Effect of Different Incoming Feeds, Defatting Procedures and Solvents on Producing of Standard Silymarin Extract

The medicinal plant milk thistle with the scientific name of Silybum marianum is an annual or biennial herb native to the Mediterranean regions and is found through the world. Extracts from the seeds of this plant have been used to cure liver disorders since ancient times. Featured phytochemicals of this medicinal plant are flavonolignan compounds and silybin is the most important one.
In this study, the effects of applying different incoming feeds, defatting procedures and solvents on silymarin extraction process from the seeds of milk thistle have been investigated.
Reflux extraction was used to obtain extracts. All extracts have been refluxed for 6 hours and the temperature was fixed at 60°C. Different incoming feeds including ground seeds, solvent defatted meal, cold press defatted meal, and separated pericarps have been subjected to the extraction system. Also, three different solvents including methanol, methanol 80%, and ethanol 80% were employed. Prepared extracts were weighed and then HPLC method analysis was used for quantifying silymarin compounds.
According to the presented data, the concentration and amount of silymarin in different extracts was compared. The extract obtained from ground seeds with methanol was able to reach the most amount of silymarin while the highest concentration of silymarin was obtained from the extract of ground pericarp with ethanol 80%.
This study shows that a higher amount of active ingredient can be extracted by using ground seeds and methanol solvent. Of course, there are more impurities in this extract.