Toxicological evaluation of L-proline in a 90-day feeding study with Fischer 344 rats.
L-proline (L-Pro) is a non-essential amino acid, and has become widely used as supplements and health foods, recently. A subchronic oral toxicity study of L-Pro was conducted with groups of 10 male and 10 female Fischer 344 rats fed a powder diet containing 0%, 0.625%, 1.25%, 2.5% and 5.0% of L-Pro for 90 days. No treatment-related clinical signs and mortality were noted. We observed no clear treatment-related effects with regard to body weight, food intake or urinalysis data. The average daily water intakes of the treated female groups were significantly increased compared to the controls. The hematology (red blood cell parameter) and serum biochemistry (glucose, blood urea nitrogen, creatinine or uric acid) of the treated male and/or female groups were lower than those of the control groups. However, these changes were lacked dose-dependence, and no abnormalities were found in corresponding pathological findings. In conclusion, the no-observed-adverse-effect-level (NOAEL) for L-Pro was determined to be a dietary dose of 5.0% (2772.9 mg/kg body weight/day for males and 3009.3mg/kg body weight/day for females) under the present experimental conditions.
Tada
Y
Y
Department of Environmental Health and Toxicology, Tokyo Metropolitan Institute of Public Health, Shin'juku, Tokyo 169-0073, Japan. Yukie_Tada@member.metro.tokyo.jp
Yano
N
N
Takahashi
H
H
Yuzawa
K
K
Ando
H
H
Kubo
Y
Y
Nagasawa
A
A
Ohashi
N
N
Ogata
A
A
Nakae
D
D
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D019587:Dietary Supplements / Q000633:toxicity*; D005260:Female; D006403:Hematologic Tests; D007668:Kidney / Q000187:drug effects / Q000473:pathology; D008297:Male; D009929:Organ Size / Q000187:drug effects; D011392:Proline / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D012737:Sex Factors; D013154:Spleen / Q000187:drug effects / Q000473:pathology; D018675:Toxicity Tests
D011392:Proline