Concentration-dependent effects of reductive pulmonary inhalants on ultrafine particle-induced oxidative stress: Insights for health risk assessment

Ya-Qi Yu; Tong Zhu

doi:10.1016/j.ese.2023.100339

Concentration-dependent effects of reductive pulmonary inhalants on ultrafine particle-induced oxidative stress: Insights for health risk assessment

Environ Sci Ecotechnol. 2023 Nov 14:19:100339. doi: 10.1016/j.ese.2023.100339. eCollection 2024 May.

Authors

Ya-Qi Yu^{1

2}, Tong Zhu¹

Affiliations

¹ BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China.
² School of Environmental Science and Engineering, Qingdao University, Qingdao, 266071, PR China.

Abstract

The impact of reductive pulmonary inhalants on ultrafine particles (UFPs)-induced pulmonary oxidative stress remains a crucial consideration, yet the concentration-dependent effects of these inhalants have remained unexplored. Here we synthesized composite UFPs simulating atmospheric UFPs, primarily composed of metals and quinones. We subjected these UFPs to varying concentrations (0-7000 μM) of two reductive pulmonary inhalants, N-acetylcysteine and salbutamol, to assess their influence on oxidative potential, measured through the dithiothreitol assay (OP^DTT). Simultaneously, we analysed the soluble metal content of UFPs to uncover potential relationships between oxidative potential and metal solubility. Our results unveil a dual role played by these inhalants in shaping the OP^DTT of composite UFPs. Specifically, OP^DTT generally increased as inhalant concentrations rose from 0 to 300 μM. However, an intriguing reversal occurred when concentrations exceeded 500 μM, resulting in a decline in OP^DTT. Relative to untreated UFPs, these inhalants induced promotion and inhibition effects within concentration ranges of 100-500 and >1000 μM, respectively. While no significant correlation emerged between OP^DTT and soluble metal content as inhalant concentrations ranged from 0 to 7000 μM, noteworthy positive correlations emerged at lower inhalant concentrations (e.g., N-acetylcysteine at 0-300 μM). These findings provide insights into the potential influence of reductive pulmonary inhalants on health risks associated with UFP exposure, further underscoring the need for continued research in this critical area.

Keywords: Concentration-dependent effects; Oxidative potential; Reductive pulmonary inhalants; Simulated atmospheric ultrafine particles; Soluble metals.