Light microscopy images (Scale bar: 20 µm) of (A) MCF-7, (B) HepG2, (C) SKOV3 and (D) A549 cell lines treated for 24 h with TOPO IC50 in the absence or presence of carvacrol (166 µM). Images were magnified at 20×. The red, green, orange and black arrows represented cell enlargement with cytoplasm shrinkage, membrane blebbing, apoptotic bodies and intercellular space increase, respectively. Images were taken from at least three independent experiments with similar conditions.