Evaluation of L-carnitine in an animal model of cholesterol- induced atherosclerosis

To explore the effect of L-carnitine on atherosclerotic plaques in hyperlipidemic rabbits.
Methods: Twenty five male white New Zealand rabbits were randomized into five groups (n = 5): In the
normal control (NC) group, the animals were fed on a plain chow diet for 75 days. In atherosclerosis
(AS) group, the animals were fed on a hypercholesterolemic diet for 75 days. In atorvastatin (ATOR)
group, the animals were fed on a hypercholesterolemic diet for 75 days and received atorvastatin via
oral gavage (20 mg/kg/day) from day 45 for 30 days. In L-carnitine (L) group, the animals were fed on a
hypercholesterolemic diet for 75 days and received intraperitoneal L-carnitine (250 mg/kg/day) from day
45 for 30 days (end of the study). In ATOR/L group, the animals were fed on a hypercholesterolemic
diet for 75 days, and received both atorvastatin and L-carnitine with the aforementioned dosage from
day 45 for 30 days. Triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL) and low-
density lipoprotein (LDL-C) in sera were determined. The aorta, including the ascending and
descending parts, was excised to measure plague size (end of the study). The blood samples were
taken from a marginal ear vein.
Results: Rabbits in AS group showed highly significant increase in serum total cholesterol and LDL-C
levels compared to NC group (p < 0.05). Daily administration of L-carnitine significantly reduced serum
levels of total cholesterol and LDL-C compared to AS (positive control) group (p < 0.05). Additionally, no
significant difference was found between serum levels of total cholesterol and LDL-C in groups that
received either atorvastatin or L-carnitine (p > 0.05). Combined administration of L-carnitine and
atorvastatin produced no benefits over either of them alone (p > 0.05).
Conclusion: The results indicate that the administration of L-carnitine has anti-atherosclerotic effects
by reducing oxidized LDL cholesterol levels but further investigations are recommended to ascertain
these findings.