3,4,5-tri-O-caffeoylquinic acid inhibits amyloid ß-mediated cellular toxicity on SH-SY5Y cells through the upregulation of PGAM1 and G3PDH.

Caffeoylquinic acid (CQA) is one of the phenylpropanoids found in a variety of natural resources and foods, such as sweet potatoes, propolis, and coffee. Previously, we reported that 3,5-di-O-caffeoylquinic acid (3,5-di-CQA) has a neuroprotective effect against amyloid-ß (Aß)-induced cell death through the overexpression of glycolytic enzyme. Additionally, 3,5-di-CQA administration induced the improvement of spatial learning and memory on senescence accelerated-prone mice (SAMP8). The aim of this study was to investigate whether 3,4,5-tri-O-caffeoylquinic acid (3,4,5-tri-CQA), isolated from propolis, shows a neuroprotective effect against Aß-induced cell death on human neuroblastoma SH-SY5Y cells. To clarify the possible mechanism, we performed proteomics and real-time RT-PCR as well as a measurement of the intracellular adenosine triphosphate (ATP) level. These results showed that 3,4,5-tri-CQA attenuated the cytotoxicity and prevented Aß-mediated apoptosis. Glycolytic enzymes, phosphoglycerate mutase 1 (PGAM1) and glyceraldehyde-3-phosphate dehydrogenase (G3PDH) were overexpressed in co-treated cells with both 3,4,5-tri-CQA and Aß. The mRNA expression of PGAM1, G3PDH, and phosphoglycerate kinase 1 (PGK1), and intracellular ATP level were also increased in 3,4,5-tri-CQA treated cells. Taken together the findings in our study suggests that 3,4,5-tri-CQA shows a neuroprotective effect against Aß-induced cell death through the upregulation of glycolytic enzyme mRNA as well as ATP production activation.

[Sample preprocessing method for residual quinolones in honey using immunoaffinity resin].

A sample preparation method was developed for determination of quinolones in honey using immunoaffinity resin. For this purpose, an immunoaffinity resin for quinolones was prepared by coupling a quinolone-specific monoclonal antibody to agarose resin. Honey samples diluted with phosphate buffer were reacted with immunoaffinity resin. After the resin was washed, quinolones were eluted with glycine-HCl. Quinolones in the eluate were determined by HPLC with fluorescence detection. No interfering peak was found on the chromatograms of honey samples. The recoveries of quinolones from samples were over 70% at fortification levels of 20 ng/g (for norfloxacin, ciprofloxacin and enrofloxacin) and 10 ng/g (for danofloxacin). The quantification limits of quinolones were 2 ng/g. This sample preprocessing method using immunoaffinity resin was found to be effective and suitable for determining residual quinolones in honey.