Inhibitory effect of the pure compounds existing in plant polyphenols on high glucose induced human retinal pigment epithelial cell proliferation

• Main Authors: Tzu-Ya, 吳慈雅
• Other Authors: 李彗禎
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/67405674735402344418

碩士 === 中山醫學大學 === 生化暨生物科技研究所 === 96 === High level of blood glucose could produce reactive oxygen species (ROS) to cause retinopathy. Our previous study demonstrated that Hibiscus sabdariffa aqueous extracts (HSE) and Hibiscus sabdariffa polyphenols extracts (HPE) could decelerate retinopathy in streptozotocin (STZ)-induced diabetic rats. In this study, we further examined the effect of protocatechuic acid, catechin, ferulic acid, gallic acid, quercetin and epicatechin existing in HSE in high glucose treating human retinal pigment epithelial (RPE) cells. We found that after treatment of high glucose (25 mM) for at least 6 days, RPE cells showed a significant increase in a dose-dependent manner. As accompanied with treatment of 10μM concentration of protocatechuic acid, quercetin, ferulic acid, catechin, gallic acid and epicatechin the increased cell could be reduced up to 51.78%, 37.4 %, 30.27 %, 30.07 %, 22.93%, 32.47%, respectively. We further examined the expressions of PKC-α, PKC-δ, PKC-λ. But, there were no significant changes in these proteins. We examined that after treatment of high glucose (25 mM) for 48 hrs, RPE cells showed the activity of MMP-2 significant increase.As accompanied with treatment of10μM concentration of protocatechuic acid, quercetin and ferulic acid the increased MMP-2 activity could be reduced to 25.9%, 14.8%, 5.9%, respectively. In conclusion, protocatechuic acid、quercetin、ferulic acid、catechin、gallic acid and epicatechin could reduce high glucose induced RPE cell proliferation, but the mechanisms should be further clarified.