Effects Of Nano-ZnO On The Energy And Protein Metabolism On The Primary Culture Mice Intestinal Epithelial Cells In Vitro And Protective Effects Against Oxidative Injury

The mice intestinal epithelial cells in primary culture were selected to evaluate effects of Nano-ZnO on the energy and protein metabolism and protective effects against oxidative injury. This study included a total of two tests:Firstly, the effects of different particle size and concentration of nano-ZnO on mice intestinal epithelial cells in energy-protein metabolism; Secondly, the protective effects of different particle size and concentration of nano-ZnO on mice intestinal epithelial cells against oxidative injuryTest 1:Cells were treated with different particle size (10-15nm,50nm, 100nm) and concentration of nano-ZnO (0,0.5,1,2,4,6,8μg ml-1) for 24 hours.The control cells were kept in the nano-ZnO free medium. The results indicate:nano-ZnO in the concentration of 0.5-6μg ml-1 could increased the LDH, SDH and Na+,K+-ATPase activities of intestinal epithelial cells significantly or extremely significantly. The results showed that nano-ZnO can promote cell energy metabolism. Nano-ZnO in the concentration of 0.5-6μg ml-1 could increased MTT OD, the total protein and MT content, NH3 content of the media, GOT, GPT, y-GT activities of intestinal epithelial cells significantly or extremely significantly, The results showed that nano-ZnO can promote cell growth, cell energy metabolism in facilitating role in enhancing the deposition of cell protein. Except the MT content, Na+,K+-ATPase and NH3 content, above-mentioned indicators depressed when 10-15nm zinc oxide containing was 8μg ml-1(P<0.05). It means the higher concentration of nano-ZnO on cellular energy and protein metabolism have a negative impact.50nm and 100nm of zinc oxide on the energy and protein metabolism of mice intestinal epithelial cells were similar with the 10-15nm nano-ZnO. There was a downward trend that the effect of the nano-ZnO on mice intestinal epithelial cells in energy-protein metabolism when particle size increased. To MTT OD value of the indicators for evaluating cell growth, three particle size (10-15,50, 100nm) ZnO optimal concentrations were:4.95,5.29 and 5.67μg ml-1.Test 2:Cells were treated with nano-ZnO (0-8μg ml-1)in the presence of H2O2(200μM) for 24 hours.The control cells were kept in the nano-ZnO free medium. The results indicate:mice intestinal epithelial cells were treated with 200μmol L-1 of H2O2 treatment, the cells MTT OD value,SOD,CAT and GSH-Px was significantly (P＜0.01) lower than the control group, the LDH in culture medium and malondialdehyde (MDA) content was significantly (P＜0.01) higher. Add 0.5 to 6μg ml-1 of the 10-15nm zinc oxide can significantly (P＜0.05) or very significant (P＜0.01) increased cell MTT OD value; significantly (P＜0.05) or very significant (and P＜0.01) reduced the culture medium LDH and MDA content, indicating that nano-ZnO could protect the integrity of mouse intestinal epithelial cells and reduce cell membrane lipid peroxidation. Cells treated with 200μmol L-1 H2O2, the cellular superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activity was significantly (P＜0.01) lower than the control group. Add 0.5 to 6μg ml-1 of the 10-15nm zinc oxide can significantly (P＜0.05) or very significant (P＜0.01) increased cellular SOD, CAT and GSH Px activity. It's showed that nano-zinc oxide can maintain cells in anti-oxidant activity, increased cellular antioxidant capacity. However,8μg ml-1 of the 10-15nm zinc oxide can significantly reduce the cellular MTT OD values, SOD, CAT and GSH-Px activity; a very significant increase in medium LDH and MDA levels, indicating a high concentration of nano-ZnO can not reduce cell oxidative damage. The effects of these indicators in 50nm and 100nm ZnO on mouse intestinal epithelial were similar with the effects of 10-15nm ZnO. Three kinds of particle size (10-15,50,100 nm) ZnO on cell oxidative damage play a protective effect of the optimal concentrations were 3.97,4.15 and 4.28μg ml-1.In summary,0.5-6μg ml-1 nano-ZnO can promote energy and protein metabolism of intestinal epithelial cells and has a certain protective effect against oxidative injury, there is a dose-dependent effect, and the 10-15nm and 50nm zinc oxide is better than the 100nm zinc oxide. The smaller particle size nano-ZnO has the higher biological activity.8μg ml-1 nano-ZnO can inhibit the energy and protein metabolism and lower antioxidant enzyme activity and cellular antioxidant capacity.