ABSTRACT
Ten selected marine organisms representing different classes of marine fauna and flora were collected from Saudi Arabia territorial water. They were Antipathes dichotoma, Rumphella sp., Dictoyota dichotoma, Hyrtios erectus, Petrosia sp., Heteroxenia fuscescens, Rumphella aggregata, Sinularia polydactyla, Sarcophyton glaucum, Sarcophyton trocheliophorum. Samples were lyophilized and extracted. Their cytotoxic activity was assessed by determining their IC[50]'s against HepG2, A549 and PC-3 cancer cell lines. The extracts showed variable activities against A549 with IC[50] in the range 388.3-0.1micro g/mL; HepG2 with IC[50] in range 382.5-0.1micro g/mL and PC-3 with IC[50] in the range 428.6-0.1micro g/mL. Dictoyota dichotoma, Hyrtios erectus, Rumphella aggregata and Sarcophyton glaucum exhibited the highest antiproliferative activity. Therefore, their impact on cell cycle was examined by flow cytometry technique. It was concluded that they cause G0/G1, S-phase and G2/M cell cycle arrest