Analysis of silybin A and silybin B in different accessions of Silybum marianum seeds

Silybum marianum more commonly known as milk thistle is one of the most well-researched medicinal plants, particularly for the treatment of liver disease. Silbyin A and silybin B are compounds found in the silymarin complex, the phytochemical responsible for the bioactivity of S. marianum. Silymarin is currently widely used as a dietary supplement. In this study, the contents of the silybin mixture (silybin A and silybin B) in different accessions of S. marianum seeds were determined using high-performance liquid chromatography (HPLC). The aqueous extracts of S. marianum were evaporated and resuspended with HPLC-grade 70% acetonitrile for the analysis. The silybin mixture was quantified using a reverse-phase column with a gradient elution system and a wavelength of 288 nm. Among a total of 14 samples (samples S1-S14) of S. marianum from different accessions, samples S4, S1, and S7 showed particularly high concentrations of silybin A and B, ranging from approximately 19 to 27 mg/g ext. Determining the presence and quantifying the content of the silybin mixture in S. marianum seeds is crucial to identify alternative and optimal sources of therapeutic compounds, thereby increasing the number of available medicines.