Lin X Y, Liu J Z, Milner J A
Department of Nutrition, Pennsylvania State University, University Park 16802.
Carcinogenesis. 1994 Feb;15(2):349-52. doi: 10.1093/carcin/15.2.349.
The present studies examined the impact of a processed garlic powder on the in vivo occurrence of DNA adducts caused by N-nitroso compounds (NOC) in rats. Addition of 2% garlic powder to diets containing aminopyrine and sodium nitrite (each at 600 mg/kg) reduced the occurrence of both 7-N-methyldeoxyguanosine (7-N-mG) and 6-O-methyldeoxyguanosine (6-O-mG) adducts to rat liver DNA by approximately 55%; and over 80% when 4% garlic was provided. Dietary supplementation with garlic powder (2 and 4%) also reduced the occurrence of 7-N-mG and 6-O-mG adducts by approximately 40 and 60% respectively, in rats intubated with N-nitrosodimethylamine (150 mg/kg body wt). The quantity of 7-N-mG and 6-O-mG adducts in mammary tissue of rats given intravenous N-methyl-N-nitrosourea (50 mg/kg body wt) was reduced over 50% in rats fed 2% garlic compared to controls. The depression in the occurrence of these adducts was approximately 70% when dietary garlic was increased to 4%. These experiments suggest the reduction in DNA adducts caused by processed garlic powder likely reflects a depression in the formation of NOC from precursors and changes in the bioactivation and/or denitrosation of NOC.
本研究检测了一种加工蒜粉对大鼠体内由N-亚硝基化合物（NOC）所致DNA加合物形成的影响。在含有氨基比林和亚硝酸钠（各为600 mg/kg）的日粮中添加2%蒜粉，可使大鼠肝脏DNA中7-N-甲基脱氧鸟苷（7-N-mG）和6-O-甲基脱氧鸟苷（6-O-mG）加合物的形成减少约55%；当蒜粉添加量为4%时，减少幅度超过80%。日粮中添加蒜粉（2%和4%）还可使经插管给予N-亚硝基二甲胺（150 mg/kg体重）的大鼠体内7-N-mG和6-O-mG加合物的形成分别减少约40%和60%。与对照组相比，给静脉注射N-甲基-N-亚硝基脲（50 mg/kg体重）的大鼠饲喂2%蒜粉后，其乳腺组织中7-N-mG和6-O-mG加合物的数量减少超过50%。当日粮中蒜粉添加量增至4%时，这些加合物形成的减少幅度约为70%。这些实验表明，加工蒜粉所致DNA加合物的减少可能反映了其对前体物质形成NOC的抑制作用以及NOC生物活化和/或脱亚硝化作用的改变。
