ABSTRACT
This study is to observe the inhibition of etoposide on allergic contact dermatitis (ACD) and explore its possible mechanism of action. Dinitrofluorobenzene was used to induce the allergic contact dermatitis in mouse ear. Three groups of animals were orally administrated with different doses of VP-16 (5, 10, and 20 mg x kg(-1)), separately, for six days. The degree of skin inflammatory reaction was observed by optical microscope. Expression of intercellular adhesion molecule (ICAM-1) was detected by immunohistochemical staining. Radioimmunoassay was applied to measure the serum level of tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10). VP-16 significantly decreased inflammatory cell infiltration and the degree of infiltration reaction, and decreased the level of TNF-a in serum and the expression of ICAM-l in skin. VP-16 can significantly inhibit allergic contact dermatitis induced by DNFB. This therapeutic effect of VP-16 on murine ACD may be due to inhibiting expression of some cytokines.
Subject(s)
Animals , Female , Male , Mice , Anti-Inflammatory Agents , Pharmacology , Dermatitis, Allergic Contact , Blood , Metabolism , Dinitrofluorobenzene , Etoposide , Pharmacology , Intercellular Adhesion Molecule-1 , Metabolism , Interleukin-10 , Blood , Random Allocation , Skin , Metabolism , Tumor Necrosis Factor-alpha , BloodABSTRACT
<p><b>AIM</b>To observe the damages induced by hydrogen peroxide in cultured bovine cerebral microvascular endothelial cells (BCMEC) and evaluate the protective effects of hydroxyethylpuerarin on hydrogen peroxide-injured BCMEC.</p><p><b>METHODS</b>BCMEC were cultured and transferred into modified Eagle medium (MEM). The viability of cells was detected by MTT assay. Cell injury was determined by lactate dehydrogenase (LDH) activity in the extracellular medium. Flow cytometry was employed to observe the occurrence of apoptosis. Morphologic changes of cells were visualized under phase contrast and electron microscopes.</p><p><b>RESULTS</b>Hydrogen peroxide (200 micromol x L(-1) for 4 hours) inhibited the viability of cultured BCMEC and stimulated LDH release. Hydrogen peroxide (100 micromol x L(-1) for 4 hours) induced the occurrence of apoptosis. Hydroxyethylpuerarin was shown to increase the survival rate and decrease the activity of LDH of BCMEC damaged by hydrogen peroxide. Hydroxyethylpuerarin was also found to protect BCMEC against apoptosis induced by hydrogen peroxide.</p><p><b>CONCLUSION</b>Hydrogen peroxide induces BCMEC injury either by apoptosis or through necrosis. Hydroxyethylpuerarin protects BCMEC against hydrogen peroxide-induced injury in a concentration-dependent manner. Its antioxidant effects might be involved as the mechanism protection.</p>