5-hydroxymethylfurfural and Hemolysis

5-HMF is widely presented in foods and produced through the degradation of hexoses and Maillard reaction during heat treatment of foods containing reducing sugars and amino acids in an acid environment. However, controversial conclusions on the biological effects of 5-HMF have been drawn in previous studies. Therefore, the main aim of this study was to investigate the antioxidant and antiproliferative activities of 5-HMF. The 2,2'-azinobis-3-ethylbenzothiazolin-6-sulfonic acid (ABTS) assay, the 1,1-diphenyl-2-picryhydrazyl (DPPH) assay, and the hemolysis assay induced by 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) were performed to evaluate the antioxidant capacity of 5-HMF. The results showed that 5-HMF exhibited novel antioxidant activity by scavenging the ABTS and DPPH free radicals and inhibited the AAPH-induced hemolysis in a dose-dependent manner. In the hemolysis assay, the reduction of ROS and MDA contents and the increase in enzyme activities of SOD, CAT, and GPx were found in erythrocytes pretreated with 5-HMF, which demonstrated that 5-HMF could prevent the peroxidation from the source to protect the erythrocytes. The morphological changes of erythrocytes was also verified by observation using atomic force microscopy. The inhibitory effect of 5-HMF on human cancer cell proliferation was investigated by MTT assay, flow cytometric analysis, and the TUNEL and DAPI costaining assay. The results showed that 5-HMF displayed higher antiproliferative activity on human melanoma A375 cells than other cell lines. Further investigation on the action mechanisms revealed that 5-HMF could induce A375 cell apoptosis and G0/G1 cell cycle arrest. The A375 cell apoptosis that 5-HMF induced was characterized by a TUNEL and DAPI costaining assay. These findings suggest that 5-HMF could be developed as a novel natural antioxidant with potential applications in cancer chemoprevention.

Topics: Antioxidants; Apoptosis; Cell Cycle; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Erythrocytes; Furaldehyde; Growth Inhibitors; Hemolysis; Humans

A specific and accurate method for the quantitation of the azomethine linkage present in non-enzymatically glycosylated haemoglobin is described. This protein is hydrolysed for 5 h in 1 M oxalic acid at 100 degrees C to yield 5-(hydroxymethyl)-2-furfur-aldehyde (5-HMF), known as a specific degradation product of hexoses linked to the protein. 5-HMF is then purified through a Sep-Pak C18 cartridge and measured by its absorption at 280 nm after separation on a C18 reversed-phase silica column. Quantitation is made accurate by using 1-methylxanthine as internal standard throughout the whole procedure. The identity and the purity of the 5-HMF chromatographic peak was ascertained by UV spectroscopy, gas chromatography on a glass capillary column and mass spectrometry. The method has been successfully used for 5-HMF determinations in monitoring diabetes mellitus patients. The mean values, expressed as nmol of 5-HMF per mg of haemoglobin were 0.64 +/- 0.13 (S.D.) for 27 controls and 1.32 +/- 0.39 for 78 diabetic patients. Unlike the usually employed thiobarbituric acid assay, the present procedure is truly specific for the 5-HMF determination.

Topics: Chromatography, Gas; Chromatography, High Pressure Liquid; Furaldehyde; Glycated Hemoglobin; Hemolysis; Humans; Hydrolysis; Mass Spectrometry; Spectrophotometry, Ultraviolet