[Neuroprotective effect of epigallocatechin gallate on oxidative-stress-injured retinal cells].
OBJECTIVE
To investigate the neuroprotective effect of epigallocatechin gallate(EGCG), the main extract from green tea, on the oxidative-stress-injured retinal ganglion cells.


METHODS
Rat retinal ganglion cells (RGC-5) were cultured into 3 groups (normal control; H2O2; H2O2 + EGCG or Trolox or NU1025). In-situ TUNEL was used to detect the apoptosis of the RGC-5 cells. Dihydroethidium (DHE) assay was used to observe the intracellular ROS generation. The activation of nuclear enzyme, PARP-1 was quantitatively detected by Western blot and the cell viability was measured by MT method.


RESULTS
Hydrogen peroxide reduced RGC-5 cell viability in a time-concentration-dependent manner. The treatment of 500 micromol/L H2O2 for 24 hours reduced RGC-5 cell viability by about 50% of control. Hydrogen peraoxide caused apoptosis of the RGC-5 cell, obviously increased intracellular ROS generation and up-regulated the PARP-1 expression. The pretreatment with EGCG was able to markedly reduce the number of apoptotic cells, attenuate intracellular ROS generation. Furthermore, MTT assay showed that the pretreatment with EGCG (50 micromol/L) increased the most cell viability to 87% of control, but pretreatment with Trolox (100 micromol/L) and NU1025 (100 micromol/L, a PARP-1 inhibitor) recovered the most cell viability to 62% and 71% of control respectively.


CONCLUSIONS
EGCG is able to effectively protect retinal ganglion cell against oxidative-stressed injury and can be used as a very potential neuroprotective drug.
Fan
Bin
B
Department of Ophthalmology, Second Hospital of Jilin University, Changchun 130041, China.
Li
Guang-yu
GY
Li
Ya-ping
YP
Cui
Ji-zhe
JZ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D006861:Hydrogen Peroxide / Q000494:pharmacology; D020287:In Situ Nick-End Labeling; D018696:Neuroprotective Agents / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013662:Tea / Q000737:chemistry
D018696:Neuroprotective Agents; D017382:Reactive Oxygen Species; D013662:Tea; D002392:Catechin; D006861:Hydrogen Peroxide; C045651:epigallocatechin gallate