Safety assessment of heat-sterilized green tea catechin preparation: a 6-month repeat-dose study in rats.
Evidence suggests that the purported health benefits associated with green tea consumption are related to tea catechins. In the present study, potential adverse effects of a standardized heat-sterilized green tea catechin (GTC-H) preparation was investigated following gavage administration to rats at doses of 0, 120, 400, 1200 mg/kg/day for 6 months. A decaffeinated high-dose group (1200 mg/kg/day) (GTC-HDC), was included for comparison. A possibly test article-related clinical finding of intermittent increased activity was noted in the 400 and 1200 mg/kg/day GTC-H groups, but was not considered to be adverse. Lower body weight gains without any decrease in food consumption were noted in the high-dose (1200 mg/kg/day)-treated GTC-H and GTC-HDC females. In the high-dose male GTC-H group, a lower total motor activity count for the 60-min session was noted prior to dosing at the study week 25 evaluations compared to the control group. Similar changes were not observed in the GTC-HDC group. Based on the results of this study, the no-observed-adverse-effect level (NOAEL) for GTC-H was 1200 mg/kg/day for males, the highest dose tested, and 400mg/kg/day for females based on reduced body weight gains. The NOAEL for GTC-HDC was 1200 mg/kg/day for males and could not be determined in females.
Morita
Osamu
O
Global R&D Safety Science, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi-ken 321-3497, Japan. morita.osamu@kao.co.jp
Kirkpatrick
Jeannie B
JB
Tamaki
Yasushi
Y
Chengelis
Christopher P
CP
Beck
Melissa J
MJ
Bruner
Richard H
RH
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001772:Blood Cell Count; D001774:Blood Chemical Analysis; D001835:Body Weight / Q000187:drug effects; D002110:Caffeine / Q000737:chemistry / Q000633:toxicity; D002392:Catechin / Q000737:chemistry / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D005123:Eye / Q000473:pathology; D005260:Female; D006358:Hot Temperature; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012727:Sex Characteristics; D013237:Stereoisomerism; D013242:Sterilization; D016019:Survival Analysis; D013662:Tea / Q000737:chemistry / Q000633:toxicity*; D016482:Urinalysis
D013662:Tea; D002110:Caffeine; D002392:Catechin