Antioxidant activity of carotenoids is suggested to be one of the factors for their disease preventing effects. Marine carotenoids fucoxanthin and its two metabolites, fucoxanthinol and halocynthiaxanthin, have been shown to exhibit several biological effects. The antioxidant activities of these three carotenoids were assessed in vitro with respect to radical scavenging and singlet oxygen quenching abilities. The 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity of fucoxanthin and fucoxanthinol was higher than that of halocynthiaxanthin, with the effective concentration for 50% scavenging (EC 50) being 164.60, 153.78, and 826.39 microM, respectively. 2,2'-Azinobis-3-ethylbenzo thizoline-6-sulphonate radical scavenging activity of fucoxanthinol (EC 50, 2.49 microM) was stronger than that of fucoxanthin (EC 50, 8.94 microM). Hydroxyl radical scavenging activity as measured by the chemiluminescence technique showed that the scavenging activity of fucoxanthin was 7.9 times higher than that by fucoxanthinol, 16.3 times higher than that by halocynthiaxanthin, and 13.5 times higher than that by alpha-tocopherol. A similar trend was observed when the hydroxyl radical scavenging was assessed by the electron spin resonance (ESR) technique. ESR analysis of the superoxide radical scavenging activity also showed the superiority of fucoxanthin over the other two carotenoids tested. Singlet oxygen quenching ability of the three carotenoids was lower than that of beta-carotene, with quenching rate constants ( k Q, x10 (10) M (-1) s (-1)) being 1.19, 1.81, 0.80, and 12.78 for fucoxanthin, fucoxanthinol, halocynthiaxanthin, and beta-carotene, respectively. The higher radical scavenging activity of fucoxanthin and fucoxanthinol compared with halocynthiaxanthin is assumed to be due to presence of the allenic bond.

Within the limitations of the present study, it is suggested that monolithic zirconia crown with chamfer width of 0.5 mm and occlusal thickness of 0.5 mm can be used in the molar region in terms of fracture resistance.

Sarcopenia is associated with increased morbidity and mortality in chronic kidney disease (CKD). Pathogenic mechanism of skeletal muscle loss in CKD, which is defined as uremic sarcopenia, remains unclear. We found that causative pathological mechanism of uremic sarcopenia is metabolic alterations by uremic toxin indoxyl sulfate. Imaging mass spectrometry revealed indoxyl sulfate accumulated in muscle tissue of a mouse model of CKD. Comprehensive metabolomics revealed that indoxyl sulfate induces metabolic alterations such as upregulation of glycolysis, including pentose phosphate pathway acceleration as antioxidative stress response, via nuclear factor (erythroid-2-related factor)-2. The altered metabolic flow to excess antioxidative response resulted in downregulation of TCA cycle and its effected mitochondrial dysfunction and ATP shortage in muscle cells. In clinical research, a significant inverse association between plasma indoxyl sulfate and skeletal muscle mass in CKD patients was observed. Our results indicate that indoxyl sulfate is a pathogenic factor for sarcopenia in CKD.

The relationship between the amount of hydroxyl radicals generated by photolysis of H 2 O 2 and bactericidal activity was examined.

-Fucoxanthin (FX), a xanthophyll derivative, is an orange-colored pigment present in edible brown algae. As a part of safety evaluation, single and repeated oral dose toxicity study of FX was ICR mice at doses of 1,000 and 2,000 mg/kg. In a repeated doses study, FX at doses of 500 and 1,000 appearance were observed. In the repeated doses study, histological observation revealed no abnormal -ly increased total cholesterol concentrations were shown by plasma biochemical analyses in all FX-treated groups. Although total bilirubin concentrations were increased by FX, it was established that presence of fucoxanthinol, a major metabolite of FX, interfered with bilirubin determination in plasma. To further ascertain the safety of FX, the mechanism by which FX induces hypercholesterolemia in mice and species differences in the induction of hypercholesterolemia should be elucidated.

It is known that gallic acid shows antimicrobial activity. In the present study, photoirradiation induced reactive oxygen species formation was investigated for augmentation of the antimicrobial activity of gallic acid. Staphylococcus aureus suspended in 4 mmol/L gallic acid was exposed to blue light of a LED at 400 nm. This treatment killed the bacteria, and a >5-log reduction of the viable counts was observed within 15 min. By contrast, neither the LED treatment alone nor the treatment with gallic acid alone showed substantial bactericidal effect. When hydroxyl radical scavengers were added to the suspension, the bactericidal effect of photoirradiated gallic acid was attenuated. Furthermore, electron spin resonance analysis demonstrated that hydroxyl radicals were generated by the photoirradiation of gallic acid. Thus, the present study suggests that the photo-oxidation can enhance the antimicrobial activity of gallic acid via hydroxyl radical formation.

The bactericidal effect of various types of photoirradiated polyphenols against Gram-positive and -negative bacteria was evaluated in relation to the mode of action. Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus, and Streptococcus mutans) and Gram-negative bacteria (Aggregatibacter actinomycetemcomitans, Escherichia coli, and Pseudomonas aeruginosa) suspended in a 1 mg/mL polyphenol aqueous solution (caffeic acid, gallic acid, chlorogenic acid, epigallocatechin, epigallocatechin gallate, and proanthocyanidin) were exposed to LED light (wavelength, 400 nm; irradiance, 260 mW/cm(2)) for 5 or 10 min. Caffeic acid and chlorogenic acid exerted the highest bactericidal activity followed by gallic acid and proanthocyanidin against both Gram-positive and -negative bacteria. It was also demonstrated that the disinfection treatment induced oxidative damage of bacterial DNA, which suggests that polyphenols are incorporated into bacterial cells. The present study suggests that blue light irradiation of polyphenols could be a novel disinfection treatment.

Fundamental anti-oxidative properties of 80% ethanol extract from garlic fermented for the relatively short period of time (40 days at 60-70 degrees C, 85-95% relative humidity) were examined. Superoxide dismutase (SOD)-like activity, scavenging activity against hydrogen peroxide and the polyphenol content of the garlic extract were increased 13-folds, more than 10-folds, and 7-folds, respectively, as compared with those of the control garlic extract. The results indicate that relatively short-term spontaneous fermentation potentiates anti-oxidative properties of garlic in fresh form, which is, at least in part, attributable to the increased level of polyphenols. Since superoxide is the primary upstream radical of the chain reaction with reactive oxygen species and hydrogen peroxide is generated from the scavenging reaction by SOD, the fermented- garlic is suggested to possess desirable anti-oxidative properties.