RP treatment improves locomotor functions, prolongs lifespan and reduces Aβ levels of AD transgenic <i>Drosophila</i>.

<p>CS, Aβ and APP/BACE transgenic flies were cultured on food containing different concentrations of RP (the triangle symbol indicates concentrations from low to high: 0.2, 0.6 and 2 mg/ml) or Memantine (120 µM). (<b>A</b>) Survival curves of flies treated with either RP or Memantine. The data are presented as the mean ± S.E.M. (<b>B</b>) The climbing ability of flies (right panels) was assessed at day 30 for CS and APP/BACE flies and at day 20 for Aβ flies. The values are the mean ± S.E.M. Each value represents the mean of three experiments. (<b>C</b> and <b>D</b>) Aβ and APP/BACE transgenic flies were cultured on SS, AT, PRP or RP (2 mg/ml). Aβ₄₀ and Aβ₄₂ levels in 500 fly heads were measured by ELISA assay. Mem = Memantine. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 <i>vs.</i> the control group.</p

SS treatment improves locomotor functions and prolongs lifespan of AD transgenic <i>Drosophila</i>.

<p>(<b>A, C and E</b>) CS, APP/BACE and Aβ transgenic flies were cultured on food containing different concentrations of SS (the triangle symbol stands for concentrations from low to high: 0.2, 0.6 and 2 mg/ml) or Memantine (120 µM). Survival curves for flies treated with either SS or Memantine. The data are presented as mean ± S.E.M. The right panel shows the mean survival days calculated according to the survival curves. (<b>B, D and F</b>) The climbing ability of CS, APP/BACE and Aβ transgenic flies treated with SS or Memantine at day 30 (for CS and APP/BACE flies) and day 20 (for Aβ flies). Values are mean ± S.E.M. Each value represents the mean of three experiments. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 <i>vs.</i> Ctrl group. Mem = Memantine.</p

SS treatment ameliorates learning and memory impairment in Morris Water Maze and Object recognition test.

<p>(<b>A</b>) MWM test for SS and vehicle-treated APP/PS1 and WT mice. The mean escape latency was given for different test days. (<b>B</b>) The mean percent time in probe trial of MWM on day 7. TQ: Target quadrant; AL: Adjacent left; AR: Adjacent right; OP: Opposite. (<b>C</b>) Representative mice search paths from different groups. (<b>D and E</b>) The latency to target quadrant (<b>D</b>) and the frequency to pass the target position (<b>E</b>) in probe trial are shown. (<b>F and G</b>) The swimming velocity (<b>F</b>) and distance (<b>G</b>) in probe trial are shown. (<b>H and I</b>) Novel object recognition analysis. Preference scores of training phase (<b>H</b>) and Recognition Index of testing phase (<b>I</b>) during a 10-min testing phase are shown, respectively. n = 9–12 for each group. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001, #<i>P</i><0.05, ##<i>P</i><0.01, ###<i>P</i><0.001.</p

AT and PRP improves locomotor function and prolongs lifespan of AD transgenic <i>Drosophila</i>.

<p>CS and Aβ transgenic flies were cultured on food containing different concentrations of AT (0.2, 0.6 and 2 mg/ml), PRP (0.2, 0.6 and 2 mg/ml) or Memantine (120 µM). (<b>A, C</b>) Survival curves for flies treated with either AT, PRP or Memantine. (<b>B, D</b>) The climbing ability of flies was assessed. The values are the mean ± S.E.M. Each value represents the mean of three experiments. Mem = Memantine. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 <i>vs.</i> the control group.</p

SS treatment alleviates Aβ levels and amyloid plaque burden, reduces gliosis and neuron loss in APP/PS1 mice.

<p>(<b>A–C</b>) Representative half brain sections of WT mice, vehicle or SS-treated APP/PS1 mice stained with antibody against Aβ (6E10) and double staining of GFAP and 6E10 are shown. Scale bar, 1 mm. (<b>B</b> and <b>C</b>) Quantitative analysis of the number of 6E10-positive amyloid plaques (<b>B</b>) and Aβ covered area (<b>C</b>). n = 5 animals per group. (<b>D</b> and <b>E</b>) ELISA of soluble and insoluble Aβ₄₀ and Aβ₄₂ levels in cortical and hippocampal tissues of APP/PS1 mice. n = 6 for each group. (<b>F</b>, <b>I</b> and <b>J</b>) Representative images of WT mice, vehicle- and SS- treated APP/PS1 mice hippocampus and cortex double immunostaining of GFAP and 6E10 (<b>F</b>), CD11b (<b>I</b>) and NeuN (<b>J</b>). Arrows indicate astrocytes surrounding the amyloid plaques. Scale bar, 200 µm. (<b>H</b>) Coincidence of GFAP and Aβ burden in the brains of SS-treated APP/PS1 mice (red; n = 17) and vehicle-treated APP/PS1 mice (black; n = 17; <i>P</i><0.0001). (<b>G</b>, <b>K</b> and <b>L</b>) The histograms depict the mean GFAP (<b>G</b>), CD11b (<b>K</b>), and NeuN (<b>L</b>) positive area ± S.E.M. in three groups. *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001.</p

RP reduces the Aβ generation in SK-N-SH-APPsw cells.

<p>Aβ₄₂ (<b>A</b>) and Aβ₄₀ (<b>B</b>) in SK-N-SH-APPsw cell culture medium and cell viability (<b>C</b>) after treatment with SS, AT, PRP, RP for 24 hours, respectively (the triangle symbol stands for concentrations from high to low: 3000, 1000, 300 and 100 µg/ml for SS; 1000, 300, 100 and 30 µg/ml for AT, PRP and RP). *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001; DAPT: a γ-secretase inhibitor.</p

AT and PRP inhibit Aβ₄₂ aggregation and exert neuroprotective effects against Aβ₄₂ in primary neurons.

<p>(<b>A</b>) The effects of SS (3000 µg/ml), AT (1000 µg/ml), PRP (1000 µg/ml) or RP (1000 µg/ml) on Aβ₄₂ aggregation, as measured by Th-T fluorescence assay. (<b>B</b>) SS, AT, PRP and RP (3000, 1000, 300, 100 and 30 µg/ml for SS; 1000, 300, 100 and 30 µg/ml for AT, PRP and RP) inhibited Aβ₄₂ aggregation in dose-dependent manner. (<b>C</b> and <b>D</b>) Cell viability of primary cultured neurons pre-treated with SS or AT, PRP for two hours followed by incubation with Aβ₄₂ oligomers (5 µM) for another 48 hours (300, 100, 30 and 10 µg/ml for SS; 100, 30, 10 and 3 µg/ml for AT and PRP). Viable cells were quantified using a CellTiter-Glo assay (<b>A</b>). Tuj1-positive cells were counted and presented (<b>D</b>). *<i>P</i><0.05 compared with the Aβ₄₂-treated group. (<b>E</b> and <b>F</b>) TUNEL analysis of the primary neurons pre-treated with SS (100 µg/ml), AT (30 µg/ml), or PRP (30 µg/ml) for two hours followed by incubation with Aβ₄₂ oligomers (5 µM) for another 24 hours. The green, TUNEL-positive cells are merged with blue DAPI-positive cells (<b>E</b>). The TUNEL-positive cells and DAPI-positive cells pre-treated with SS or AT, PRP (300, 100, 30 and 10 µg/ml for SS; 100, 30, 10 and 3 µg/ml for AT and PRP) were counted in three independent experiments (<b>F</b>). *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001 <i>vs.</i> the Aβ₄₂-treated group, ##<i>P</i><0.01 <i>vs.</i> the control group.</p