Abstract: ObjectiveTo explore the effect of Quqian-Yizhi Oral Liquid(QYOL)on learning and memory ability in lead-exposed rats.MethodsSeventy-two SD rats were randomly divided into six groups.One group was negative control group treated with distilled water,and the others were lead poisoning groups treated with 2.0% lead acetate for three weeks.The model control group was gavaged with distilled water.EDTA group was treated with 0.5% EDTA-N as by abdominal cavity injection and the last three groups were gavaged with low,medium,and high-dose of QYOL(1 250,2 500,and 5 000 mg/kg·bw)for three weeks.At the end of the experiment, the learning and memory ability of rats were tested by shuttling and avoiding dark box and Morr is water maze methods.Lead concentrations in blood and hippo campus samples were measured by hydride generated-a tomic absorption spectrographic method.ResultsCompared with model control group,intiative avoidance percentages(IAP)were significantly increased(68.1±9.7,70.3±11.9 v s 54.9±10.4);the latencies of passive avoidance(LOPA)were remarkbaly shortened(16.44±5.17,13.88±3.21 v s 27.43±5.27)and the retainment percents of memory were enhanced(49.5±10.2,67.4±261.5 vs 38.3±10.3,P<0.05 or P<0.01)in med-and high-dose QYOL treated groups.Lead concentrations of blood and hippo campus samples in three QYOL groups were lower than those of in model control group(P<0.05 or P<0.01).There was a positive correlation bewteen LOPA and lead levels in hippo-campus tissue(r=0.475,P=0.014).While IAP and retainment percents of memory negatively correlated with lead levels in hippocampus(r=-0.353,P=0.002;r=-01246,P=0.039).ConclusionThe QYOL can markedly improve the impaired ability of learning and memory in lead-exposed rats by decreasing lead concentrations in blood and hippo campus tissue.