β-carotene as an interceptor of free radicals

Ozhogina, O. A.; Касаикина, О. Т.

doi:10.1016/0891-5849(95)00064-5

Cited by 62 publications

(34 citation statements)

References 9 publications

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“…Particularly, it can exert antioxidant function at low oxygen tension (Ozhogina and Kasaikina 1995). Beta carotene concentration decreased at 120 min and 24 h in the XTZ group (p < 0.05), while it decreased only at 120 min in the FTZ group (p < 0.05).…”

Section: Discussionmentioning

confidence: 93%

Comparison between Xylazine-Tiletamine-Zolazepam and Fentanyl-Tiletamine-Zolazepam Anaesthetic Combinations on Plasma Oxidative Status in Sheep

Aydılek

2007

Acta Vet. Brno

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It is important to determine varying effects of anaesthetics agents. One of the adverse effects of general anaesthetics are the exogenous sources of reactive oxygen species. In this study, the effects of xylazine-tiletamine-zolazepam (XTZ) and fentanyl-tiletamine-zolazepam (FTZ) combinations on plasma oxidant-antioxidant indicators were compared in sheep. Ten ewes received two different anaesthetic combinations in a ten-day interval. XTZ group was injected with xylazine and tiletamine-zolazepam. FTZ group was injected with fentanyl and tiletamine-zolazepam. Blood samples were collected before and at the 30, 60, 120 min, 24 h and 3 days after anaesthesia. Both anaesthetic regimens caused an increase in malondialdehyde (MDA) concentrations in plasma. The MDA concentrations at 60, 120 min and 24 h in the XTZ group were significantly higher than in the FTZ group. Glutathione (GSH) concentration at 30, 60, 120 min and 24 h was significantly lower than baseline values in XTZ group, while there was only a decrease at 120 min in the FTZ group. GSH concentrations in the XTZ group were significantly lower at 60 and 120 min compared with the FTZ group. Beta carotene concentration was decreased at 120 min and 24 h in the XTZ group, while it decreased only at 120 min in the FTZ group. Glutathione peroxidase (GSH-Px) and catalase (CAT) activities decreased at 120 min and 24 h only in the XTZ group. There were no significant differences in -carotene concentration, activities CAT and GSH-Px activities between groups. In conclusion, both XTZ and FTZ anaesthetic regimens induced oxidative stress in sheep. XTZ combination has more detrimental effect than FTZ combinations on particularly MDA and GSH concentrations. Therefore, FTZ anaesthetic combination is considered to be more suitable for sheep anaesthesia, due to less deteriorating effects on oxidant/antioxidant balance. Anaesthesia, oxidative status, sheepGeneral anaesthesia is commonly used for surgical manipulations in small ruminants. An anaesthetic regimen with minimal side effects is desirable when anaesthesia is required for longer than 1 h in sheep (Lagutchik et al. 1991). One of the undesirable complications of general anaesthetics can be induced by reactive oxygen species (ROS) that occur during anaesthesia (Godin and Garnett 1994). Reactive oxygen species are produced as by-products of metabolism. In organisms, enzymatic (superoxide dismutase, catalase, glutathione peroxidase) and non-enzymatic (urate, cysteine, vitamin E, vitamin C, β-carotene) antioxidant defence systems maintain ROS concentrations in the physiological range. Oxidative stress occurs when the balance between ROS and antioxidants defence is disturbed. ROS cause cellular destruction by oxidative damage of DNA, proteins, lipids and carbohydrates, by changing the structure and function of key cellular constituents that result in mutation, cell damage and death (Simeonova et al. 2004). Thus, ROS play an important role in the pathogenesis of different diseases such as inflammation, carcinogenesis and isch...

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Section: Discussionmentioning

confidence: 93%

Comparison between Xylazine-Tiletamine-Zolazepam and Fentanyl-Tiletamine-Zolazepam Anaesthetic Combinations on Plasma Oxidative Status in Sheep

Aydılek

2007

Acta Vet. Brno

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“…The independence of MFI from β-carotene concentration indicates that the reactions of vinyl groups do not always lead to the chain extension of the polymer, though the latter is characteristic for the degradation of Phillips type polyethylenes [10]. This can be attributed to the radical trapping ability of β-carotene at low oxygen concentrations [31,41,42]. β-carotene protects the polymer from oxidation during processing.…”

Section: Processing Stabilitymentioning

confidence: 99%

“…In the absence of β-carotene the polymer oxidises slightly (0.042 mmol C=O/mol PE), but carbonyl groups are not formed when the concentration of reacted β-carotene is ≥200 ppm. These results can be explained by the reactivity of β-carotene towards oxygen and different radicals (carbon-centred, oxy) [30,31,39]. β-Carotene reacts fast with molecular oxygen present in small concentrations in the extruder and hinders the formation of peroxy macroradicals which are the precursors of oxidised derivatives.…”

Section: Processing Stabilitymentioning

confidence: 99%

“…It can even prevent the photosensitisation of human skin [40]. According to Ozhogina and Kasaikina [31] β-carotene reacts primarily by the addition of free radicals to its conjugated system. The radical-trapping behaviour of β-carotene depends on the partial pressure of oxygen [41,42].…”

Section: Introductionmentioning

confidence: 99%

“…Oxidation results in a change of colour to orange or red, the powder becomes similar in appearance and composition to laboratory samples available commercially [25]. The oxidation of β-carotene with molecular oxygen is an autocatalytic free radical process which leads to the formation of different epoxycarotenoids, apocarotenals, small molecular mass products, and some oligomeric/polymeric materials, some of them representing the key aroma compounds in certain flowers, vegetables, and fruits [28][29][30][31][32][33]. The initial site of the oxygen attack on the β-carotene molecule occurs at the terminal double bonds resulting in predominant formation of epoxides [30,34].…”

Section: Introductionmentioning

confidence: 99%

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Study of the effect of natural antioxidants in polyethylene: Performance of β-carotene

Tátraaljai

Major

Földes

et al. 2014

Polymer Degradation and Stability

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The effect of β-carotene on the behaviour of polyethylene stabilized with α-tocopherol and a phosphonite antioxidant was studied under processing and storage conditions. The amount of β-carotene ranged between 0 and 2000 ppm. The polymer was characterised by different methods after processing then during and after storage at ambient temperature in light and dark. β-Carotene hinders the oxidation of polyethylene and does not increase the chain extension reactions during processing, though more vinyl groups and phosphonite molecules react. β-Carotene colours polyethylene strongly already at low concentrations. The reactions of the polymer and β-carotene are affected strongly by the storage conditions. The presence of β-carotene does not influence the stabilizing efficiency of the primary and secondary antioxidants. In dark the molecular structure of the polymer does not change appreciably, while the reactions of β-carotene lead to an increase in the yellowness index. In light the molecular characteristics of polyethylene undergo significant changes indicating long chain branching. The polymer fades rapidly after an induction period. The length of the induction period is not influenced by light. The rate of the degradation reactions of β-carotene during storage is controlled by its concentration and film thickness. Visible autoaccelerated decomposition in light renders β-carotene candidate as an indicator in active packaging materials.

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β-Carotene and lipid oxidation

Yanishlieva¹,

Aitzetmüller²,

Raneva

1998

Fett/Lipid

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demonstrated six different b-carotene-plus-vitamin A-ester patterns in European margarines [43,45].Balz et al. [46] succeeded in separation of all-trans retinol, its cis isomer and their esters, b-carotene and the four tocopherols, the four tocotrienols, and tocopheryl acetate by HPLC using a nitro column and a three-step gradient elution with n-hexane and tert-butyl methyl ether mixtures.b-Carotene has the highest provitamin A activity of all carotenoids and is often used in foods, e.g. in extruded maize products [47]. It occurs widely as a lipoprotein complex in all green parts of plants. It is found in abundance in carrots, some tropical fruits such as papayas and mangoes, and in all dark green leafy vegetables.Carotene research has progressed rapidly in the past few years. Burri [48] recently discussed the important new developments in b-carotene research, and provided an interpretation of how these results reflect the impact of b-carotene on human health.The recent renewed interest in carotenoids can be partly attributed to the role of b-carotene in reducing the risk of certain cancers through a mechanism that does not require its conversion to vitamin A [49], as well as to its postulated high effectivity in preventing coronary cardiac disease [50].b-Carotene predominantly exists in all-trans, 9-cis, 13-cis and 15-cis forms [51]. In nature, mainly the all-trans form of b-carotene occurs [52]. A separation of trans and cis isomers of b-carotene can be performed by HPLC [53] and SFC [54,55]. Strohschein et al. [56] reported the structure elucidation of b-carotene isomers by NMR coupled to reversed-phase HPLC (RP-HPLC) using a C 30 -bonded-phase column. Oxidation of b-CaroteneThe antioxidative behaviour of b-carotene is closely related to its own oxidation. The kinetics of its oxidative degradation at different conditions, as well as the structure of the products formed allow the mechanism of its action in the oxidation process to be clarified.Because of the conjugated double-bond structure of the molecule, b-carotene is highly reactive to molecular oxygen. On exposure to air, the UV-VIS absorption at the maximum wavelength drops to 25% of its initial value in 6 weeks at 20°C either in darkness or in light [57]. It is almost completely destroyed at 45°C in air after 6 weeks [57].Light, elevated temperature, the nature of the solvent, the acidity of the medium, the presence of unsaturated fatty acids, and other factors affect the oxidative decomposition of the carotene molecule [58]. Free radical oxidation and products formedHunter and Krackenberger [59] oxidized b-carotene at 50 °C in benzene and in peanut oil, and found that the rate of the oxidation process was much higher in benzene than in the oil. They attributed this fact to the presence of a natural antioxidant in the peanut oil. b-Carotene was more easily oxidized in air at 37°C when the process was carried out in ethyl linoleate as compared with butanol as solvent [60]. The observed effect should be explained with the high oxidizability of pure ethyl l...

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β-carotene as an interceptor of free radicals

Cited by 62 publications

References 9 publications

Comparison between Xylazine-Tiletamine-Zolazepam and Fentanyl-Tiletamine-Zolazepam Anaesthetic Combinations on Plasma Oxidative Status in Sheep

Comparison between Xylazine-Tiletamine-Zolazepam and Fentanyl-Tiletamine-Zolazepam Anaesthetic Combinations on Plasma Oxidative Status in Sheep

Study of the effect of natural antioxidants in polyethylene: Performance of β-carotene

β-Carotene and lipid oxidation

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