Neuroprotective effects of L-carnitine and vitamin E alone or in combination against ischemia-reperfusion injury in rats.
BACKGROUND
Neurological injury because of transient cerebral ischemia is a potential complication of cardiovascular surgery. In this study, the neuroprotective effects of L-carnitine, vitamin E, and the combination of these agents on ischemia/reperfusion (I/R) injury were determined in a rat model of transient global cerebral I/R.


METHODS
Rats were pretreated with L-carnitine (100 mg/kg, i.v.) and vitamin E (50 mg/kg, i. v.), alone or in combination and then subjected to cerebral I/R induced by a four-vessel-occlusion technique for a duration of 15 min followed by 15 min of reperfusion. Malondialdehyde (MDA) levels, superoxide dismutase (SOD) activity, and glutathione (GSH) levels were measured in the cerebral tissues. Histopathological examinations were also carried out under light and electron microscopy.


RESULTS
The results showed that I/R elevated MDA levels, which were accompanied by a reduction in SOD activities and GSH levels. Surviving neurons was markedly decreased in CA1 and CA3 subfield of hippocampus in I/R animals. L-carnitine, vitamin E, and their combination restored MDA levels and SOD activities, with a tendency to increase surviving neurons in CA1 and CA3 subfield. Combined treatment of L-carnitine and vitamin E had better GSH levels than individual treatment of these agents.


CONCLUSIONS
The results suggest that L-carnitine has a potent neuroprotective effect against cerebral-I/R-induced injury in rat brain that is comparable to that of vitamin E. However, the combined use of L-carnitine and vitamin E does not further protect from neuronal injury, although it provides an increase in GSH levels.
Onem
Gokhan
G
Department of Cardiovascular Surgery, Pamukkale University School of Medicine, Denizli, Turkey. gonem@pamukkale.edu.tr
Aral
Erinc
E
Enli
Yasar
Y
Oguz
Emin Oguzhan
EO
Coskun
Erdal
E
Aybek
Hulya
H
Ozcan
Ali Vefa
AV
Sacar
Mustafa
M
Bir
Levent Sinan
LS
Baltalarli
Ahmet
A
Baycu
Cengiz
C
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001921:Brain / Q000473:pathology*; D001927:Brain Diseases / Q000209:etiology / Q000517:prevention & control; D002545:Brain Ischemia; D002331:Carnitine / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D005978:Glutathione / Q000032:analysis; D007262:Infusions, Intravenous; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000150:complications* / Q000517:prevention & control*; D013482:Superoxide Dismutase / Q000032:analysis; D014803:Vitamin B Complex / Q000494:pharmacology*; D014810:Vitamin E / Q000494:pharmacology*
D000975:Antioxidants; D014803:Vitamin B Complex; D014810:Vitamin E; D008315:Malondialdehyde; D013482:Superoxide Dismutase; D005978:Glutathione; D002331:Carnitine