ABSTRACT
Aim To investigate the effects of total saponins from Trillium tschonoskii maxim(TST)on cognitive impairment and mitochondrial autophagy in aging rats induced by D-galactose(D-gal). Methods Male SD rats were randomly divided into normal control group,model group(D-gal,subcutaneous injection),intervention group(TST,low,medium and high dose groups by intragastric administration),with 10 rats in each group,and administered for 6 weeks. Morris water maze was used to evaluate the cognitive function. HE and Nissl staining were used to test the hippocampal and brain cortex morphology. Immunohistochemistry staining was applied to detect the localization expression of Pink1 and Parkin. Western blot was employed to detect the expressions of Pink1,Parkin,LC3-Ⅱ,p62 and Beclin1. Results Compared with the normal control group,the escape latency time was prolonged and the number of crossing platform decreased in D-gal model group(P<0.05). The number of neurons in hippocampus significantly decreased. The positive cells labeled by Pink1 and Parkin staining in hippocampus significantly decreased. The expressions of Pink1,Parkin,LC3-Ⅱ and Beclin1 were markedly reduced,while the expression of p62 was significantly raised(P<0.05). Compared with D-gal model group,the escape latency time of TST dose groups was shortened,the Times of crossing the platform was more,and the time of staying in the platform quadrant increased(P<0.05). The number of neurons in hippocampus significantly increased. The positive cells labeled by Pink1 and Parkin staining in hippocampus significantly increased. The expressions of Pink1,Parkin,LC3-Ⅱ and Beclin1 in hippocampus were apparently up-regulated,while the protein expression of p62 was evidently down-regulated(P<0.05). Conclusions TST has neuroprotective effects on the learning and memory capacities in aging rats induced by D-gal,which may be related to the increasing levels of Pink1,Parkin,LC3-Ⅱ and Beclin1 proteins and the activation of mitochondrial autophagy.