Objective: To observe and explore the antagonism of rhizoma gastrodiae (RGT) to the impairment of learning and memory ability induced by lead in rats.
Methods: 36 Wistar rats were randomly divided into 3 groups, 12 rats in every group, (1) control group: treated with distilled water; (2) lead group: treated with lead acetate (0.1 g.kg-1.d-1); (3) lead-RGT group: lead acetate (0.1 g.kg-1.d-1) + RGT(4.0 g.kg-1.d-1). The ability of learning and memory of the rats was measured monthly by swimming test; 3 months later, the rats were decapitated and nitric oxide(NO) and total antioxidative capacity(TAOC) in hippocampus were measured immediately and the examination for pathology was also made.
Results: (1) In swimming test, the number of seeking for anchorage in lead group(1, 2, 3 month: 10.10 +/- 1.10, 7.80 +/- 1.32, 5.40 +/- 0.97 respectively) were significantly decreased, compared with the control(P < 0.01); the number of seeking for anchorage in RGT-lead group(1, 2, 3 month: 11.90 +/- 0.95, 10.90 +/- 0.95, 9.70 +/- 0.96 respectively) were significantly increased, compared with lead group(P < 0.01). (2) NO (0.733 +/- 0.015) mumol/g pro and TAOC (0.945 +/- 0.017) U/mg pro in hippocampus of lead group were significantly decreased compared with the control(P < 0.01) whereas NO(0.769 +/- 0.021) mumol/g pro and TAOC(0.986 +/- 0.010) U/mg pro in hippocampus of RGT-lead group were significantly increased compared with lead group(P < 0.01). (3) Pathological examination showed that in lead group, marked atrophy in hippocampus, cellular denaturation and necrosis, dissolution and disappearance in axon were found. In lead-RGT group, the atrophy of hippocampus was not obvious, the cell morphology was nearly normal, no obvious abnormal changes were seen.
Conclusion: RGT is antagonistic to the impairment of hippocampus and of learning and memory ability induced by lead.