ABSTRACT
<p><b>OBJECTIVE</b>To compare the effects of oral treatment with tetrandrine (TD) and N-acetylcys-teine (NAC) separately or jointly on silica-exposed rats.</p><p><b>METHODS</b>40 sprague-Dawly (SD) rats were randomly divided into normal saline group, quartz group, TD treatment group (50 mg/kg), NAC treatment group (500 mg/kg) and combined treatment group (TD: 50 mg/kg + NAC: 500 mg/kg). Rats in normal saline group and other groups received intratracheal instillation of normal saline and quartz dust suspension respectively. Treatment groups were given TD, NAC separately or jointly via esophagus the next day after instillation, once a day and six times a week for 30 consecutive days. At the end of experiment, the pathological changes of lung tissues were evaluated by the methods of Foot, HE and Masson staining, the level of hydroxyproline (HYP), malondjalde-hyde (MDA), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in lung tissues were measured by alkaline hydrolysis method, the barbituric acid method and enzyme-linked immunosorbent assay (ELISA) respectively.</p><p><b>RESULTS</b>Compared with the quartz group, lymph nodes/body coefficients in all treatment groups and lung/body coefficient in combined treatment group were significantly decreased (P < 0.05). Pathology results showed that the normal saline group demonstrated no obvious evidence of lung damage. The quartz group lungs silicotic lesions focused on II~III level, the TD treatment group was mainly with I level, the NAC treatment group was mainly with I~II level, and the combined treatment group only showed little silicotic nodule, no obvious fibrosis. HYP content in TD treatment group and combined treatment group were significantly lower than that in the quartz group (P < 0.05), while it showed no obvious change in NAC treatment group. MDA content in lung tissues of each treatment group (TD treatment group, NAC treatment group and combined treatment group) were 18.80 ± 2.94, 20.13 ± 4.01 and 17.05 ± 3.52 nmol/ml respectively, which lower than in the quartz group (23.99 ± 3.26 nmol/ml). The level of IL-6 in lung tissues of the quartz group were 89.57 ± 8.78 pg/ml. After TD and NAC monotherapy, the IL-6 content decreased to 79.22 ± 9.65 pg/ml and 81.63 ± 5.72 pg/ml, and it decreased more significantly after combined medication (74.37 ± 3.17 pg/ml). The level of TNF-α in the quartz group were 59.05 ± 4.48 pg/ml. After TD and NAC monotherapy, the TNF-α content decreased to 50.48 ± 2.76 pg/ml and 54.28 ± 4.30 pg/ml, and it decreased more significantly after combined medication (49.10 ± 4.98 pg/ml).</p><p><b>CONCLUSION</b>NAC and TD could reduce MDA, TNF-α and IL-6 levels in lung tissue, and alleviate SiO2-induced pulmonary fibrosis in rats. Combined treatment with TD and NAC was more effective than TD or NAC treatment separately.</p>
Subject(s)
Animals , Rats , Acetylcysteine , Pharmacology , Benzylisoquinolines , Pharmacology , Disease Models, Animal , Dust , Hydroxyproline , Metabolism , Interleukin-6 , Metabolism , Lung , Pathology , Malondialdehyde , Metabolism , Pulmonary Fibrosis , Drug Therapy , Quartz , Toxicity , Rats, Wistar , Silicon Dioxide , Toxicity , Silicosis , Drug Therapy , Tumor Necrosis Factor-alpha , MetabolismABSTRACT
Objective To know the pollution status and the cytotoxicity of PM2.5 in Hangzhou,Zhejiang.Methods PM2.5 was collected in the center of Hangzhou city in spring and summer in 2005,the weighting method was used for PM 2.5 collection.WI-38 cell line was used as the target and the cells were treated with PM2.5 at different doses.The cytotoxicity of PM2.5 was tested by cloning efficiency.Results According to the Air Quality Standard for PM2.5 of U.S.EPA(issued in 1997),it was showed that the rates exceeding standard of PM2.5 concentration in spring and summer were 96.7% and 90.0%,respectively,but the rates were 33.3% and 20.0% compared with the standard newly issued in 2006.WI-38 cell survival rate was 100%,99.6%,96.2%,85.0%,73.8%,54.6% and 100%,97.0%,96.9%,88.0%,83.0%,64.7% respectively when treated with PM2.5 in spring and in summer of 0,25,50,100,200,500 ?g/ml.There was a significant difference except 25 ?g/ml and 50 ?g/ml in summer.Conclusion There is an obvious PM2.5 pollution in Hangzhou,which is heavier in spring than in summer,the cytotoxicity of PM2.5 in the polluted air may be higher.