Qianliguang (Senecio scandens) safety dilemma: dose is the key?
Qianliguang ( SENECIO SCANDENS) is a common Chinese medicinal herb. Qianliguang-containing herbal proprietary products are registered as over-the-counter remedies in China and exported to Western countries. The safety of using Qianliguang and its products has raised general concerns because of a potential risk of the presence of hepatotoxic pyrrolizidine alkaloids (PAs). A systematic toxicological study is thus required to verify this public concern. In the present article, we report, for the first time, that S. SCANDENS contains nine hepatotoxic PAs with a content of 6.95-7.19 microg/g. At a dose equivalent to the daily intake recommended by the Pharmacopoeia of China, the total content of toxic PAs in Qianliguang was determined to be 3.48 microg/kg/day, which is far below the lowest dose to cause hepatotoxicity (15 microg/kg/day) suggested by the International Program on Chemical Safety. No significant hepatotoxic effects were observed in rats fed with the extract at this human-equivalent dose for 14 consecutive days. However, a single overdose of the herbal water extract (6 g/kg), which was about 8-fold higher than the recommended dose, produced typical PA-induced hepatotoxicity in rats. Therefore, appropriate dosage guidelines should be implemented for the herbal industry, for export/import retailers, and for herbal medicine practitioners to ensure the safe and beneficial use of these herbal medicines.
Lin
Ge
G
Department of Pharmacology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. linge@cuhk.edu.hk
Li
Song-Lin
SL
Li
Mi
M
Li
Na
N
Sun-Kin Chan
Sunny
S
Chan
Wood-Yee
WY
Zhao
Zhong-Zhen
ZZ
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012674:Senecio / Q000737:chemistry*
D010936:Plant Extracts