Silymarin is a traditional drug and food supplement employed for numerous liver disorders. The available studies indicate that its activities may be broader, in particular due to claimed benefits in some cardiovascular diseases, but the contributions of individual silymarin components are unclear. Therefore, we tested silymarin flavonolignans as pure diastereomers as well as their sulfated metabolites for potential vasorelaxant and antiplatelet effects in isolated rat aorta and in human blood, respectively. Eleven compounds from a panel of 17 tested exhibited a vasorelaxant effect, with half maximal effective concentrations (EC50) ranging from 20 to 100 µM, and some substances retained certain activity even in the range of hundreds of nM. Stereomers A were generally more potent as vasorelaxants than stereomers B. Interestingly, the most active compound was a metabolite-silychristin-19-O-sulfate. Although initial experiments showed that silybin, 2,3-dehydrosilybin, and 2,3-dehydrosilychristin were able to substantially block platelet aggregation, their effects were rapidly abolished with decreasing concentration, and were negligible at concentrations ≤100 µM. In conclusion, metabolites of silymarin flavonolignans seem to have biologically relevant vasodilatory properties, but the effect of silymarin components on platelets is low or negligible.

• Klíčová slova
• Silybum marianum, aorta, blood coagulation, metabolites, milk thistle, sulfates, thrombocytes, vasorelaxant,
• MeSH
• agregace trombocytů účinky léků   MeSH
• aorta účinky léků   MeSH
• flavonolignany chemie   farmakologie   MeSH
• inhibitory agregace trombocytů chemie   farmakologie   MeSH
• krysa rodu Rattus MeSH
• lidé MeSH
• molekulární struktura MeSH
• vazodilatancia MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• flavonolignany MeSH
• inhibitory agregace trombocytů MeSH
• vazodilatancia MeSH