RT - Journal Article T1 - The Effects of Pre-Treatment and Post-Treatment of Thymol against tert-Butyl Hydroperoxide (t-BHP) Cytotoxicity in MCF-7 Cell Line and Fibroblast Derived Foreskin JF - rbmb YR - 2020 JO - rbmb VO - 9 IS - 3 UR - http://rbmb.net/article-1-516-en.html SP - 338 EP - 347 K1 - Breast Cancer K1 - MCF-7 Cells K1 - Oxidative Stress K1 - tert-Butyl Hydroperoxide K1 - Thymol. AB - Background: Some recent studies have reported anti-tumor activity for Thymol, but the findings are inconsistent. This study aimed to investigate and compare Thymol's effects on MCF-7 cancer cells and fibroblasts while treated with tert-Butyl hydroperoxide (t-BHP). Methods: In the pre-treatment, MCF-7 and fibroblast cells were treated with various Thymol concentrations and incubated for 24 h. Then, t-BHP was added to a final concentration of 50 μM, and the cells were incubated for one h. In the post-treatment, cells were incubated first with 50 μM t-BHP for one h and then treated with Thymol. Cell viability was tested by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Thymol's antioxidant capacity was measured by DPPH and FRAP assays, and lipid peroxidation levels were determined by the TBARS method. Results: The thymol effects were dose-dependent, and despite their antioxidant properties, at concentrations of 100 µg/ml or more, increased t-BHP toxicity and reduced cancer cell viability. MTT assay result showed that pre-treatment and post-treatment with Thymol for 24 hours effectively reduced MCF-7 and fibroblast cell viability compared with the untreated control group. Both pre- and post-treatment of Thymol, normal fibroblast cell viability was significantly greater than that of the MCF-7 cells. Conclusions: Our finding showed that Thymol appears to be toxic to MCF-7 cells at lower concentrations than fibroblasts after 24 hours of incubation. Pre-treatment with Thymol neutralized the oxidative effect of t-BHP in fibroblasts but was toxic for MCF-7 cells. LA eng UL http://rbmb.net/article-1-516-en.html M3 10.29252/rbmb.9.3.338 ER -