Protective effects of noradrenaline on benzo[a]pyrene-induced oxidative stress responses in brain tumor cell lines
- 14 Downloads
Benzo[a]pyrene (B[a]P) is an ubiquitous environmental pollutant that is generated during combustion of fossil fuels. We examine the effect of noradrenaline (NA) on B[a]P-induced neurotoxicity in brain tumor cell lines like neuroblastoma (Neuro2a) and glioma (C6). We pre-treated tumor cells with NA for 6 h, followed by addition of B[a]P for additional 24 h. Cell viability was measured using trypan blue dye-exclusion assay and comet assay was performed to measure DNA damage. Cell cycle status was analyzed using flow cytometry and oxidative DNA damage (8-oxodG) production was examined by immunostaining. The intracellular Ca2+ concentration was analyzed using Fura-2AM. Our results showed viability of Neuro2a and C6 cells declined (24% and 20%) in B[a]P-treated groups. However, pre-treating with NA increased viability of cells by reducing percentage of cell death in both. Furthermore, B[a]P-induced deregulation of cell cycle (G2/M and S phase cell arrest) was significantly restored by pre-treatment with NA in Neuro2a cells as compared to C6 cells. We further observed increased 8-oxodG production in B[a]P-treated cells; however, NA pre-treatment significantly (p < 0.05) reduced the 8-oxodG production in Neuro2a, while C6 cells were less affected possibly due to better protective machinery. B[a]P-induced intracellular Ca2+ influx was significantly reduced in both the cell lines due to co-treatment of NA possibly by reducing Ca2+ influx. NA protects brain tumor cells against B[a]P-induced neurotoxicity may be by decreasing percentage of G2 cell arrest, oxidative DNA damage, and reducing intracellular Ca2+ influx. These findings suggested that NA may be considered as a natural potential protective agent against B[a]P-induced neurotoxicity.
KeywordsBenzo[a]pyrene Noradrenaline Neuro2a C6 cells DNA damage Comet assay Calcium influx
The authors also thank all members of Neurobiology Laboratory, School of Life Sciences, JNU, New Delhi, for their kind help, technical support, and instrumentation facility.
This work was supported by funding from the Project DAE-BRNS, Mumbai, No. 37(1)14/27/2015/ BRNS and DRDO, New Delhi, No. O/o DG (TM)/81/48222/LSRB-294/PEE&BS/2017 to Manorama Patri.
Compliance with ethical standards
The authors declare that they have no competing interests.
- ATSDR (1995) Toxicological profile for polycyclic aromatic hydrocarbons (PAHs). U.S. Department of Health and Human Services, AtlantaGoogle Scholar
- Nebert DW, Roe Al, Dieter MZ, Solis WA, Wang Y, Dalto TP (2002) Role of the aromatic hydrocarbon receptor (Ah) gene battery in the oxidative stress response cell cycle control and apoptosis. Biochem Pharmacol 5965–5985Google Scholar
- Nwagbara O, Darling-Reed SF, Tucker A, Harris C, Abazinge M, Thomas RD et al (2007) Induction of cell death, DNA strand breaks, and cell cycle arrest in DU145 human prostate carcinoma cell line by benzo[a]pyrene and benzo[a]pyrene-7,8-diol-9,10- epoxide. Int J Environ Res Public Health 4(1):10–14CrossRefGoogle Scholar
- Ordway GA, Schwartz MA, Frazer A (eds) (2007) Brain noradrenaline neurobiology and therapeutics. 1 ed. Cambridge University Press, New YorkGoogle Scholar
- Patel B, Das SK, Patri M (2016) Neonatal benzo[a]pyrene exposure induces oxidative stress and DNA damage causing neurobehavioural changes during the early adolescence period in rats. Dev Neurosci 38(2):150–162Google Scholar
- Takamasa I, Yumi T, Koichi S, Masaki M, Rintaro Y, Kayo Y, Hiromi O, Noboru K, Munehiro N, Yorihiro Y, Phil SH, Naoaki I (2017) Endogenous reactive oxygen species cause astrocyte defects and neuronal dysfunctions in the hippocampus: a new model for aging brain. Aging Cell 16:39–51CrossRefGoogle Scholar
- Troadec JD, Marien M, Mourlevat S, Debeir T, Ruberg M, Colpaert F, Michel PP (2002) Activation of the mitogen-activated protein kinase (ERK(1/2)) signaling pathway by cyclic AMP potentiates the neuroprotective effect of the neurotransmitter noradrenaline on dopaminergic neurons. Mol Pharmacol 62(5):1043–1052CrossRefGoogle Scholar