title: Qianliguang (Senecio scandens) safety dilemma: dose is the key?
abstract: 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.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. linge@cuhk.edu.hk
authors.forename: Ge
authors.initials: G
authors.lastname: Lin
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Li
authors.forename: Mi
authors.initials: M
authors.lastname: Li
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Sunny
authors.initials: S
authors.lastname: Sun-Kin Chan
authors.forename: Wood-Yee
authors.initials: WY
authors.lastname: Chan
authors.forename: Zhong-Zhen
authors.initials: ZZ
authors.lastname: Zhao
mesh_terms: 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*
chemical_list: D010936:Plant Extracts