To study the anticancer effects of aloe emodin against the MIAPaCa-2 and PANC-1 human pancreatic adenocarcinoma cancer cell lines by evaluating its effect on autophagic cell death, mitochondrial membrane potential (ΛΨm) loss and cell cycle arrest.The MTT assay was employed to examine the anti-proliferative effect of aloe emodin on these cells, and inverted phase contrast and fluorescence microscopes were used to evaluate apoptotic induction. Flow cytometry was performed to examine the effects of aloe emodin on ΛΨm and cell cycle phase distribution.The findings indicated that aloe emodin induced dose-dependent cytotoxicity in both pancreatic carcinoma cells with MIAPaCa-2 cells being more susceptible than PANC-1, along with inhibiting cancer cell colony formation. Aloe emodin-treated cells exhibited cell shrinkage along with distortion of the normal cell morphology. In addition, these cells showed chromatin condensation, membrane blebbing and predominantly emitted red fluorescence, which signified apoptosis. Following treatment with aloe emodin (10, 40 and 80 µM) the early apoptotic cell percentage increased to 17.5, 39.6 and 58.8%, respectively, while late apoptotic cells percentage increased to 22.3, 27.6 and 37.2% respectively. There was also a marked increase in the loss of ΛΨm in the aloe emodin-treated cells, as well as dose-dependent sub-G1 cell cycle arrest. Furthermore, aloe emodin treatment led to a substantial enhancement of the conversion of light chain 3 (LC3)-l to LC3-ll and this increase was shown to follow aloe emodin dose-dependent pattern, thus indicating that aloe emodin may induce autophagy in addition to apoptosis.To sum up, aloe emodin inhibits cancer cell growth in human pancreatic carcinoma cells and it was shown that these anticancer effects are mediated via both apoptotic and autophagic pathways, cell cycle arrest and loss of mitochondrial membrane potential.
