Antioxidant thymoquinone and eugenol alleviate TiO₂ nanoparticle-induced toxicity in human blood cells in vitro

Abstract

Titanium dioxide (TiO₂) nanoparticles (NPs) are used extensively in a variety of commercial, industrial, and medical products, due to which human exposure is inevitable. This study aimed to explore the potential of eugenol and thymoquinone (TQ), two well-known antioxidants, in counteracting the NP-induced toxicity in human blood cells in vitro. Fresh lymphocytes and erythrocytes were isolated from volunteer human blood donors and incubated with 50 μg/mL of TiO₂ NPs in the presence and absence of 50 μM of TQ and 20 μg/mL of eugenol for 3 h. Results showed that NP-treatment-induced hemolysis, oxidative stress, lactate dehydrogenase (LDH) leakage, and reduced ATPase activity in the erythrocytes. In the lymphocytes treated with NPs alone (50 μg/mL), cytotoxicity in MTT assay and DNA damage in comet assay were observed; in addition, mitochondrial membrane potential collapsed and ADP/ATP ratio increased indicating mitochondrial function impairment. However, in the presence of antioxidants, all these NP-induced changes were mitigated significantly. The results were more significant when both antioxidants eugenol and TQ were given together. Thus, it seems that antioxidants eugenol and TQ can be used as a protective agent against TiO₂ NP-induced toxicity.

Keywords:

• TiO₂ nanoparticles
• hemolysis
• oxidative stress
• cytotoxicity
• thymoquinone
• eugenol

Ethical approval

Institutional Ethics Committee of Jawaharlal Nehru Medical College (JNMC), Aligarh Muslim University, Aligarh has approved this work and guidelines set by 1964 Helsinki declaration and its later amendments were followed. Informed consent was obtained from all individual participants included in the study.

Acknowledgements

MRW is the recipient of DST INSPIRE Fellowship from Department of Science and Technology (DST), New Delhi.

Author contributions

MRW and GGHAS conceived and designed the work, performed the experiments and data analysis. MRW wrote the manuscript. All the authors read and approved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.