Introduction: This study aimed to evaluate the antioxidant property of Silymarin (SM)
extracted from the seed of Silybum marianum and its anticancer activity on KB and A549 cell lines
following 24, 48, and 72 h of treatment.
Methods: Ten grams of powdered S. marianum seeds were defatted using n-hexane for 6 hours
and then extracted by methanol. The Silymarin extracted of extraction components. The extracted
components of Silymarin were measured by spectrophotometric assay and HPLC analysis. 2, 2-
diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, phenol content, total flavonoid content, and
total antioxidant capacity were measured to detect the antioxidant properties of SM. The anticancer
activity of the SM on cell lines evaluated by MTT.
Results: In HPLC analysis, more than 50% of the peaks were related to silybin A and B. SM was
reduced DPPH (the stable free radical) with a 50% inhibitory concentration (IC50) of 6.56 μg/ ml
in comparison with butylated hydroxyl toluene (BHT), which indicated an IC50 of ~3.9 μg/ ml.
The cytotoxicity effect of SM on the cell lines was studied by MTT assay. The cytotoxicity effect
of the extracted Silymarin on KB and A549 cell lines was observed up to 80 and 70% at 156 and
78 μg/ml, respectively. The IC50 value of the extracted SM on KB and A549 cell lines after 24
hours of treatment was seen at 555 and 511 μg/ml, respectively.
Conclusion: Due to the good antioxidant and anticancer properties of the isolated Silymarin, its
use as an anticancer drug is suggested.