Tzeng Hui-Ping, Chiang Wenchang, Ueng Tzuu-Huei, Liu Shing-Hwa
Institute of Toxicology, College of Medicine, National Taiwan University, Taipei.
J Toxicol Environ Health A. 2005 Sep;68(17-18):1557-65. doi: 10.1080/15287390590967504.
This study evaluated the abortifacient effects of the extracts of seeds of Coix lachryma-jobi L. var. ma-yuen Stapf (adlay) in pregnant rats. Pregnant rats were treated with oral administration of adlay seed extracts on d 6 of pregnancy and their fetuses were examined for growth and malformations on d 20 of pregnancy. Following oral administration of 1 g/kg body weight of water extracts but not methanolic extracts, fetal resorptions were significantly increased and mortality of postimplantation was increased. There were no significant differences in the uterine and fetal weight compared to control. Fetal malformations were not observed in the adlay seed extracts-treated pregnant rats. The contractile activity of uteri isolated from rats on d 20 of pregnancy was assessed. The spontaneous uterine contractions were significantly enhanced in rats treated with water extracts of adlay seeds (1 g/kg body weight). Immunoblotting of uteri from rats treated with water extracts of adlay seeds demonstrated an induction of cyclooxygenase-2 (COX-2) protein expression. The water extracts of adlay seeds also enhanced extracellular signal-regulated protein kinase (ERK) 1/2 phosphorylation and protein kinase C (PKC)-alpha translocation from cytosolic to particulate fractions in uteri. These results indicate that the water extracts of adlay seeds are capable of inducing embryotoxicity and enhancing uterine contractility during pregnancy. The enhanced activities of PKC-alpha, ERK1/2, and COX-2 may contribute to these responses.
本研究评估了薏苡仁变种（薏米）种子提取物对妊娠大鼠的堕胎作用。妊娠大鼠在妊娠第6天经口给予薏米种子提取物，并在妊娠第20天检查其胎儿的生长和畸形情况。经口给予1 g/kg体重的水提取物而非甲醇提取物后，胎儿吸收显著增加，着床后死亡率升高。与对照组相比，子宫和胎儿重量无显著差异。在经薏米种子提取物处理的妊娠大鼠中未观察到胎儿畸形。评估了从妊娠第20天的大鼠分离的子宫的收缩活性。经薏米种子水提取物（1 g/kg体重）处理的大鼠，其子宫自发收缩显著增强。对经薏米种子水提取物处理的大鼠子宫进行免疫印迹分析，结果显示环氧化酶-2（COX-2）蛋白表达上调。薏米种子水提取物还增强了子宫中细胞外信号调节蛋白激酶（ERK）1/2的磷酸化以及蛋白激酶C（PKC）-α从胞质向颗粒部分的转位。这些结果表明，薏米种子水提取物在妊娠期间能够诱导胚胎毒性并增强子宫收缩性。PKC-α、ERK1/2和COX-2活性增强可能导致了这些反应。
