ABSTRACT
<p><b>OBJECTIVE</b>To investigate the preventive effects of Qiangzhi Decoction (, QZD) on influenza A pneumonia through inhibition of inflammatory cytokine storm in vivo and in vitro.</p><p><b>METHODS</b>One hundred ICR mice were randomly divided into the virus control, the Tamiflu control and the QZD high-, medium-, and low-dose groups. Mice were infected intranasally with influenza virus (H1N1) at 10 median lethal dose (LD50). QZD and Tamiflu were administered intragastrically twice daily from day 0 to day 7 after infection. The virus control group was treated with distilled water alone under the same condition. The number of surviving mice was recorded daily for 14 days after viral infection. The histological damage and viral replication and the expression of inflammatory cytokines were monitored. Additionally, the suppression capacity on the secretion of regulated on activation normal T cells expressed and secreted (RANTES) and tumor necrosis factor-α (TNF-α) in epithelial and macrophage cell-lines were evaluated.</p><p><b>RESULTS</b>Compared with the virus control group, the survival rate of the QZD groups significantly improved in a dose-dependent manner (P<0.05), the viral titers in lung tissue was inhibited (P<0.05), and the production of inflammatory cytokines interferon-γ (IFN-γ), interleukin-6 (IL-6), TNF-α, and intercellular adhesion molecule-1 (ICAM-1) were suppressed (P<0.05). Meanwhile, the secretion of RANTETS and TNF-α by epithelial and macrophage cell-lines was inhibited with the treatment of QZD respectively in vitro (p<0.05) CONCLUSIONS: The preventive effects of QZD on influenza virus infection might be due to its unique cytokine inhibition mechanism. QZD may have significant therapeutic potential in combination with antiviral drugs.</p>
Subject(s)
Animals , Dogs , Humans , Cell Line , Cell Survival , Chemokine CCL5 , Metabolism , Chemokines , Metabolism , Cytokines , Metabolism , Drugs, Chinese Herbal , Pharmacology , Therapeutic Uses , Enzyme-Linked Immunosorbent Assay , Hemagglutination, Viral , Inflammation , Pathology , Influenza A Virus, H1N1 Subtype , Physiology , Influenza A Virus, H1N2 Subtype , Lung , Pathology , Madin Darby Canine Kidney Cells , Mice, Inbred ICR , Orthomyxoviridae Infections , Pathology , Pneumonia , Pathology , Protective Agents , Pharmacology , Therapeutic Uses , Survival Rate , Tumor Necrosis Factor-alpha , PharmacologyABSTRACT
To compare the DAAO expression level in different Pichia pastoris host strains, the gene encoding DAAO from Trigonopsis variabilis was cloned into plasmid pPIC3.5k and then transformed into P. pastoris GS115 and KM71 respectively. The positive transformants PDK13 (MutS) and PD27 (Mut+) were obtained by PCR analysis. Their optimal and different expression conditions were investigated. To compare with PD27, PDK13 was determined to poss a slower consumption of methanol, a longer induction time, a lower oxygen request and apparently higher expression of DAAO. The highest expression levels were reached up to 2700, 2500 IU/L in shaking flask and 10140, 8463.5 IU/L in fermentor respectively. The over-expression of DAAO can meet its large demand for production of 7-ACA, alpha-keto acid and L-amino acid. In addition, the phenylpyruvate and L-phenylalanine were obtained by crude DAAO reacting with DL-phenylalanine at 37 degrees C for 3h.