Carnitine esters prevent oxidative stress damage and energy depletion following transient forebrain ischaemia in the rat hippocampus

1. The present study investigated whether propionyl-L-carnitine (PLC) has neuroprotective effects, similar to those reported for acetyl-l-carnitine (AC), against transient forebrain ischaemia-induced neuronal damage and biochemical derangement in the rat hippocampal CA1 region. 2. In total, 105 adult male Wistar albino rats were divided into seven groups of 15 animals each. The first three groups were injected i.p. with normal saline, AC (300 mg/kg) or PLC (300 mg/kg) for 7 successive days. The next three groups were injected i.p. with the same doses of normal saline, AC or PLC immediately after the induction of 10 min forebrain ischaemia and i.p. injections were continued for 7 successive days. Rats in the seventh group were subjected to sham-operated ischaemia and injected with normal saline for 7 successive days. 3. Seven days after treatment, animals were killed and their brains isolated for histopathological examination and biochemical studies. 4. Forebrain ischaemia resulted in a significant decrease in the number of intact neurons (77%), ATP concentration (51%) and glutathione content (32%), whereas there was a significant increase in the production of thiobarbituric acid-reactive substances (TBARS; 71%) and total nitrate/nitrite (NOx; 260%) in hippocampal tissues. 5. Administration of either AC or PLC attenuated forebrain ischaemia-induced neuronal damage, manifested by a greater number of intact neurons, ATP and glutathione, as well as a decrease in TBARS and NOx in hippocampal tissues. 6. Results from the present study suggest, for the first time, that PLC attenuates forebrain ischaemia-induced neuronal injury, oxidative stress and energy depletion in the hippocampal CA1 region. Propionyl-L-carnitine has neuroprotective effects similar to AC and could have a potential use in the treatment of neurodegenerative diseases. 7. The results of the present study will open up new perspectives for the use of PLC in the treatment of neurodegenerative diseases associated with, or secondary to, myocardial ischaemia-reperfusion injury and chronic circulatory failure.