Silymarin content in Silybum marianum extracts as a biomarker for the quality of commercial tinctures

In this study, we report the determination of the total silymarin content in eleven different commercial tinctures retailed in the U.K. using a convenient and accurate HPLC-UV method. The tinctures analyzed differed in the ratio between herb and liquid as well as percentage of ethanol used during the extraction process. Our results showed a direct correlation between the silymarin content in tinctures and the alcohol strength. Following our protocol, silymarin could not be detected in tinctures extracted with 25% ethanol. Effective therapeutic doses were found only in tinctures with a concentration ratio herb to liquid 1:1 (kg/L) and an alcoholic content of 70%. To guarantee quality and safety of herbal medicinal products, legal requirements to produce plant-based products under regulatory frameworks are needed.
Source: Journal of Herbal Medicine - Category: Complementary Medicine Source Type: research