Antioxidant Properties of Carnosine Re-evaluated in a Ferrylmyoglobin Model System and in Cooked Pork Patties

2002 ◽  
Vol 50 (24) ◽  
pp. 7164-7168 ◽  
Author(s):  
Charlotte U. Carlsen ◽  
Maiken Kröger-Ohlsen ◽  
Marianne Nissen Lund ◽  
Tina Lund-Nielsen ◽  
Birgitte Rønn ◽  
...  
1997 ◽  
Vol 41 (4) ◽  
pp. 743-747 ◽  
Author(s):  
K Osaka ◽  
V B Ritov ◽  
J F Bernardo ◽  
R A Branch ◽  
V E Kagan

The antifungal effects of amphotericin B are believed to be due to two possibly interrelated mechanisms: an increase in permeation by binding to sterols in cellular membranes and a prooxidant effect causing oxidative damage in target cells. However, the seven conjugated double bonds in amphotericin B raise the possibility that it could be highly susceptible to autoxidation, causing an antioxidant effect. In the present study, we investigated the prooxidant and antioxidant properties of amphotericin B in a model system in which oxidation of a reporter molecule, cis-parinaric acid, was induced by azo initiators of peroxyl radicals. Since interactions of amphotericin B with sterols are essential for its pharmacological and toxic actions, we also studied the effects of cholesterol on the prooxidant and antioxidant properties of amphotericin B. Amphotericin B caused a noncollisional quenching of a characteristic fluorescence of cholesteryl cis-parinarate integrated in liposomes, suggesting the formation of amphotericin B-cholesteryl cis-parinarate complex. This effect of amphotericin B was ablated by increasing concentrations of cholesterol. We found that amphotericin B inhibited oxidation of cis-parinaric acid complexed with human serum albumin [using a water-soluble azo initiator, 2,2'-azobis(2aminopropane)dihydrochloride] and in liposomes [using a lipid-soluble azo initiator, 2,2'-azobis(2,4-dimethylvaleronitrile)]. The inhibitory effect of amphotericin B on 2,2'-azobis(2,4-dimethylvaleronitrile)-induced peroxidation of cis-parinaric acid in liposomes was also diminished by cholesterol. The antioxidant effect of amphotericin B in this model system suggests that amphotericin B does not exert its pharmacological and toxicological responses through a prooxidant effect to cause damage in target cells.


2019 ◽  
Vol 37 (No. 4) ◽  
pp. 268-275
Author(s):  
Jan Bedrníček ◽  
Ivana Laknerová ◽  
Zuzana Linhartová ◽  
Jaromír Kadlec ◽  
Eva Samková ◽  
...  

Onion skin is a waste produced in thousands of tons annually in the European Union. It is a rich natural source of flavonoids and its water extracts (as an environmentally friendly solvent) could be used as an antioxidant material for meat products. Therefore, antioxidant properties of onion skin water extracts (OSWEs) were tested on cooked pork patties. Pork patties were divided into five treatments: control (no antioxidant), 10 and 20% (w/w) of yellow OSWE, and 10 and 20% (w/w) of red OSWE. Antioxidant activity, total polyphenols, thiobarbituric acid reactive substances (TBARS), and sensory analysis were assessed. Patties with added antioxidants showed significantly (P < 0.05) higher antioxidant activity and total polyphenol content. Samples with OSWEs, after 5-day storage (5°C), had significantly (P < 0.05) lower TBARS values compared to control. Two main phenolic compounds were identified in OSWEs by liquid chromatography – mass spectrometry using electrospray ionisation in negative mode: quercetin (m/z 301) and quercetin monoglucoside (m/z 463). OSWEs demonstrated the potential to be used as a source of natural antioxidants with strong antioxidant activity in meat products.


1992 ◽  
Vol 69 (6) ◽  
pp. 545-551 ◽  
Author(s):  
M. F. King ◽  
L. C. Boyd ◽  
B. W. Sheldon

2021 ◽  
Vol 9 (4) ◽  
pp. 21-29
Author(s):  
Sh. N. Galimov ◽  
Yu. Yu. Gromenko ◽  
I. D. Gromenko ◽  
K. Sh. Galimov ◽  
I. R. Gilyazova ◽  
...  

Introduction. According to the results of numerous studies and meta-analyses, the effectiveness of male infertility therapy with micronutrients-antioxidants in various variants remains low, especially concerning the increase in live-birth rates and the incidence of clinical pregnancy. This may be due to both the empirical nature of such therapy with an imbalance of ejaculate redox systems, and an overdose of individual ingredients of antioxidant complexes.Purpose of the study. To evaluate the antioxidant activity of complex preparation based on L-carnitine for the treatment of male infertility in an experimental model system.Materials and methods. The dietary supplements «AndroDoz®» («Nizhfarm» JSC, Russian Federation) and «Proxeed® plus» (Sigma-Tau Pharmaceuticals Inc., Italy) were tested. The antioxidant properties of the preparations were determined in vitro by recording chemiluminescence in model systems generating reactive oxygen species using the «LKB-Wallac 1256 chemiluminometer» (Wallac Oy/PerkinElmer®, Finland). Chemiluminescence was evaluated by the light sum and the maximum amplitude of the glow, the antioxidant activity in the biological environment was studied when adding drugs to chicken yolk lipids similar to blood lipoprotein complexes.Results. The introduction of «AndroDoz®» and «Proxeed® plus» into the incubation medium in an amount comparable to the physiological level of L-carnitine in seminal plasma, inhibited the luminescence of the model system. At the same time, if «Proxeed® plus» almost completely inhibited the formation of radicals, then an equivalent dose of «AndroDoz®» reduced the intensity of chemiluminescence by 60%. Approximately in the same proportions, the preparations suppressed the intensity of lipid peroxidation processes in a model system with lipoprotein complexes similar to blood lipids, that is, the antioxidant activity was preserved in the biological environment. A decrease in the value of the chemiluminescence light sum was also found against the background of the use of these dietary supplements, which may indicate their protective effect on biological membranes, including subcellular structures of spermatozoa.Conclusion. The combined dietary supplements used in the study have a high antioxidant potential. The preparation «Proxeed® plus» can completely suppress the processes of lipoperoxidation with the possible development of a deficiency of free radicals that provide vital processes. The preparation «AndroDoz®» has a milder effect on free-radical phenomena probably due to a lower content of active ingredients and a balanced composition, which reduces the risk of complications in the form of an «antioxidant paradox» or reductive stress.


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