title: In vitro cancer chemopreventive properties of polysaccharide extract from the brown alga, Sargassum latifolium.
abstract: Polysaccharides of edible algae attracted extensive interest due to their numerous biological activities. Sargassum latifolium (Turner) C. Agardh, belongs to Sargassaceae, is a brown algae in red sea shores in Egypt. This work is a novel attempt to explore the cancer chemopreventive activity of different fractions of water-soluble polysaccharide extract derived from S. latifolium. Estimation of cancer chemopreventive activity, specifically anti-initiation, including the modulation of carcinogen metabolism and the antioxidant capacity, revealed that E1 and E4 were potent anti-initiators, where they lead not only to an inhibition in the carcinogen activator cytochrome P450 1A (IC50 2.54 and 10.30 microg/ml, respectively), but also to an induction in the carcinogen detoxification enzymes glutathione-S-transferases (144% and 225% of the control, respectively). E1 and E4 inhibited 59% and 63% of the induced-DNA damage, as measured by comet assay. Similarly both E1 and E4 possessed potential anti-promoting properties as indicated by their anti-inflammatory activity. E1 and E4 enhanced the macrophage proliferation; however they dramatically inhibited the stimulated NO (30.7% and 59.3%), TNF-alpha (38.2% and 54.9) and COX-2 (20% and 18%), respectively. E3 showed a selective cytotoxicity against lymphoblastic leukemia (1301 cells), while other fraction extracts had no cytotoxic effect against all tested cell lines. E3 led to a major disturbance in cell cycle including arrest in both S-phases in 1301 cells. This disturbance was associated with an induced-cell death due to apoptosis, but not necrosis. In conclusion, E1 and E4 are promising cancer chemopreventive fractions, since they had tumor anti- initiating activity via their protective modulation of carcinogen metabolism, and tumor anti-promoting activity via their anti-inflammatory activity, while E3 can be considered as a promising anti-cancer agent against leukemia.
authors.affiliation: Cancer Biology Laboratory, Center of Excellency for Advanced Sciences, National Research Centre, Dokki 12622, Cairo, Egypt. aeldeen@hotmail.com
authors.forename: Amira M
authors.initials: AM
authors.lastname: Gamal-Eldeen
authors.forename: Eman F
authors.initials: EF
authors.lastname: Ahmed
authors.forename: Mona A
authors.initials: MA
authors.lastname: Abo-Zeid
mesh_terms: D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D016588:Anticarcinogenic Agents; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects; D009369:Neoplasms / Q000473:pathology / Q000517:prevention & control*; D009569:Nitric Oxide / Q000378:metabolism; D011134:Polysaccharides / Q000737:chemistry / Q000494:pharmacology*; D044647:Sargassum / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016588:Anticarcinogenic Agents; D000975:Antioxidants; D052246:Cyclooxygenase 2 Inhibitors; D011134:Polysaccharides; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase