ABSTRACT
Objective: To observe the growth inhibition effect of Aconiti Lateralis Radix Praeparata polysaccharide on the gastric cancer xenografts in nude mice and the expressions of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-14 (MMP-14) in tumor tissues. Method: The nude mice xenograft model was established and randomly divided into model group, 5-fluorouracil group (5-FU, 0.01 g · kg-1), high and low-dose Aconiti Lateralis Radix Praeparata polysaccharide groups (0.2, 0.1 g · kg-1). Each group was given drug by gavage for 15 days. The effect of Aconiti Lateralis Radix Praeparata polysaccharide on the weight of gastric cancer in nude mice was observed. Morphological changes of tumor cells were observed under light microscope. The content of transforming growth factor-β1 (TGF-β1) in serum was determined by enzyme-linked immunosorbent assay (ELISA). The protein and mRNA expressions of MMP-2, MMP-14 in tumor tissues were detected by immunohistochemistry, Western blot and Real-time PCR. Result: The tumor inhibition rates of high and low-dose Aconiti Lateralis Radix Praeparata polysaccharides were 52.83%,40.57%, respectively. Compared with model group, the tumor weight of high and low-dose Aconiti Lateralis Radix Praeparata polysaccharide was significantly lower (Pβ1 content in nude mice (PPPPPPPConclusion: Aconiti Lateralis Radix Praeparata polysaccharide can inhibit the growth of gastric cancer xenografts in nude mice and the expression of TGF-β1.The anti-tumor mechanism may be related to the down-regulation of MMP-2, MMP-14 protein and mRNA expressions.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the anti-matrix metalloproteinase (MMP) activity of a novel crosslinking quaternary ammonium methacrylates, 2-methacryloxylethyl dodecylmethyl ammonium bromide (MAE-DB).</p><p><b>METHODS</b>The effects of MAE-DB at different concentrations (1%, 3%, 5%, 7%) on soluble matrix metalloproteinase-8 (MMP-8) were investigated using fluorescent assay kit. Readings were taken every 20 min for 3 h. The 1, 10-phenanthroline provided by the assay kit served as control group. Demineralized dentin beams were randomly divided into three groups (n = 50) and immersed in different solutions: artificial saliva, MAE-DB incorporated artificial saliva and chlorhexidine incorporated artificial saliva. After temperature cycling, the changes of ultimate tensile strength were measured to determine the effect of MAE-DB on the activity of matrix-bound endogenous matrix metalloproteinases. The morphology of dentin collagen fibrils in the three groups was observed via transmission electron microscopy (TEM).</p><p><b>RESULTS</b>MAE-DB could effectively inhibit the activity of soluble MMP-8. The inhibition percentage of 3% MAE-DB was 99.53% after 1 h, and it was significantly higher than that of 1, 10-phenanthroline (95.71%, P < 0.05). After temperature cycling, the ultimate tensile strengths of MAE-DB groups were significantly higher than those of the artificial saliva groups and the chlorhexidine groups (P < 0.05). TEM micrographs of MAE-DB group revealed that the microstructure of the collagen fibrillar was intact, while the fibrillar in the artificial saliva group was disrupted, indicating a protective function of MAE-DB on dentin collagen.</p><p><b>CONCLUSIONS</b>MAE-DB can inhibit the activity of MMP and protect dentin collagen from enzyme degradation.</p>
Subject(s)
Ammonium Compounds , Pharmacology , Chlorhexidine , Pharmacology , Dentin , Matrix Metalloproteinase 8 , Methacrylates , ChemistryABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effect of quaternary ammonium methacrylates incorporation into a dental adhesive on the resistance of enzymatic degradation of resin-dentine interfaces.</p><p><b>METHODS</b>Thirty caries-free extracted human third molars were randomly divided into three groups (n = 10): 2-methacryloxylethyl dodecylmethyl ammonium bromide (MAE-DB) incorporated adhesive served as the experimental group, pre-treatment with chlorhexidine (CHX) served as a positive control, Adper(TM) Single Bond 2 served as a negative control. The resin-dentin interfaces were prepared using total etch bond system. After storage in distilled water at 37 °C for 24 h, the bonded teeth were vertically sectioned into beams. Beams were respectively immersed in artificial saliva containing 2 g/L MMP-8 at 37 °C for 0 h, 24 h and 120 h (n = 30). Micro-tensile bond strength, failure modes and nanoleakage were examined.</p><p><b>RESULTS</b>There were no significantly differences of micro-tensile bond strength between groups before hydrolysis (P > 0.05). After the enzymatic hydrolysis of 24 h and 120 h, the micro-tensile bond strength of MAE-DB groups [(31.13 ± 8.77) MPa, (24.14 ± 6.64) MPa] were significantly higher than that of the negative control groups [(25.63 ± 6.90) MPa, (15.22 ± 6.57) MPa] (P < 0.05). Most of the failures were found in the base part of the hybrid layer in the negative control group, while failures occurred through the top of the hybrid layer in CHX and MAE-DB groups after the enzymatic hydrolysis.Specimens from each immediate group showed minor silver deposits in hybrid layer. After beams being enzymatic hydrolyzed for 120 h, it was shown that the silver nitrate uptake in the negative control group were significantly different from those in the CHX and MAE-DB groups (P < 0.05).</p><p><b>CONCLUSIONS</b>Dental adhesive incorporation of MAE-DB could improve the anti-degrade ability of resin-dentin interfaces.</p>