Abstract
Abstract: :
Purpose: Green tea suppressed oxygen-induced neovascularization (NV) in the neonatal rat model. Matrix metalloproteinases (MMP) plays a major role in extracellular matrix degradation. This study investigated the effect of green tea on MMP during the induction phase of retinal NV which was induced by maintaining 80% oxygen (23.5 h)/room air (0.5 h) cycle till postnatal day 11(P11). Methods: Rats were treated once daily with oral administration of 5 ul/10 g body weight 25% green tea, 15% green tea, or saline from P6 to P17. On P12, P13, P15, or P18, the rats were sacrificed and the retinal MMP activity determined by gelatin zymography. In addition, VEGF was also determined by immunoassay kit (R&D system Inc.) on P18. Results: MMP-2 activity in retina was increased by 80% oxygen treatment on P13, P15, and P18, but on P13 and P15, MMP-2 activity in rat retina was suppressed by 25% green tea treatment. The amounts of VEGF were not changed by green tea treatment (25% green tea:102.915.9 pg/mg protein, 15% green tea: 102.913.6 pg/mg protein, saline: 92.310.2 pg/mg protein). Conclusion: These data suggest that orally administrated green tea inhibits MMP activity, but does not inhibit VEGF, those are important factors in oxygen-induced NV in the neonatal rat.
Keywords: 321 antioxidants • 483 neovascularization • 566 retinal neovascularization