between thein vitroantioxidant effectiveness of flavonoids and their ability to suppress indices of oxidationin vivo. Compared with dα-tocopherol, repletion of vitamin E deficient rats with quercetin, kaempferol, or myricetin did not significantly affect indices of lipid peroxidation and tissue damage. Direct antioxidant effect of flavonoidsin vivowas not apparent probably due to low bioavailability although indirect redox effects through stimulation of the antioxidant response element cannot be excluded.


2021 ◽  
Author(s):  
Patrick Chukwuyenum ICHIPI-IFUKOR ◽  
Samuel Ogheneovo ASAGBA ◽  
Chibueze NWOSE ◽  
Joseph Chukwufumnanya MORDI ◽  
John Chukwuma OYEM

Abstract Background: The probable mechanism of an earlier reported capacity of palm oil extracts to confer protection against high dose cadmium poisoning in rats was reported in this study. Similar experimental design earlier reported by us was retained. Rats therefore were sacrificed at intervals of twelve; twenty four and forty eight hours post CdCl2 insult. Results: Oxidative stress and antioxidant status (malondialdehyde, superoxide dismutase, catalase and glutathione) were assessed in tissues (liver, kidney, heart, brain, muscle) and serum. Oxidative stress indicators showed a significantly (p<0.05) increased lipid peroxidation and alterations in antioxidant defence systems occasioned by drop in catalase and superoxide dismutase enzymes (serum, liver, heart, brain and kidneys) of the rats. Also observed were significant (p<0.05) reduction in the non-enzymatic antioxidant reduced glutathione over time. Pre-administration of rats with the crude palm oil and its extracts modulated cadmium mediated depletion of the antioxidant capacities of rats acutely exposed to cadmium and rising lipid peroxidation profile. Conclusions: Regulation of stress and antioxidant response was the underlying mechanism by which the extracts conferred protection against high dose cadmium insult thus suggesting its potential as a viable therapeutic target against its deleterious effects.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1010D-1010
Author(s):  
Hope Jones ◽  
Chieri Kubota

In vitro culture of orchid plantlets within conventional photomixotrophic micropropagation (PMM) systems (sucrose containing media in a non-enriched CO2 environment) often induces vigorous growth and multiplication. However, transition to ex vitro conditions frequently results in significant plantlet loss during the acclimatization process. Recent studies investigating micropropagation within photoautotrophic (PAM) systems (sucrose-free media in enriched CO2 conditions) have demonstrated improved plantlet survival during the acclimatization period due to greater root growth and stomata adaptation. Laelia purpurata var. alba, an orchid with many endangered relatives, was chosen as a model orchid species to investigate if plantlet culture within PAM in vitro systems has the potential to improve propagation success and ex vitro survival of endangered Laelia species. Protocorm-like bodies with developed two fully extended leaves were transferred into PMM (photosynthetic photon flux 50 μmol·m-2·s-1 under non-enriched CO2 conditions) and PAM (photosynthetic photon flux 150 μmol·m-2·s-1, CO2 level enriched to 1500 μmol·mol-1) systems. After 6 weeks, plantlet rooting within the PMM system was variable and inconsistent, while all PAM plantlets produced healthy robust root systems. Average fresh weights and percent shoot development were not significantly different between treatments. Induction of improved root growth by PAM systems may improve orchid plantlet survival rates during acclimatization and advance our ability to increase endangered orchid populations.


1991 ◽  
Vol 261 (4) ◽  
pp. H989-H995 ◽  
Author(s):  
V. Lee ◽  
A. K. Randhawa ◽  
P. K. Singal

The role of free radicals in adriamycin (Adr)-induced acute myocardial changes was examined by using different antioxidants. Exposure of papillary muscles to Adr (100 microM) in a tissue bath for 60 min reduced developed force by 42%, increased lipid peroxidation by 200%, and resulted in characteristic ultrastructural changes. Catalase (4 x 10(4) U/l), an enzyme effective in the hydrolysis of hydrogen peroxide (H2O2), was more effective in maintaining the developed force than mannitol (20 mM), a hydroxyl radical scavenger. A small protection of developed force seen with superoxide dismutase (1.2 x 10(5) U/l), a quencher of superoxide radical, was evident for the first 15 min only. Only catalase and mannitol showed significant protection against Adr-induced increase in lipid peroxidation. Ultrastructural changes due to Adr alone included mitochondrial swelling, intramitochondrial granules, vacuolization, and disruption of sarcomeres. All of these changes were reduced in the presence of both catalase and mannitol, whereas superoxide dismutase was without any effect. Complete structural or functional protection was not seen with any of the antioxidants used in the study. Although both H2O2 and hydroxyl radical appear to be involved in Adr-induced deleterious effects, data on developed force also indicate that H2O2 may have a major role in mediating the acute effects of Adr in vitro.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chandrashekar Annamalai ◽  
Rohit Seth ◽  
Pragasam Viswanathan

Globally, acute kidney injury (AKI) is associated with significant mortality and an enormous economic burden. Whereas iron is essential for metabolically active renal cells, it has the potential to cause renal cytotoxicity by promoting Fenton chemistry-based oxidative stress involving lipid peroxidation. In addition, 1,25-dihydroxyvitamin D3 (calcitriol), the active form of vitamin D, is reported to have an antioxidative role. In this study, we intended to demonstrate the impact of vitamin D on iron-mediated oxidant stress and cytotoxicity of Vero cells exposed to iohexol, a low osmolar iodine-containing contrast media in vitro. Cultured Vero cells were pretreated with 1,25-dihydroxyvitamin D3 dissolved in absolute ethanol (0.05%, 2.0 mM) at a dose of 1 mM for 6 hours. Subsequently, iohexol was added at a concentration of 100 mg iodine per mL and incubated for 3 hours. Total cellular iron content was analysed by a flame atomic absorption spectrophotometer at 372 nm. Lipid peroxidation was determined by TBARS (thiobarbituric acid reactive species) assay. Antioxidants including total thiol content were assessed by Ellman’s method, catalase by colorimetric method, and superoxide dismutase (SOD) by nitroblue tetrazolium assay. The cells were stained with DAPI (4 ′ ,6-diamidino-2-phenylindole), and the cytotoxicity was evaluated by viability assay (MTT assay). The results indicated that iohexol exposure caused a significant increase of the total iron content in Vero cells. A concomitant increase of lipid peroxidation and decrease of total thiol protein levels, catalase, and superoxide dismutase activity were observed along with decreased cell viability in comparison with the controls. Furthermore, these changes were significantly reversed when the cells were pretreated with vitamin D prior to incubation with iohexol. Our findings of this in vitro model of iohexol-induced renotoxicity lend further support to the nephrotoxic potential of iron and underpin the possible clinical utility of vitamin D for the treatment and prevention of AKI.


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