Antiulcer effects and mechanism study of Veronicastrum axillare on ethanol induced gastric ulcer rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To study the antiulcer effects and the mechanism of Veronicastrum axillare (Sieb. et Zucc) Yamazaki (VAY) on ethanol induced gastric ulcer rats.</p><p><b>METHODS</b>Totally 48 healthy SD rats were randomly divided into 6 groups, i.e., the normal group, the model group, the ranitidine group, the high dose VAY group, the medium dose VAY group, and the low dose VAY group, 8 in each group. Rats in the normal group and the model group were administered with normal saline respectively. Rats in the ranitidine group were administered with 0.18% ranitidine suspension (at the daily dose of 0.027 g/kg) by gastrogavage. Those in the high dose VAY group, the medium dose VAY group, and the low dose VAY group were administered with VAY at the daily dose of 2.8 g/kg, 1.4 g/kg, and 0.7 g/kg by gastrogavage, once daily for 14 consecutive days. The gastric ulcer model was established using absolute ethanol after the last gastrogavage. The ulcer index and the ulcer inhibitory rate were compared. The concentrations of malonyldialdehyde (MDA), nitric oxide (NO), epidermal growth factor (EGF), and the activity of superoxide dismutase (SOD) in the serum and the homogenate of the gastric mucosa tissue were detected.</p><p><b>RESULTS</b>Compared with the model group, the gastric ulcer index in the rest groups obviously decreased (P < 0.01). The ulcer index was dose-dependent with VAY (P < 0.01), with the highest gastric ulcer index shown in the high dose VAY group (P < 0.01). Compared with the normal group, the concentrations of MDA and NO significantly increased in the serum and the gastric mucosa tissue, the activity of SOD and the EGF content in the gastric mucosa tissue of rats in the model group significantly decreased (P < 0.01). Compared with the model group, the MDA concentrations in the serum and the gastric mucosa tissue decreased, the serum NO content increased, the NO content in the gastric mucosa tissue decreased, the serum SOD activity increased, the EGF content in the gastric mucosa tissue increased in the rest groups, all showing statistical difference (P < 0.05, P < 0.01).</p><p><b>CONCLUSIONS</b>The water extract of VAY had significant effects on ethanol induced gastric ulcer. Its mechanisms might lie in reducing the generation of free radicals, promoting the oxygen free radical clearance, restraining lipid peroxidation, regulating and controlling the in vivo contents of NO and EGF.</p>

Expression of the gene coding for a thermostable alpha-amylase from Pyrococcus furious in Chiamydomonas reinhardtii chloroplast / 生物工程学报

Thermostable alpha-amylase from Pyrococcus furious is an important industrial enzyme in brewing and alcohol production. Eexpression of the thermostable a-amylase in plants can reduce greatly costs in the production of alcohol using crop plants. A chloroplast expression vector, p64A, containing the thermostable alpha-amylase gene from Pyrococcus furious, was constructed with clpP-trnL-petB-chlL-rp123-rpl2 as Chlamydomonas reinhardtii plastid homologous recombinant fragments and spetinomycin-resistant aadA gene as select marker. The plasmid p64A was transferred into the chloroplast genome of C. reinhardtii by the biolistic method. Nine independently transformed lines were obtained by 100 mg/L spectinomycin selection. PCR amplification, Southern blot analysis of the transgene and cultivation in the dark all showed that the a-amylase gene had been integrated into chloroplast genome of C. reinhardtii. The activity of amylase expressed in the chloroplast of C. reinhardtii was detected by amylase activity assay and found to be as high as 77.5 u/g fresh weight of cells. These experimental results demonstrated the possibility of using transgenic chloroplasts of plant as bioreactors for production of industrial enzymes.