Zhi-Qiang Chang

Mechanism of macrophage activation induced by β-glucan produced from Paenibacillus polymyxa JB115

Beta-glucans are heterogeneous groups of glucose polymers found in the cell walls of fungi, plants and some bacteria. Our previous report showed that a novel beta-1,3/1,6-glucan produced from Paenibacillus (P.) polymyxa JB115 can induce nitric oxide (NO) production in RAW264.7 cells. In the present study, the beta-glucan significantly increased luciferase activity in cells transfected with NFkappaB or AP1, but not STAT1, reporter vector DNA, which contain their binding promoter site. All specific NFkappaB and MAPKs pathway inhibitors (pyrrolidine dithiocarbamate, AG490, U0126, SB203580 and SP600125) remarkably attenuated NO production induced by the beta-glucan. Furthermore, Western blot analysis revealed that the stimulation of Raw264.7 cells by beta-glucan induced phosphorylation of IkappaB and the consequent translocation of NFkappaB into the nucleus. Meanwhile, phosphorylation of ERK1/2, JNK/SAPK and p38 MAPKs in cytoplasm were also confirmed. All these results indicated that beta-glucan from P. polymyxa JB115 activates macrophages through MAPKs and NFkappaB signaling pathway.

Mycoplasma hyopneumoniae induces pro-inflammatory cytokine and nitric oxide production through NFκB and MAPK pathways in RAW264.7 cells

In the present study, we confirmed the ability of M. hyopneumoniae to induce the secretion of large amount of proinflammatory cytokine and nitric oxide (NO) in murine macrophage RAW 264.7 cells. Moreover, M. hyopneumoniae-induced activation of the MAPK and NF-кB pathways by phosphorylation of ERK1/2, p38 and JNK/SAPK and by dissociation of IκB from NF-κB. Translocation of transcription factor NF-κB and its binding was confirmed through western blot and electromobility shift assay. From these results, we further hypothesized that these signal proteins were involved in M. hyopneumoniae-induced proinflammatory cytokines and NO productions in macrophages. Hence, we utilized specific blockers of MAPK and NF-κB to investigate the signaling pathway involvement in cytokine and NO production through pharmacological approaches. The results demonstrated significant inhibition of TNF-α, IL-1β, IL-6 and NO by MAPK inhibitors. NF-κB inhibitor PDTC significantly inhibited IL-1β and NO production. These findings contribute to the understanding of the mechanisms of immune reactivity and may ultimately prove useful in the development of new therapeutic strategies. In summary, we found critical evidence for the involvement of NF-κB and MAPK signaling pathways in the upregulation of proinflammatory cytokine and NO induced by M. hyopneumoniae.

Integration of Pharmacokinetic and Pharmacodynamic Indices of Orbifloxacin in Beagle Dogs after a Single Intravenous and Intramuscular Administration

ABSTRACT The pharmacokinetics (PK) and pharmacodynamics (PD) of orbifloxacin were studied in beagle dogs after intravenous (i.v.) and intramuscular (i.m.) administration at a dose of 2.5 mg/kg body weight. An absolute bioavailability of 100.1% ± 4.76%, a terminal half-life of 4.23 ± 0.2 h and 3.95 ± 0.15 h after i.v. and i.m. administration, a steady-state volume of distribution of 1.61 ± 0.13 liters/kg, and clearance of 0.31 ± 0.03 liters/h/kg were observed. Orbifloxacin showed rapid, concentration-dependent killing against the Escherichia coli, Staphylococcus aureus, Staphylococcus intermedius, and Proteus mirabilis clinical isolates. Computations based on PK-PD analysis indicated that the recommended dose is unlikely to be clinically effective against some strains like S. intermedius. Therefore, a higher dose of orbifloxacin would be worthy of consideration for treatment of certain bacterial infections in dogs.

Anti-Obesity Activity, Anti-Cancer Activity and Single Oral Dose Toxicity of Inonotus xeranticus Extracts

In this study, we investigated the in vitro anti-obesity, anti-cancer activity and single oral dose toxicity of Inonotus xeranticus extracted by methanol (INXM) or ethyl acetate (INXE). In order to investigate anti-obestity effect of Inonotus xeranticus extracts, the 3T3-L1 cells were treated with these extracts at various concentrations(1, 10, 100 and 300 ㎍/㎖). It was observed that 3T3-L1 cells treated with 100 ㎍/㎖ of Inonotus obliquus ethyl acetate extract (INOE), INXM and INXE, in the absence of differentiation cocktail (0.5 mM isobutylmethylxanthine (IBMX) 1 μM dexamethasone, 1 ㎍/㎖ insulin), differentiated at a rate of 78.5, 80.9, and 76.4% respectively. Differentiation rates of 86.6% and 83.4% were observed in 3T3-L1 cells which were treated with differentiation cocktail at 100 ㎍/㎖ of INXM and INXE, respectively. The anti-cancer effect of Inonotus xeranticus extracts was investigated using a method of sulforhodamine B in sarcoma 180 cell line. The cells were treated with these extracts (1, 10, 100 and 300 ㎍/㎖) for 48 hours. The growth of cells which were treated with 300 ㎍/㎖ of INXM was inhibited by 80.1%. The growth of sarcoma 180 cells which were treated with 100 and 300 ㎍/㎖ of INXE was inhibited by 74.7% and 64.5%, respectively. In single oral dose toxicity study, no differences were observed between control and treated groups in clinical signs, body weight gains, and feed and water consumptions. The results indicated that Inonotus xeranticus extracts did not show any toxic effects at 2,000 ㎎/㎏ in mice, and the LD?? of these extracts was found to be higher than 2,000 ㎎/㎏ in this experiment. From the above results, Inonotus xeranticus methanol and ethyl acetate extracts might have useful clinical applications in the management of cancer and obesity and may also be useful as a medicinal food.

A novel β-glucan produced by Paenibacillus polymyxa JB115 induces nitric oxide production in RAW264.7 macrophages

The effect of extracellular β-(1→3), (1→6)-glucan, produced by Paenibacillus polymyxa JB115, on nitric oxide (NO) production in RAW264.7 macrophages was investigated. β-glucan induced the production of NO by RAW264.7 macrophages in a concentration- and time-dependent manner. Moreover, β-glucan stimulation increased the mRNA expression of iNOS, COX-2 and IL-6 in RAW264.7 macrophages in a concentration-dependent manner.

Clinical pharmacokinetics of norfloxacin-glycine acetate after intravenous and oral administration in pigs.

The pharmacokinetics and dosage regimen of norfloxacin-glycine acetate (NFLXGA) was investigated in pigs after a single intravenous (i.v.) or oral (p.o.) administration at a dosage of 7.2 mg/kg body weight. After both i.v. and p.o. administration, plasma drug concentrations were best fitted to an open two-compartment model with a rapid distribution phase. After i.v. administration of NFLXGA, the distribution (t1/2α) and elimination half-life (t1/2β) were 0.36 ± 0.07 h and 7.42 ± 3.55 h, respectively. The volume of distribution of NFLXGA at steady state (Vdss) was 4.66 ± 1.39 l/kg. After p.o. administration of NFLXGA, the maximal absorption concentration (Cmax) was 0.43 ± 0.06 µg/ml at 1.36 ± 0.39 h (Tmax). The mean absorption (t1/2ka) and elimination half-life (t1/2β) of NFLXGA were 0.78 ± 0.27 h and 7.13 ± 1.41 h, respectively. The mean systemic bioavailability (F) after p.o. administration was 31.10 ± 15.16%. We suggest that the optimal dosage calculated from the pharmacokinetic parameters is 5.01 mg/kg per day i.v. or 16.12 mg/kg per day p.o.

Immunomodulatory activities and subacute toxicity of a novel β-glucan from Paenibacillus polymyxa JB115 in rats

Subacute toxicity and immunopharmacological activities of β-glucan from P. polymyxa JB115 was evaluated in a 28-day feeding study in rats. The white blood cell count, red blood cell count, hematocrit, hemoglobin, thrombocytes (THR) and thrombocytocrit were significantly higher in male fed with β-glucan than control rats and the insignificant lower eosinophil count, mean corpuscular volume, mean cell hemoglobin and uninfected THR (uTHR) levels were observed in male whereas no marked changes in female rats. No other significant differences in serum chemistry and liver, kidney, and spleen weights were observed. The pathological changes and other abnormal indicators were not detected in urine. Female rats fed with diet supplemented with 0.01% β-glucan also showed marked increase in the percentage of blood cytotoxic T-lymphocytes compared to that of the control group while not significant differences in the percentage of blood B-lymphocytes. No adverse effects on general condition and behavior, growth, feed and water consumption and feed conversion efficiency were found. The results suggest that consumption of the novel β-1, 3/1, 6-glucan from P. polymyxa JB115 was not associated with any obvious toxic effects in rats, indicating its safety as a potential immunostimulant or as an adjuvant of some animal vaccines.