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04/03/2010
Um dos mecanismos de ação propostos para o efeito anti-aging da carnosina é como scavenger dos radicais carbonila (R2-C=O), fortes oxidantes do protoplasma.
Use of carnosine as a natural anti-senescence drug for human beings.
Wang AM, Ma C, Xie ZH, Shen F. Biochemistry (Mosc). 2000 Jul;65(7):869-71.
Department of Biochemistry, Harbin Medical University, Harbin 150086, PR China. Wangam@ems.hrbmu.edu.cn.
Carnosine is an endogenous free-radical scavenger. The latest research has indicated that apart from the function of protecting cells from oxidation-induced stress damage, carnosine appears to be able to extend the lifespan of cultured cells, rejuvenate senescent cells, inhibit the toxic effects of amyloid peptide (A beta), malondialdehyde, and hypochlorite to cells, inhibit glycosylation of proteins and protein-DNA and protein-protein cross-linking, and maintain cellular homeostasis. Also, carnosine seems to delay the impairment of eyesight with aging, effectively preventing and treating senile cataract and other age-related diseases. Therefore, carnosine may be applied to human being as a drug against aging.
PMID: 10951108
Carnosine and protein carbonyl groups: a possible relationship.
Hipkiss AR. Biochemistry (Mosc). 2000 Jul;65(7):771-8.
Division of Biomolecular Sciences, GKT School of Biomedical Sciences, King's College London, London SE1 1UL, UK. alan.hipkiss@kcl.ac.uk.
Carnosine has been shown to react with low-molecular-weight aldehydes and ketones and has been proposed as a naturally occurring anti-glycating agent. It is suggested here that carnosine can also react with ("carnosinylate") proteins bearing carbonyl groups, and evidence supporting this idea is presented. Accumulation of protein carbonyl groups is associated with cellular ageing resulting from the effects of reactive oxygen species, reducing sugars, and other reactive aldehydes and ketones. Carnosine has been shown to delay senescence and promote formation of a more juvenile phenotype in cultured human fibroblasts. It is speculated that carnosine may intracellularly suppress the deleterious effects of protein carbonyls by reacting with them to form protein-carbonyl-carnosine adducts, i.e., "carnosinylated" proteins. Various fates of the carnosinylated proteins are discussed including formation of inert lipofuscin and proteolysis via proteosome and RAGE activities. It is proposed that the anti-ageing and rejuvenating effects of carnosine are more readily explainable by its ability to react with protein carbonyls than its well-documented antioxidant activity.
PMID: 10951094
A possible new role for the anti-ageing peptide carnosine.
Hipkiss AR, Brownson C. Cell Mol Life Sci. 2000 May;57(5):747-53.
Biomolecular Sciences Division, GKT School of Biomedical Sciences, King's College London, UK. alan.hipkiss@kcl.ac.uk
The naturally occurring dipeptide carnosine (beta-alanyl-L-histidine) is found in surprisingly large amounts in long-lived tissues and can delay ageing in cultured human fibroblasts. Carnosine has been regarded largely as an anti-oxidant and free radical scavenger. More recently, an anti-glycating potential has been discovered whereby carnosine can react with low-molecular-weight compounds that bear carbonyl groups (aldehydes and ketones). Carbonyl groups, arising mostly from the attack of reactive oxygen species and low-molecular-weight aldehydes and ketones, accumulate on proteins during ageing. Here we propose, with supporting evidence, that carnosine can react with protein carbonyl groups to produce protein-carbonyl-carnosine adducts ('carnosinylated' proteins). The various possible cellular fates of the carnosinylated proteins are discussed. These proposals may help explain anti-ageing actions of carnosine and its presence in non-mitotic cells of long-lived mammals.
PMID: 10892341 [PubMed - indexed for MEDLINE
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