Comparative effects of emodin on biological activities of MCF-7 and MDA-231 cell lines

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Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Turkey

Approval Date: 2010

Thesis Language: English

Student: Elif Sakallı

Supervisor: MESUDE İŞCAN

Open Archive Collection: AVESIS Open Access Collection

Abstract:

Emodin (1,3,8-trihydroxy-6-methylanthraquinone) is a phytoestrogenic component of Rheum plant extracts which has been used for medical treatment since ancient times. It has been shown to have anti-inflammatory and anti-cancer effects. In our research, we aimed to study the biological effects of emodin on MCF-7 and MDA-231 cell lines. Cytotoxicity assays showed that emodin treatment for 48hours caused a concentration dependent decrease in viable cell numbers of both cell lines. As determined by cell counting with tryphan blue, IC50 values were 8.40 and 12.17 µg/ml for MCF-7 and MDA-231 cells, respectively. Apoptotic effects of emodin was investigated by measuring the changes in apoptotic and antiapoptotic gene expressions by qRT-PCR. In MCF-7 cells, Bax expression increased with increasing emodin concentrations, while Bcl-2 expression was downregulated. Bax/Bcl-2 ratio was calculated as 9.2 fold at 10µg emodin/ml treatment for 48 hours, indicating stimulation of apoptosis. However, Bax/Bcl-2 ratio was found 1.6 fold for MDA-231 cells. These results were in accordance with the results obtained from microarray analysis of related gene expressions. MCF-7 cells were more apoptotic in comparison to MDA-231 cells. DNA fragmentation was observed in MCF-7 cells by TUNEL method. GST enzyme activity that was measured using CDNB as substrate, was increased 100% with respect to control up to 5µg emodin/ml treatment of MCF-7 cells for 48 hours. However, effect of emodin on GST activity in MDA-231 cells was found insignificant. According to microarray analysis results, emodin affected the gene expressions of GST isozymes in MCF-7 cells much more than in MDA-231 cells.