The Effect Of Carnosine On DNA Oxidant Damage And Its Antixoxidant Mechenism

DNA is the genetic matter of life and the damage of it can induce many kinds of disease. Thus, it both has theoretical value and practical meaning to search for effective and natural DNA protect drugs. Carnosine ( β -alanyl-L-histidine) is a naturally occurring depeptide that was found in skeletal muscle. Carnosie has been shown as a multifunctional antioxidant in animal body.The effects of camosine on oxidative DNA damage levels are studied in four systems in this paper: I Phen-Cu2+-VitC system; II BLMA5-Fe2+ system; III VitV-Fe2+ system; IV Phen-Cu2+-VitC-H2O2 system. Common antioxidants Mannitol, Benzoate, DMSO were made as controls and the antioxidant abilities were compared among them. The effects of carnosine's constituent: imidazole 1-histidine β-alanine in the four system were also studied. The inhibit curves of this six drugs in every one of the four system were drew. The antioxidant mechanism of camosine was expected to be understood from the comparation among the six different matiarialsIn system I , Phen-Cu2+-VitC system was used to produce OH to make DNA damage and the damage were observed by TBA reaction. We added different concentrations of carnosine, 1-histidine, B-alanine, mannitol, benzoate, DMSO to the system. The results indicated that carnosine had a significant inhibited effect on DNA oxidant damage (P < 0.05) and the inhibitation of it is a dose depended manner, camosine has a better protec effect than mannitol and benzoate et al. in the right system. Its antioxidative curve is similar to that of 1-histidine. There was no significant difference in protecting deoxyribose damage among carnosine,l-histidine B-alanine Mannitol Benzoate DMSO (P > 0.05).Cleavage action of DNA by bleomycinA5-Fe2+ was determined by thiobarbituric acid reaction. The change of DNA breaks was obserbed after we added camosine, 1-histidine B-alanine, mannitol, benzoate, DMSO to BLMA5-Fe2+ system. The results suggested that when under the concentration of 8mmol/l, camosine has a significant further oxidant character on DNA damage (P < 0.05). But when the concentration increased beyond 8mmol/l canosine showed a protect effect on DNA damage and its protect effect is better than the common antioxidant: mannitol, benzoate, DMSO. The action of 1-histidine was the same as camosine. In this system we found that...