Anti-genotoxic effect of the Sargassum dentifolium extracts: prevention of chromosomal aberrations, micronuclei, and DNA fragmentation.

The alga Sargassum dentifolium (Turner) C. Agardh, belongs to Sargassaceae, is a brown seaweed in red sea shores in Egypt. This work aimed to extract different water-soluble polysaccharide extracts (E1, E2, and E3) from S. dentifolium and to investigate their protective effect against cyclophosphamide (CP)-induced genotoxicity. Mice bone marrow cells (BMCs) were collected and analyzed for the chromosomal aberration, micronucleated BMCs (MN-BMCs), the mitotic index, DNA fragmentation by comet assay, and histone deacetylases (HDACs), and radical scavenging capacity of extracts was evaluated by the oxygen radical absorbance capacity assay. The results indicated that E2 and E3 significantly inhibited CP-induced multiple chromosomal aberrations, where E1 and E3 significantly suppressed the number of CP-induced formation of tetraploidy. The extracts prohibited the cytotoxic effect of CP and recovered the mitotic activity, whereas E1 possessed the highest recovery and mitosis. In absence of MN, CP induced formation of bi- and poly-nucleated BMCs. E1 prohibited CP-induced formation of bi-nucleated BMCs, while E2 and E3 prohibited CP-induced formation of poly-nucleated BMCs. CP-induced MN-BMCs were accompanied with mono-, bi- and poly-nucleated cells. E1 and E3 remarkably suppressed mono-nucleated MN-BMCs, while E2 inhibited bi-nucleated MN-BMCs. All the extracts significantly inhibited the CP-induced formation of poly-nucleated MN-BMCs. CP-induced DNA fragmentation was inhibited by all extracts, where E1 was the strongest inhibitor as concluded from the comet tail moment. All the extracts were strong OH scavengers, while only E3 was ROO scavenger. The results revealed a drastic decline in HDACs activity by E1 and E3. In conclusion, S. dentifolium polysaccharide extracts E1 and E3 possessed a potential anti-genotoxic and a promising anti-mutagenic activity.