Simple and effective method for the extraction of silymarin from Silybum marianum (L.) gaertner seeds

Introduction
One of the top 10 herbal remedies used in both developing and developed countries is milk thistle. The authors previous work showed that most milk thistle tinctures commercially available to herbal practitioners did not contain the required amount of its active ingredient silymarin. The aim of this project is to develop an easy and effective method for the preparation of milk thistle tinctures which guarantees an adequate therapeutic dosage of silymarin for the treatment of liver-associated diseases.

Methods
Whole and ground whole seeds as well as whole and ground pericarp were macerated at room temperature with 70 % v/v hydro-alcoholic solution using a plant material to solvent ratio of 1:1 and 1:2 for 1, 3 and 7 days. The total silymarin content was quantified by HPLC and expressed as the mean (mg/L) ± standard deviation.

Results
The above method yielded 36.23 ± 6.38 mg/mL, 38.02 ± 1.44 mg/mL and 40.93 ± 1.23 mg/mL of silymarin when ground whole seeds, whole and ground whole pericarps were macerated for 7 days using a plant material to solvent ratio of 1:1. No significant statistical differences was observed (P = 0.66 and P = 0.06)

Conclusion
An efficient and easy method for silymarin tincture production was achieved by macerating ground whole seeds with 70 % v/v hydro-alcoholic solution and an herb to solvent ratio of 1:1 for 7 days. However, all the investigated 7-days extractions yielded concentrations of silymarin that met the recommended content of active ingredient of at least 25 mg/mL.