Abstract:

It has been proved that ursolic acid has diverse bioactivities such as antivirus and antitumor actions, antioxidation, anti-inflammation and reducing blood lipid, etc. However, whether it has no any acute and genetic toxicity remains unknown. In this study, in order to understand the acute toxicity of ursolic acid extract from Ledum pulastre L., the acute oral toxicity test was conducted in mice according to the Horn's method, and the mouse bone marrow micronucleus and chromosomal aberration tests were also conducted to investigate the genetic toxicity of this ursolic acid extract. The results showed that the LD50 of the ursolic acid extract in mice was 9.26 g/ kg. The frequencies of micronucleus in mice administered with high, medium and low doses of the ursolic acid extract were 2, 2 and 1.8, respectively. No significant differences (p ＞ 0.05) in frequency of micronucleus were observed between the mice administered with the ursolic acid extract and normal mice, while the difference (p ＜ 0.05) was significant between the former and the mice from positive control group. The chromosomal aberration rates in the mice administered with high, medium and low doses of the ursolic acid extracts were 1.2%, 1.2% and 1.0%, respectively, and these results were not significantly different from those in normal mice, but significantly differed from those in the positive control mice. The results suggested that the ursolic acid extract from Ledum pulastre L. is safe with low acute toxicity but without genetic toxicity.

Key words: Ledum pulastre L., ursolic acid, acute toxicity, genetic toxicity