Assessing Plant Antioxidants by Cellular Antioxidant Activity Assay Based on Microfluidic Cell Chip with Arrayed Microchannels

An integrated microfluidic chip with arrayed micro channels consisted of eight repeat arrayed 6×6 cell culture chamber was designed and fabricated. The analytical microsystem combined with designed microchip, measuring device and environmental control unit was established for the cell culture and parallel cellular antioxidant activity (CAA) analysis of plant antioxidants. The microfluidic chip included a PDMS cover and a glass substrate which consisted of two hundreds and eighty-eight round cell culture micro chambers and forty-eight independent parallel array channels. Eight groups of different samples with six different concentrations could be investigated simultaneously with multimode reader in one test. HepG2 cells were successfully cultured on the microchip. Moreover, the viability percentage of the HepG2 cells exposed to these plant antioxidants solutions at different concentrations for 24 h was higher than 90%. With 2′,7′-Dichlorofluorescin diacetate (DCFH-DA) as a fluorescence probe, 2,2′-azobis(2-amidinopropane) dihydrochloride (ABAP) as the initiator of intracellular reactive oxygen species (ROS), we tested the inhibitory effect of several plant antioxidants such as quercetin, rutin and kaempferol on free radicals. The CAA units were calculated by the data measured from cellular morphology and fluorescence intensity over time. It was shown that the CAA units of quercetin, rutin and kaempferol were (71.42 ± 0.19) μM, (74.31 ± 0.36) μM and (69.92 ± 0.09) μM (x ± s, n = 3), while the calculated IC50 were (7.20 ± 0.06) μM, (52.06 ± 0.14) μM and 32.55±0.03 μM (x ± s, n = 3), respectively.

A homemade integrated microfluidic chip with arrayed micro channels which was suitable for the microplate reader was used to cellular antioxidant activity analysis.Figure optionsDownload as PowerPoint slide