Visualization of Recrystallization Induced by Ultraviolet Degradation of a Polypropylene Film Using Raman Imaging.

Raman images were constructed for polypropylene (PP) films before and after ultraviolet (UV) irradiation (100 mW, 248-436 nm) for 10 h using several intensity ratios of Raman bands that are sensitive to crystallization of PP. In the images of PP films before the irradiation the intensity ratios are nearly uniform for the films but for those of the PP films after the irradiation, the ratios become large with a mottled pattern, indicating that recrystallization occurs in the PP films upon the irradiation of the UV light. The UV-irradiated PP films show worm-like shaped structures in few micrometer order representing the recrystallization of PP. The temperature gradient of PP is low (273 K), and thus, it is very likely that due to UV energy and polymer fragmentation, PP molecules become more mobile and some parts of molecular chains in amorphous parts of PP molecules lead to their rearrangement and recrystallization. In this study, we demonstrate that Raman imaging clearly detects subtle changes in the crystallinity with a micrometer order structure which morphological images cannot observe.

Inhibitory effects of geranium essential oil and its major component, citronellol, on degranulation and cytokine production by mast cells.

We investigated the effects of geranium essential oil (GEO) on anaphylaxis. GEO can exert antioxidant and anti-inflammatory effects, but its roles in allergic reactions are incompletely understood. Here, we used mouse cells to show that GEO inhibited the degranulation of cultured mast cells (CMCs). Citronellol is the major component of GEO and inhibited CMC degranulation. The l-enantiomer of citronellol more effectively suppressed CMC degranulation than did d-citronellol. We also examined whether citronellol could inhibit the immunoglobulin (Ig) E-induced production of tumor necrosis factor (TNF)-α. Treatment with various concentrations of citronellol before CMC activation with IgE significantly inhibited the induction of TNF-α in a dose-dependent manner. Mechanistically, citronellol suppressed the phosphorylation of mitogen-activated protein kinase (ERK), which is critical for ERK activation and the production of inflammatory cytokines in mast cells. These findings suggest that citronellol may represent a candidate compound for the effective treatment of allergic diseases.

Inhibitory effects of water-soluble low-molecular-weight ß-(1,3-1,6) D-glucan isolated from Aureobasidium pullulans 1A1 strain black yeast on mast cell degranulation and passive cutaneous anaphylaxis.

We investigated the effects of water-soluble low-molecular-weight ß-(1,3-1,6) D-glucan isolated from Aureobasidium pullulans 1A1 strain black yeast (LMW-ß-glucan) on mast cell-mediated anaphylactic reactions. Although it is known that LMW-ß-glucan has anti-tumor, anti-metastatic and anti-stress effects, the roles of LMW-ß-glucan in immediate-type allergic reactions have not been fully investigated. We examined whether LMW-ß-glucan could inhibit mast cell degranulation and passive cutaneous anaphylaxis (PCA). LMW-ß-glucan dose-dependently inhibited the degranulation of both rat basophilic leukemia (RBL-2H3) and cultured mast cells (CMCs) activated by calcium ionophore A23187 or IgE. However, LMW-ß-glucan had no cytotoxicity towards RBL-2H3 cells and CMCs. Furthermore, orally administered LMW-ß-glucan inhibited the IgE-induced PCA reaction in mice. These results show LMW-ß-glucan to be a possible compound for the effective therapeutic treatment of allergic diseases.

The bifidogenic growth stimulator inhibits the growth and respiration of Helicobacter pylori.

BACKGROUND: Triple therapy with amoxicillin, clarithromycin, and a proton-pump inhibitor is a common therapeutic strategy for the eradication of Helicobacter pylori (H. pylori). However, frequent appearance of clarithromycin-resistant strains is a therapeutic challenge. While various quinones are known to specifically inhibit the growth of H. pylori, the quinone 1,4-dihydroxy-2-naphthoic acid (DHNA) produced by Propionibacterium has strong stimulating effect on Bifidobacterium. We were interested to see whether DHNA could inhibit the growth of H. pylori in in vitro or in vivo experimental setting. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) of DHNA was determined by the agar dilution method. The inhibitory action of DHNA on the respiratory activity was measured by using an oxygen electrode. Germ-free mice infected with H. pylori were given DHNA in free drinking water containing 100 µg/mL for 7 days. RESULTS: DHNA inhibited H. pylori growth at low MIC values, 1.6-3.2 µg/mL. Likewise, DHNA inhibited clinical isolates of H. pylori, resistant to clarithromycin. However, DHNA did not inhibit other Gram negative or anaerobic bacteria in the normal flora of the human intestine. Both H. pylori cellular respiration and adenosine 5'-triphosphate (ATP) generation were dose-dependently inhibited by DHNA. Similarly, the culture filtrates of propionibacterial strains inhibited the growth of H. pylori, and oral administration of DHNA could eradicate H. pylori in the infected germ-free mice. CONCLUSIONS: The bifidogenic growth stimulator DHNA specifically inhibited the growth of H. pylori including clarithromycin-resistant strains in vitro and its colonization activity in vivo. The bactericidal activity of DHNA was via inhibition of cellular respiration. These actions of DHNA may have clinical relevance in the eradication of H. pylori.

Inhibitory effects of guarana seed extract on passive cutaneous anaphylaxis and mast cell degranulation.

This study investigated the effects of guarana seed extract (GSE) on an anti-allergic mechanism. GSE orally administered inhibited the anti-dinitrophenol IgE-induced passive cutaneous anaphylaxis reaction in mice. Furthermore, it inhibited the degranulation of rat basophilic leukemia RBL-2H3 cells. It had no cytotoxicity on RBL-2H3 cells. These results show that GSE is a candidate for effective therapeutic material for allergic diseases.