Comparison of protective effects of safflor injection and extract of Ginkgo biloba on lung ischemia/reperfusion injury in rabbits.

OBJECTIVE: To observe the protective effects of safflor Injection (SI) and extract of Ginkgo biloba (EGB) on lung ischemia-reperfusion injury (LIRI) and investigate its mechanism. METHODS: In vivo rabbit model of LIRI was reconstructed. Forty rabbits were randomly and equally divided into four groups: sham-operation group (sham group), ischemia-reperfusion group (model group), ischemia-reperfusion plus SI group (safflor group) and ischemia-reperfusion plus EGB injection group (EGB group). Malondialdehyde (MDA) content, superoxide dismutase (SOD) and xanthine oxidase (XO) activity in serum were measured. The wet/dry weight ratio (W/D) of the lung tissue and activity of myeloperoxidase (MPO) were also tested. Ultrastructure change of the lung tissue was observed by the electron microscope. The expression of intercellular adhesion molecule-1 (ICAM-1) was measured by immunohistochemistry (IHC). RESULTS: In the model group, MDA and XO increased and SOD decreased in serum compared with the sham group (P<0.01). The values of W/D, MPO and ICAM-1 of the model group were higher than those of the sham group (P<0.01), but those of the safflor group and EGB group were significantly lower than those of the model group (P<0.01). The IHC demonstrated that ICAM-1 expression in lung tissue of the model group was significantly higher than those of the safflor group (P<0.01). Compared with safflor group, in the EGB group MDA, XO, MPO decreased, SOD and ICAM-1 expression increased (P<0.05), but the change of W/D was not statistically significant (P>0.05). CONCLUSIONS: SI and EGB may attenuate LIRI through antioxidation, inhibition of neutrophil aggregation and down-regulation of ICAM-1 expression. But EGB had more effect on the antioxidation, while SI did better on regulating ICAM-1 expression.

Differential display of vincristine-resistance-related genes in gastric cancer SGC7901 cell.

AIM: To isolate and clone the vincristine-resistance-related genes in gastric cancer SGC7901 cell line and to clarify the multidrug-resistant molecular mechanism of gastric cancer cells. METHODS: The modified differential-display polymerase chain reaction (DD-PCR) was used to examine differences in the mRNA composition of Vincristine-resistant gastric cancer SGC 7901 cells (SGC7901/VCR), induced by vincristine sulfate versus SGC7901cells. The differentially expressed cDNA fragments were confirmed by reverse Northern analysis, sequencing, BLAST analysis and Northern bolt analysis. RESULTS: The DD-PCR identified that 54 cDNA fragments were preferentially expressed in SGC 7901/VCR cells. When these cDNA fragments were analyzed by reverse Northern blot, twenty were reproducibly expressed at high level in SGC7901/VCR. Sequencing and BLAST analysis revealed that seven of the genes were known genes:ADP-ribosylation factor 4, Cytochrome oxidase subunit II, Ss-A/Ro ribonucleoprtein autoantigen 60kd subunit,ribosomal protein S13, galaectin-8 gene, oligophrenin 1 mRNA, ribosomal protein L23 mRNA; thirteen of the genes were unknown genes. The length and abundance of the four unknown genes were further confirmed by Northern blot analysis. CONCLUSION: The twenty differential known and unknown genes may be related to the vincristine-resistant mechanism in human gastric cancer SGC7901 cell line.

Screening and identification of proteins mediating senna induced gastrointestinal motility enhancement in mouse colon.

AIM: To isolate the proteins involved in pharmacologic action of senna extract (SE) from mouse gastrointestinal tract and to explore the molecular mechanism of gastrointestinal motility change induced by SE. METHODS: SE was administrated to mice by different routes. Gastrointestinal motility of mice was observed using cathartic, gastrointestinal propellant movement experiments and X-ray analysis. Mouse model for gastrointestinal motility enhancement was established through continuous gastric administration of SE at progressively increased dose. At 3 h and week 3, 4, 6 and 10, morphological changes of gastrointestinal tissues were found under light microscope. Ultrastructural changes of intestinal and colonic tissues at week 6 were observed under transmission electron microscope. The colonic proteomic changes in model mice were examined by two-dimension polyacrylamide gel electrophoresis with immobilized pH gradient isoelectric focusing to screen the differentially expressed proteins, and their molecular masses and isoelectric points were determined. Two N-terminal sequences of the samples were also determined by mass spectrometry. RESULTS: SE (0.3g) caused diarrhea after gastric administration in 1-6h and enhanced gastrointestinal propellant (65.1+/-7.5%; 45.8+/-14.6%, P<0.01) in mice, but intramuscular and hypodermic injection had no cathartic effect. X-ray analysis of gastrointestinal motility demonstrated that gastric administration of SE enhanced gastric evacuation and gastrointestinal transferring function. At 3 h and week 3 and 4 after gastric administration of SE, light microscopic examination revealed no apparent change in gastrointestinal mucosal tissues, but transmission electron microscopic examination revealed inflammatory changes in whole layer of intestinal and colonic wall. Twenty differential proteins were detected in the colonic tissues of the model mice by two-dimensional electrophoresis, and the N-terminal amino acid sequences of two proteins were determined. CONCLUSION: SE causes diarrhea and enhances gastrointestinal motility through digestive tract administration. Long-term gastric administration of SE induces inflammatory changes and cell damage in the whole gastrointestinal tract. The differential proteins screened from the colonic tissues of the model mice might mediate the enhancing effect of SE on gastrointestinal motility.

Effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats.

AIM: To investigate the effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats. METHODS: Rats with cirrhosis induced by carbon tetrachloride were randomly divided into two groups, one n =13 receiving 0.5mg.kg(-1) per day of N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, for 10 days, whereas the other group (n =13) and control (n =10) rats were administrated the same volume of 9g.L(-1) saline. Half gastric emptying time and 2h residual rate were measured by SPECT, using (99m)Tc-DTPA-labeled barium sulfate as test meal. Gastrointestinal transition time was recorded simultaneously. Serum concentration of nitric oxide (NO) was determined by the kinetic cadmium reduction and colorimetric methods. Immunohistochemical SABC method was used to observe the expression and distribution of three types of nitric oxide synthase (NOS) isoforms in the rat gastrointestinal tract. Western blot was used to detect expression of gastrointestinal NOS isoforms. RESULTS: Half gastric emptying time and trans-gastrointestinal time were significantly prolonged(124.0 +/- 26.4 min; 33.7 +/- 8.9 min; 72.1 +/- 15.3 min; P<0.01), (12.4 +/- 0.5h; 9.5 +/- 0.3h; 8.2 +/- 0.8h; P<0.01), 2h residual rate was raised in cirrhotic rats than in controls and cirrhotic rats treated with L-NAME (54.9 +/- 7.6%,13.7 +/- 3.2%, 34.9 +/- 10.3%, P<0.01). Serum concentration of NO was significantly increased in cirrhotic rats than in the other groups (8.20 +/- 2.48) micromol.L(-1), (5.94 +/-1.07) micromol.L(-1) and control (5.66 +/- 1.60 micromol.L(-1), P<0.01. NOS staining intensities which were mainly located in the gastrointestinal tissues were markedly lower in cirrhotic rats than in the controls and cirrhotic rats after treated with L-NAME. CONCLUSION: Gastrointestinal motility was remarkably inhibited in cirrhotic rats, which could be alleviated by L-NAME. Nitric oxide may play an important role in the inhibition of gastrointestinal motility in cirrhotic rats.

Protective effect of Ulinastatin against murine models of sepsis: inhibition of TNF-α and IL-6 and augmentation of IL-10 and IL-13.

AIM: Excessive production of inflammatory mediators during invasive infection plays a key role in the pathogenesis of sepsis. In an attempt to improve survival of patients with this lethal syndrome, agents were developed to selectively inhibit mediators in this inflammatory response. Ulinastatin (UTI), a human protease inhibitor, inhibits the enhanced production of pro-inflammatory molecules. However, it is unknown if Ulinastatin treatment could result in protective effects for sepsis. The aim of this study was to investigate the role of Ulinastatin on septic rats. METHODS: Sixty male Wistar rats were divided into six groups, 10 of each: sham-operation plus PBS (5 ml), cecal ligation and puncture (CLP) plus PBS (5 ml), CLP plus UTI (5000 U/kg), CLP plus UTI (10,000 U/kg), CLP plus UTI (20,000 U/kg) and sham-operation plus UTI (10,000 U/kg). Rats in the UTI groups after CLP operation were treated with Ulinastatin by intraperitoneal injection at different doses and then compared with untreated sepsis control animals. RESULTS: The intestinal concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-13 (IL-13) were significantly higher in septic rats than those in normal rats. Ulinastatin administration effectively suppressed the levels of TNF-α and IL-6, whereas it markedly enhanced the levels of IL-10 and IL-13. CONCLUSION: Ulinastatin may possess a protective role in the septic process by inhibiting TNF-α and IL-6, and augmenting IL-10 and IL-13 concentrations in intestine of septic rats.

Unbalanced MMP/TIMP-1 expression during the development of experimental pulmonary fibrosis with acute paraquat poisoning.

Paraquat (PQ)-induced pulmonary toxicity is known to result in pulmonary edema, infiltration of inflammatory cells and damage to the alveolar epithelium, which may progress to severe fibrosis. Matrix metalloproteinases (MMPs) and their physiological inhibitors, tissue inhibitors of matrix metalloproteinases (TIMPs), which degrade and remodel the excess extracellular matrix, are believed to play an important role in the development of fibrotic tissue. In this study, we examined the sequential expression of MMP-2, MMP-9 and TIMP-1 in a rat model of pulmonary fibrosis induced by PQ. Adult male Sprague-Dawley rats were treated intraperitoneally with PQ (20 mg/kg) and saline (control group). Rats were sacrificed at days 1, 3, 7 and 21 after the PQ treatment. Lungs were excised for histological evaluation and immunohistochemical analyses, as well as the determination of collagen content, gene expression by fluorimeter-based quantitive RT-PCR assay and gelatinolytic activity by zymography. Lung MMP-2 and -9 mRNA expression progressively increased and reached a peak on day 7 after PQ treatment, while TIMP-1 mRNA levels in the PQ-treated lungs reached a peak on day 21 after modeling. Lung zymography revealed an increase in progelatinase B, progelatinase A and their active forms. In conclusion, unbalanced MMP/TIMP-1 expression and excessive gelatinolytic activity contribute to PQ-induced pulmonary fibrosis. Their precise role should be studied in depth as they may represent relevant therapeutic targets for PQ poisoning-induced pulmonary fibrosis.