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The Components of Flemingia macrophylla Attenuate Amyloid β-Protein Accumulation by Regulating Amyloid β-Protein Metabolic Pathway.

Lin YL, Tsay HJ, Liao YF, Wu MF, Wang CN, Shiao YJ - Evid Based Complement Alternat Med (2012)

Bottom Line: Therefore, the effects of F. macrophylla on Aβ production and degradation were studied.The effect of F. macrophylla on Aβ metabolism was detected using the cultured mouse neuroblastoma cells N2a transfected with human Swedish mutant APP (swAPP-N2a cells).The effects on Aβ degradation were evaluated on a cell-free system.

View Article: PubMed Central - PubMed

Affiliation: Division of Medicinal Chemistry, National Research Institute of Chinese Medicine, Taipei 112, Taiwan.

ABSTRACT
Flemingia macrophylla (Leguminosae) is a popular traditional remedy used in Taiwan as anti-inflammatory, promoting blood circulation and antidiabetes agent. Recent study also suggested its neuroprotective activity against Alzheimer's disease. Therefore, the effects of F. macrophylla on Aβ production and degradation were studied. The effect of F. macrophylla on Aβ metabolism was detected using the cultured mouse neuroblastoma cells N2a transfected with human Swedish mutant APP (swAPP-N2a cells). The effects on Aβ degradation were evaluated on a cell-free system. An ELISA assay was applied to detect the level of Aβ1-40 and Aβ1-42. Western blots assay was employed to measure the levels of soluble amyloid precursor protein and insulin degrading enzyme (IDE). Three fractions of F. macrophylla modified Aβ accumulation by both inhibiting β-secretase and activating IDE. Three flavonoids modified Aβ accumulation by activating IDE. The activated IDE pool by the flavonoids was distinctly regulated by bacitracin (an IDE inhibitor). Furthermore, flavonoid 94-18-13 also modulates Aβ accumulation by enhancing IDE expression. In conclusion, the components of F. macrophylla possess the potential for developing new therapeutic drugs for Alzheimer's disease.

No MeSH data available.


Related in: MedlinePlus

The effect of insulin and bacitracin on Aβ1-40 degradation in the N2a-conditioned medium. Aβ1-40 (10 ng) were incubated in the N2a-conditioned medium with indicated concentrations of insulin and bacitracin, at 37°C for 16 h. The level of remaining Aβ1-40 was determined by ELISA. Results are means ± SD from three independent experiments. Significant differences between control and FM fractions-treated cells are indicated by ***P < 0.001.
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fig3: The effect of insulin and bacitracin on Aβ1-40 degradation in the N2a-conditioned medium. Aβ1-40 (10 ng) were incubated in the N2a-conditioned medium with indicated concentrations of insulin and bacitracin, at 37°C for 16 h. The level of remaining Aβ1-40 was determined by ELISA. Results are means ± SD from three independent experiments. Significant differences between control and FM fractions-treated cells are indicated by ***P < 0.001.

Mentions: For bypassing the involvement of Aβ anabolic and trafficking pathway, a cell-free Aβ degradation assay using N2a cell-conditioned medium as the source of secreted protease and the synthetic Aβ1-40 was employed as the substrate. The results showed that Aβ degradation was inhibited by insulin in a concentration-dependent manner (Figure 3). The added synthetic Aβ1-40 (10 ng) was degraded to 0.83 ± 0.17 ng in the conditioned medium without containing insulin, and 10, 100, and 1000 nM insulin increased the level of remaining Aβ1-40 to 3.65 ± 0.82 ng, 7.13 ± 0.55 ng, and 10.34 ± 1.11 ng, respectively, indicating that the degradation of 10 ng Aβ was completely abolished by 1 μM insulin (Figure 3). Treatment with 2 nM, 5 nM bacitracin, or 2 nM bacitracin combined with 100 nM insulin increased the remaining level of Aβ1-40 to 4.83 ± 0.96, 5.51 ± 0.65, and 9.81 ± 0.35 ng, respectively (Figure 3), suggesting a synergism of insulin and bacitracin on inhibiting Aβ degradation.


The Components of Flemingia macrophylla Attenuate Amyloid β-Protein Accumulation by Regulating Amyloid β-Protein Metabolic Pathway.

Lin YL, Tsay HJ, Liao YF, Wu MF, Wang CN, Shiao YJ - Evid Based Complement Alternat Med (2012)

The effect of insulin and bacitracin on Aβ1-40 degradation in the N2a-conditioned medium. Aβ1-40 (10 ng) were incubated in the N2a-conditioned medium with indicated concentrations of insulin and bacitracin, at 37°C for 16 h. The level of remaining Aβ1-40 was determined by ELISA. Results are means ± SD from three independent experiments. Significant differences between control and FM fractions-treated cells are indicated by ***P < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3376484&req=5

fig3: The effect of insulin and bacitracin on Aβ1-40 degradation in the N2a-conditioned medium. Aβ1-40 (10 ng) were incubated in the N2a-conditioned medium with indicated concentrations of insulin and bacitracin, at 37°C for 16 h. The level of remaining Aβ1-40 was determined by ELISA. Results are means ± SD from three independent experiments. Significant differences between control and FM fractions-treated cells are indicated by ***P < 0.001.
Mentions: For bypassing the involvement of Aβ anabolic and trafficking pathway, a cell-free Aβ degradation assay using N2a cell-conditioned medium as the source of secreted protease and the synthetic Aβ1-40 was employed as the substrate. The results showed that Aβ degradation was inhibited by insulin in a concentration-dependent manner (Figure 3). The added synthetic Aβ1-40 (10 ng) was degraded to 0.83 ± 0.17 ng in the conditioned medium without containing insulin, and 10, 100, and 1000 nM insulin increased the level of remaining Aβ1-40 to 3.65 ± 0.82 ng, 7.13 ± 0.55 ng, and 10.34 ± 1.11 ng, respectively, indicating that the degradation of 10 ng Aβ was completely abolished by 1 μM insulin (Figure 3). Treatment with 2 nM, 5 nM bacitracin, or 2 nM bacitracin combined with 100 nM insulin increased the remaining level of Aβ1-40 to 4.83 ± 0.96, 5.51 ± 0.65, and 9.81 ± 0.35 ng, respectively (Figure 3), suggesting a synergism of insulin and bacitracin on inhibiting Aβ degradation.

Bottom Line: Therefore, the effects of F. macrophylla on Aβ production and degradation were studied.The effect of F. macrophylla on Aβ metabolism was detected using the cultured mouse neuroblastoma cells N2a transfected with human Swedish mutant APP (swAPP-N2a cells).The effects on Aβ degradation were evaluated on a cell-free system.

View Article: PubMed Central - PubMed

Affiliation: Division of Medicinal Chemistry, National Research Institute of Chinese Medicine, Taipei 112, Taiwan.

ABSTRACT
Flemingia macrophylla (Leguminosae) is a popular traditional remedy used in Taiwan as anti-inflammatory, promoting blood circulation and antidiabetes agent. Recent study also suggested its neuroprotective activity against Alzheimer's disease. Therefore, the effects of F. macrophylla on Aβ production and degradation were studied. The effect of F. macrophylla on Aβ metabolism was detected using the cultured mouse neuroblastoma cells N2a transfected with human Swedish mutant APP (swAPP-N2a cells). The effects on Aβ degradation were evaluated on a cell-free system. An ELISA assay was applied to detect the level of Aβ1-40 and Aβ1-42. Western blots assay was employed to measure the levels of soluble amyloid precursor protein and insulin degrading enzyme (IDE). Three fractions of F. macrophylla modified Aβ accumulation by both inhibiting β-secretase and activating IDE. Three flavonoids modified Aβ accumulation by activating IDE. The activated IDE pool by the flavonoids was distinctly regulated by bacitracin (an IDE inhibitor). Furthermore, flavonoid 94-18-13 also modulates Aβ accumulation by enhancing IDE expression. In conclusion, the components of F. macrophylla possess the potential for developing new therapeutic drugs for Alzheimer's disease.

No MeSH data available.


Related in: MedlinePlus