Study On The Protective Effect Of Curcumin On The Damage Of RPE Cells Induced By Blood Glucose Fluctuations

Background: Studies have shown that the occurrence and development of diabetes mellitus and its complications are not only related to the increase of blood glucose level,but also closely related to the fluctuation of blood glucose level in the body.The damage caused by unstable blood glucose levels has attracted more and more attention.However,there are few studies related to diabetic retinopathy(DR)with high volatility of glucose.Objective: Study the protection of curcumin to retinal pigment epithelial cells(RPE)under the condition of fluctuant high sugar,as providing theoretical basis for the prevention and control of DR.Method: ARPE-19 cells were cultured to the logarithmic stage and then were divided into normal groups(NG),osmotic control(OC)and high glucose group(HG),intermittent high glucose group(IHG),intermittent high glucose + low dose group(10?g/ml curcumin)? intermittent high glucose + medium dose group(20?g/ml curcumin)?intermittent high glucose + high dose group(40?g/ml curcumin).The cell morphology of each group was observed under an inverted light microscope after the cells being cultured in groups for 3 days.Cell viability was evaluated by cck-8.Intracellular ROS levels in each group were detected by immunofluorescence assay and the content of TNF?-and IL-1? in each group was determined by ELISA.Results:1.In the normal group,the cells were spindle-shaped and clear,and the cells were closely connected and grew in sheets.Some OC cells in the fluctuating hyperosmolar group were ovoid,but most of them were in the same shape as the normal group.Only a few cells in the high glucose group(HG)and the fluctuation group(IHG)showed normal long spindle shape,and most cells in the fluctuation group were not complete.With the increase of curcumin content,the cells gradually tended to be normal.Most of the cells were spindle shaped and had a complete shape when the curcumin content reached 40?g/m L,suggesting that this group of cells had the least damage under the condition of fluctuating high glucose.2.The cell viability of NG,HG and IHG groups decreased successively(P<0.05),and there was no significant difference between OC and NG group(P>0.05).With the increase of curcumin concentration,the cell activity of the drug group increased significantly compared with the IGH group(P<0.05).3.Intracellular ROS levels increased successively in the NG,HG and IHG groups(P<0.05),but there was no significant difference between OC and NG group(P>0.05).The ROS level decreased with the increase of curcumin concentration in the dosing group(P<0.05).4.The concentration of TNF-? and IL-1? in the supernatant fluid in NG,HG and IHG group increased successively(P<0.05),and there was no significant difference between OC group and NG group(P>0.05).TNF-? and IL-1? levels of the treated group decreased with the increase of curcumin(P>0.05).Conclusion: Fluctuating high glucose can decrease the vitality of ARPE-19,increase the level of oxidative stress,and overexpress inflammatory factors such as TNF-??IL-1?.The cellular damage caused by fluctuating hyperglycemia was independent of osmotic pressure.Curcumin can effectively inhibit the damage of ARPE-19 under fluctuating high glucose conditions.