Speaker
Description
Silymarin is a mixture of flavonolignans of the plant Silybum marianum (L.) Gaerth derives mainly from its fruits. S. marianum has been found to exhibit antioxidant, lipid-lowering, antihypertensive, antidiabetic, antiatherosclerotic, anti-obesity, and hepatoprotective effects. In modern therapy, standardized silymarin products are used. According to the European Pharmacopoeia (Ph.Eur.11.0), the nominal silymarin content in the dried seeds is a minimum of 1.5% m/m, and of the refined and quantified milk thistle dry extract is within the range of 30-65%.
Therefore, the aim of our research work was to assess the silymarin content in wild and cultivated milk thistle fruits as well as in commercially available dry extracts according to the monograph in Ph.Eur.11.0 and speed up the analysis bringing in a rapid quantification, using Raman spectroscopy. Ph.Eur.11.0 method comprises very long and complex sample preparation followed by extensive HPLC analysis.
The obtained HPLC results of the samples of cultivated milk thistle fruits’, collected throughout several different years, showed silymarin content that varies within 0.3-1.8% m/m. The same extracts were analyzed using a portable Raman spectrometer, and the collected spectra were assigned and used for building partial least-squares (PLS) model for quantification, where HPLC was used as a reference technique. Using the developed model, the extracts from the wild-growing plants were quantified and the content in all samples was found above 1.5%. Furthermore, the dietary supplements, containing silymarin-rich dry extract (35.0% m/m), were quantified, both, with HPLC and Raman method, and the obtained results were complementary and met the Pharmacopoeial requirements for silymarin content.
