Aqueous extracts of the edible Gracilaria tenuistipitata are protective against H₂O₂-induced DNA damage, growth inhibition, and cell cycle arrest.
Potential antioxidant properties of an aqueous extract of the edible red seaweed Gracilaria tenuistipitata (AEGT) against oxidative DNA damage were evaluated. The AEGT revealed several antioxidant molecules, including phenolics, flavonoids and ascorbic acid. In a cell-free assay, the extract exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity that significantly reduced H₂O₂-induced plasmid DNA breaks in a dose-response manner (P < 0.001). The AEGT also suppressed H₂O₂-induced oxidative DNA damage in H1299 cells by reducing the percentage of damaged DNA in a dose-response manner (P < 0.001) as measured by a modified alkaline comet-nuclear extract (comet-NE) assay. The MTT assay results showed that AEGT confers significant protection against H₂O₂-induced cytotoxicity and that AEGT itself is not cytotoxic (P < 0.001). Moreover, H₂O₂-induced cell cycle G2/M arrest was significantly released when cells were co-treated with different concentrations of AEGT (P < 0.001). Taken together, these findings suggest that edible red algae Gracilaria water extract can prevent H₂O₂-induced oxidative DNA damage and its related cellular responses.
Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 811, Taiwan.
Jing-Iong
JI
Yang
Chi-Chen
CC
Yeh
Jin-Ching
JC
Lee
Szu-Cheng
SC
Yi
Hurng-Wern
HW
Huang
Chao-Neng
CN
Tseng
Hsueh-Wei
HW
Chang
D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000737:chemistry; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects; D004249:DNA Damage / Q000187:drug effects*; D005419:Flavonoids / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D044724:Gracilaria / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010957:Plasmids; D059808:Polyphenols / Q000737:chemistry
D000975:Antioxidants; D005419:Flavonoids; D016166:Free Radical Scavengers; D010936:Plant Extracts; D059808:Polyphenols; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid