Comparative evaluation of silibinin effect on apoptosis in human breast cancer MCF-7 cell line in vitro and in vivo

Silibinin, a natural flavonoid from the seeds of milk thistle, has been used for over 2000 years to treat a range of liver disorders, because of its strong antioxidant effects. In recent times it has been shown that silibinin has anticancer activities, including growth inhibition, inhibition of angiogenesis, cell cycle arrest, anti-proliferative effects, apoptosis induction and inhibition of invasion and metastasis. Due to its non-toxic character, silibinin is well tolerated and largely free of any adverse effects. The aim was to evaluate and compare the effect of silibinin on apoptosis in human breast cancer cell line MCF-7 in vitro and in vivo. For the first time, we evaluated the silibininapoptosis effect in MCF-7 cell line in vivo by CAM assay. Cancer cells were grafted onto a chicken chorioallantoic membrane (CAM) and xenografts were analyzed immunohistochemically. The apoptosis was detected via TUNEL assay.For comparison, we also performed 2D cell culture apoptosis assay with Annexin/Pl with the same concentration and time exposure. In 2D cell culture, silibinin induced significant apoptosis cell death in MCF-7 cells. Flow cytometry experiments indicated 25.9 ± 1.8%, p<0.05 apoptosis by both Annexin V+ and Annexin V+PI+ evaluations and 12±1.7 necrosis (only PI+) under 150 μM silibinin supplementation at 48h. CAM assay results confirmed apoptosis induction of silibinin in vivo. Our study confirms the ability of silibinin to suppress breast cancer progression through the induction of apoptosis.

Keywords:

Silibinin , MCF-7 , Apoptosis