Ab83464

Cells were seeded in 24-well plates for 24 h and then treated with UVB and IPL radiation for 18 h. Intracellular ROS levels were measured by DCFDA assay (excitation: 485 nm; emission: 535 nm) with a microplate reader (SPECTROstar Nano, BMG Labtech, Ortenberg, Germany).
Catalase activity was examined in 50 μg of protein from cell lysates with an assay solution containing 0.01 M phosphate buffer (pH 7.0) and 0.015 M hydrogen peroxide in a final volume of 1 mL. Catalase activity was evaluated according to the change in the optical density at 570 nm with a microplate reader and a catalase activity assay kit (ab83464, Abcam, Cambridge, UK). One unit of enzyme activity was defined as the amount of the enzyme required to scavenge hydrogen peroxide per minute under defined conditions. SOD activity was determined at 450 nm via inhibition of tetrazolium salt reduction; a formazan dye was produced upon reduction with a superoxide anion (HT Superoxide Dismutase Assay Kit, R&D Systems, Minneapolis, MN, USA).
Resistance to oxidative stress was calculated by estimating the cell survival rate under hydrogen peroxide treatment conditions (0.1 M, 4 h) with a Cell Counting Kit-8 (Dojindo, Japan).

In order to evaluate the effect of cinnamon samples on the activity of HepG-2 and BJ-1, cells were seeded in RPMI-1640 medium containing 25 mg/mL of each cinnamon sample, with one 106 cell per flask, and incubated for 48 h at 37 °C under a humidified atmosphere of 5% CO₂. After this, the cell medium was converted to serum-free medium (SFM) comprising 10 µL/mL of yogurt extract. Then, trypsin 0.05%/0.53 mM EDTA solutions were used to trypsinize the cell cultures after incubation. After washing in PBS, the cells were centrifuged at 2000 rpm for 5 min at 4 °C and resuspended in 1 mL PBS containing 0.1% Triton X-100. Using a 1.5 mL micro centrifuge tube, cells were sonicated twice for 10 s at 100 Hz (Vibra-cell, Sonics & Material) and centrifuged for 30 min at 4 °C at 14,000 rpm. The cells were sonicated for 2 min at 100 Hz in a 1.5 mL micro centrifuge tube placed on ice, then centrifuged at 14,000 rpm for 30 min at 4 °C after the sonication (Vibra-cell, Sonics & Material). Enzyme activity was tested in the supernatant of the tube. We measured the enzyme activity of SOD, CAT, GSH, and GPx in cell culture according to the manufacturer’s instructions for colorimetric kits ab65354, ab83464, ab142044, and ab102530 Abcam.