Objective:To explore the effects of Ginsenoside Rg1 on the spatial learning and memory capacity

the activities of SOD

the amounts of MDA

the expression of P16INK4a and P21Cip1/Waf1 mRNA and protein in brain aging rats induced by D-galactose.Methods:15 normal adult SD rats were randomly divided into control group

brain aging model group and Rg1 anti-brain aging group.In the brain aging model group and the Rg1 anti-brian aging group

D-galactose(120 mg/(kg·d))was given to rats for 6 weeks by subcutaneous injection.Ginsenoside Rg1(20 mg/(kg·d))was also given to rats by intra-peritoneal injection for 4 weeks after 2 weeks in the Rg1 anti-aging group

and saline was given to the control group by subcutaneous and intra-peritoneal injection or to the aging group by intra-peritoneal injection.Learning and memory abilities were measured by a Morris water maze test 42 days after modeling.The activities of SOD and the amounts of MDA in brain were quantified by chromatometry.The changes in the expressions of P16INK4a and P21Cip1/Waf1 mRNA or protein in brain were determined by real time quantitative RT-PCR and Western blot.Results:Compared with the brain aging group

the spatial learning and memory capacities were significantly enhanced;the SOD activities were significantly increased while the MDA level was significantly reduced and the expressions of the P16INK4a or P21Cip1/Waf1 mRNA and protein in brain were reduced in the Rg1 anti-brian aging group.Conclusion:Improvement of the antioxidation ability

downregulation of the expressions of aging-associated P16INK4a and P21Cip1/Waf1 mRNA and protein in brain may be the underlying anti-aging mechanism of Ginsenoside Rg1.