The Protection Mechanism Of The Lemongrass Essential Oil Induced Damage By Benzo[a]pyrene In Mice Lung

Objective: The aim of this paper was to discuss the protective effects of the lemongrass essential oil(LEO) induced damage by Benzo[a]pyrene in mice Lung tissue,included to detecte the relevant indicators of oxidative stress, and the levels of B[a]P metabolites, 3- hydroxyl-benzo [a]pyrene(3-OHB[a]P) and(+)-anti-benzo[a] pyrene diolepoxide-DNA adducts((+)-anti- BPDE-DNA adducts)by high performance liquid chromatography(HPLC), and further detecte the expression of p53 gene and bcl-2 gene in rats lung tissue. Method: 1.Establishment of the packet to mice and experiment model. Kunming mice(6-8 weeks old, 18g-22g) half of male on gender,reared apart, a total of 288. The mice who used to experiment were normal fed under standard conditions domestication, the temperature among 22 ℃. The mice were randomly divided into 9 groups, 32 rats in each group. The B[a]P solution with the concentration is 96% dissolved in olive oil, formulated as the concentration of 6.25mg/m L solution, and then each mouse intragastrically with 0.2m L. LEO was configured as three concentration which was 0.05%, 0.1%, 0.25%, and then aerosol inhalation of LEO solution 30 min each day. Three months later, kill the mice by removing carotid artery rupture, washed the lung tissue of mice in physiological saline, surface moisture dry the tissue surface moisure by filter paper, the organs divided into two parts, a weighing organ wet weight plus saline into tissue homogenate solution, another save backup. All lung tissue samples were kept in-80℃.Two mice were randomly selected from each group,its lung tissue were made pathological sections.2.Determination of index of correlation experiment. The experiment detected the content of superoxide dismutase(SOD), catalase(CAT), malondialdehyde(MDA),total antioxidant capacity(T-AOC), 8- hydroxydeoxyguanosine(8-OHd G) in mice lung tissue by using SOD kit, CAT ELISA kit, MDA kit, T-AOC assay kit and mouse 8-OHd G kit. Determination 3-OHB[a]P and(+)-anti-BPDE-DNA content in mice lung tissue by using HPLC. The production of immunohistochemical sections,high power microscope to observe the changes of lung tissue in mice. Pathological section H-E staining method for making the lung tissue of mice.Detecting the expression of p53 and bcl-2 gene by real-time fluorescence quantitative PCR and western blot in gene and protein level. Results:1.The results of kit test: Compared with the control group, B[a]P treated group can cause the content of SOD, CAT and T-AOC decreased in lung tissue of mice(P <0.05), at the same time the content of MDA and 8-OHd G increase(P <0.05); compared with B[a]P exposure group, in the three groups which with LEO protection the content of SOD, CAT and T-AOC was increased(P <0.05), at the same time, the content of MDA and 8-OHd G were decreased(P <0.05). 2.The HPLC test results: Compared with the control group, B[a]P treated group could cause the content of 3-OHB[a]P and(+)-anti-BPDE-DNA were increase in lung tissue of mice(P <0.05); compared with B[a]P exposure group, in the three groups which with LEO protection the content of3-OHB[a]P was increased(P <0.05), at the same time,the content of(+)-anti-BPDE-DNA was decreased(P <0.05). 3 The pathological and immunohistochemical results: After subchronicly exposed for three months,the cells of mice lung appeared injury and apoptosis. The three groups lung of mice which alone gave LEO looked not far different from the normal mice. 4.The molecular Biology experiments: Compared with the normal group, the expression of p53 gene is up-regulation in B[a]P the exposed group(P<0.05), at the same time the bcl-2 gene expression was also up-reglated(P <0.05); Compared with the B[a]P treated group, three groups of LEO protection group p53 gene expression up-regulated enhancement(P <0.05), bcl-2gene expression was up-regulated decreased(P <0.05). Conclusion: The LEO was ableto reduce oxidative stress injury of the mice lung tissue, had the functions of antioxidant and lung protection. LEO could make the(+)-anti-BPDE-DNA which was produced from B[a]P in the mice lung decreased, it also could make the content of3-OHB[a]P increased. At the same time the the gene named p53 expressed upregulation,and Bcl-2 downregulation. In a word, the LEO has the function of Inhibiting cell cancerization...