Determination of astilbin in dietary supplements containing Smilax glabra using high-performance liquid chromatography

Smilax glabra rhizoma (SGR) has been used in traditional medicine remedies for the treatment of joint pain and inflammation, and recently, has been presented in dietary supplements for supporting arthritis and gout treatment. In the 5th Vietnamese Pharmacopoeia, astilbin was chosen as a chemical marker for the quality control of Smilax glabra as herbal medicine. A high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of astilbin in dietary supplements containing Smilax glabra. Ultrasonic extraction with 60% methanol was used for astilbin extraction from herbal products. HPLC analysis was performed with a C18 column and a mobile phase consisting of methanol and water in gradient mode, with UV detection at 291 nm. The method was validated according to AOAC International’s requirements with high specificity and precision.