Role of L-carnitine in the modulation of immune response in aged rats.
BACKGROUND
The immune system undergoes alterations in functions with aging which results in progressive deterioration in the ability to respond to infection. The importance of nutrients in regulating immune responses has widened attempts on interventions that improve immune functions with aging. L-carnitine serves as a vital factor in the mitochondrial transport of fatty acids, a process essential for fatty acid oxidation and energy release. L-carnitine is categorized as a conditionally essential nutrient factor and its concentrations are reported to be decreased with aging.


METHODS
The immunomodulatory role of L-carnitine was assessed in aged rats after administration of L-carnitine (300 mg/kg body weight/day) for 7, 14 and 21 days by evaluating neutrophil functions, delayed-type hypersensitivity (DTH) responses and immunoglobulin concentrations.


RESULTS
Aged animals exhibited decreased non-specific immune functions, delayed-type hypersensitivity responses and immunoglobulin concentrations compared to younger controls. Treatment with L-carnitine improved neutrophil functions, delayed-type hypersensitivity responses and the concentrations of immunoglobulins A and G in aged animals in a significant manner. However L-carnitine treatment did not have any impact on IgM concentration and type responses.


CONCLUSIONS
This study demonstrated that aging is associated with a decline in immune functions and supplementing L-carnitine had a positive effect in improving immune responses in aged animals.
Thangasamy
Thilakavathy
T
Department of Nutritional Sciences, University of Arizona, Tucson, AZ 85721, USA. t_thilaka@yahoo.com
Subathra
Marimuthu
M
Sittadjody
Sivanandane
S
Jeyakumar
Preethi
P
Joyee
Antony George
AG
Mendoza
Erin
E
Chinnakkanu
Panneerselvam
P
D000375:Aging / Q000276:immunology*; D000818:Animals; D000917:Antibody Formation; D002331:Carnitine / Q000502:physiology*; D007111:Immunity, Cellular; D051381:Rats; D017208:Rats, Wistar
D002331:Carnitine