Hesperetin, a Selective Phosphodiesterase 4 Inhibitor, Effectively Suppresses Ovalbumin-Induced Airway Hyperresponsiveness without Influencing Xylazine/Ketamine-Induced Anesthesia.

Hesperetin, a selective phosphodiesterase (PDE)4 inhibitor, is present in the traditional Chinese medicine, "Chen Pi." Therefore, we were interested in investigating its effects on ovalbumin- (OVA-) induced airway hyperresponsiveness, and clarifying its rationale for ameliorating asthma and chronic obstructive pulmonary disease (COPD). Hesperetin was revealed to have a therapeutic (PDE4(H)/PDE4(L)) ratio of >11. Hesperetin (10 ~ 30 µmol/kg, intraperitoneally (i.p.)) dose-dependently and significantly attenuated the airway hyperresponsiveness induced by methacholine. It also significantly suppressed the increases in total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL)-2, IL-4, IL-5, interferon-γ, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF). It dose-dependently and significantly suppressed total and OVA-specific immunoglobulin E levels in the BALF and serum. However, hesperetin did not influence xylazine/ketamine-induced anesthesia, suggesting that hesperetin has few or no emetic effects. In conclusion, the rationales for ameliorating allergic asthma and COPD by hesperetin are anti-inflammation, immunoregulation, and bronchodilation.

Biochanin a, a phytoestrogenic isoflavone with selective inhibition of phosphodiesterase 4, suppresses ovalbumin-induced airway hyperresponsiveness.

The present study investigated the potential of biochanin A, a phytoestrogenic isoflavone of red clover (Triflolium pratense), for use in treating asthma or chronic obstructive pulmonary disease (COPD). Biochanin A (100 µmol/kg, orally (p.o.)) significantly attenuated airway resistance (R(L)), enhanced pause (P(enh)), and increased lung dynamic compliance (C(dyn)) values induced by methacholine (MCh) in sensitized and challenged mice. It also significantly suppressed an increase in the number of total inflammatory cells, neutrophils, and eosinophils, and levels of cytokines, including interleukin (IL)-2, IL-4, IL-5, and tumor necrosis factor (TNF)-α in bronchoalveolar lavage fluid (BALF) of the mice. However, it did not influence interferon (IFN)-γ levels. Biochanin A (100 µmol/kg, p.o.) also significantly suppressed the total and ovalbumin (OVA)-specific immunoglobulin E (IgE) levels in the serum and BALF, and enhanced the total IgG(2a) level in the serum of these mice. The PDE4(H)/PDE4(L) value of biochanin A was calculated as >35. Biochanin A did not influence xylazine/ketamine-induced anesthesia. Biochanin A (10~30 µM) significantly reduced cumulative OVA (10~100 µg/mL)-induced contractions in the isolated guinea pig trachealis, suggesting that it inhibits degranulation of mast cells. In conclusion, red clover containing biochanin A has the potential for treating allergic asthma and COPD.

Surface cleaning of the nanowire field-effect transistor for gene detection.

The efficiency of DNA immobilization by using various surface cleaning methods is studied in this work. The degree of surface cleaning is evaluated by the surface tension measurement to reveal the contribution from the polar and apolar terms. The observation from the fluorescent microscope images indicates the effectiveness of surface clean by the acetone and ethanol mixtures, as well as the sulphuric acid and hydrogen peroxide mixtures. We also fabricate a series of back-gated, 60-nm nanowired (NW) field-effect transistor (FET) sensors for mutation gene detection by following the developed acetone and ethanol mixtures. Electrical properties of the NWFET sensor demonstrate the n-channel depletion characteristics. The current of the sensor is reduced once the attachment of negative charge molecules. The single-stranded capture DNA is chemically immobilized onto the surface of silicon NWFET by three-step reactions. The sensor surface demonstrates the great performance of current shift after the suitable cleaning. The NWFET sensor is successfully applied to detect the BRAF(V599E) mutation genes from the hybridized processes. The sensing behaviour estimated from the electrical signal reaches the femtomolar level.

Genistein, a competitive PDE1-4 inhibitor, may bind on high-affinity rolipram binding sites of brain cell membranes and then induce gastrointestinal adverse effects.

The affinities of genistein on phosphodiesterase (PDE)1-4 and cause of gastrointestinal adverse effects of genistein remain unclear. Female BALB/c mice were actively sensitized by intraperitoneal injections of ovalbumin and challenged by aerosolized ovalbumin (1%). After secondary challenge, aerosolized methacholine (6.25-50mg/ml) induced increases of enhanced pause (P(enh)) values in conscious mice in a concentration-dependent manner. Genistein (30-100 micromol/kg, i.p.) markedly inhibited methacholine (12.5-50mg/ml)-induced increase of P(enh) value in the sensitized and challenged mice. In addition, genistein significantly reduced total inflammatory cells, macrophages, lymphocytes, neutrophils, and eosinophils in bronchoalveolar lavage fluid, with the exception that lymphocytes and neutrophils were not significantly inhibited by genistein at the lowest dose (10 micromol/kg). Genistein also markedly attenuated the release of cytokines, including interleukin (IL)-2, IL-4, IL-5, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha. Genistein competitively inhibited PDE1-4, with a K(i) value ranging from 4.3 to 13.7 microM. Genistein (3-300 microM) concentration-dependently displaced 2nM [(3)H]-rolipram bound on high-affinity rolipram binding sites of brain cell membranes. The therapeutic ratio of genistein was calculated to be 7.9. Genistein (100 micromol/kg, s.c.) significantly shortened xylazine/ketamine-induced anesthesia, suggesting that genistein administered at a higher dose may have gastrointestinal adverse effects. In conclusion, owing to the low therapeutic ratio of genistein, the gastrointestinal adverse effects may be induced via the binding of genistein on high-affinity rolipram binding sites of brain cell membranes, when it is used for a long term or at higher doses for treating allergies, asthma or chronic obstructive pulmonary disease.

Bronchodilatory effects of S-isopetasin, an antimuscarinic sesquiterpene of Petasites formosanus, on obstructive airway hyperresponsiveness.

In the presence of neostigmine (0.1 microM), S-isopetasin competitively antagonized cumulative acetylcholine-induced contractions in guinea pig trachealis, because the slope [1.18+/-0.15 (n=6)] of Schild's plot did not significantly differ from unity. The pA2 value of S-isopetasin was calculated to be 4.62+/-0.05 (n=18). The receptor binding assay for muscarinic receptors of cultured human tracheal smooth muscle cells (HTSMCs) was performed using [3H]-N-methylscopolamine ([3H]-NMS). Saturation binding assays were carried out with [3H]-NMS in the presence (non-specific binding) and absence (total binding) of atropine (1 microM). Analysis of the Scatchard plot (y=0.247-1.306x, r2=0.95) revealed that the muscarinic receptor binding sites in cultured HTSMCs constituted a single population (n(H)=1.00). The equilibrium dissociation constant (Kd) and the maximal receptor density (B(max)) for [3H]-NMS binding were 766 pM and 0.189 pmol/mg of protein, respectively. The -logIC50 values of S-isopetasin, methoctramine, and 1,1-Dimethyl-4-diphenylacetoxypiperidinium iodide (4-DAMP) for displacing 0.4 nM [3H]-NMS-specific binding were 5.05, 6.25, and 8.56, respectively, which suggests that [3H]-NMS binding is predominantly on muscarinic M3 receptors of cultured HTSMCs. The inhibitory effects of S-isopetasin on enhanced pause (P(enh)) value were similar to that of ipratropium bromide, a reference drug. The duration of action of S-isopetasin (20 microM), also similar to that of ipratropium bromide (20 microM), was 3 h. In contrast to ipratropium bromide, which non-selectively acts on muscarinic receptors, S-isopetasin preferentially acts on muscarinic M3 receptors. In conclusion, S-isopetasin may be beneficial as a bronchodilator in the treatment of chronic obstructive pulmonary disease and asthma exacerbations.