Acute and subchronic oral toxicities of Pu-erh black tea extract in Sprague-Dawley rats.
BACKGROUND
Pu-erh black tea, which is obtained by first parching crude green tea leaves and then undergoes secondary fermentation with microorganisms, has been believed to be beneficial beverages for health for nearly 2000 years in China, Japan and Taiwan area. But its potential toxicity when administered at a high dose as concentrated extracts has not been completely investigated.


OBJECTIVE
The present study was aimed at evaluating potential toxicity of Pu-erh black tea extracts (BTE) from acute and sub-chronic administration to male and female Sprague-Dawley (SD) rats.


METHODS
A single BTE dose of 10,000 mg/kg of body weight was administered by oral gavage for acute toxicity in SD rats. Four groups (10 males and 10 females per group) of dose levels of 1250, 2500, and 5,000 mg/kg/day of the test article, as well as controls (distilled water) were tested as the subchronic toxicity study.


RESULTS
No deaths and signs of toxicity occurred during the 14 days of the study. There were no test article related mortalities, body weight gain, feed consumption, clinical observation, organ weight changes, gross finding, clinical or histopathological alterations during the 91-day administration.


CONCLUSIONS
The LD(50) of BTE can be defined as more than 10,000 mg/kg, and a dose of 5,000 mg/kg/day was identified as the no-observed-adverse-effect-level (NOAEL) in this study.
Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, 13 Hangkong Road, Wuhan 430030, PR China.
Di
D
Wang
Kunlong
K
Xu
Ying
Y
Zhong
Xiao
X
Luo
Rong
R
Xiao
Yan
Y
Hou
Wei
W
Bao
Wei
W
Yang
Hong
H
Yan
Ping
P
Yao
Liegang
L
Liu
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D006403:Hematologic Tests; D008297:Male; D009929:Organ Size / Q000187:drug effects; D010936:Plant Extracts / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013662:Tea / Q000737:chemistry*; D016482:Urinalysis
D010936:Plant Extracts; D013662:Tea