Toxicological evaluation of a tea from leaves of Vernonia condensata

Teas of Vernonia condensata Baker (Asteraceae) are widely used in Brazil fo r gastro-intestinal disorders and to treat several other diseases. In this study, we evaluated the acute toxicity, embryotoxicity and mutagenicity of a lyophilized aqueous extract (LAE) from V. condensata leaves. Single doses of LAE, up to 5000 mg/kg body weight, were given orally or intraperitoneal ly to male and female Swiss albino mice. No toxicity was observed after ora l administration. The 'Approximate Lethal Dose' after intraperitoneal injec tions was 3400 mg/kg for males and 5000 mg/kg for females. Embryotoxicity w as investigated in Han:NMRI mice. LAE (0, 500 and 2000 mg/kg/day) was given by gavage on days 10, 11 and 12, and dams were submitted to caesarean sect ions on day 18 of pregnancy. Fetuses were weighed, examined for externally visible malformations, and evaluated for skeletal anomalies. Except for a s light reduction of fetal body weight accompanied by signs of delayed ossifi cation at the highest dose, no other embryotoxic effect was noted in the ex posed offspring. LAE-induced mutagenicity was evaluated in the Salmonella/m icrosome assay without and with S9 mixture. LAE, tested up to 5000 mug/plat e, was not mutagenic to tester strains TA97a, TA98 and TA100. Results there fore suggest that V. condensata aqueous extracts present low acute toxicity and pose neither teratogenic nor mutagenic risks. (C) 2001 Elsevier Scienc e Ireland Ltd. All rights reserved.