Unveiling the antioxidant and immunomodulatory potential of Silybum marianum seed extract.

Abstract

Silybum marianum or milk thistle, is a medicinal plant belonging to the Asteraceae family. In this study, the methanolic extract of the seeds of Silybum marianum was studied through the quantification of its total phenolic and flavonoid contents using spectrophotometric methods. Three tests were carried out to evaluate the antioxidant activity of the seed extract, namely DPPH free radical scavenging, total antioxidant capacity (TAC), and anti-hemolytic activity assays. Additionally, the immunomodulatory effect has been evaluated in vivo using mouse models. The seed extract exhibited a high phenolic content of 213.62 µg GAE/mg and a total flavonoid content of 25.86 µg RE/mg of the extract. Evaluation of antioxidant activity using DPPH assay revealed an IC₅₀ value of 34.24 ± 0.3 µg/ml, reflecting remarkable free radical scavenging activity. Moreover, the seed extract exhibited an A₀.₅₀ value of 41.09 ± 5.3 µg/ml in the total antioxidant capacity (TAC) assay and demonstrated a noticeable protective effect against hemolysis in the anti-hemolytic assay. At a concentration of 1000 µg/ml, the extract achieved a protection of 77.29%, comparable with that of quercetin (81.76%). Furthermore, the immunomodulatory treatment with the extract resulted in significant immunostimulation of antibody production in mice immunized with sheep red blood cells