<p>Memory Impairment Induced by Chronic Psychosocial Stress Is Prevented by L-Carnitine</p>

Abstract

Introduction: Psychosocial stress (STS) negatively influences memory. This might be associated to oxidative stress-induced progressive destruction of numerous brain structures and functions. L-carnitine (L-CAR) is a widely used antioxidant compound that is endogenously made in mammalian species. The current study investigated the effect of L-CAR on STS-induced memory impairment in the rat hippocampus. Methods: The STS was induced using intruder model, where two rats were randomly switched from each one cage to another, once/day for 6 weeks. Concurrently, L-CAR (300mg/kg/day) was intraperitoneally administered for 6 weeks. After that, radial arm water maze (RAWM) was used to assess spatial learning memory in rats. Hippocampal biomarkers of oxidative stress, including thiobarbituric acid reactive substance (TBARs), oxidized glutathione (GSSG), reduced glutathione (GSH), glutathione peroxidase (GPx), catalase, and superoxide dismutase (SOD), and Brain-derived neurotrophic factor (BDNF) were examined. Results: The results showed impairment of short-term memory (P < 0.05) during STS, whereas L-CAR treatment protected against this effect. Furthermore, while no change was observed in GSH, GSSG, GPx, catalase, and SOD, L-carnitine normalized STS-induced reduction in the hippocampal BDNF levels and increase in TBARS levels. Discussion: Chronic psychosocial stress-induced memory impairment was prevented via L-CAR administration, which could have been achieved via normalizing changes in lipid peroxidation (TBARs) and BDNF levels in the hippocampus.

L-carnitine Modulates Cognitive Impairment Induced by Doxorubicin and Cyclophosphamide in Rats; Insights to Oxidative Stress, Inflammation, Synaptic Plasticity, Liver/brain, and Kidney/brain Axes

“…), respectively, five times per week for three weeks. Doses of L-carnitine were selected according to previous studies (Rababa'h et al 2019;Jamali-Raeufy et al 2021). Group E received IV saline once weekly and L-carnitine at a dose of 300 mg/kg, i.p., five times per week for three weeks.…”

L-carnitine attenuates acoustic startle reflex dysfunction in adult male rats exposed to mancozeb

“…Today, neuroprotective effects of L-carnitine administration have been reported in Parkinson’s disease (Burks et al, 2019), autism spectrum disorders (ASD) (Malaguarnera and Cauli, 2019), and Alzheimer’s disease (Kepka et al, 2020). It is also reported that daily administration of acetyl-L-carnitine at a dose of 300 mg/kg for 6 weeks improved memory loss and learning owing to mental stress in rats in the radial maze through increasing levels of the antioxidant enzymes glutathione reductase, catalase, and glutathione peroxidase (Rababah et al, 2019). However, in humans, L-carnitine consumption at 100 and 200 mg/kg/day for 1–6 months may improve ASD symptoms, but side effects such as diarrhea have been reported at high doses (Malaguarnera and Cauli, 2019).…”