*2.5. Intracellular ROS Assay*

HaCaT cells were seeded at a density of 1.5 × 10<sup>5</sup> in 8-well Lab Teck chamber containing DMEM supplemented with 10% FBS and were grown to 80% confluence. These cells were first treated with 1.5 μM Ectoine, followed by exposure to 3 J/cm<sup>2</sup> UVA irradiation for the prescribed amount of time. Cells were washed with PBS and DCFH2-DA method was used to determine the intracellular ROS production using the Olympus Software solution software for each condition [21].
