Evaluation of antibacterial and antioxidant activity of extracts of eelgrass Zostera marina Linnaeus

Abstract

Zostera marina L. is one of marine flowering plants, which plays an important role in coastal ecosystems by generating oxygen and organic substance and providing a habitat for other organisms. However, its residues on seashore have caused serious environmental problems in some coasts worldwide. In this paper, crude extract of Z. marina L. was prepared using methanol-water (1:1, v/v) and further separated into petroleum ether fraction, ethyl acetate fraction, n-butanol fraction and water fraction. The antibacterial activity and antioxidant activity of different fractions from Z. marina L. were evaluated in order to provide information for utilizing the marine plant. Antibacterial bioassay showed that n-butanol fraction was effective only for Staphylocccus aureus, petroleum ether fraction was effective for S. aureus and Bacillus anthracis, ethyl acetate fraction was effective for S. aureus, B. anthracis, Diphtheroid bacilli and Staphylococcus epidermidis, while water fraction had no effect on all the tested strains. Antioxidant assay indicated that all of the four fractions showed α-diphenyl-β-picrylhydrazyl (DPPH) radical-scavenging activity and Fe 3+ reducing activity, and ethyl acetate fraction exhibited the maximum activity.