[Chronic toxicity test of fangyouling by transdermal administration in rabbits].

OBJECTIVE: To observe the toxicity of fangyouling after one month' s transdermal administration in rabbits and evaluate its security. METHODS: Forty rabbits were randomly divided into 4 groups including a control group and low, middle and high dose groups of fangyouling. The rabbits in the control group were administered with sunflower oil, and the other rabbits were administrated dermally with fangyouling of 50,300 and 2,000 mg/kg respectively once a day for 4 weeks. The general condition, the skin irritation reaction, body weight, food consumption, hematology, blood biochemistry, organ coefficients and histopathological changes of all the rabbits were observed. RESULTS: There was no obvious effect on the general condition in all the rabbits. However, the mild skin irritation was observed in 2 rabbits of the middle dose group and 4 rabbits of the high-dose group. The decreases of body weight and food consumption were noted in the high dose group. No changes were detected of hematology, blood biochemistry or viscera pathological at all dose levels. CONCLUSION: The dose of non-toxic response of fangyouling is 50 mg/kg at this study condition.

[Toxic effects of aqueous extract of crotalariae assamicae semen in rats and possible mechanism in association with liver damage].

OBJECTIVE: To study the toxic effects of aqueous extract of Crotalariae Assamicae Semen (CAS), one of the pyrrolizidine alkaloid-containing Chinese herbal medicines, in rats and the possible mechanism in association with liver damage. METHOD: The aqueous extract of CAS (CASE) was prepared by the conventional water extracting-alcohol precipitating method. The LD50 value of CASE in rats was determined by Kärber method. Rats were randomly divided into four groups in which three groups were orally administered with different doses of the CASE and one group with distilled water as control. Toxic effects were assessed by morphological, biochemical and histopathological changes. Moreover, in vitro metabolism using rat liver microsomes was also conducted and applied for the exploration of the underlying mechanism of liver damage. RESULT: The LD50 value of CASE in Wistar rats was (2.36 +/- 0.26) g x kg(-1). The toxic effects were found in all groups of rats dosed with CASE, in which serum levels of ALT and AST were significantly elevated, and the obvious and dose-dependent damages in liver and lung were observed by histopathological examination. Moreover, the liver tissue-bound pyrroles were detected and generated in a dose-dependent manner, and the pyrrole metabolites observed in the in vitro microsomal metabolism. All the evidences suggested a strong correlation between metabolism and toxicity of CASE in rats. CONCLUSION: CASE could induce the acute toxicity in rats, of which liver and lung were the major targets. Toxic effects were strongly correlated with pyrrolizidine alkaloids in CAS. The possible mechanism for its liver toxicity may be related to the formation of pyrrole metabolites as well as the corresponding tissue-binding products.