Figure 1.
The effect of ginsenoside Rg1 on cognitive impairment caused by D-gal administration (±s, n = 5).
The Morris water maze test was carried out to test the spatial learning and memory ability of rats. A. Latencies to find a hidden platform in the water maze during the seven days of place navigation training. On the eighth day, another set of tests was performed when the target platform was removed: B. The escape latency of the rats when the platform was removed. C. The times of rats’ crossing the target quadrant. D. The percentage of time that the rats stayed in the quadrant where the platform was once placed. Different letters represent significantly different values as assessed by ANOVA and LSD tests with P<0.05.
Figure 2.
Ginsenoside Rg1 reduced the SA-β-Gal stainings in area CA3 in hippocampus of brain-aged rats (×200).
The hippocampuses were collected and fixed after the treatment. The SA-β-gal (senescence-associated β-galactosidase) staining was carried out on the slides to explore the aging of the hippocampus. The aged cells are stained in blue in the cytoplasm. The intensity of SA-β-gal-positive was evaluated by means of a ROD (relative optical density) value (Table 1).
Table 1.
The effect of ginsenoside Rg1 on the senescence-associated SA-β-Gal stainings in area CA3 in the hippocampus of brain-aged rats (±s, n = 5).
Figure 3.
The effect of ginsenoside Rg1 on the telomere lengths and telomerase activity in hippocampus of brain-aged rats (±s, n = 5).
A. The effect of ginsenoside Rg1 on the telomere lengths. The DNA of the hippocampus in each group was collected, and telomere lengths were evaluated by Southern Blot. B. The effect of ginsenoside Rg1 on the telomerase activity. The supernatant of the hippocampus in each group was collected and the telomerase activities were detected by silver staining TRAP-PCR. The bar graph indicates quantitative results of telomere lengths and telomerase activity. Different letters represent significantly different values as assessed by ANOVA and LSD tests with P<0.05.
Figure 4.
The effect of ginsenoside Rg1 on the NSCs/NPCs differentiation in DG area of hippocampus in brain-aged rats (×400).
Hippocampuses in each group were collected and fixed after the treatment. Immunofluorescence was performed on the frozen sections of the hippocampus to visualize neurons, astrocytes and oligodendrocytes. Neurons were positive for β-tubulin III with relatively large and round cell body and less branches. Astrocytes were positive for GFAP with ramified branches. Astrocytes were activated by exhibiting hypertrophy, with very thick, highly ramified and intensely immunostained branches. Oligodendrocytes were positive for Gal-C with a few branches. DAPI was used for nuclear staining (blue). Numbers of the three types of cells in the DG area were analyzed under a fluorescence microscope (Table 2).
Table 2.
The effect of ginsenoside Rg1 on the cell distributions in DG area of hippocampus in brain-aged rats.
Figure 5.
The effect of ginsenoside Rg1 on the expression of SOX2, Nestin and Aeg1 in hippocampus of brain-aged rats.
Hippocampuses in each group were collected. A. SOX2 protein expression was detected by western-blot, and β-actin was served as an internal standard. Relative intensities were quantified. B and C. Nestin and Aeg1 mRNA expression was detected by realtime qRT-PCR. All values were normalized against Gapdh and expressed as a percentage of control. The experiments were performed three times with similar results. Data are expressed as mean ± SD. Different letters represent significantly different values as assessed by ANOVA and LSD tests with P<0.05.
Figure 6.
The effect of ginsenoside. Rg1 on cell proliferation in the DG area of the hippocampus of brain-aged rats.
BrdU were administrated to the rats in each group three times on day 41 of the treatment to mark the newly generated cells. Hippocampuses were collected on the next day. Frozen slides were incubated with anti-BrdU antibodies. Arrows indicate newly generated cells which are stained by anti-BrdU antibody (green) around the nucleus (blue) during the final 24 hours of the treatment. Numbers of BrdU+ cells in the DG area were analyzed under a fluorescence microscope (Table 2).
Table 3.
The effect of ginsenoside Rg1 on anti-oxidant ability in the hippocampus of brain-aged rats (±s, n = 5).
Table 4.
The effect of ginsenoside Rg1 on the levels of of IL-1β, IL-6 and TNF-α in the hippocampus of brain-aged rats (±s, n = 5, pg/mg).
Figure 7.
Ginsenoside Rg1 down-regulated the expression of p19Arf, p53, p21Cip1/Waf1mRNA in hippocampus of brain-aged rats.
The mRNA of hippocampus in each group was collected. Senescence-associated gene expressions were detected by qRT-PCR. All values were normalized against Gapdh and expressed as a percentage of control. The experiments were performed three times with similar results. Different letters represent significantly different values as assessed by ANOVA and LSD tests with P<0.05.