Safety evaluation of Astragalus extract mixture HT042 and its constituent herbs in Sprague-Dawley rats.

Background: Astragalus extract mixture HT042 is a combination of three standardized extracts from Astragalus membranaceus root, Eleutherococcus senticosus stem, and Phlomis umbrosa root, which has proven to stimulate children's height growth.

Purpose: The aim of this study was to demonstrate the safety of HT042 and its three constituent herbs when administered orally.

Methods: Acute and sub-chronic oral toxicity studies were conducted using male and female Sprague-Dawley rats. In the acute toxicity study, HT042 and each of the herbs was administered at single doses of up to 5000 mg/kg. In the 13-week sub-chronic toxicity study, HT042 was administered at repeated doses of up to 4000 mg/kg/day.

Results: In the acute toxicity study of HT042 and each of the herbs, no deaths occurred and there was no indication of toxicity, on the basis of clinical signs, body weight, and necropsy findings. In the sub-chronic toxicity study of HT042, there were no deaths and no changes in clinical signs or the findings of ophthalmic examinations. Although there were some treatment-related changes in other findings, these alterations were not considered toxicologically significant because they remained within normal ranges or recovered during the recovery period.

Conclusion: The oral approximate lethal doses of HT042 and each of the herbs were > 5000 mg/kg, and the no-observed-adverse-effect level of HT042 was 4000 mg/kg/day in male and female rats.