Aquatic Plants from Minnesota Part 3 - Antimicrobial Effects

Abstract

In this study the antimicrobial activity of the following 22 Minnesotan aquatic plants was investigated: Anacharis Canadensis, Calla Polustris, Carex lacstris, Ceratophyllum demersum, Chara vulgaris, Elecharis smallii, Lemna minor, Myriophyllum exalbescens, Nuphar variegatum, Nymphaea turberosa, Potamogeton amplifolius, P. natans, P. pectinatus, P. richardsonu, P. zosteriformis, Sagittaria cuneata, S. latifolia, Sparganium eurycarpum, S. fluctuans, Typha angustifolia, Vallisneria amiercana, and Zizania aquetica, Furthermore, the chemical constituents responsible for the significant antimicrobial effect were isolated and identified. The skellysolve F. chloroform, 80% ethanol and fresh water extracts of plant species were treated for antimicrobial activity employing the qualitative filter paper disc diffusion method and reference antibiotic discs. Ethanol (80%) extracts of Myriophyllum exalbescens (activity ratio of .34 as compared to the 30 mcg chloramphenicol discs) Nymphaea tuberose (leaf: .40, stem: .45) were moderately active against S. aureus. Ethanol (80%) extracts of Carex lacustris (activity ratio of .34 as compared to the 10 mcg streptomycin discs), Nymphaea tuberose (leaf: 1.01, stem: 1.10) and Nuphar variegatum collected in Lake Minnetonka (leaf: .73, stem: .58) were active against M. smegmatis. All extracts were relatively inactive against E. coli except the water extract of Potamogeton natans where a low activity ration of .10 as compare to the 30 mcg chloramphenicol discs was indicated. Skellysolve F stem extracts of Nuphar variegatum collected in the Pine Lake and Sparganium fluctuans showed a rather distinct action against C. albicans, the activity ratio as compared to the 100 units mycostatin discs were 2.06 and 1.08, respectively. Regarding antifungal activity, ethanol (80%) extracts of Carex lacustris (activity ratio of 1.08 as compared to 5% aq. Phenol standard), Nymphaea tuberosa (stem: .72) and skellysolve F extract of Potamogeton zosteriformis (.60) were active against Alternaria sp., 80% ethanol stem extracts of Nymphaea tuberosa and Nuphar variegatum were active against F. roseum with the activity ratios of .41 and .48 respectively, as compared to the 5% aqueous phenol standard. In general, the plant pathogenic fungi are more resistant than animal pathogenic organisms toward the actions of aquatic plant extract.