Synthetic Coolant WS-23 increases E-Cigarette Generated Aerosolized Acellular Reactive Oxygen Species (ROS) Levels

There has been a substantial rise in e-cigarette (e-cig) use or vaping in the past decade, prompting growing concerns about their adverse health effects. Recently, e-cig manufacturers have been using synthetic cooling agents, like WS-23 and WS-3, to provide a cooling sensation without the "menthol taste". Studies have shown that aerosols/vapes generated by e-cigs can contain significant levels of reactive oxygen species (ROS). However, studies investigating the role of synthetic coolants in modulating ROS levels generated by e-cigs are lacking. This study seeks to understand the potential of synthetic coolants, e-cigarette additives that have become increasingly prevalent in e-liquids sold in the United States (US), on acellular ROS production. Aerosols were generated from e-liquids with and without synthetic coolants through a single-puff aerosol generator; subsequently, acellular ROS was semi-quantified in H2O2 equivalents via fluorescence spectroscopy. Our data suggest that adding WS-3 to e-liquid base (PG:VG), regardless of nicotine content, has a minimal impact on modifying e-cigarette-generated acellular ROS levels. Additionally, our data also suggest that the addition of WS-23 to nicotine-containing e-liquid base significantly modifies e-cigarette-generated acellular ROS levels. Together, our data provide insight into whether adding synthetic coolants to e-liquids significantly impacts vaping-induced oxidative stress in the lungs.