Das Ila, Saha Tapas
Departments of Cancer Chemoprevention and Cancer Detection and Screening, Chittaranjan National Cancer Institute, Kolkata, India.
Nutrition. 2009 Apr;25(4):459-71. doi: 10.1016/j.nut.2008.10.014. Epub 2008 Dec 11.
Naturally occurring phytochemicals display an active cancer preventive strategy to inhibit, delay, or reverse human carcinogenesis. Studies have indicated that certain daily-consumed dietary phytochemicals have cancer protective effects mediated by carcinogens. Lipid peroxide plays a detrimental role in all cancers including skin carcinogenesis. Garlic, a phytochemical, has acquired a special position in the folklore of many cultures as a formidable prophylactic and therapeutic medicinal agent. In this report, we pursue the chemopreventive effect of aqueous garlic on skin carcinogenesis.
"Swiss albino mice" were divided into five groups depending on the combination of skin cancer-inducing 7,12-dimethylbenz[a]anthracene and garlic treatments. Histology of the affected skin and biochemical assays for lipid peroxide, catalase, superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase were performed to demonstrate the effect of garlic in mice. Immunoblotting was performed with cyclo-oxygenase-2, p53, and caspase-3 to demonstrate expressions of the respective proteins in skin lysates.
Garlic extracts inhibited the oxidative modification of lipids, thus protecting cells from injury by the oxidized molecules. The best chemopreventive action of garlic was observed in mice in which garlic treatment was performed before and after the induction of skin carcinogenesis. Garlic ingestion delayed formation of skin papillomas in animals and simultaneously decreased the size and number of papillomas, which was also reflected in the skin histology of the mice treated.
The protective effects against skin cancer elicited by garlic in mice are believed to be due at least in part to the induction cellular defense systems.
天然存在的植物化学物质展现出一种积极的癌症预防策略，可抑制、延缓或逆转人类致癌过程。研究表明，某些日常食用的膳食植物化学物质具有由致癌物介导的癌症保护作用。脂质过氧化物在包括皮肤致癌在内的所有癌症中都起着有害作用。大蒜作为一种植物化学物质，在许多文化的民间传说中已占据特殊地位，被视为一种强大的预防和治疗药物。在本报告中，我们探究大蒜水溶液对皮肤致癌的化学预防作用。
根据诱发皮肤癌的7,12 - 二甲基苯并[a]蒽与大蒜处理的组合，将“瑞士白化小鼠”分为五组。对受影响皮肤进行组织学检查，并对脂质过氧化物、过氧化氢酶、超氧化物歧化酶、谷胱甘肽 - S - 转移酶和谷胱甘肽过氧化物酶进行生化检测，以证明大蒜对小鼠的作用。用环氧化酶 - 2、p53和半胱天冬酶 - 3进行免疫印迹，以证明皮肤裂解物中各蛋白质的表达。
大蒜提取物抑制脂质的氧化修饰，从而保护细胞免受氧化分子的损伤。在皮肤致癌诱导前后均进行大蒜处理的小鼠中，观察到大蒜的最佳化学预防作用。摄入大蒜可延缓动物皮肤乳头瘤的形成，同时减小乳头瘤的大小并减少其数量，这也反映在接受治疗的小鼠皮肤组织学中。
大蒜对小鼠皮肤癌的保护作用据信至少部分归因于诱导细胞防御系统。
