刚离乳大鼠给予百蕊草浸膏粉的重复给药毒性评价方法探索

Study on the toxicity evaluation method of repeated administration of thesium chinense extract powder in weaning rats

目的:探索刚离乳幼龄大鼠的中药非临床安全性评价方法,观察给药百蕊草浸膏粉4周对刚离乳SD大鼠的毒性反应。方法:SD幼龄大鼠120只,按体重随机分为4组,每组30只,雌雄各半,分为溶剂对照组,百蕊草浸膏粉低(浸膏0.6 g·kg-1)、中(浸膏9.0 g·kg-1)和高(浸膏15.0 g·kg-1)剂量组;PND21开始给药,qd,共4周,给药期结束时剖杀2/3的动物,剩余动物恢复观察2周。探索动物年龄和发育毒性指标的选择方法,检测一般状况、体重、摄食量、生长发育、血液学、血液生化学、凝血、尿液、免疫、激素、脏器系数和病理组织学变化。结果:15.0 g·kg-1高剂量组雌雄幼龄大鼠的生长发育指标(雄鼠顶臀长减少,雌鼠阴道张开时间延迟),血液学指标(网织红细胞计数RET#和RET%增加趋势明显),脏器重量,脏体比和脏脑比(胸腺减轻、肾脏或肝脏增加),雄性幼龄大鼠体重降低,血生化指标(ALT,BUN和TBIL增加)等有所改变。受试物对雄性幼龄大鼠的影响更加明显,但影响均可逆。结论:在本试验条件下,百蕊草浸膏粉灌胃幼龄SD大鼠4周,无毒性反应剂量(no observed adverse effect level,NOAEL)为浸膏9.0 g·kg-1(相当于生药量164.9g·kg-1),是以临床剂量换算的大鼠等效剂量的32.3倍,是临床使用剂量的194倍。

Objective： To explore the non-clinical safety evaluation method of Chinese herbal medicine in weaning rats,and to observe the toxic effects of thesium chinense extraction powder administered for 4 weeks on weaning SD rats. Methods： One hundred and twenty juvenile SD rats were randomly divided into 4 groups with 30 of each gender in each group. The rats were orally administered with thesium chinense extract at doses of 0,0. 6,9. 0 and 15. 0 g·kg^-1 qd from PND21 for 4 weeks respectively. Two thirds of the animals were killed immediately after the last administration,and the others were observed for 2 weeks after medicine withdraw. Factors including animal age and the choice of developmental toxicity parameters were explored to address strategies for juvenile toxicity assessment. Parameters were examined including general condition,body weight,food intake,development index,hematological and biochemical index,blood coagulation parameter,urinalysis value,immune system,hormone,organ coefficient,and histopathological examination. Results： The juvenile rats of both sexes in the high dose group had changes in growth and development indexes（ male crown-rump length decrease,female vaginal opening time delay）,hematology indexes（ RET#reticulocyte count and RET% obvious increase trend）,organ weight,the ratio of visceral weight to body weight,the ratio of visceral weight to brain weight（ thymus decrease,kidney or liver weigh increase） in both sexes at 15. 0 g·kg^-1 and significant decrease in body weight,blood biochemical（ ALT,BUN and TBIL） in male rats. The influence of the tested substances on male juvenile rats were more obvious. The influence could be reversed. Conclusion： Under the test conditions,the no observed adverse effect level（ NOAEL）of thesium chinense particles for juvenile rats was 9. 0 g·kg^-1（ equivalent to 164. 9 g·kg^-1） when administered by gavage for 4 weeks,which is 32. 3 times of rat dosage and 194 times of clinical dosage.