Safety evaluation of tea (Camellia sinensis (L.) O. Kuntze) flower extract: Assessment of mutagenicity, and acute and subchronic toxicity in rats

• Published in: Journal of ethnopharmacology 2011-01, Vol.133 (2), p.583-590
• Main Authors: Li, Bo, Jin, Yuxia, Xu, Yi, Wu, Yuanyuan, Xu, Jiying, Tu, Youying
• Format: Article
• Language: English
• Subjects: Acute toxicity; Ames test; animal tissues; Animals; Biological and medical sciences; Blood; blood chemistry; Body weight; Camellia sinensis; Camellia sinensis - chemistry; Camellia sinensis - toxicity; China; Cough; Deodorization; dosage; dose response; Drugs, Chinese Herbal - chemistry; Drugs, Chinese Herbal - toxicity; Ethnopharmacology; Expectorants; Female; Flowers; Flowers - chemistry; General pharmacology; herbal medicines; histopathology; in vitro studies; lethal dose 50; Male; Medical sciences; medicinal properties; Metabolic activation; mortality; Mutagenicity; Mutagenicity Tests; Mutagens - chemistry; Mutagens - toxicity; no observed adverse effect level; oral administration; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; plant extracts; Plant Extracts - chemistry; Plant Extracts - toxicity; Rats; Rats, Sprague-Dawley; Salmonella typhimurium; Salmonella typhimurium - drug effects; Salmonella typhimurium - genetics; signs and symptoms (animals and humans); Skin; strains; Subchronic toxicity; Survival; Tea; Tea - chemistry; Tea - toxicity; Tea flower; Theaceae
• ISSN: 0378-8741; 1872-7573
• DOI: 10.1016/j.jep.2010.02.030

Tea flower extract does not possess mutagenic potential, and that both acute and subchronic toxicity towards animals is very low. Tea (Camellia sinensis (L.) O. Kuntze, Theaceae) flowers possess many physiological functions and have been used in traditional medicines for deodorization, skin care, cough suppressant and expectorant in China. However, there is a little information about its possible toxicity. The present investigation was carried out to evaluate the safety of tea flower extract by mutagenicity and acute and subchronic toxicity studies. Mutagenicity of tea flower extract was evaluated by the Ames test in Salmonella typhimurium strains TA97, TA98, TA100 and TA102 at concentrations of 0.008, 0.04, 0.2, 1.0, 5.0mg/plate. In the acute toxicity study, Sprague–Dawley rats were administered a single dose of 12.0g/kg of body weight by gavage, and were monitored for 14 days. In the subchronic toxicity study, tea flower extract was administered by gavage at doses of 1.0, 2.0 and 4.0g/kg body weight daily for 13 weeks to Sprague–Dawley rats. In the Ames test, there was no mutagenic effect of tea flower extract (up to 5.0mg/plate) towards four tested strains (TA97, TA98, TA100, TA102), with or without metabolic activation (S9). In the acute toxicity study, all animals gained weight and appeared active and normal, so the LD50 value must be >12.0g/kg body weight. In the subchronic toxicity study, no dose-related effects on survival, growth, hematology, blood chemistry, organ weights, or pathologic lesions were observed. These results indicate that tea flower extract does not possess mutagenic potential, and that both acute and subchronic toxicity towards animals is very low. A no-observed adverse-effect level (NOAEL) for tea flower extract is 4.0g/kgbw/day for rats under the conditions of this study.