Reactive oxygen species H2O2 and OH, but not O2− promote oridonin-induced phagocytosis of apoptotic cells by human histocytic lymphoma U937 cells

► Oridonin induced ROS generation in U937 cells and H2O2, OH were the dominant types. ► ROS was involved in oridonin-enhanced phagocytosis of apoptotic cells by U937 cells. ► ROS decreased MMP which was independent of the generation of ATP during engulfment. ► ROS promoted phagocytosis of apoptotic cells by an autophagy dependent mechanism. ► ROS mediated activation of PI3K-Akt and PLC γ-Ras-Raf-ERK signaling pathways.