ROS level with or without melatonin treatment in LPS-treated mouse embryo. (A) Fluorescence microscopy images of intracellular ROS expression in blastocyst stained with CellROX (green) and Hoechst 33342 (blue). (B) A graph of relative ROS expression fluorescence intensity in embryo at stage of blastocyst development. Data are expressed as mean ± standard error mean (SEM) expressed in one-way ANOVA. A significant difference between treatments indicates as p-value; **p < 0.01. LPS, in vitro culture medium with 12.5 µg/mL LPS; MT, melatonin 10 µM/mL.