Table 10.
Effect of marine phenolics on the prevention of infectious diseases.
| Compounds/Marine Source | Test Model | Outcome | Ref. |
|---|---|---|---|
| Phlorotannins purified extracts isolated from ten brown algal species (Cystoseira tamariscifolia, C. nodicaulis, C. usneoides, Sargassum vulgare, F. spiralis, Halopteris filicina, Stypocaulon scoparium, Cladostephus spongiosus, P. pavonica and Saccorhiza polyschides) from Portugal | In vitro broth microdilution assay | Less effective against fungi than bacteria Phlorotannin extracts were more effective against Gram-positive than Gram-negative bacteria Cystoseira species and F. spiralis were the most active against Staphylococcus and M. luteus (minimum MIC of 2.0 mg/mL) F. spiralis and C. nodicaulis extracts were the most effective against the studied fungi (MIC = 3.9 mg/mL) |
[131] |
| Aqueous methanolic extracts isolated from Irish brown seaweed H. elongata | In vitro broth microdilution assay | High antimicrobial activity against the Gram-positive bacteria, L. monocytogenes and E. faecalis High antimicrobial activity against the Gram-negative bacteria, P. aeruginosa and S. abony |
[276] |
| Turtlegrass Thalassia testudinum | Inoculations of healthy turtlegrass blades with Labyrinthula sp. | The emergence of Labyrinthula sp. lesions on turtlegrass blades causes a “pseudo-induction” of plant phenolic acids as carbon resources over-accumulate in tissues located above wound sites | [83] |
| Extracts isolated from Eelgrass Zostera marina, whose leaf surface contained hydroxycinnamic acids, flavones and flavanols | In vitro bioassays against microbial foulers | Involvement of surface-associated phenolic compounds to control yeasts | [5] |
| Free phenolic acid extracts from Nannochloropsis sp. and Spirulina sp., as well as pure compounds | In vitro antifungal activity of phenols | Antifungal activity of phenolic acid extracts of the microalgae Higher activity of the natural free phenolic acid extracts (EC50 values of 49.6 μg/mL and 33.9 μg/mL for Nannochloropsis sp. and Spirulina sp., respectively) than the synthetic mixtures |
[27] |
| Ethanolic extracts isolated from nine marine microalgae (Nannochloropsis gaditana, Dunaliella salina, Dunaliella sp., Phaedactylum tricornutum, Isochrysis sp., Navicula sp., Chaeotoceros sp., Chlorella sp. and Tetraselmis sp.) | In vitro broth microdilution assay | Variable inhibitory activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus (Tetraselmis sp. was the most active of all those tested with MIC of 2.6 to 3.0 mg/mL of extract) Inhibition of the growth of Candida albicans (N. gaditana showed the highest activity with a MIC of 4.0 mg/mL of extract) Aspergillus niger (fungus) was resistant to the effects of the extracts Activity of the extracts was due to the presence of fatty acids, carotenoids and phenols |
[50] |
| Methanol, ethanol and hexane extracts from four marine microalgae (Chaetoceros calcitrans, Skeletonema costatum, Chroococcus turgidus and Nannochloropsis oceanica) | In vitro disc diffusion method | Inhibitory activity against Staphylococcus aureus, Streptococcus pyogenes and Bacillus subtilis Antifungal activity only in Skeletonema costatum and Chroococcus turgidus |
[59] |
| Diphlorethohydroxycarmalol isolated from Ishige okamurae | In vitro antiviral enzyme assay | Inhibited the activity of HIV-1 reverse transcriptase and integrase with IC50 values of 9.1 μM and 25.2 μM, respectively | [278] |
| 8,4′’-Dieckol isolated from E. cava | In vitro: H9, H9/HIV-1IIIB, CEM-SS, C8166 cells (1–50 μM of phenol) | Inhibited the activity of HIV-1 reverse transcriptase (RT) enzyme (91% inhibition ratio at 50 μM) and HIV-1 entry Exhibited the inhibitory effects against HIV-1 induced syncytia formation, lytic effects and viral p24 antigen production |
[280] |
| 6,6′-Bieckol isolated from E. cava | In vitro: H9, H9/HIV-1IIIB, CEM-SS, C8166 cells (0.1–30 μM of phenol) | Inhibited the activity of HIV-1 RT enzyme (EC50 1.07 μM) as well as HIV-1 entry Exhibited the inhibitory effects against HIV-1 induced syncytia formation (EC50 1.72 μM), lytic effects (EC50 1.23 μM) and viral p24 antigen production (EC50 1.26 μM) |
[279] |
MIC: minimum inhibitory concentration; HIV-1: human immunodeficiency virus-1; RT: reverse transcriptase; AIDS: acquired immunedeficiency syndrome.