Effects of Corexit Dispersants on Cytotoxicity Parameters in a Cultured Human Bronchial Airway Cells, BEAS-2B

Abstract

The objective of this study was to assess the cytotoxicity of COREXIT dispersants EC9500A, EC9527A, and EC9580A on human airway BEAS-2B epithelial cells. Cells were exposed to dispersants for 2 or 24 h at concentrations ranging from 0 to 300 ppm. COREXIT EC9527 at 100 ppm produced 50% viability loss as measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) at 24 h. COREXIT 9527 at 200 ppm produced 50% cell death at 2 h and 100% at 24 h. At 300 ppm COREXIT 9527 induced 100% cell death at 2 or 24 h. In the case of COREXIT 9500A 50% cell viability was noted with 200 ppm at 2 or 24 h, with a significant decrease in cell survival to 2% at 300 ppm. In contrast, no marked change in cell viability was observed in cells treated at any COREXIT 9580A concentration examined. Western blot analysis showed an increase in expression of LC3B, a marker of autophagy, in cells treated for 2 h with 300 ppm COREXIT EC9527A as well as 100 or 300 ppm Corexit EC9500A. No marked effect on LC3B expression was observed for any COREXIT 9580A concentration. Apoptosis markers as measured by cleaved caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) were detectable only in cells incubated with 300 ppm COREXIT EC9527A. Although all three dispersants induced enhanced generation of reactive oxygen species (ROS) after 2-h treatment at 300 ppm, Western blot analysis revealed that 2-h incubation was not sufficient to induce a significant change in the protein expression of superoxide dismutases SOD1, SOD2, and SOD3. Data thus indicate exposure to certain dispersants may be harmful to human airway epithelial cells in a concentration-dependent manner.

Effects of corexit oil dispersants and the WAF of dispersed oil on DNA damage and repair in cultured human bronchial airway cells, BEAS-2B

“…As previously demonstrated, WAF-dispersed oil is more toxic than WAF-crude oil (Shi et al, 2013), and exposure to Corexit dispersant is toxic (Shi et al, 2013) and causes DNA damage (Fig. 2).…”

“…Previous data demonstrated that exposure of BEAS-2B cells to low concentrations (100–300 ppm) of Corexit EC9527A and EC9500A dispersants significantly reduced cell viability after 2 h and eliminated almost 100% of the cell culture by 24 h (Shi et al, 2013). To determine the influence of dispersants the WAF-dispersed oil samples, cell viability of BEAS-2B cell following treatment with the WAF-crude, WAF-9500 + oil and WAF-9527 + oil mixed samples was investigated using the MTT assay.…”

“…The threshold for cell death appeared to be significant at concentrations greater than 10,000 ppm. Although the exposure to WAF-dispersed oil is not as cytotoxic as dispersants alone (Shi et al, 2013), these mixtures show higher toxicity than crude oil alone. Overall, none of the WAF crude oil concentrations evaluated reduced cell viability, while the higher concentrations of the WAF –dispersed oil reduced cell viability by ~70% at all exposure time points evaluated.…”

Corexit 9500 Inactivates Two Enveloped Viruses of Aquatic Animals but Enhances the Infectivity of a Nonenveloped Fish Virus

“…Therefore, it is important to define the lower limit of detection imposed by the toxicity of chemical disinfectants on cell cultures (22). Since Corexit 9500 has been shown to be cytotoxic to mammalian (9) and fish (23) cells in culture, the effect of the oil dispersant on the viability of the two fish cell lines, EPC and CHSE-214, that were used to monitor the viruses after their exposure to Corexit 9500 was examined. Corexit 9500 at a starting concentration of 10% (vol/vol) was serially diluted in a mock TCID 50 assay from 10 Ϫ1 to 10 Ϫ6 ; the 10 Ϫ1 TCID 50 dilution corresponded to a Corexit 9500 concentration of 1%, 10 Ϫ2 to 0.1%, 10 Ϫ3 to 0.01%, 10 Ϫ4 to 0.001%, 10 Ϫ5 to 0.0001%, and 10…”

“…For human health, the research has ranged from clinical assessments (8) to studies of cell lines (9). For the environment, the possible influence of dispersants on a range of metazoans, including corals, crustaceans, mollusks, fish, and birds (7,10,11), has been investigated.…”