Effect Of Oxymatrine On High Glucose-induced Injury Of RPE Cells

Diabetes mellitus(DM) is a major health problem worldwide. Current studies have revealed a definite global increase in the incidence and prevalence of diabetes, with the World Health Organization projecting that there will be up to 285 million cases in the year 2025.The blood vessel of the retina are one of the major target organs of diabetes. More than half the diabetic patients now living with a related retinopathy, among which, 1 or 2 percent have a progressive from that will lead to blindness. The clinical hallmark of diabetic retinoparhy is the presence of hemorrhages, microaneurysms, exudates and cotton-wool spots(microinfacts) in the posterior portions of the fundus. The larger retinal vessels, those ordinarily seen with the ophthalmoscope, are normal unless hypertension, arteriosclerosis or stasis is superimposed on the diabetic vasculopathy. The most serious form of the disease is that in which blood repeatedly oozes into the vitreous, causing gliovascular proliferation, obscuring the media and detaching the retina.The pathogenesis of DR is associated with changes in the activities of retinal pigment epithelium(RPE), a monolayer of highly specialized cells located between the retinal photoreceptors and the choroidal vasculature. Since RPE cells play a central role in retinal homeostasis by forming the outer retinal barrier and supporting the function of photoreceptors.And oxymatrine has been confirmed to possess anti-inflammatory, anti-tumor, anti-viral, anti-oxidant and antiapoptotic properties in both preclinical and clinical investigations.Objective: To study the effects of Oxymatrine on high glucose-induced injury of RPE cells.This include antioxidation and anti-inflammatory impact.Methods: Culture SD rat RPE cells in vitro,and then divided into six groups. ①Control group(glucose concentration:5.56mmol/L).②High-glucose group(glucose concentration:30mmol/L).③Hypertonic control group(glucose concentration:5.56mmol/L+mannitol:24.44mmol/L).④High-glucose+OMT treatment group(glucose concentration:30mmol/L+OMT concentration: 100μmol/L). ⑤High-glucose+OMT treatment group(glucose concentration: 30mmol/L + OMT concentration: 50μmol/L).⑥High-glucose+OMT treatment group(glucose concentration: 30mmol/L+OMT concentration: 25μmol/L). All groups are cultured for 24 hours, 48 hours, 72 hours, respectively. Finally, Cells were collected and to detect the cell activity by MTT assay and the expression of NRF2, SOD1, γ-GCS, NQO1, TNF-α, IL-1α and IL-6 by RT-PCR.Results:Compared with control group, high glucose group cell viability decreased significantly(P<0.05), the differences of viability of mannitol group were no statistical significance; each concentration treatment group cell viability were statistically significant lower than in controls(P<0.05), and the concentration of OMT was obvious differences exist between 100μmol/L and 50μmol/L of the cell viability. Also, these two groups compared with high-glucose group also had significant differences, were higher than that of high glucose group(P<0.05). The concentration of OMT was no obvious differences exist between 50μmol/L and 25μmol/L of the cell viability, but they still higher then that of high-glucose group.In different period of time, there are no differences in expression of Nrf2, SOD1, γ-GCS, NQO1, TNF-α, IL-1α, IL-6 compared with the control group. A slight increase in expression of high glucose group index Nrf2, SOD1, γ-GCS, NQO1(P<0.05). The expression of TNF-α, IL-1α, IL-6 increased significant(P<0.05).The expression of OMT concentration in treatment groups were also different(P<0.05), and higher than control group. Compared with high glucose group, the expression of Nrf2, SOD1, γ-GCS, NQO1 there were difinite differences in OMT concentration treatment group(P<0.05). Significant difference could be seen in the expression level of TNF-α, IL-1α, IL-6(P<0.05).Conclusions:1 High glucose can induce RPE cell injury in rats, and RPE cells viability is decreesed. OMT can decreesed the cell damage caused by high glucose environment, and increased cell activity.2 OMT can inhibit the damage of RPE cells caused by high glucose. Therefore the expression of Nrf2, SOD1, γ-GCS and NQO1 were significantly increased. In the other side, the expression of TNF-α IL-1α, and IL-6 were decreased.Which suggesting that the OMT may maintain balance within RPE cells through antioxidant and anti-inflammatory roles in protecting the normal function of RPE cells in SD rats.