Quality evaluation of Heshouwu, a Taoist medicine in Wudang, China.

Polygonum multiflorum Thunb., which is known as Heshouwu in China, is a Taoist medicine sourced from the Wudang mountain area. At present, the quality of the Heshouwu sourced from this region is unknown. The present study aimed to evaluate the quality of wild Heshouwu collected from the Wudang mountain area, particularly the 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (TSG) and combined anthraquinone (CAQ) content, compared with that of commercially available Heshouwu. Furthermore, the potential quantities of organic pesticide residues were determined. High performance liquid chromatography with a diode array detector was used to quantify TSG and CAQ content, whereas gas chromatography (GC), performed using a temperature gradient, was used to detect the presence of organochlorine, pyrethroid and organophosphorus pesticides. The average TSG content present in the wild Heshouwu from the Wudang mountain area and in the commercially available Heshouwu was 2.39 and 1.10%, respectively. In addition, the average content of CAQ in these was 1.41 and 3.46%, respectively. GC did not detect residues of organic pesticides in the wild Heshouwu, thus this plant met the criterion of the Chinese Pharmacopeia (2010 edition). The results of the present study indicated that wild Heshouwu from the Wudang mountain area may be suitable for use as a Chinese medicine across China.