scholarly journals Structural aspects of the antioxidant activity of lutein in a model of photoreceptor membranes.

2012 ◽  
Vol 59 (1) ◽  
Author(s):  
Anna Wisniewska-Becker ◽  
Grzegorz Nawrocki ◽  
Mariusz Duda ◽  
Witold K Subczynski

It was shown that in membranes containing raft domains, the macular xanthophylls lutein and zeaxanthin are not distributed uniformly, but are excluded from saturated raft domains and about ten times more concentrated in unsaturated bulk lipids. The selective accumulation of lutein and zeaxanthin in direct proximity to unsaturated lipids, which are especially susceptible to lipid peroxidation, could be very important as far as their antioxidant activity is concerned. Therefore, the protective role of lutein against lipid peroxidation was investigated in membranes made of raft-forming mixtures and in models of photoreceptor outer segment membranes and compared with their antioxidant activity in homogeneous membranes composed of unsaturated lipids. Lipid peroxidation was induced by photosensitized reactions using rose Bengal and monitored by an MDA-TBA test, an iodometric assay, and oxygen consumption (using EPR spectroscopy and the mHCTPO spin label as an oxygen probe). The results show that lutein protects unsaturated lipids more effectively in membranes made of raft-forming mixtures than in homogeneous membranes. This suggests that the selective accumulation of macular xanthophylls in the most vulnerable regions of photoreceptor membranes may play an important role in enhancing their antioxidant properties and ability to prevent age-related macular diseases (such as age-related macular degeneration (AMD)).

2020 ◽  
Vol 9 (5) ◽  
pp. 1347 ◽  
Author(s):  
Norihiro Nagai ◽  
Sakiko Minami ◽  
Misa Suzuki ◽  
Hajime Shinoda ◽  
Toshihide Kurihara ◽  
...  

To explore predisease biomarkers, which may help screen for the risk of age-related macular degeneration (AMD) at very early stages, macular pigment optical density (MPOD) and photoreceptor outer segment (PROS) length were analyzed. Thirty late AMD fellow eyes, which are at high risk and represent the predisease condition of AMD, were evaluated and compared with 30 age-matched control eyes without retinal diseases; there was no early AMD involvement in the AMD fellow eyes. MPOD was measured using MPS2® (M.E. Technica Co. Ltd., Tokyo, Japan), and PROS length was measured based on optical coherence tomography images. MPOD levels and PROS length in the AMD fellow eyes were significantly lower and shorter, respectively, than in control eyes. MPOD and PROS length were positively correlated in control eyes (R = 0.386; p = 0.035) but not in AMD fellow eyes. Twenty (67%) AMD fellow eyes met the criteria of MPOD < 0.65 and/or PROS length < 35 μm, while only five (17%) control eyes did. After adjusting for age and sex, AMD fellow eyes more frequently satisfied the definition (p < 0.001; 95% confidence interval, 3.50–60.4; odds ratio, 14.6). The combination of MPOD and PROS length may be a useful biomarker for screening predisease AMD patients, although further studies are required in this regard.


Planta Medica ◽  
2019 ◽  
Vol 85 (17) ◽  
pp. 1292-1303 ◽  
Author(s):  
Isabel Martínez-Solís ◽  
Nuria Acero ◽  
Francisco Bosch-Morell ◽  
Encarna Castillo ◽  
María Eugenia González-Rosende ◽  
...  

AbstractLike other tissues of the central nervous system, the retina is susceptible to damage by oxidative processes that result in several neurodegenerative disease such as age-related macular degeneration, diabetic retinopathy, glaucoma, ischaemic retinal disease, retinal disease produced by light oxidation, and detached retina, among other diseases. The use of antioxidant substances is a solution to some health problems caused by oxidative stress, because they regulate redox homeostasis and reduce oxidative stress. This is important for neurodegeneration linked to oxidation processes. In line with this, Ginkgo biloba is a medicinal plant with excellent antioxidant properties whose effects have been demonstrated in several degenerative processes, including retinal diseases associated with neurodegeneration. This review describes the current literature on the role of ginkgo in retinal diseases associated with neurodegeneration. The information leads to the conclusion that G. biloba extracts might be a good option to improve certain neurodegenerative retinal diseases, but more research is needed to determine the safety and efficacy of G. biloba in these retinal degenerative processes.


2006 ◽  
Vol 1 (2) ◽  
pp. 1934578X0600100
Author(s):  
Soumyaditya Mula ◽  
Birija S. Patro ◽  
Govind P. Kalena ◽  
Subrata Chattopadhyay

A novel method for the prenylation of phenols has been developed using 2-methyl-but-3-ene-2-ol as the prenylating agent in the presence of Amberlyst 15. The prenylated catechols and quinols showed better antioxidant activity than the corresponding non-prenylated compounds in the in vitro DPPH and lipid peroxidation assay. The resorcinol derivatives did not show significant antioxidant activity.


2006 ◽  
Vol 3 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Predrag Ljubuncic ◽  
Suha Dakwar ◽  
Irina Portnaya ◽  
Uri Cogan ◽  
Hassan Azaizeh ◽  
...  

Teucrium poliumL. (Lamiaceae) (RDC 1117) is a medicinal plant whose species have been used for over 2000 years in traditional medicine due to its diuretic, diaphoretic, tonic, antipyretic, antispasmodic and cholagogic properties. The therapeutic benefit of medicinal plants is often attributed to their antioxidant properties. We previously reported that an aqueous extract of the leaves and stems of this plant could inhibit iron-induced lipid peroxidation in rat liver homogenate at concentrations that were not toxic to cultured hepatic cells. Others have reported that organic extracts of the aerial components of this plant could inhibit oxidative processes. Against this background, we felt further investigation on the antioxidant action of the extract ofT. poliumprepared according to traditional Arab medicine was warranted. Accordingly, we assessed (i) its ability to inhibit (a) oxidation of β-carotene, (b) 2,2′-azobis(2-amidinopropan) dihydrochloride (AAPH)-induced plasma oxidation and (c) iron-induced lipid peroxidation in rat liver homogenates; (ii) to scavenge the superoxide ($${\hbox{ O }}_{2}^{\bullet -}$$) radical and the hydroxyl radical (OH•); (iii) its effects on the enzyme xanthine oxidase activity; (iv) its capacity to bind iron; and (v) its effect on cell glutathione (GSH) homeostasis in cultured Hep G2 cells. We found that the extract (i) inhibited (a) oxidation of β-carotene, (b) AAPH-induced plasma oxidation (c) Fe2+-induced lipid peroxidation in rat liver homogenates (IC50 = 7 ± 2 μg ml−1); (ii) scavenged $${\hbox{ O }}_{2}^{\bullet -}$$(IC50 = 12 ± 3 μg ml−1) and OH• (IC50 = 66 ± 20 μg ml−1); (iii) binds iron (IC50 = 79 ± 17 μg ml−1); and (iv) tended to increase intracellular GSH levels resulting in a decrease in the GSSG/GSH ratio. These results demonstrate that the extract prepared from theT. poliumpossesses antioxidant activityin vitro. Further investigations are needed to verify whether this antioxidant effect occursin vivo.


1988 ◽  
Vol 64 (5) ◽  
pp. 2092-2099 ◽  
Author(s):  
E. R. Pacht ◽  
W. B. Davis

Lung epithelial lining fluid (ELF) is a thin layer of plasma ultrafiltrate and locally secreted substances that may provide antioxidant protection and serve as a "front-line" defense for the lower respiratory tract epithelium. To characterize the antioxidant properties of ELF, young, healthy, nonsmoking volunteers underwent bronchoalveolar lavage with determination of ELF volumes and ELF proteins. ELF (greater than 0.4 ml) is a potent inhibitor of lipid peroxidation as measured by malondialdehyde (MDA) production in an in vitro iron-dependent assay system. Two serum proteins, transferrin and ceruloplasmin, were quantitated in ELF and found to be potent inhibitors of lipid peroxidation. Other ELF components, including vitamin E, vitamin C, and albumin, did not function as antioxidants in this system. Several experimental observations suggest that ELF transferrin was more important than ceruloplasmin in inhibiting lipid peroxidation: 1) ELF concentrations of transferrin were 20-fold higher than those for ceruloplasmin; 2) ELF antioxidant activity was abolished by preincubation with Fe3+; 3) ELF antioxidant activity was minimally affected by sodium azide, which is known to inhibit ceruloplasmin ferroxidase activity; and 4) ELF ceruloplasmin ferroxidase activity was virtually nondetectable. ELF possesses a significant antioxidant activity that may be important in vivo in protecting the lung from oxidant injury.


2019 ◽  
Vol 20 (12) ◽  
Author(s):  
M Miftahudin ◽  
Rini Hasibuan ◽  
Tatik Chikmawati

Abstract. Miftahudin, Hasibuan RS, Chikmawati T. 2019. Antioxidant activity of ethanolic extract of three Selaginella species from Java Island, Indonesia. Biodiversitas 20: 3715-3722. Three Selaginella species, S. ornata, S. plana, and S. willdenowii, from Java Island, Indonesia, have been known to have antioxidant properties; however, in vivo antioxidant activities of these species have not been reported. This research aimed to evaluate the in vivo antioxidant activity of ethanolic extract of three Selaginella species. The 70% ethanol extract of three Selaginella species at four different doses was administered to mice one day before being treated with oxidative stress. The liver tissue of mice treated with or without oxidative stress was analyzed their lipid peroxidation by measuring MDA concentration and Superoxide Dismutase (SOD) activities. The results showed that there were variations in antioxidant activity among the three Selaginella species. In general, the dose of 0.3 g extract kg-1 BW has been able to reduce lipid peroxidation and increase SOD activity. The administration of S. ornata extract to the mice at 1.2 g extract kg-1 BW reduced the MDA concentration to the lowest level, but the same dose of two other Selaginella extracts caused toxic effects in mice. The antioxidant activities of S. ornata and S. plana were better than that of S. willdenowii extract, and among those species, S. ornata has the best antioxidant activity.


2018 ◽  
Vol 31 (4) ◽  
pp. 186-189
Author(s):  
Anatolii Gordiienko ◽  
Mykola Blazheyevskyi ◽  
Ivan Iurchenko

Abstract For comparative purposes, a quantitative estimation of antioxidant activity of phenolic compounds of different classes was conducted by way of the polarography method, via the ADP-Fe2+ model of the induced ascorbate-dependent lipid peroxidation of rat liver micro-somes within an in-vitro system. As a result, it was recognized that the antioxidant properties of phenolic compounds depend on the nature and chemical structure of several substances. In respect of such activity, leaders in the classes of investigated polyphenolic compounds are: Propyl gallate = Gallotannin (Phenolcarboxylic acids and their derivatives) > Quercetin = Myricetin (Flavonols) > Luteolin (Flavo n) = Mangiferin (Xanthones) > Kaempferol (Flavonols) = Catechin (Flavans). Thus, the assessment of the inhibition ability of the lipid peroxidation of microsomes by phenolic compounds can be used as an accessible test for the preliminary quantitative estimation of their antioxidant properties.


2020 ◽  
Vol 13 ◽  
Author(s):  
Methiye Mancak Karakuş ◽  
Ufuk Koca Çalışkan

Background: Tissue cells of the eye are sensitive to oxidative stress leading to oxidative damage and inflammation, which have crucial roles in the pathogenesis of most of the eye diseases. Moreover, factors such as age, angiogenesis, ischemia, genetic predisposition, diabetes, obesity, and smoking affect the onset and progression of ocular anomalies. Major eye diseases are either age-related such as Age-related macular degeneration, cataracts, diabetic retinopathy, glaucoma, dry eye, or inflammatory eye diseases such as blepharitis, conjunctivitis, uveitis and other retinal pathologies, which can cause ocular damage and visual problems through oxidative stress, inflammation pathways. Although there are conventional chemical or surgical treatments, due to their mainly antiapoptotic, anti-inflammatory and antioxidant properties, phytotherapeutic preparations and their natural compounds can be applied to prevent or treat eye disease as follows: oral, topical or both. Thus, this study aims to comprehensively evaluate the pre-clinical and clinical studies of the phytotherapeutics and natural compounds used in the prevention and treatment of common serious and painful eye diseases. Moreover, for the first time, nature-derived preparations/supplements commonly used for eye problems also included in this review to present applications of the extracts/compounds in the pharmaceutical field.


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