TABLE 6 |.
Effects of microplastics in oxidative stress and membrane integrity.
| End-point | Polymer type | Exposure time | Size | Concentration range | Assay | Cell type | Outcome | Ref |
|---|---|---|---|---|---|---|---|---|
|
| ||||||||
| Oxidative stress | Polystyrene (PS) and arsenic (As) | 12 h | 0.1 and 5 um | 20 ug/ml (0.1 um), 80 ug/ml (0.5 um) As:75 and 150 ug/l | DCFH-DA kit assay | Caco-2 cells | ROS increased after the co-exposure (PS + As), comparing to just arsenic exposure | Wu et al. (2019) |
| Polystyrene (PS) | 12 h | 0.1 and 5 um | 1–200 ug/ml | DCFH-DA kit assay | Caco-2 cells | ROS production only increased after 200 ug/ml exposure to 0.1 um and 5 um PS. | Wu et al. (2019) | |
| 24 h | 1.72 ± 0.26 um | 10–1000 ug/cm2 | Western blot (HO-1) DCFH-DA kit assay | BEAS-2B cells | HO-1 protein level significantly increased after 10 and 1000 ug/cm2 DCFH-DA increased at 1000 ug/cm2 | Dong et al. (2020) | ||
| 10 um | 0.05–10 mg/L | DHE solution | T98G and HeLa cells | ROS increased in both cell lines. EC50 9.6 mg/L in T98G and EC50 13.56 mg/L in HeLa cells | Schirinz et al. (2017) | |||
| 24 h, 48 h | 5 um | 12.5–50 mg/L | SOD, GSH, MDA detection and CAT activity | Caco-2 cells | No effect on SOD, GSH and MDA levels. Activity of catalase was inhibited only after 24 and 48 h exposure to 50 mg/L of 5 um PS | Wu et al (2020). | ||
| Polyethylene (PE) | 24 h | 3–16 um | 0.05–10 mg/L | DHE solution | T98G and HeLa cells | ROS increased only in T98G cells. EC50 41.22 mg/L | Schirinzi et al. (2017) | |
| Polypropylene (PP) | 6 h | 20 and 25–200 um | 50–1,000 ug/ml in powder and DMSO | DCFH-DA kit assay | HDF cells | ROS increased after exposure to 20 um PP (in DMSO) at 1000 ug/mL. When administered in powder, ROS did not increase | Hwan et al. (2019) | |
| Membrane integrity | Polystyrene (PS) | 12 h | 0.1 and 5 um | 1–80 ug/mL | JC1 assay, LDH assay and TMA-DPH | Caco-2 cells | Mitochondrial membrane depolarization occurred after 20 to 80 ug/mL for 0.1 um PS and after all the concentrations of 5 um. No effects on LDH leakage or polarization | Wu et al. (2019) |
| 24 h | 1.72 ± 0.26 um | 10–1000 ug/cm2 | TEER, ELISA (ZO-1 and AAT) and Western blot (ZO-1) | BEAS-2B cells | TEER value decreased in the epithelial barrier after 10 and 1,000 ug/cm2 exposure. ZO-1 levels decreased after exposure to 10 and 1000 ug/cm2. AAT level decreased after exposure to 1,000 ug/cm2 | Dong et al. (2020) | ||
| COOH-modified polystyrene (PS) | 24 h | 5 um | 10–100 μg/ml | TEER | GIT barrier and placental barrier coculture model | No effect in GIT or placental barrier were observed | Hesler et al. (2019) | |
| Immune response | Polystyrene (PS) | 24 h | 1.72 ± 0.26 um | 10–1000 ug/cm2 | ELISA (IL-6, IL-8) | BEAS-2B cells | IL-6 significantly increased at 10 and 1000 ug/cm2 exposure. 1000 ug/cm2 exposure increased IL-8 expression | Dong et al. (2020) |
| 24 h, 48 h | 5 um | 12.5–50 mg/L | RT-PCR | Caco-2 cells | Four inflammation related genes (TRPV1, iNOS, IL-1β, IL-8) were up-regulated | Wu et al. (2020) | ||
| 24 h, 72 h | 1, 4 and 10 um | 100,000/ml (1 um), 250,000/ml (4 um), 60,000/ml (10 um) | Macrophage polarization (Western Blot and RT-PCR) | THP-1 cells | No macrophage differentiation | Stock et al. (2019) | ||
| Polypropylene (PP) | 4 h, 72 h, 4 days | 20 and 25–200 um | 10–1,000 ug/ml | ELISA (IL-2, IL-6, IL-10, TNF-α) | PBMC | PBMC: IL-6 increased after 20 um PP at 1,000 and 100 ug/ml and TNF-α increased after 100 ug/mL after 20 um size exposure | Hwang et al.,(2019) | |
| 48 h | 20 and 25–200 um | 100 ug/ml and 500 ug/ml (20 um and 25–200 um) | Histamine by ELISA kit | HMC-1 cells | Histamine was released after exposure to 500 ug/ml 20 um PP in HMC-1 cells | Hwang et al.,(2019) | ||
Abbreviations: PS, Polystyrene; PE, Polyethylene; PP, Polypropylene.