Objective: This study was conducted to investigate whether fractions of jellyfsh Cassiope andromeda venom,
could selectively induce toxicity on mitochondria isolated from cancer tissue of patients with breast adenocarcinomas.
Methods: Firstly, we extracted two fractions, (f1 and f2) from crude jellyfsh venom by gel fltration on Sephadex
G-200.Then different dilutions of these extracted fractions were applied to mitochondria isolated from human breast
tumoral- and extra-tumoral tissues. Parameters of mitochondrial toxicity including generation of reactive oxygen
species (ROS), mitochondrial membrane potential (MMP) collapse, swelling, cytochrome c release, activation of
caspase3 and apoptosis were then assayed. Result: Our results demonstrate that fraction 2 of Cassiopea andromeda
crude venom signifcantly (P<0.05) decreased mitochondrial succinate dehydrogenase activity, increased mitochondrial
ROS production, induced mitochondrial swelling, MMP collapse and cytochrome c release, activated caspase3 and
induced apoptosis only in tumoral mitochondria, and not in mitochondria obtained from extra-tumoral tissue (P<0.05).
Conclusion: In conclusion this study suggested that fraction 2 of Cassiopea andromeda crude venom selectively induces
ROS mediated cytotoxicity by directly targeting mitochondria isolated from human breast tumor tissue.