ABSTRACT
Degranulation inhibitors in plants are widely used for prevention and treatment of immediate-type allergy. We previously isolated a new ellagic acid glucoside, okicamelliaside (OCS), from Camellia japonica leaves for use as a potent degranulation inhibitor. Crude extracts from leaves also suppressed allergic conjunctivitis in rats. In this study, we evaluated the in vivo effect of OCS using a pure sample and performed in vitro experiments to elucidate the mechanism underlying the extraordinary high potency of OCS and its aglycon. The IC(50) values for degranulation of rat basophilic leukemia cells (RBL-2H3) were 14 nM for OCS and 3 µM for aglycon, indicating that the two compounds were approximately 2 to 3 orders of magnitude more potent than the anti-allergic drugs ketotifen fumarate, DSCG, and tranilast (0.17, 3, and >0.3 mM, respectively). Antigen-induced calcium ion (Ca(2+)) elevation was significantly inhibited by OCS and aglycon at all concentrations tested (p<0.05). Upstream of the Ca(2+) elevation in the principle signaling pathway, phosphorylation of Syk (Tyr525/526) and PLCγ-1 (Tyr783 and Ser1248) were inhibited by OCS and aglycon. In DNA microarray-screening test, OCS inhibited expression of proinflammatory cytokines [interleukin (IL)-4 and IL-13], cytokine-producing signaling factors, and prostaglandin-endoperoxidase 2, indicating that OCS broadly inhibits allergic inflammation. During passive cutaneous anaphylaxis in mice, OCS significantly inhibited vascular hyperpermeability by two administration routes: a single intraperitoneal injection at 10 mg/kg and per os at 5 mg/kg for 7 days (p<0.05). These results suggest the potential for OCS to alleviate symptoms of immediate-type allergy.
Subject(s)
Anti-Allergic Agents/pharmacology , Cell Degranulation/drug effects , Ellagic Acid/analogs & derivatives , Glucosides/pharmacology , Leukemia, Basophilic, Acute/immunology , Passive Cutaneous Anaphylaxis/drug effects , Animals , Antigens/immunology , Calcium/immunology , Cell Line, Tumor , Cyclooxygenase 2/genetics , Cytokines/genetics , Dinitrobenzenes/immunology , Down-Regulation , Ellagic Acid/pharmacology , Gene Expression Regulation/drug effects , Immunoglobulin E/immunology , Intracellular Signaling Peptides and Proteins/immunology , Male , Mice , Mice, Inbred ICR , Oligonucleotide Array Sequence Analysis , Passive Cutaneous Anaphylaxis/immunology , Protein-Tyrosine Kinases/immunology , Rats , Syk KinaseABSTRACT
BACKGROUND: Previously, we investigated the possibility of using near-infrared (NIR) spectroscopy for the diagnosis of human immunodeficiency virus type-1 (HIV-1) infection. Here, we further analyze NIR spectra using molecular clones of various HIV-1 subtypes. METHODS: Culture supernatants of pNL4-3- (HIV-1 molecular clone) or pUC18- (empty vector) transfected 293 T cells were used. In addition, culture supernatants obtained using pBal (HIV-1 subtype B molecular clone) or pIndieC (HIV-1 subtype C molecular clone) were used. Near-infrared radiation (NIR) spectra, obtained using the culture supernatants, were subjected to principal component analysis (PCA) to extract and analyze their properties. RESULTS: The PCA demonstrated that HIV-1 in medium altered wavelength absorption at around 950 and 1030 nm, suggesting that the HIV-1 altered OH vibration in water. In addition, absorption varied among subtypes at around 950, 1030 and 1060 nm, suggesting that the interaction between HIV-1 and water varies among subtypes. CONCLUSIONS: These differences in the NIR spectra may make it possible to delineate HIV-1 subtypes spectroscopically.