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Background and Objective: Curcumin is an effective anti-cancer agent used in thyroid cancer treatments. However, its use in clinical applications is limited due to low solubility and bioavailability. In this study, a novel combination strategy was applied by combining curcumin with Suberoylanilide Hydroxamic Acid (SAHA) to increase both bioavailability of curcumin and the efficiency of SAHA, which have limited efficiency when used alone. Methods: MTT assay was used to determine the cell viability of B-CPAP cells upon treatment with SAHA, curcumin and their combinations. Synergistic interactions between two agents were analyzed by Calcusyn software. Apoptosis and cell cycle assays were measured by flow cytometry. Expressions of apoptotic and cell cyclerelated proteins (PARP, P21/CDKN1A/WAF1, P27/KIP1) were examined by western blot analysis. Broth microdilution assay was performed to determine Minimum Inhibitory Concentration (MIC) values against S. aureus. Results: Based on MTT assay, IC50 values for SAHA and curcumin were determined as 0.91μM and 20.97μM, respectively. The combination index CI value was determined as 0.891 in B-CPAP cells, which demonstrate synergistic activity. The apoptotic effect was achieved by combination treatment (51.85%) on B-CPAP cells using half of the dose required for SAHA and curcumin alone. Combination treatment showed a significant increase in the percentage of B-CPAP cells in the S-phase due to cell arrest. Cleaved-PARP, P21/CDKN1A/ WAF1 and P27/KIP1 protein expressions were upregulated. Curcumin was found to have better anti-microbial activity than SAHA as having a lower MIC value, and checkerboard synergy analysis revealed that the two compounds co-operate synergistically for the in vitro killing of S. aureus. Conclusion: In the present study, synergistic combinations of SAHA and curcumin were shown to have both anti-cancer and antibacterial activities that would provide a novel thyroid cancer treatment strategy.

Background: Different cellular responses influence the progress of cancer. In this study, the effects of hydrogen peroxide and quercetin induced changes on cell viability, apoptosis, and oxidative stress in human hepatocellular carcinoma (HepG2) cells were investigated. Methods: The effects of hydrogen peroxide and quercetin on cell viability, cell cycle phases, and oxidative stress related cellular changes were investigated. Cell viability was assessed by WST-1 assay. Apoptosis rate, cell cycle phase changes, and oxidative stress were measured by flow cytometry. Protein expressions of p21, p27, p53, NF-Kβ-p50, and proteasome activity were determined by Western blot and fluorometry, respectively. Results: Hydrogen peroxide and quercetin treatment resulted in decreased cell viability and increased apoptosis in HepG2 cells. Proteasome activity was increased by hydrogen peroxide but decreased by quercetin treatment. Conclusion: Both agents resulted in decreased p53 protein expression and increased cell death by different mechanisms regarding proteostasis and cell cycle phases.

Recent work from several laboratories has suggested involvement of lipid peroxidation in the pathogenesis of atherosclerosis. In the present study, the relationship between lipid profile and lipid peroxidation was investigated in plasma and erythrocytes of hyperlipidemic individuals