Abstract:

Abstract:Objective To discuss the effects of ginsenoside Rb1 on bone lead content,learning and memory,the activities of superoxide dismutase (SOD) and nitric oxide synthase(NOS) in brain of  mice exposure to lead.
Methods The lead-exposed models of mice were induced by lead acetate contained in drinking water.The mice were divided into control group,model group and different doses of ginsenoside Rb1 groups （100,50,25 mg·kg^-1）.　Passive avoidance experiment and Morris water maze test were used to evaluate the effects of ginsenoside Rb1 on learning and memory of lead mice,and to determine the bone lead content,the activities of SOD and NOS in brain.Results Compared with control group,lead-exposuring could lead the following results: shortening the incubation period of avoid dark  experiment（P<0.01）,increasing the number of errors（P<0.05）,extending the search distance and the incubation period in Morris water maze test（P<0.05）,reducing the activity of SOD,increasing the activity of NOS and the bone lead content（P<0.01）.
Compared with model group,the incubation period of  passive avoidance experiment was obviously extended,the number of errors was clearly reduced,the search distance and the incubation period in ginsenoside Rb1 groups were apparently shortened（P<0.05 or P＜0.01）,the activity of SOD was increased（P<0.05 or P<0.01）,the activity of NOS and the bone lead content were decreased（P<0.05 or P<0.01.All the effects were dosage-dependent.And the effect of 25 mg·kg^-1 ginsenoside Rb1 was significantly different  compared with   100 and 50 mg·kg-1 ginsenoside Rb1（P<0.05）.Conclusion Ginsenoside Rb1　can reduce the lead content significantly,and obviously alleviate learning and memory of lead mice.It could meanwhile effectively resume the vitality of the antioxidant system of lead mice and protect their nerve cells.

Key words: lead;ginsenoside Rb1;learning;memory;bone lead