Safety Evaluations of Davallia Formosana Extraction

In this study, we evaluated the safety of 70% ethanolic extract of Davallia formosana (DFE). The LD50 value for oral administration of DFE was greater than 10 g/kg. Repeated dosing toxicity study was carried out by orally administering daily doses of 0.28, 0.83, and 2.5 g/kg of DFE to groups of male and female rats for 13 weeks. The mean body weights at weekly intervals were not affected by the administration of DFE during the 13-weeks dosing period. Scattered significant differences in WBC differential count, plasma alanine aminotranferase, alkaline phosphatase, sodium and chloride were found, but all these were still within the range of normal physiological reference or had no dose-correlation. A significant increase was seen in the absolute and relative weight of spleen treated with DFE 0.28 g/kg in female rats, but without dose-correlation. From the microscopic evaluations, there were no treatment-related pathological lesions in the tissue/organs. The no-observed adverse effect level is higher than 2.5 g/kg in rats. Reproductive test study indicated no-effect dose level of DFE was greater than 3.8 g/kg for dams, fetuses, and apparent teratogenicity of offspring. But, DFE markedly reduced the body weight of dams and offsprings in lactating period. The results of three genotoxicity studies, including Ames test, CHO-K1 chromosomal aberration test, and micronucleus test, demonstrated that DFE had no genotoxicity. Our findings provided scientific evidence for the safe use of DFE. But it should be contraindicated in lactating female.