Development of a Convenient and Quantitative Method for Evaluating Photosensitizing Activity Using Thiazolyl Blue Formazan Dye.

Photosensitizers cause oxidative damages in various biological systems under light. In this study, the method for analyzing photosensitizing activity of various dietary and medicinal sources was developed using 1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan (thiazolyl blue formazan; MTT-F) as a probe. Significant and quantitative decolorization of MTT-F was observed in the presence of photosensitizers used in this study under light but not under dark conditions.

Enhancement of Solubility, Stability, Cellular Uptake, and Bioactivity of Curcumin by Polyvinyl Alcohol.

The biological activities and related mechanisms of curcumin, a major polyphenolic compound in turmeric, the rhizome of , have been extensively investigated. Due to its poor solubility in water, the analysis of curcumin's biological activities is limited in most aqueous experimental systems. In the present study, the effects of polyvinyl alcohol (PVA), a dietary-compatible vehicle, on the solubility, stability, cellular uptake, and bioactivities of curcumin were investigated.

Interfering with Color Response by Porphyrin-Related Compounds in the MTT Tetrazolium-Based Colorimetric Assay.

Porphyrin compounds are widely distributed in various natural products and biological systems. In this study, effects of porphyrin-related compounds including zinc protoporphyrin (ZnPP), protoporphyrin IX (PPIX), cyanocobalamin (CBL), hemin, and zinc phthalocyanine (ZnPC) were analyzed on color response of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) tetrazolium-based assay, a commonly-used method for analyzing cell viability. Color responses of MTT formazan formed in cells treated with ZnPP, PPIX, or ZnPC were significantly reduced even at submicromolar concentrations without affecting cell viability, whereas hemin and CBL did not.

Changes in the chemical properties and anti-oxidant activities of curcumin by microwave radiation.

Curcumin is a dietary phenolic compound that has numerous beneficial health effects. In the present study, changes in the chemical properties and anti-oxidant activities of curcumin by microwave radiation were investigated. Degradation of curcumin dissolved in distilled water was accelerated according to the increase in radiation time or radiation intensity.

Cholecalciferol inhibits lipid accumulation by regulating early adipogenesis in cultured adipocytes and zebrafish.

Cholecalciferol (CCF) is a common dietary supplement as a precursor of active vitamin D. In the present study, the effect of CCF on lipid accumulation was investigated in adipocyte cells and zebrafish models. CCF effectively inhibited lipid accumulation in both experimental models; this effect was attributed to the CCF-mediated regulation of early adipogenic factors.