The antioxidant activities of brown algal phlorotannins were evaluated using the inhibition of phospholipid peroxidation in the liposome system, and by determining radical scavenging activities against the superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH). Oligomers of phloroglucinol (1,3,5-trihydroxybenzene), eckol (a trimer), phlorofucofuroeckol A (a pentamer), dieckol and 8,8′-bieckol (hexamers), isolated from the Laminarian brown algae Eisenia bicyclis, Ecklonia cava and Ecklonia kurome, showed potent inhibition of phospholipid peroxidation at 1 μM in the liposome system. The phlorotannins had significant radical scavenging activities against the superoxide anion (50% effective concentration values: 6.5-8.4 μM) and DPPH (50% effective concentration values: 12-26 μM), and were more effective compared to ascorbic acid and α-tocopherol. For the purpose of using phlorotannins as functional food ingredients, the antioxidant activity of a complex of crude phlorotannins and soybean protein was examined. The complex had a pronounced DPPH-radical scavenging activity. These results suggest that phlorotannins are potent anti-inflammatory substances, and that the Laminariaceous brown algae, which are abundant in phlorotannins, may be useful as a new functional foodstuff or supplement with anti-inflammatory activity.

Patients with essential hypertension exhibit blunted endothelium-dependent vasodilator responses, which may be largely attributable to reduced bioactivity of nitric oxide (NO). Therefore, we measured the end product of NO, nitrate plus nitrite (nitrogen oxide), and examined the relationship between the degree of hypertension and plasma nitrate plus nitrite levels in patients with essential hypertension. The combined plasma concentration of nitrate plus nitrite, end products of NO metabolism, was reduced in individuals with essential hypertension relative to that in control subjects (15.7+/-1.1 versus 22.8+/-1.4 mmol x L(-1), P<.001); individuals with borderline hypertension showed values that were intermediate between those of the other two groups (18.2+/-1.2 mmol x L(-1), P<.001). The plasma nitrogen oxide concentration showed significant inverse correlations with both systolic and diastolic blood pressures. The basal concentration of nitrogen oxide in the plasma was reduced, at least in the peripheral circulation, in individuals with essential hypertension.

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A new method for phylogenetic classification of bacterial strains using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) is proposed. This method was developed using a bioinformatics-based approach to the rapid identification of bacteria as previously proposed by Demirev and co-workers, which uses ribosomal proteins composed of approximately 50 subunit proteins as biomarkers. Although the amino acid sequences of ribosomal proteins are highly conserved, slight sequence variations can occur at the strain level. Since ribosomal subunit proteins are a complex of housekeeping proteins that have different phylogenetic evolution rates, sequence variation detected as mass differences by MALDI-MS may be useful for the phylogenetic classification of bacteria at strain level. In our proposed method, the first step is the selection of reliable biomarkers through characterization of the expressed ribosomal subunit proteins of a reference strain (usually a genome-sequenced strain) by MALDI-MS. The observed masses in the MALDI mass spectra of cell lysates of sample strains are then compared with the biomarker masses of the reference strain. The biomarkers for each sample strain were designated as present or absent at the reference masses, indicated by 1 or 0, respectively, which were summarized in a table. This table is processed by cluster analysis, generating a phylogenetic tree. In this study, the success of this approach was confirmed by classification of Pseudomonas putida strains because its classification is much more complicated than that of other bacterial strains. Forty-three reliable biomarkers were selected from ribosomal sub-unit proteins of a genome-sequenced strain, P. putida KT2440. The numbers and kinds of biomarkers observed for 16 strains of P. putida, including different biovars, were markedly different, reflecting the variety of the strains. The classification results by the proposed method were highly comparable to those based on the DNA gyrase subunit B gene (gyrB) sequence analysis, suggesting our proposed method would be a useful high-throughput method for phylogenetic classification of newly isolated bacteria.