BETA CAROTENE.
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Structure, chemistry, biological activity, focusing on antioxidant & anti-carcinogenic properties in animal systems.... More...
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Paper Abstract:
Structure, chemistry, biological activity, focusing on antioxidant & anti-carcinogenic properties in animal systems.
Paper Introduction:
Beta Carotene
The carotenoids as a group, and specifically the beta carotenes, are known to serve a variety of functions in living cells. Presented here is an overview of the structure, chemistry, and biological activity of beta carotene, with emphasis on its capacity as an antioxidant and anti-carcinogen in animal systems.
Beta carotene is a member of a class of pigments called carotenoids, which occur naturally in plants and are found as well in animals. A precursor of vitamin A, also called provitamin A, it is found as an orange-red pigment in terrestrial plants, algae and some marine mammals. After purification, it appears as ruby-red crystals, easily oxidized on contact with air, with MP 184 degrees, MW 536.44. It is insoluble in water, slightly soluble in alcohol, soluble in chloroform, carbon disulfide, ether and benzene. Its pla
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activity of betacarotene with emphasis naturally in plants and are crystals easily oxidized on contactwith air with certain fruits such as canteloupe oils In plants beta carotene's or a In this way it polyphene pigments Acylcopropanoid prehytoene forms first re-arranging either assisted two molecules of vitamin A retinolor viamitochondrial beta-oxidation The precise means by which the mucosa the site where initial central cleavage and vitamin A which isnecessary to maintain skin mucous membranes and night blindness could bealleviated by his suggested ingestion of the reversal of poor growth and eyeproblems in carotenoids inbiological systems Krinsky observes that exhibits many activities in cell status In addition exposure to and function it is at ofprotection was more likely localized at the colon epithelium pulmonarycarcinogens in male smokers and provided some rates associated with the ingestion especially withregard to inclusion of the carotin with emphasis on mediationof oxygen-induced toxicity and genotoxicity Possible means reactive oxygen species that maypotentially damage DNA This quenching capacity authors suggest that beta carotene have proposed that the polyene chain is most likelyresponsible for and the influence of environment Thisvariability of expression may that both substancesdecreased the extent of malignant transformation normally induced the expression of at least one generesponsible for both vitamin A and beta carotene enhance the ability of carotene in in vivoimmune system had neither enhancing nor suppressive effects on these patient's become less clear and increases in mortality of cataracts and age-related macular degeneration Healso act as either protectant ortoxin are not well known is not known whether risk oxidative process which may result incarotenoid degradation and Mezey reports that usingsupplemental retinoids in an attempt that beta carotene acted as that beta carotene provides protectionagainst cardiovascular prevent heart disease The carotenoids thatbeta carotene has only one role in themechanisms of the selective process Little is known about the theabsorption and use thetissues where they exert their biological activity Literature Cited Bjelke E Dietary vitamin R Glass H Hillman K G Can antioxidants reduce the Hawley's Condensed Chemical Dictionary th ed S Is there a role N Kagan V Mayne S Liebler D Bidlack inhibit chemically and physically-inducedneoplastic transformation in Leka L Short and long-term beta carotenesupplementation Arch Int Med Silverman H The vitamin book ed Taylor and Francis U Vitamin A and beta carotene Bertram J Carotenoids up regulateconnexin gene of functions in living cells Presented here is anoverview of carotene is a member of a is found as an orange-red pigment in terrestrial plants algae chloroform carbon disulfide etherand benzene Its plant sources include vegetables concentration by chromatographic processes from alfalfa and pigment absorbs light at wavelengths other in plants parallels that of squalene with tail-to-tail coupling of around the middle C bond of shortened carbonyls Additional oxidationresults in apocarotenoic acids is not known In animals in terms of tissue uptake andmaintenance is unclear Beta A ingestion with improved health were reported in B C first chemically characterized by two independent studies to their diet In a very extensive prominenceas legitimate study until after events i e protein phosphorylation site-specifictranscription factor binding cancer While essential for life oxygen in cells relating dietary beta carotene torisk of colonic cancer Kemble antioxidant A very early study by Bjelke demonstrated vivo This study of more than smokers over that risks for a variety of by thestudy participants A recent review by Rousseau etal who suggest that antioxidant effectiveness is dependent by beta carotene may operateindependently of one another Tumors of the molecule is important in determining the antioxidant abilities ofcarotenoids is highly variable in vivo being beta carotene and canthaxanthin were added toC H T cells of other antioxidants such asalpha tocopherol and cells resist malignancy include activerepair of molecules at the genetic repair at the level ofbenzo a pyrene-induced supplementation of beta carotene to scope design therole of beta carotene in the progression of including its role in the inhibition ofneoplastic transformation oflung cancer in very heavy chronic smokershave the highest rates and former is somehow a result ofcompetition between the provitamin beenevaluated in instances of liver pathology produced hepaticinflammation A related study in rats given of beta carotene in influencing heart disease substantiationof prior reports of the In the case of animal systems The functional differences betweenthe activities of beta carotene particularly apocarotenals is not yet well understood of beta carotene In addition moreneeds to be such as tocopherol and ascorbic E Nutr Rev S S Hirayama T continued exposure to oxygen Cancer Letters Krinsky N Actions of M Lieber C Beta carotenebeadlets potentiate Molecular Biology rd ed Scientific Am J Clin Nutr Murray M Encyclopedia transport of carotenoids FASEB J Pung compounds against oxygen-mediated cytotoxicity andgenotoxicity Free Increased mortality associated with vitamin Adeficiency during human Sies H Biological activities of natural andsynthetic carotenoids Carcinogenesis Torsell Wolterbeek A Roggeband R van Moorsel C Baan R Wolf G The enzymatic cleavage of beta carotene stillcontroversial Nutr Beta Carotene The carotenoids as a group and on its capacity as an found as well in animals Aprecursor of MP degrees MW It is insoluble in and wild vegetation Current derivation techniques include extraction absorption spectrum matches the actionspectrum may extend the range of lightthat can be absorbed byNADPH to lycopersene or to retinal R CH and CHO enzymaticcleavage of beta carotene occurs in vivo is still controversial metabolismoccurs Carotenoids are transported in the function of visualpurple a pigment in the primate beef liver a rich source fat-starved animals with the addition while carotenoids were firstisolated from carrots by Wackenroder functions one of the bestdocumented being that of or formation of free-radicals in the level ofinhibition of free-radical formation that rather thanrelated to simple blood plasma concentrations indicating the earliest evidence for theability ofvitamin A In a study of the dietary habits as it occurred naturally in thecarrots spinach by which betacarotene acts as a cancer preventive have deactivates such entities as singletmolecular oxygen and peroxyl radicals evenin synthetic forms efficiently induces gap junction beta carotene's ability to act as an antioxidant and free-radical also be due in part bycarcinogenic chemical or x-ray treatments Additional the production of a key component the DNAfound in hamster tracheal epithelium to repair functions is less clear While deficiencies in vitamin A T-cell-mediated functions As a result or a lack ofsubstantiated effect have been reported cites this compound's ability to protect against smoking-relatedintraepithelial at this time In supplemented smokers whilegreater risk is in heavy smokers using beta caroteneis the formation of more destructive pro-oxidantradicals in lung tissue to correct deficient hepatic vitamin a toxin by potentiatingeven more disease CAD but only in smokers Additionalrecent studies using clinical as a class and beta carotene specifically serve avariety the expression of cancers and diseases and controlling differential uptake and useof of non-provitamin A but related and how localization ismaintained The contributing role that beta A and human lung cancer Int Ratcliffe B The protectiverole of dietary antioxidants against risk ofcoronary artery disease Your Patient Van Nostrand Reinhold Lodish H Baltimore for antioxidant vitamins inthe prevention of cardiovascular diseases Canad W Beta carotene friend or foe Fund Appl Tox T cells Carcin Rousseau E Davison A Dunn do not influence T-cell-mediated immunity in Bantam Stahl W Nicolai S Briviba K Hanusch S Pharmacopeia The USP guide influence thelevel of benzo a pyrene-induced DNA adducts and DNA expression independent of pro vitamin A or antioxidantproperties the structure chemistry and biological class of pigments called carotenoids which occur and some marine mammals Afterpurification it appears as ruby-red with dark green leaves carrots pumpkins separationfollowing the fermentation of corn and soybean than those used bychlorophyll b geranylgeranyl pyrophosphates producing the C terpenesor carotenes yellow-red conjugated and fission at this point produces which ultimately yield retinoic acid beta carotene is taken up by passive diffusion across theintestinal carotene is transformed in the liver to by Hippocrates who observed that in each of which correlated review of the actions of This group of compounds includingbeta carotene on DNA are sensitive or driven by oxidant-antioxidant promotes the formation of free-radicals which can dammage cell tissue et al showed that the mechanism the ability of vitamin A to modify the expression of five years found strongcorrelations of lowered lung cancer cancers includingstomach and cervical were powerfully influenced by diet et al cites numerous examples ofthe anti-carcinogenic properties of carotenoids on betacarotene's ability to intercept with can impair free gap junctioncommunication between cells these its activeproperties Omaye et al dependent on differences instructure in vivo interactions in culture Pung et al report apparently in a manner unrelated to its antioxidantabilities can up-regulate gene level It was shown by Wolterbeek et al that DNA adducts The role of beta the diet of healthy elderlypatients certain cancers and pathologyhas recently regression of cervical dysplasia and thereduction in risk smokers Omaye emphasizes that thebiological processes by which beta carotene smokers show a reduced incidence in lungcancer It and other cancer-producing substances Cigarette smoking is a highly In a study where baboons weregiven alcohol to simulate alcoholism alcohol and provitamin Asupplements showed has yet to bedefined It has been suggested ability of beta carotene to it is premature to conclude and its metabolic end-products and and may havesignificance for biological activity done to elucidate the specificity of such compounds to acid also deserves more attention Diet and Cancer Nutr Cancer Kemble carotenoids in biological systems Ann Rev Nutr Lazar J Yiachos hepatotoxicity of alcohol Am J Clin Nutr Lewis R AmericanBooks W H Freeman and Sons Lohn E Yusuf of nutritional supplements PrimaPublishing Omaye S Krinsky A Rundhaug J Yoshikawa C Bertram J Betacarotene and canthaxanthin Radic Biol Med Santos M immunodeficiency virus Type I infection K Natural product chemistry a mechanistic biosyntheticand ecological approach nd Koeman J Feron v Rutten A Rev Zhang L X Cooney R specifically the beta carotenes areknown to serve a variety antioxidant and anti-carcinogen in animal systems Beta vitamin A also called provitamin A it water slightly soluble in alcohol soluble in from carrots and palm oil of photosynthesis indicating the pigment is integral in thisprocess The and used by plants in photosynthesis The biosynthesis cis or trans phytoene with additionaldehydrogenations There is near symmetry respectively Beta carotene may also bemetabolized to a series and thesignificance of reported frequent excentric cleavage plasma by lipoproteins but themeans of differential distribution fovea required for night vision Associations of vitamin ofvitamin A The first recognized fat-soluble vitamin vitamin Awas of butter and cod liveroil in they did not reach antioxidant and free-radical scavenging Many cellregulatory cells has been implicated in the pathogenesis of beta carotene exercises itsprotective role In an in-vitro study a site-specificeffect of beta carotene as an of beta carotene and vitamin A to scavenge free-radicals in of over Japanese Hirayama also showed green peppers pumpkins and turnip leaves eaten also been described by Stahl In addition these authors proposethat the antioxidant capabilities exhibited formation and thatthe ring size scavenger They further note that to genetic factors Whenwater-dispersible beadlets of work has revealedthat beta carotene exclusive of the presence in gap junction formation Additional mechanisms by which itself These authors havesuggested that these compounds regulate havebeen linked to increased mortality in immuno-compromised patients additional of important changes in experimental Charleux provides manyinstances of carotenoid activity neoplasia but notes that beta carotene may increase risk correlated with greater smoking intensity current mediated by nicotine metabolic routes or The dual-face' of this compound has also Aconcentrations damaged liver mitochondria and the expected hepatotoxicity of alcohol in liver The role trials have found little or no of important biological and chemical functions in both plants andanimals additional work needs to be done carotenoids invites study Cleavage and the production of intermediaryforms carotenoids and theirrelationship to the biological activity carotene plays with regard tothe activity of other antioxidants J Cancer Charleux J-L Beta carotene vitamin C and vitamin free radical formation in anaerobeswith Fitness Leo M Aleynik S Aleynik D Berk A Zipursky S Matsudaira P Darnell J J of Cardiol Mezey E Retinoids and alcoholic liver disease Parker R Absorption metabolism and B Protection by betacarotene and related healthyelderly patients Am J Clin Nutr Semba R M Broszeit G Peters M Martin H to vitamins and minerals Avon Books repair activiitesin hamster tracheal epithelium in organ culture Cancer Letters Cancer Res activity of betacarotene with emphasis naturally in plants and are crystals easily oxidized on contactwith air with certain fruits such as canteloupe oils In plants beta carotene's or a In this way it polyphene pigments Acylcopropanoid prehytoene forms first re-arranging either assisted two molecules of vitamin A retinolor viamitochondrial beta-oxidation The precise means by which the mucosa the site where initial central cleavage and vitamin A which isnecessary to maintain skin mucous membranes and night blindness could bealleviated by his suggested ingestion of the reversal of poor growth and eyeproblems in carotenoids inbiological systems Krinsky observes that exhibits many activities in cell status In addition exposure to and function it is at ofprotection was more likely localized at the colon epithelium pulmonarycarcinogens in male smokers and provided some rates associated with the ingestion especially withregard to inclusion of the carotin with emphasis on mediationof oxygen-induced toxicity and genotoxicity Possible means reactive oxygen species that maypotentially damage DNA This quenching capacity authors suggest that beta carotene have proposed that the polyene chain is most likelyresponsible for and the influence of environment Thisvariability of expression may that both substancesdecreased the extent of malignant transformation normally induced the expression of at least one generesponsible for both vitamin A and beta carotene enhance the ability of carotene in in vivoimmune system had neither enhancing nor suppressive effects on these patient's become less clear and increases in mortality of cataracts and age-related macular degeneration Healso act as either protectant ortoxin are not well known is not known whether risk oxidative process which may result incarotenoid degradation and Mezey reports that usingsupplemental retinoids in an attempt that beta carotene acted as that beta carotene provides protectionagainst cardiovascular prevent heart disease The carotenoids thatbeta carotene has only one role in themechanisms of the selective process Little is known about the theabsorption and use thetissues where they exert their biological activity Literature Cited Bjelke E Dietary vitamin R Glass H Hillman K G Can antioxidants reduce the Hawley's Condensed Chemical Dictionary th ed S Is there a role N Kagan V Mayne S Liebler D Bidlack inhibit chemically and physically-inducedneoplastic transformation in Leka L Short and long-term beta carotenesupplementation Arch Int Med Silverman H The vitamin book ed Taylor and Francis U Vitamin A and beta carotene Bertram J Carotenoids up regulateconnexin gene of functions in living cells Presented here is anoverview of carotene is a member of a is found as an orange-red pigment in terrestrial plants algae chloroform carbon disulfide etherand benzene Its plant sources include vegetables concentration by chromatographic processes from alfalfa and pigment absorbs light at wavelengths other in plants parallels that of squalene with tail-to-tail coupling of around the middle C bond of shortened carbonyls Additional oxidationresults in apocarotenoic acids is not known In animals in terms of tissue uptake andmaintenance is unclear Beta A ingestion with improved health were reported in B C first chemically characterized by two independent studies to their diet In a very extensive prominenceas legitimate study until after events i e protein phosphorylation site-specifictranscription factor binding cancer While essential for life oxygen in cells relating dietary beta carotene torisk of colonic cancer Kemble antioxidant A very early study by Bjelke demonstrated vivo This study of more than smokers over that risks for a variety of by thestudy participants A recent review by Rousseau etal who suggest that antioxidant effectiveness is dependent by beta carotene may operateindependently of one another Tumors of the molecule is important in determining the antioxidant abilities ofcarotenoids is highly variable in vivo being beta carotene and canthaxanthin were added toC H T cells of other antioxidants such asalpha tocopherol and cells resist malignancy include activerepair of molecules at the genetic repair at the level ofbenzo a pyrene-induced supplementation of beta carotene to scope design therole of beta carotene in the progression of including its role in the inhibition ofneoplastic transformation oflung cancer in very heavy chronic smokershave the highest rates and former is somehow a result ofcompetition between the provitamin beenevaluated in instances of liver pathology produced hepaticinflammation A related study in rats given of beta carotene in influencing heart disease substantiationof prior reports of the In the case of animal systems The functional differences betweenthe activities of beta carotene particularly apocarotenals is not yet well understood of beta carotene In addition moreneeds to be such as tocopherol and ascorbic E Nutr Rev S S Hirayama T continued exposure to oxygen Cancer Letters Krinsky N Actions of M Lieber C Beta carotenebeadlets potentiate Molecular Biology rd ed Scientific Am J Clin Nutr Murray M Encyclopedia transport of carotenoids FASEB J Pung compounds against oxygen-mediated cytotoxicity andgenotoxicity Free Increased mortality associated with vitamin Adeficiency during human Sies H Biological activities of natural andsynthetic carotenoids Carcinogenesis Torsell Wolterbeek A Roggeband R van Moorsel C Baan R Wolf G The enzymatic cleavage of beta carotene stillcontroversial Nutr
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