Figure 2.

Protection of H₂O₂-induced ROS generation and DNA damage by EESS in SW1353 chondrocytes. (A) Cells were pretreated with the indicated concentrations of EESS for 1 h, and then stimulated with or without 1 mM H₂O₂ for 1 h. The cells were incubated at 37 °C in the dark for 20 min with culture medium containing 10 µM DCF-DA to monitor ROS production. The degree of ROS production was measured by flow cytometer. The data are the means of the two different experiments; (B,C) Cells were pretreated with EESS for 1 h, and cultured in the presence or absence of H₂O₂ for 24 h. (B) To detect cellular DNA damage, the comet assay was performed, and representative photographs of the comets were taken by fluorescence microscopy (original magnification, 200×); (C) The cells were lysed, and then equal amounts of cell lysates were separated on SDS-polyacrylamide gels, and transferred to membranes. The membranes were probed with specific antibodies against γH2AX and p-γH2AX, and the proteins were visualized using an ECL detection system. Actin was used as an internal control.