Protective effects of various antioxidants during ischemia-reperfusion in the rat retina.
BACKGROUND
Oxidative stress during ischemia-reperfusion (I/R) is thought to be a major cause of retinal injury after I/R. The present study was aimed at investigating the protective role of antioxidant application.


METHODS
Four commonly used antioxidants (vitamin E=alpha tocopherol, lutein, fenugreek=Trigonella foenum-graecum and germander=Teucrium multicaule) were applied in ischemia-reperfusion (I/R) injury of the right retinae of 51 adult pigmented rats. Each of the antioxidants was administered every 6 h, beginning 6 h before the ischemia. After 60 min ischemia and 24 h reperfusion, we assayed (1) oxidative damage by measuring malondialdehyde (MDA), (2) apoptosis by measuring activated caspase-3 (using immunoblots), and (3) intrinsic antioxidative capacity by measuring glutathione (GSH) levels in the retinae.


RESULTS
In the order of lutein>Trigonella>vitamin E>Teucrium, all four compounds were effective in preventing retinal damage by I/R, as (1) they significantly decreased the formation of MDA (8.83, 16.48, 17.24, 18.5 nmol/100 mg tissue wet weight, respectively) compared with I/R without protection (23.29 nmol/100 mg tissue wet weight; controls: 8.0 nmol/100 mg tissue wet weight); (2) they significantly inhibited the activation of caspase-3 [0.01, 0.02, 0,02, and 0.04 arbitrary units (AU), respectively, versus control, 0.0, and I/R, 0.08 AU]; and (3) they significantly decelerated the loss of GSH (from control levels of 36.04 nmol/100 mg tissue wet weight) to 30.4, 15.98, 18.1, 15.02 nmol/100 mg tissue wet weight, respectively (lutein, Trigonella, vitamin E, Teucrium), compared with unprotected I/R (12.84 nmol/100 mg tissue wet weight).


CONCLUSIONS
Our study shows that lutein, Trigonella, Teucrium and vitamin E exert protection against in vivo retinal I/R injury in rats; this may recommend these compounds (in particular, lutein) for clinical use in patients with different types of ocular I/R injuries.
Dilsiz
Nihat
N
Department of Biology, Faculty of Science, Harran University, Osmanbey Kampusu, Sanliurfa, Turkey. ndilsiz@hotmail.com
Sahaboglu
Ayse
A
Yildiz
M Zulfu
MZ
Reichenbach
Andreas
A
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D005978:Glutathione / Q000378:metabolism; D014975:Lutein / Q000008:administration & dosage; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D018384:Oxidative Stress; D008517:Phytotherapy; D028321:Plant Preparations / Q000008:administration & dosage; D051381:Rats; D020318:Rats, Long-Evans; D015427:Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D012160:Retina / Q000378:metabolism; D012164:Retinal Diseases / Q000378:metabolism / Q000517:prevention & control*; D012171:Retinal Vessels / Q000187:drug effects* / Q000378:metabolism; D031367:Teucrium; D029910:Trigonella; D014810:Vitamin E / Q000008:administration & dosage
D000975:Antioxidants; D028321:Plant Preparations; D014810:Vitamin E; D008315:Malondialdehyde; D053148:Caspase 3; D005978:Glutathione; D014975:Lutein