黄芩苷对双酚A致小鼠生殖损伤的保护作用

Protective effects of baicalin on reproductive damage in offspring mice induced by Bisphenol A

为研究黄芩苷对双酚A（Bisphenol A,BPA）所致子代小鼠生殖毒性的缓解作用。本试验将60只昆明孕鼠随机分为A、B、C共3组,每组20只。A组为对照组,孕鼠妊娠1-14d灌胃生理盐水同时饲喂普通鼠粮;B组为BPA组,孕鼠妊娠1-7d给予生理盐水,妊娠8-14d给予500mg/kg BPA;C组为黄芩苷＋BPA组,孕鼠妊娠1-7d灌胃1mg/kg黄芩苷,妊娠8-14d给予500mg/kg BPA,待孕鼠自然分娩。观察记录仔鼠死亡情况。至仔鼠8周龄剖杀,分离血清,摘取睾丸或卵巢,ELISA试剂盒分析仔鼠血清睾酮（T）、雌二醇（E2）及黄体生成素（LH）水平,HE染色观察卵巢或睾丸组织结构的变化,免疫组化及免疫荧光方法检测仔鼠睾丸或卵巢Bax,Bcl-2蛋白的表达。结果显示：黄芩苷能够降低BPA致子代小鼠死亡率,升高仔鼠T（♂）、LH（♀）含量,降低仔鼠（♀）E2水平（P〈0.05）。HE染色结果表明,BPA组仔鼠睾丸组织损伤严重,间质细胞减少,卵巢组织结构空泡逐渐增多,颗粒数量逐渐减少。黄芩苷能改善BPA引起的睾丸及卵巢组织损伤。免疫组化结果显示,BPA对仔鼠睾丸或卵巢Bax蛋白表达无影响,但对睾丸或卵巢Bcl-2蛋白表达有降低作用。预先给于黄芩苷后能够升高仔鼠睾丸或卵巢Bcl-2蛋白表达,但对Bax蛋白表达无显著影响。免疫荧光结果发现,BPA升高仔鼠睾丸或卵巢组织中Bax阳性蛋白表达,降低Bcl-2阳性蛋白表达。黄芩苷降低睾丸或卵巢Bax蛋白表达,升高睾丸或卵巢Bcl-2蛋白表达。本试验结果表明,孕鼠妊娠期给予黄芩苷降低BPA引起的子代小鼠死亡率,平衡生殖激素水平和睾丸/卵巢中相关凋亡蛋白表达,缓解BPA染毒孕鼠对子代小鼠所致的生殖毒性。

The present study was conducted to investigate the protective effect of baicalin on the reproductive toxicity induced by BPA.Sixity pregnant Kunming mice were randomly divided into 3 groups（groups A,B and C）with 20 of each.Group A was the control group and the mice were gavaged with normal saline from pregnancy day 1 to day 14 and received conventional feedstuffs.Mice in group B were gavaged normal saline from pregnancy day 1 to day 7 and were given 500 mg/kg BPA daily from pregnancy day 8 to day 14.Mice in group C were gavaged 1 mg/kg baicalin from pregnancy day 1 to day 7 and were given 500 mg/kg BPA daily from pregnancy day 8 to day 14.The death rates of the offsprings were calculated weekly.The offspring mice were sacrificed at 8 weeks of age.The levels of estradiol（E2）,luteinizing hormone（LH）and testosterone（T）in mice serum were detected by ELISA.The histology of ovary and testicular tissues were examined with hematoxylin-eosin staining（HE）.The protein levels of Bax and Bcl-2 in ovary or testicular tissues were detected by immunohistochemistry and immunofluorescence.Results showed that exposure of the mother to BPA increased the mortality and baicalin reduced this rate.Baicalin treatment increased the levels of T（♂）,LH（♀）（P0.05）,and downregulated E2（♀）level in the adult offsprings.BPA exposure caused testicular damage as shown by less Leydig cells and ovarian injury as shown by less corpus granules in the adult offspring mice but Baicalin decreased the damage of testicular and ovarian induced by BPA.Immunohistochemistry revealed that maternal exposure to BPA decreased Bcl-2 levels,but did not change Bax at the protein levels in ovary and testicular tissues in the offspring mice.Baicalin increased Bcl-2 at the protein levels,but did not change Bax at the protein levels in ovary and testicular tissues in the offspring mice.Immunofluorescence revealed that maternal exposure to BPA increased Bax and decreased Bcl-2 at the protein levels in testicular and ovary tissues in the offspring mice.Baicalin decreased Bax at the protein levels in testicular and ovary,but did not change Bcl-2 at the protein levels in ovary tissues in the offspring mice.These findings suggest that mice fed with baicalin during special period of pregnancy could increase the survival rate of offspring mice,and balance the reproductive hormones and proteins expressions in the reproductive organs of the offspring mice.