Schaffer E M, Liu J Z, Green J, Dangler C A, Milner J A
Department of Nutrition, The Pennsylvania State University, University Park 16802, USA.
Cancer Lett. 1996 Apr 19;102(1-2):199-204. doi: 10.1016/0304-3835(96)04160-2.
Our previous studies demonstrated that dietary garlic powder supplementation inhibits N-nitrosamine induced DNA alkylation in liver and mammary tissue. The present studies compared the impact of dietary supplementation with garlic powder or two garlic constituents, water-soluble S-allyl cysteine (SAC) and oil-soluble diallyl disulfide (DADS), on the incidence of mammary tumorigenesis induced by N-methyl-N-nitrosourea (MNU). Female Sprague-Dawley rats were fed semi-purified casein based diets with or without supplements of garlic powder(20g/kg), SAC (57 micromol/kg) or DADS (57 micromol/kg) for 2 weeks prior to treatment with MNU (15 mg/kg body wt). Garlic powder, SAC and DADS supplementation significantly delayed the onset of mammary tumors compared to rats receiving the unsupplemented diet. Tumor incidence 23 weeks after MNU treatment was reduced by 76, 41 and 53% in rats fed garlic, SAC and DADS, respectively, compared to controls (P<0.05). Total tumor number was reduced 81, 35 and 65% by these supplements, respectively (P<0.05). In a separate study the quantity of mammary DNA alkylation occurring 3 h after MNU treatment was reduced in rats fed garlic, SAC or DADS (P<0.05). Specifically, O(6)-methylguanine adducts were reduced by 27, 18 and 23% in rats fed supplemental garlic, SAC and DADS, respectively, compared to controls. N(7)-Methylguanine adducts decreased by 48, 22 and 21% respectively, compared to rats fed the control diet. These studies demonstrate that garlic and associated allyl sulfur components, SAC and DADS, are effective inhibitors of MNU-induced mammary carcinogenesis.
我们之前的研究表明，膳食中补充大蒜粉可抑制N-亚硝胺诱导的肝脏和乳腺组织中的DNA烷基化。本研究比较了膳食补充大蒜粉或两种大蒜成分，即水溶性S-烯丙基半胱氨酸（SAC）和油溶性二烯丙基二硫化物（DADS），对N-甲基-N-亚硝基脲（MNU）诱导的乳腺肿瘤发生发生率的影响。在给予MNU（15mg/kg体重）处理前2周，给雌性Sprague-Dawley大鼠喂食以半纯化酪蛋白为基础的日粮，添加或不添加大蒜粉（20g/kg）、SAC（57μmol/kg）或DADS（57μmol/kg）。与接受未补充日粮的大鼠相比，补充大蒜粉、SAC和DADS显著延迟了乳腺肿瘤的发生。与对照组相比，MNU处理23周后，喂食大蒜、SAC和DADS的大鼠肿瘤发生率分别降低了76%、41%和53%（P<0.05）。这些补充剂使肿瘤总数分别减少了81%、35%和65%（P<0.05）。在另一项研究中，喂食大蒜、SAC或DADS的大鼠在MNU处理3小时后发生的乳腺DNA烷基化量减少（P<0.05）。具体而言，与对照组相比，喂食补充大蒜、SAC和DADS的大鼠中O(6)-甲基鸟嘌呤加合物分别减少了27%、18%和23%。与喂食对照日粮的大鼠相比，N(7)-甲基鸟嘌呤加合物分别减少了48%、22%和21%。这些研究表明，大蒜以及相关的烯丙基硫成分SAC和DADS是MNU诱导的乳腺致癌作用的有效抑制剂。
