The Isolated and Combined Effects of Folic Acid and Synthetic Bioactive Compounds against Aβ(25-35)-Induced Toxicity in Human Microglial Cells

Abstract

Folic acid plays an important role in neuronal development. A series of newly synthesized bioactive compounds (NSCs) was reported to exhibit immunoactive and neuroprotective functions. The isolated and combined effects of folic acid and NSCs against β-amyloid (Aβ)-induced cytotoxicity are poorly understood. These effects were tested using human microglia cells (C13NJ) subjected to Aβ(25-35) challenge. According to an MTT assay, treatment of C13NJ cells with Aβ(25-35) at 10~100 μM for 48 h induced 18%~43% cellular death in a dose-dependent manner (p < 0.05). Aβ(25-35) treatment at 25 μM induced nitrite oxide (NO) release, elevated superoxide production, and reduced the distribution of cells in the S phase. Preincubation of C13NJ with 100 μM folic acid protected against Aβ(25-35)-induced cell death, which coincided with a reduction in NO release by folic acid supplements. NSC47 at a level of 50 μM protected against Aβ(25-35)-induced cell death and reduced Aβ-promoted superoxide production (p < 0.05). Folic acid in combination with NSC47 at their cytoprotective doses did not synergistically ameliorate Aβ(25-35)-associated NO release, superoxide production, or cell cycle arrest. Taken together, folic acid or NSC treatment alone, but not the combined regimen, protected against Aβ(25-35)-induced cell death, which may partially, if not completely, be mediated by free radical-scavenging effects.

NeuroAiD® (MLC601) and Amyloid Precursor Protein Processing

“…3). So far, 13 of the components found within MLC601 have been found to have the ability to reverse and prevent events associated with Aβ-induced toxicity [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45]. Specifically, radix salviae miltiorrhizae, radix paeoniae rubrae, radix angelicae sinensis, radix astragali, rhizoma chuanxiong and Carthamus tinctorius have all been shown to ameliorate critical toxic events within the amyloid cascade hypothesis (fig.…”