[Safety and structural analysis of polymers produced in manufacturing process of alpha-lipoic acid].
Alpha-Lipoic acid has recently been permitted for use in foodstuffs and is contained in tablets and capsules. Although alpha-lipoic acid is synthesized from adipic acid, the safety of polymers produced during the purification and drying processes has been an issue of concern. Hence, we examined the safety profiles of thermally denatured polymer (LAP-A) and ethanol-denatured polymer (LAP-B) produced in the manufacturing process of alpha-lipoic acid. Furthermore, we conducted structural analysis of these polymers by 1H-NMR and FAB-MS spectroscopy. In a consecutive ingestion test, male and female mice ingested diet containing 0.1 and 0.2% LAP-A and -B for 4 weeks. Blood uric acid, potassium and lactate dehydrogenase (LDH) tended to increase without dose-dependency. Relative liver weights were also increased. However, male dogs that were orally administered LAP-B (500 mg/kg) once did not show any abnormalities in blood parameters or general condition. These findings indicate that alpha-lipoic acid polymers are not acutely toxic; however, chronic ingestion of these polymers may affect liver and kidney functions.
Shimoda
Hiroshi
H
Oryza Oil & Fat Chemical Co., Ltd., 1 Numata, Kitagata-cho, Ichinomiya-city, Aichi 493-8001, Japan.
Tanaka
Junji
J
Seki
Azusa
A
Honda
Haruya
H
Akaogi
Seiichiro
S
Komatsubara
Hirobumi
H
Suzuki
Nobuo
N
Kameyama
Mayumi
M
Tamura
Satoru
S
Murakami
Nobutoshi
N
D000818:Animals; D004285:Dogs; D005260:Female; D005503:Food Additives; D008297:Male; D051379:Mice; D011108:Polymers / Q000737:chemistry* / Q000633:toxicity*; D012449:Safety; D008063:Thioctic Acid
D005503:Food Additives; D011108:Polymers; D008063:Thioctic Acid