ABSTRACT
Within a project focusing on the chemopreventive potential of algal phenols, two phloroglucinol derivatives, belonging to the class of fucophlorethols, and the known fucotriphlorethol A were obtained from the ethanolic extract of the brown alga Fucus vesiculosus L. The compounds trifucodiphlorethol A and trifucotriphlorethol A are composed of six and seven units of phloroglucinol, respectively. The compounds were examined for their cancer chemopreventive potential, in comparison with the monomer phloroglucinol. Trifucodiphlorethol A, trifucotriphlorethol A as well as fucotriphlorethol A were identified as strong radical scavengers, with IC(50) values for scavenging of 1,1-diphenyl-2 picrylhydrazyl radicals (DPPH) in the range of 10.0-14.4 microg/ml. All three compounds potently scavenged peroxyl radicals in the oxygen radical absorbance capacity (ORAC) assay. In addition, the compounds were shown to inhibit cytochrome P450 1A activity with IC(50) values in the range of 17.9-33 microg/ml, and aromatase (Cyp19) activity with IC(50) values in the range of 1.2-5.6 microg/ml.
Subject(s)
Antioxidants/pharmacology , Aromatase Inhibitors/pharmacology , Biphenyl Compounds/pharmacology , Cytochrome P-450 Enzyme Inhibitors , Fucus/chemistry , Phenyl Ethers/pharmacology , Phloroglucinol/pharmacology , Terphenyl Compounds/pharmacology , Animals , Antineoplastic Agents, Phytogenic/isolation & purification , Antineoplastic Agents, Phytogenic/pharmacology , Antineoplastic Agents, Phytogenic/therapeutic use , Antioxidants/isolation & purification , Antioxidants/therapeutic use , Aromatase Inhibitors/isolation & purification , Aromatase Inhibitors/therapeutic use , Biphenyl Compounds/isolation & purification , Biphenyl Compounds/therapeutic use , Cell Line, Tumor , Humans , Inhibitory Concentration 50 , Mice , Neoplasms/drug therapy , Phenyl Ethers/isolation & purification , Phenyl Ethers/therapeutic use , Phloroglucinol/analogs & derivatives , Phloroglucinol/therapeutic use , Picrates , Plant Extracts/chemistry , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Terphenyl Compounds/isolation & purification , Terphenyl Compounds/therapeutic useABSTRACT
Marine brown algae such as Ascophyllum nodosum and Fucus vesiculosus accumulate polyphenols composed of phloroglucinol units. These compounds are of ecological importance and, due to their antioxidative activity, of pharmacological value as well. In this study four methods for the quantitative determination of phlorotannins are compared: spectrophotometric determinations using Folin-Ciocalteu's phenol reagent or 2,4-dimethoxybenzaldehyde (DMBA), quantitative (1)H NMR spectroscopy (qHNMR), and gravimetrical measurements. On the basis of the relative standard deviation and the F-test, the determination using Folin-Ciocalteu's phenol reagent and qHNMR proved to be the most reliable and precise methods.
