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Synergistic Neuroprotective Effects of Two Herbal Ingredients via CREB-Dependent Pathway

View Article: PubMed Central - PubMed

ABSTRACT

As two natural oligosaccharide esters, 3,6’-Disinapoyl sucrose (DISS) and tenuifolisideA (TFSA) are originating from the root of Polygala tenuifolia Willd, a traditional Chinese medicine used in treatment of mental disorders. Previous reports have shown that both of them possess in vitro neuroprotective effects by stimulating different upstream pathways related with cyclic AMP-responsive element-binding protein (CREB). In the present study, we investigated the additive neuroprotective effects of DISS and TFSA on Glu-induced damage of SY5Y cells and purposed the possible underlying mechanism. The interaction between DISS and TFSA showed a clear-cut synergistic effect as evidenced by combination index (CI). Additional evidence from biochemical (NOS activity) assays confirmed their additive inhibition on the Glu-induced NOS hyperactivation. Moreover, we showed that co-treatment of DISS and TFSA resulted in an additively up-regulated phosphorylation of CREB as well as increased expressions of CRTC1 and BDNF. Neuroprotective effects of DISS and TFSA on Glu-induced decrease in cell viability were blocked by MAPK/ERK1/2 inhibitor (U0126) and PI3-K inhibitor (LY290042). Nevertheless, the CRTC1 or BDNF expression induced by these two compounds was significantly reduced in the presence of either ERK or PI3-K inhibitor, indicating that the two oligosaccharide esters shared some common pathways in the regulation of CREB-BDNF pathway. Taken together, we, for the first time, showed that DISS and TFSA exerted the additive neuroprotective effects on CREB-BDNF signaling pathway through complementary mechanisms.

No MeSH data available.


Combination effect of DISS and TFSA on cell viability in SY5Y cells (n = 18). SY5Y cells were exposed to 8 mM Glu for 24 h, followed by combination treatment of DISS and TFSA as well as inhibitors (U0126, LY294002). (A) Cells were treated by DISS and inhibitors. (B) Cells were treated by TFSA and inhibitors. (C) Cells were treated by combination of DISS, TFSA and inhibitors. ∗p < 0.05 and ∗∗p < 0.01 compared with the Glu group. Red ∗∗p < 0.01 compared with control group. #p < 0.05, #p < 0.001, and red #p < 0.05 compared with its compound alone.
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Figure 2: Combination effect of DISS and TFSA on cell viability in SY5Y cells (n = 18). SY5Y cells were exposed to 8 mM Glu for 24 h, followed by combination treatment of DISS and TFSA as well as inhibitors (U0126, LY294002). (A) Cells were treated by DISS and inhibitors. (B) Cells were treated by TFSA and inhibitors. (C) Cells were treated by combination of DISS, TFSA and inhibitors. ∗p < 0.05 and ∗∗p < 0.01 compared with the Glu group. Red ∗∗p < 0.01 compared with control group. #p < 0.05, #p < 0.001, and red #p < 0.05 compared with its compound alone.

Mentions: Based on this Glu-induced decrease in cell activity, the neuronal cytotoxicity of Glu could be partially inhibited by the pretreatment of DISS or TFSA in a dose-dependent manner. More importantly, the co-treatment of TFSA and DISS at two testing doses (75 μM + 25 μM and 150 μM + 25 μM) could produce a significant neuroprotective activity as compared with individual compounds alone, exhibiting increased cell viability from 48% to more than 85%. Figures 2A,B shows that such a protective effect of DISS at 150 and 75 μM could be blocked by the MAPK/ERK1/2 inhibitor, U0126 (10 μM), but not by the PI3-K inhibitor, LY290042 (20 μM). In contrast, the LY290042, but not U0126, inhibited the neuroprotective effect of TFSA. Moreover, the inhibitory effect of combination of U0126 and LY290042 became even more obvious, showing reduced cell viability from 85% to less than 60% (Figure 2C).


Synergistic Neuroprotective Effects of Two Herbal Ingredients via CREB-Dependent Pathway
Combination effect of DISS and TFSA on cell viability in SY5Y cells (n = 18). SY5Y cells were exposed to 8 mM Glu for 24 h, followed by combination treatment of DISS and TFSA as well as inhibitors (U0126, LY294002). (A) Cells were treated by DISS and inhibitors. (B) Cells were treated by TFSA and inhibitors. (C) Cells were treated by combination of DISS, TFSA and inhibitors. ∗p < 0.05 and ∗∗p < 0.01 compared with the Glu group. Red ∗∗p < 0.01 compared with control group. #p < 0.05, #p < 0.001, and red #p < 0.05 compared with its compound alone.
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Figure 2: Combination effect of DISS and TFSA on cell viability in SY5Y cells (n = 18). SY5Y cells were exposed to 8 mM Glu for 24 h, followed by combination treatment of DISS and TFSA as well as inhibitors (U0126, LY294002). (A) Cells were treated by DISS and inhibitors. (B) Cells were treated by TFSA and inhibitors. (C) Cells were treated by combination of DISS, TFSA and inhibitors. ∗p < 0.05 and ∗∗p < 0.01 compared with the Glu group. Red ∗∗p < 0.01 compared with control group. #p < 0.05, #p < 0.001, and red #p < 0.05 compared with its compound alone.
Mentions: Based on this Glu-induced decrease in cell activity, the neuronal cytotoxicity of Glu could be partially inhibited by the pretreatment of DISS or TFSA in a dose-dependent manner. More importantly, the co-treatment of TFSA and DISS at two testing doses (75 μM + 25 μM and 150 μM + 25 μM) could produce a significant neuroprotective activity as compared with individual compounds alone, exhibiting increased cell viability from 48% to more than 85%. Figures 2A,B shows that such a protective effect of DISS at 150 and 75 μM could be blocked by the MAPK/ERK1/2 inhibitor, U0126 (10 μM), but not by the PI3-K inhibitor, LY290042 (20 μM). In contrast, the LY290042, but not U0126, inhibited the neuroprotective effect of TFSA. Moreover, the inhibitory effect of combination of U0126 and LY290042 became even more obvious, showing reduced cell viability from 85% to less than 60% (Figure 2C).

View Article: PubMed Central - PubMed

ABSTRACT

As two natural oligosaccharide esters, 3,6&rsquo;-Disinapoyl sucrose (DISS) and tenuifolisideA (TFSA) are originating from the root of Polygala tenuifolia Willd, a traditional Chinese medicine used in treatment of mental disorders. Previous reports have shown that both of them possess in vitro neuroprotective effects by stimulating different upstream pathways related with cyclic AMP-responsive element-binding protein (CREB). In the present study, we investigated the additive neuroprotective effects of DISS and TFSA on Glu-induced damage of SY5Y cells and purposed the possible underlying mechanism. The interaction between DISS and TFSA showed a clear-cut synergistic effect as evidenced by combination index (CI). Additional evidence from biochemical (NOS activity) assays confirmed their additive inhibition on the Glu-induced NOS hyperactivation. Moreover, we showed that co-treatment of DISS and TFSA resulted in an additively up-regulated phosphorylation of CREB as well as increased expressions of CRTC1 and BDNF. Neuroprotective effects of DISS and TFSA on Glu-induced decrease in cell viability were blocked by MAPK/ERK1/2 inhibitor (U0126) and PI3-K inhibitor (LY290042). Nevertheless, the CRTC1 or BDNF expression induced by these two compounds was significantly reduced in the presence of either ERK or PI3-K inhibitor, indicating that the two oligosaccharide esters shared some common pathways in the regulation of CREB-BDNF pathway. Taken together, we, for the first time, showed that DISS and TFSA exerted the additive neuroprotective effects on CREB-BDNF signaling pathway through complementary mechanisms.

No MeSH data available.