Protective Role Of Drinking Tea In Lung Tissue Damage Induced By Uranium Dust In Rats

Objective: To explore the effects on cytokines in lung tissue induced by uranium dust. By drinking green tea, red tea or black tea, we want to observe the protective role of drinking tea to lung tissue injuries which is induced by low doses of uranium dust.Methods: 150 adult Wister male rats were divided into five groups, i.e. control group, uranium dust group, green tea + uranium dust group, red tea + uranium dust group, and black tea + uranium dust group, 30 rats in a group, according to the principles of randomized. Non-exposed endotracheal instillation method was used. Uranium dust group and three groups with tea + uranium dust were exposed 20mg/ml uranium dust suspension each rat of 0.5ml, i.e. 10mg uranium dust in a rat. Meanwhile control group was exposed normal saline each rat of 0.5ml. Post-exposed uranium dust, the rats of 3 groups with tea drank 1.5% tea in green tea, or red tea, or black tea per day respectively. But the rats of control group and uranium dust group drank water. After exposed uranium dust at 30d, 60d and 90d, 10 rats in each group were randomly killed. Meanwhile peripheral blood and lung tissue were collected. The pathological changes in lung tissue were observed by microscope, the peripheral blood cells were determined by automated hematology analyzer, 10 cytokines in lung homogenate such as MIP-1α,MCP-1,RANTES etc were determined by Bio-Plex liquid suspension protein biochip detective system.Results: 1. WBC counts in the peripheral blood were increased obviously post-exposed low doses uranium dust in early. After exposed uranium dust, WBC counts in the peripheral blood were increased significantly compared with control group (P<0.01) at 30d, 60d. But RBC and BPC counts in the peripheral blood were non difference compared with control group (P>0.05). Post-exposed uranium dust with tea, the results were showed that green tea could reduce significantly the increased effect of WBC count induced by uranium dust, and the role was weaker in red tea and black tea.2. Lung tissue injury induced by low doses of uranium dust was showed inflammation in lung tissue in the early days. Inflammatory cell infiltration, congestion, edema, and necrosis can be seen in lung tissue under the microscope. While mild fibrosis performance in the trachea and bronchus, interstitial pulmonary and inflammatory decline in lung tissue were observed after exposed low doses uranium dust at 90d. Post-exposed uranium dust with tea, the results were showed that green tea could repair significantly the damage in lung tissue induced by low doses of uranium dust. The green tea could reduce the inflammation in lung tissue, inhibit pulmonary interstitial fibrosis. The effect of reducing inflammation in lung tissue for green tea was remarkable significantly than red tea and black tea.3. In lung tissue injury induced by low doses of uranium dust, the levels of some cytokines were increased. Post-exposed low doses uranium dust, the levels of chemokines in lung homogenate such as MCP-1α, MCP-1 and RANTES were increased significantly compared with control group (P<0.01). The levels of interleukins in lung homogenate such as IL-1β, IL-6, IL-10 and IL-13 were higher, while IL-2 was decreased, compared with the control group the difference was highly significant (P <0.01), The levels of IFN-γand TNF-αin lung homogenate were increased significantly compared with control group (P<0.01). Post-exposed uranium dust with tea, the results were showed that all kinds of tea had a protective effect on cytokines. Green tea could return the levels of MCP-1α, MCP-1, RANTES, IL-1β, IL-6, IL-10, IL-13, IFN-γand TNF-αto normal levels, while the role was weaker in red tea and black tea.Conclusions: 1. Exposed to low doses of uranium dust can induce lung tissue injuries which are inflammation mainly in early and mild pulmonary interstitial fibrosis in later.2. In lung tissue injury induced by low doses of uranium dust, the levels of chemokines in lung homogenate such as MCP-1αand MCP-1, interleukins such as IL-10 and IL-13, IFN-γand TNF-αare increased significantly, while IL-2 is decreased.3. Post-exposed uranium dust with tea, three kinds of tea have a protective effect on lung tissue injury induced by low doses of uranium dust. But green tea was most remarkable significantly.