Effects of Gametophytes of Ecklonia Kurome on the Levels of Glucose and Triacylglycerol in db/db, Prediabetic C57BL/6J and IFN-γ KO Mice.

We have studied edible algae that have the potential to down-regulate blood glucose. In Japan, Ecklonia species have been believed to improve the circulation of blood. In this study, we used leptin receptor deficient type 2 diabetes model mice (db/db) and prediabetic C57BL/6J mice. We also focused on the role of IFN-γ in the control of blood levels of triacylglycerol and glucose, because it is reportedly engaged in the regulation of energy consumption together with leptin. We report that gametophytes of Ecklonia kurome down-regulate the blood level of glucose and serum level of triacylglycerol in db/db. We also report that gametophytes of Ecklonia kurome down-regulate the level of glucose but not the level of triacylglycerol in prediabetic C57BL/6J mice induced by a high fat diet. They increased the level of triacylglycerol compared to that of control group in C57BL/6J, but not in IFN-γ KO mice. Gametophytes of Ecklonia kurome were administered orally to prediabetic C57BL/6J and IFN-γ KO mice and oral glucose tolerance tests were performed to evaluate the effects of algae. During the administration of the normal diet, we found a higher level of blood glucose in a glucose tolerance test of IFN-γ KO mice compared with that of C57BL/6J. Although a high fat diet induced a higher level of blood glucose compared with a normal diet group in a glucose tolerance test of C57BL/6J mice, this effect of high fat diet was not observed clearly at first but appeared three hours after glucose administration in IFN-γ KO mice. Gametophytes of Ecklonia kurome down-regulated the level of blood glucose in both C57BL/6J and IFN-γ KO mice, when administered a normal diet after making them prediabetic. These results suggest that Ecklonia kurome are effective to down-regulate the blood glucose and IFN-γ is involved in the regulation of blood glucose and triacylglycerol.

Isolation and characterization of a feather-degrading enzyme from Bacillus pseudofirmus FA30-01.

We isolated the feather-degrading Bacillus pseudofirmus FA30-01 from the soil sample of poultry farm. The isolate completely degraded feather pieces after liquid culture at 30 degrees C (pH 10.5) for 3 days. Strain FA30-01 is a Gram-positive, spore-forming, rod-shaped bacterium and was identified with B. pseudofirmus based on 16S rDNA analysis. The keratinase enzyme produced by strain FA30-01 was refined using ammonium sulfate precipitation, negative-ion DEAE Toyopearl exchange chromatography, and hydroxyapatite chromatography. The refinement level was 14.5-fold. The molecular weight of this enzyme was 27.5 kDa and it had an isoelectric point of 5.9. The enzyme exhibited activity at pH 5.1-11.5 and 30-80 degrees C with azokeratin as a substrate, although the optimum pH and temperature for keratinase activity were pH 8.8-10.3 and 60 degrees C, respectively. This enzyme is one of the serine-type proteases. Subtilisin ALP I and this enzyme had 90% homology in the N-terminal amino acid sequence. Since this enzyme differed from ALP I in molecular weight, heat resistance and isoelectric point, they are suggested to be different enzymes.

IL-5-Induced Eosinophils Suppress the Growth of Leishmania amazonensis In Vivo and Kill Promastigotes In Vitro in Response to Either IL-4 or IFN-gamma.

In IL-5 transgenic mice (C3H/HeN-TgN(IL-5)-Imeg), in which 50% of peripheral blood leukocytes are eosinophils, the development of infection by Leishmania amazonensis was clearly suppressed. To determine mechanistically how this protozoan parasite is killed, we performed in vitro killing experiments. Either IL-4 or IFN-gamma effectively stimulated eosinophils to kill Leishmania amazonensis promastigotes, and most of the killing was inhibited by catalase but not by the NO inhibitor L-N5-(1-iminoethyl)-ornithine, suggesting that hydrogen peroxide is responsible for the killing of L. amazonensis by eosinophils. There was no significant degranulation of eosinophils in the culture, because eosinophil peroxidase was not detected in culture supernatants when L. amazonensis promastigotes were killed by activated eosinophils. Such resistance was also observed in BALB/c mice, which are highly susceptible to L. amazonensis. Expression plasmids for IL-4, IL-5, and IFN-gamma were transferred into muscle by electroporation in vivo starting 1 week before infection. Expression plasmid for IL-5 was most effective in slowing the development of infection among three expression plasmids. Expression plasmid for IL-4 was slightly effective and that for IFN-gamma had no effect on the progress of disease. These results suggest that IL-5 gene transfer into muscle by electroporation is useful as a supplementary protection method against L. amazonensis infection.