ABSTRACT
Abstract Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid. Objectives: Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT). Methodology: Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 μm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements. Results: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control. Conclusion: Chlorhexidine and fluoride were effective in reducing root caries progression.
ABSTRACT
OBJECTIVE@#To investigate the effect of Modified Xiaochaihu Decoction (MXD, ) on collagen degradation in rats with chronic pancreatitis (CP).@*METHODS@#Rats were injected dibutyltin dichloride (DBTC, 7 mg/kg of body weight) into the right caudal vein to induce CP model. Thirty heallhy male Wistar rats were randomly divided into three groups by a random number table: the control, the model and the treatment groups. Rats of treatment group were administered MXD (10 g/kg of body weight) orally once daily starting from the day post-model establishment. Pancreatic tissues were harvested after 28-day feeding and fibrosis was evaluated by picro-sirius red staining. The contents of collagen type I and III were detected using enzymelinked immunosorbent assay (ELISA), the expression of matrix metalloproteinase 13 (MMP13) and tissue inhibitor of metalloproteinase 1 (TIMP1) was analyzed by Western blot and real-time polymerase chain reaction (PCR).@*RESULTS@#The fibrosis scoring of pancreatic tissues, the concentrations of collagen type I and III, the expression levels of MMP13 and TIMP1 proteins and mRNA in the model group were all increased compared with the control group (P0.05).@*CONCLUSIONS@#MXD could promote collagen degradation and reverse pancreatic fibrosis in CP rats via a mechanism involve up-regulation of MMP13 expression.
ABSTRACT
Objective To investigate the invasion ability and collagenolytic activity of human glioma cells in vitro.Methods Boyden chamber invasion assay was employed to evaluate the cell migration ability of human malignant glioma cell line U87MG in vitro and the effect of conditioned medium of U87MG cells on matrix collagenolytic activity was tested by agar-gelatin gel.Results The number of U87MG glioma cells migrating through the Matrigel-coated membrane was more than that of addition of EDTA or anti-MMP-2 antibody in U87MG glioma cells(P0.05).EDTA or anti-MMP-2 antibody markedly inhibited the number of the migrated cells,the inhibitory rates were 79.2% and 77.1%,respectively. The conditioned medium collected from the U87MG cells showed an increase in the transparent ring area on agar-gelatin gel.Inhibition of MMP-2 enzymatic activity by EDTA or anti-MMP-2 antibody reduced the transparent ring area on agar-gelatin gel.Conclusion Both invasion ability and collagenolytic activity of U87MG cells are depended on MMP-2,suggesting that MMP-2 plays an important role in glioma invasiveness.