Mishra Prachi, Kar Anand, Kale Raosaheb K
School of Life Sciences, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, 110067, India.
Mol Cell Biochem. 2009 May;325(1-2):149-57. doi: 10.1007/s11010-009-0029-1. Epub 2009 Feb 13.
Isoflavones are biologically active plant derived compounds that have several health promoting effects. In the present study hitherto unknown effects of one of the well known isoflavonoids, daidzein, has been evaluated on its chemo-preventive action against breast cancers in pre-pubertal rats. Either daidzein (500 mug/g bwt) or vehicle, dimethyl sulphoxide (DMSO), was administered at 16th, 18th, and 20th day post-partum and the chemopreventive efficacy was evaluated in dimethylbenz[a]nthracene (DMBA) induced Sprague-Dawley rats, at 50th day. To elucidate the mechanism of action, the antioxidative status was also examined in the liver and mammary gland of prebubertal rats using two different doses of daidzein (0.5 mg/kg bwt and 50 mg/kg bwt, p.o.) for 10 days. The specific activity of antioxidant enzymes as well as reduced glutathione (GSH) level and peroxidative damage were evaluated spectrophotometrically, both in liver as well as in mammary gland. Animals treated with daidzein pre-pubertally, showed a significant reduction in the tumorigenesis of mammary gland up to 37.4% as compared to animals induced for tumors with DMBA. In animals treated with 50 mg/kg of daidzein, a significant increase in the specific activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione transferase (GST), DT-diaphorase (DTD), and in GSH content were observed in both liver and mammary gland. Expectedly, the specific activity of lactate dehydrogenase (LDH) and level of peroxidative damage was decreased, as compared to that of control group of animals. Our results suggest that, daidzein can be considered as a potent chemopreventive agent against mammary carcinogenesis in pre-pubertal animals, with modulation of antioxidant enzymes being one of its mechanisms of actions.
异黄酮是具有多种促进健康作用的生物活性植物衍生化合物。在本研究中，已对一种著名的异黄酮——大豆苷元对青春期前大鼠乳腺癌的化学预防作用进行了评估，其迄今未知的作用效果也得以呈现。在产后第16、18和20天，分别给大鼠灌胃大豆苷元（500微克/克体重）或溶剂二甲基亚砜（DMSO），并在第50天评估其对二甲基苯并[a]蒽（DMBA）诱导的斯普拉格-道利大鼠的化学预防效果。为阐明作用机制，还对青春期前大鼠的肝脏和乳腺进行了抗氧化状态检测，给大鼠口服两种不同剂量的大豆苷元（0.5毫克/千克体重和50毫克/千克体重），持续10天。通过分光光度法评估了肝脏和乳腺中抗氧化酶的比活性、还原型谷胱甘肽（GSH）水平以及过氧化损伤情况。青春期前接受大豆苷元治疗的动物，与DMBA诱导肿瘤的动物相比，乳腺肿瘤发生率显著降低，降幅高达37.4%。在接受50毫克/千克大豆苷元治疗的动物中，肝脏和乳腺中抗氧化酶如超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）、谷胱甘肽转移酶（GST）、DT-黄递酶（DTD）的比活性以及GSH含量均显著增加。与对照组动物相比，乳酸脱氢酶（LDH）的比活性和过氧化损伤水平预期降低。我们的研究结果表明，大豆苷元可被视为青春期前动物乳腺致癌作用的有效化学预防剂，调节抗氧化酶是其作用机制之一。
