Inhibitory effect of Milk thistle seed extract on cadmium chloride induced DNA damage in liver cells


Cadmium (Cd) is a biologically non-essential but economically valuable metal. Its increase in the environment has been linked to various diseases such as diabetes, organs failure, bone damage, endocrine hormone imbalance and cancer in humans and animals. Cd mainly accumulates in the liver and lead to its malfunction. In the present paper, we investigated the inhibitory effect of milk thistle (Silybum marianumseed (MTS) extract on cell death and DNA damage induced by cadmium chloride (CdCl2) in rat liver cells. The alkaline and neutral comet assays were used to evaluate double and single breaks in DNA. The treatment of the cells with CdClalone resulted in dose dependent decrease in cell viability compared to control cells; while cells co-treated with MTS extract resulted in increased cell viability. Furthermore, treatment of the cells with CdClalone caused increase in DNA damage as shown by the % DNA in the tail and olive tail moment in both alkaline and neutral comet assays. Co-treatment with MTS extract inhibited the Cd-induced DNA damage as shown by the decreased % DNA in the tail and olive tail moment. Our results clearly showed the inhibitory effect of MTS extract on Cd-induced DNA damage in rat liver cells.

Key words: Cadmium, Milk thistle, inhibition, comet assay, DNA damage.

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