Studies On The Protective Role Of Uric Acid On 6-hydorxydopamine-induced Injury Of PC12 Cells

PARTⅠProtective effects of uric acid against 6-OHDA-induced cell injury in PC12 cells through antioxidant actionObjective To investigate the protective effects of uric acid on the injury of oxidative stress induced by 6-hydroxydopamine (6-OHDA) in PC12 cells.Methods The highly differentiated PC12 cells were divided into 4 groups: the control (the PBS group), 6-hydroxydopamine (6-OHDA), uric acid (UA) and 6-OHDA+UA. Each group was subdivided into a further 3 subgroups and cultured for 6, 12 and 24 hours in vitro respectively. The content of Lactate dehydrogenas (LDH) , 8-hydroxy 2'-deoxyguanosine (8-OHdG)in the culture medium and intracellular malondialdehyde (MDA) were detected.Results The release of LDH in the group treated with 100μmol.L^-1 6-OHDA for 12h and 24 h were significantly increased compared with the control group(757.57±27.77 U/L vs 175.57±10.50 U/L, 874.83±16.93 U/L vs 161.76±9.71 U/L, P<0.05), the contents of 8-OHdG was significantly increased(66.55±4.08 ng/L vs 19.61±2.04 ng/L, 82.88±5.40 ng/L vs 20.97±5.14 ng/L, P<0.05),the level of MDA was also increased (2.96±0.13μmol/g pro vs 0.67±0.10μmol/g pro,4.22±0.35μmol/g pro vs 0.68±0.09μmol/g pro, P<0.05). However, there was no difference on the levels of LDH, 8-OHdG and MDA between UA group and the control group.While the release of LDH was decreased (472.73±18.18 U/L vs 757.57±27.77 U/L, 522.25±16.37 U/L vs 874.83±16.93 U/L, P<0.05), contents of 8-OHdG was decreased (51.59±3.12 ng/L vs 66.55±4.08 ng/L,63.83±4.25 ng/L vs 82.88±5.40 ng/L, P<0.05), contents of MDA was also decreased (2.08±0.29 μmol/g pro vs 2.96±0.14μmol/g pro, 2.55±0.36μmol/g pro vs 4.22±0.35μmol/g pro, P<0.05) in 6-OHDA+UA group compared with 6-OHDA group.Conclusion Uric acid can prevent PC12 cells from oxidative stress induced by 6-hydroxydopamine (6-OHDA).PARTⅡThe protective role of uric acid in the 6-OHDA-mediated PC12 cells through increased SOD and GSH activityObjective To investigate the effective of uric acid on the decrease of SOD and GSH activity induced by 6-hydroxydopamine (6-OHDA) in PC12 cells.Methods The highly differentiated PC12 cells were divided into 4 groups: the control (the PBS group), 6-OHDA, UA and 6-OHDA plus UA. Each of group was subdivided into a further 3 subgroups and cultured in vitro for 6, 12 and 24 hours respectively. The content of superoxide dismutase (SOD) and glutathione (GSH) in PC12 cells were detected by colorimetric method. Results The activity of SOD in PC12 cells treated with 100μmol.L^-1 6-OHDA for 12 and 24 h were significantly decreased compared with the control group (13.48±0.53 U/L vs 30.40±0.53 U/L,10.02±2.16 U/L vs 30.49±0.62U/L, P<0.05), the level of GSH was also decreased (2.93±0.53μmol/g pro vs 5.72±0.35μmol/g pro, 2.41±0.24μmol/g pro vs 6.23±0.40μmol/g pro, P<0.05).There was no difference on the levels of SOD and GSH between UA group and the control group.While the level of SOD was increased (19.47±2.14 U/L vs 13.480±0.529 U/L, 16.09±1.71 U/L vs 10.02±2.16 U/L, P<0.05), the activity of GSH was also increased (3.94±0.20μmol/g pro vs 2.93±0.53μmol/g pro, 3.68±0.13μmol/g pro vs 2.41±0.24μmol/g pro, P<0.05) in 6-OHDA+UA group compared with 6-OHDA group.Conclusion These results suggest that uric acid prevented PC12 cells from oxidative injury induced by 6-OHDA, which may associated with the increased activity of SOD and GSH.