Effects of total lignans of Schisandra chinensis on memory impairment in rats with Alzheimer's disease / 国际中医中药杂志

ABSTRACT

Objective To study the effects of total lignans of Schisandra chinensis on memory impairment in rats with Alzheimer's disease, and to discuss its mechanism of action. Methods The rats were randomly into the blank control group, the sham injury group, the pathological model group, the low dose group of Schisandra chinensis and the high dose group of Schisandra chinensis with 15 rats in each group. The animals were given medicine at 3 days after the model establishment. The ainimals of the pathological model group, the low dose group of Schisandra chinensis and the high dose group of Schisandra chinensis established the AD model by D-gal intraperitoneal injection of compound Aβ hippocampal localization injection. The low dose group of Schisandra chinensis and the high dose group of Schisandra chinensis were administrated by means of intragastric administration 1mL physiological saline containing Schisandra chinensis total lignans 50 mg×kg-1×d-1 and 100 mg×kg-1×d-1, and the blank control group, the sham injury group, the pathological model group were administrated 0.9% Sodium Chloride Injection 1 ml×d-1by means of intragastric administration. After two weeks of continuous administration, the behavioral tests were carried out on the experimental animals, and the expressions of caspase-3, Bax, Bcl-2 and mRNA in the hippocampus of rats were measured by RT-PCR. Results Compared with the pathological model group,the escape latency shortened of the low dose group and the high dose group of Schisandra chinensis were significantly shortened (P<0.05). The number of traversing platforms (3.82 ± 1.23, 5.82 ± 1.18 vs. 2.13 ± 1.48), the percentage of swimming time (39.43% ± 7.12%, 48.63% ± 7.15% vs. 59.98% ± 6.13%) of the low dose group and the high dose group of Schisandra chinensis significantly decreased (P<0.05). Compared with the pathological model group, the expression of caspase-3(6.11 ± 1.25,4.42 ± 1.13 vs.7.88 ± 1.28)and Bax mRNA(5.84 ± 1.62,4.63 ± 1.51 vs.7.54 ± 2.14) significantly decreased (P<0.05), and the expression of the Bcl-2 mRNA(1.73 ± 0.82, 3.04 ± 1.29 vs. 0.93 ± 0.62) wese increased (P<0.05). Conclusions The diatomite Soxhlet extraction method is suitable for the isolation and purification of total lignans from Schisandra chinensis, and the total lignans of Schisandra chinensis can up-regulate the expression of Bcl-2, down-regulate the expression of caspase-3 and Bax, inhibit the apoptosis of neurons induced by A beta, improve the memory impairment of AD animal models, and the intervention effect is dose dependent.