N. Salamat - ۱Department of Marine Biology, Faculty of Marine Science, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.
Negin Derakhshesh - Iran Fisheries Organization, Administration of Khozestan Province, Abadan, Iran.
N. Shiry - Department of clinical Science, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
S.J. Alavinia - Department of Fisheries, Faculty of Natural Resource, University of Tehran, Karaj, Iran.

The resistance of cancerous cells to anti-cancer drugs is one of the most common problems in medicine and therefore, finding new anti-cancer compounds with the least side effects seems to be necessary. The present study was performed to investigate the anti-cancer potential of Padina gymnospora and Acanthophora spicifera, two native algae species of the Persian Gulf, in vitro. In this regard, methanol, chloroform, n-hexane, and ethyl acetate extracts of both algae species were added to cultivated MCF-۷ cells at different concentrations (۱۲۵, ۲۵۰, ۵۰۰, and ۱۰۰۰ μg/mL). ۳-[۴,۵-dimethylthiazol-۲-yl]-۲,۵ diphenyl tetrazolium bromide (MTT) assay was used to determine the toxicity effects of algae extracts on MCF-۷ cells. DNA isolation and agarose gel electrophoresis were also performed to assess DNA fragmentation induced by these two algae species. Based on the MTT results, the sensitivity of cultivated MCF-۷ cells to P. gymnospora and A. spicifera extracts was increased in a dose-dependent manner. The highest concentration of methanolic extract of both algae species significantly affected the MCF-۷ cells and led to the highest cell death. Moreover, the IC۵۰ of P. gymnospora and A. spicifera methanolic extracts for the MCF-۷ cells were equal to ۵۵۷.۷۸ and ۹۱۰.۶۱ μg/ml, respectively, which indicates P. gymnospora has more cytotoxic activity and anti-tumor potency. The lowest concentration of all types of algae extracts was not considerably cytotoxic to cultivated MCF-۷ cells. The DNA fragmentation of MCF-۷ cells was increased with increasing the concentration of the algal extracts. The highest amount of DNA fragmentation caused by ۱۰۰۰ μg/mL of P. gymnospora and A. spicifera extract; however, methanolic extract of P. gymnospora caused more DNA fragmentation in MCF-۷ cells than A. spicifera.

Cytotoxic activity, Secondary metabolites Algae, MTT assay, MCF-۷.