No abstract

The control of inflammation, which arises from complex biological responses to harmful stimuli, is an important determinant of both clinical outcomes and patient comfort. However, the side effects of many current therapies such as non-steroidal anti-inflammatory drugs mean that new safe treatments are required. We previously reported that 12.5 µg/ml hydroxytyrosol (HT) suppressed gene expression of the inducible nitric oxide (NO) synthase (iNOS) isoform and NO production, in mouse peritoneal macrophages treated with lipopolysaccharide (LPS), where nuclear factor-κB (NF-κB) gene expression was not altered. The present study evaluated the anti-inflammatory effects of various concentrations of HT in LPS-induced RAW264.7 mouse macrophages. HT suppressed NF-κB signaling and downregulated LPS-mediated expression of iNOS, cyclooxygenase-2, tumor necrosis factor alpha, and interleukin-1β at 12.5 µg/ml, resulting in reduced production of NO and prostaglandin E2. At lower concentrations, HT seemed to act via another signaling pathway to regulate the inflammatory response. In contrast, HT did not suppress LPS-induced expression of phosphorylated p44/42 mitogen-activated protein kinase. This study showed that HT had anti-inflammatory effects on LPS-stimulated RAW264.7 cells. HT is already available as a nutritional supplement and no toxic effects have been reported. Hence, HT represents a potential novel anti-inflammatory agent.

A rapid, facile and selective detection of anti-H5 subtype avian influenza virus (AIV) antibody in serum by fluorescence polarization immunoassay (FPIA) was achieved. A fragment of recombinant H5 subtype AIV hemagglutinin was produced and labeled with fluorescein to use it as a labeled antigen in FPIA. This labeled antigen was mixed with anti-AIV sera (H1-H16 subtypes) and FP of the mixture was measured using a portable FP analyzer on a microdevice. It was found that FP increased in proportion to the concentration of anti-H5 AIV antibody (serum) and was significantly higher than FP obtained with the other sera. The selective detection of anti-H5 subtype AIV antibody was confirmed. The required volume of original sample was 2 μL and analysis time was within 20 min. This detection system realizes an efficient on-site diagnosis and surveillance of AIV.

-Guinea pigs are the most frequently used animals in phototoxicity studies. However, general toxicity studies most often use Sprague-Dawley (SD) rats. To reduce the number of animals needed for drug development, we examined whether skin phototoxicity studies could be performed using SD rats. A total of 19 drugs that had previously been shown to have phototoxic potential and 3 known phototoxic compounds were administered transdermally to guinea pigs and SD rats. Eleven of the potentially phototoxic drugs and 2 of the known phototoxic compounds were also administered orally to guinea pigs and SD rats. After administration, the animals were irradiated with UV-A (10 J/cm 2 ) and UV-B (0.25 J/cm 2 in guinea pigs and 0.031 J/cm 2 in SD rats) with doses based on standard phototoxicity study guidelines and the results of a minimum erythema dose test, respectively. In the transdermal administration study, all of the known phototoxic compounds and 7 of the drugs induced phototoxic reactions. In the oral administration study, both known phototoxic compounds and 5 drugs induced phototoxic reactions in both species; one compound each was found to be toxic only in SD rats or guinea pigs. The concordance rate of guinea pigs and SD rats was 100% in the transdermal administration study and 85% in the oral administration study. This study demonstrated that phototoxicity studies using SD rats have the same potential to detect phototoxic compounds as studies using guinea pigs.