Combined Toxicity of the Most Common Indoor Aspergilli

Abstract

The most common Aspergilli isolated from indoor air samples from occupied buildings and a grain mill were extracted and analyzed for their combined (Flavi + Nigri, Versicolores + Nigri) cytotoxic, genotoxic and pro-inflammatory properties on human adenocarcinoma cells (A549) and monocytic leukemia cells induced in macrophages (THP-1 macrophages). Metabolite mixtures from the Aspergilli series Nigri increase the cytotoxic and genotoxic potency of Flavi extracts in A549 cells suggesting additive and/or synergistic effects, while antagonizing the cytotoxic potency of Versicolores extracts in THP-1 macrophages and genotoxicity in A549 cells. All tested combinations significantly decreased IL-5 and IL-17, while IL-1β, TNF-α and IL-6 relative concentrations were increased. Exploring the toxicity of extracted Aspergilli deepens the understanding of intersections and interspecies differences in events of chronic exposure to their inhalable mycoparticles.

Keywords: cytotoxicity; genotoxicity; proinflammatory cytokines; section Flavi; series Nigri; series Versicolores.

Figure 1

Cytotoxicity of A549 cells upon the treatment with the extracted Aspergilli from the section Flavi and the series Nigri (a) and the series Versicolores and Nigri (b), single and mixed as specified. The viability of the cells (% control treatment) is presented as mean and standard deviation derived from the MTT assay performed in triplicate at least. *—significantly different compared to control treatment (C), a—significantly different compared to AF1a or AF2a (a) and AV1a, AV2a or AV3a (b), b—significantly different compared to AF1b or AF2b (a) and AV1b, AV2b or AV3b (b), c—significantly different compared to AN1, AN2 or AN3 (a,b). *^,a,b,c p < 0.05 was considered statistically significant for all calculations. Viability of A549 cells following the control treatment (DMSO-containing) was 91.91 ± 9.154% of viability produced in DMSO-free medium.

Figure 2

Cytotoxicity of THP-1 macrophage-like cells upon the treatment with the extracted Aspergilli from the sections Flavi and the series Nigri (a) and the series Versicolores and Nigri (b), single and mixed as specified. The viability of the cells (% control treatment) is presented as mean and standard deviation derived from the MTT assay performed in triplicate at least. *—significantly different compared to control treatment (C), a—significantly different compared to AF1a or AF2a (a) and AV1a, AV2a or AV3a (b), b—significantly different compared to AF1b or AF2b (a) and AV1b, AV2b or AV3b (b), c—significantly different compared to AN1, AN2 or AN3 (a,b). *^,a,b,c p < 0.05 was considered statistically significant for all calculations. Viability of THP-1 macrophages following the control treatment (DMSO-containing) was 101.6 ± 3.088% of viability produced in DMSO-free medium.

Figure 3

Genotoxicity of A549 cells upon the treatment with the extracted Aspergilli from the section Flavi and the series Nigri (a) and the series Versicolores and Nigri (b), single and mixed as specified. The DNA damage is evaluated through percentage of the DNA in comet tail and presented as mean ± SD derived from 200 measured cells. Each comet assay was performed in duplicate. *—significantly different compared to control treatment (C), a—significantly different compared to AF1a or AF2a (a) and AV1a, AV2a or AFVa (b), b—significantly different compared to AF1b or AF2b (a) and AV1b, AV2b or AV3b (b), c—significantly different compared to AN1, AN2 or AN3 (a,b). *^,a,b,c p < 0.05 was considered statistically significant for all calculations.

Figure 4

Relative concentration of the cytokines measured in the supernatant of THP-1 macrophage-like cells upon treatment with the extracted Aspergilli from the section Flavi and the series Nigri (a) and the series Versicolores and Nigri (b), applied as a single or combined treatment and compared to the control treatment. Values are presented as arithmetic mean and standard error of the mean. *—significantly different compared to control treatment (C), a—significantly different compared to AF1a or AF2a (a) and AV1a, AV2a or AV3a (b), b—significantly different compared to AF1b or AF2b (a) and AV1b, AV2b or AV3b (b), c—significantly different compared to AN1, AN2 or AN3 (a,b). *^,a,b,c p < 0.05 was considered statistically significant for all calculations.