Effects of Thymoquinone on Cell Proliferation, Oxidative Damage, and Toll-like Signaling Pathway Genes in H1650 Lung Adenocarcinoma Cell Line

<i>Background and Objectives</i>: Lung cancer is the leading cause of cancer-related mortality worldwide. In most cases, lung cancer is diagnosed at an advanced stage. For advanced-stage disease, treatment options are generally systemic and while novel treatment approaches offer hope, they may also lead to significant adverse effects. Therefore, alternative therapeutic strategies have been investigated for many years. Thymoquinone (TQ) is one such candidate. Previous studies have demonstrated its antioxidant, anti-inflammatory, antibacterial, and immunomodulatory properties. In our study, we aimed to evaluate the roles of TQ in the progression of H1650 lung adenocarcinoma cells. <i>Materials and Methods</i>: In this study, the antiproliferative effect of TQ on H1650 lung cancer cells was evaluated using MTT assay, its effect on oxidative damage was determined using 8-OHdG, and total antioxidant status (TAS), total oxidant status (TOS), and its effect on apoptosis were demonstrated using caspase-3 ELISA method. In addition, total RNA was extracted from both control and treatment groups, cDNA was synthesized, and mRNA expression changes of Toll-like receptor related genes (<i>TLR</i>) were analyzed using RT-PCR. <i>Results</i>: The decrease in the viability of H1650 lung cancer cells was observed in a time- and dose-dependent manner. The IC₅₀ dose of TQ in the H1650 lung cancer cell line at 48 h was 26.59 µM. TQ treatment decreased the level of TOS and increased the level of TAS in H1650 lung cancer cells. Oxidative stress index decreased in the TQ-treated dose group in H1650 lung cancer cells. Elisa 8-OHdG and caspase-3 levels were not statistically significant. Compared to the control group, no statistically significant changes were observed in <i>TLR1</i>, <i>TLR2</i>, <i>TLR3</i>, <i>TLR4</i>, <i>TLR6</i>, <i>TLR7</i>, <i>TLR8</i>, and <i>TLR9</i> gene expressions in the treatment group treated with 26.59 µM TQ for 48 h. <i>Conclusions</i>: TQ shows potential as an anticancer agent and may contribute to the development of therapeutic approaches for lung cancers.