The assessment of inflammatory activity and toxicity of treated sewage using RAW264.7 cells

Toxicity and inflammatory activity of wastewater samples were evaluated using RAW264.7 cells as a bioassay model. The RAW264.7 cell cultures were exposed to sterile filtered wastewater samples collected from a sewage treatment plant. Cell viability was evaluated using WST-1 and XTT assays. Inflammatory effects of samples were assessed by determination of nitric oxide (NO) and interleukin 6 (IL-6). The NO was estimated using the Griess reaction and IL-6 was measured by enzyme-linked immunoassay. All samples had no toxicity effects to RAW264.7 cells, however they significantly (P < 0.001) induced NO and IL-6 production. The highest NO (12.5 ± 0.38 μM) and IL-6 (25383.84 ± 2327 pg/mL) production was induced by postbiofiltration sample. Final effluent induced the lowest inflammatory response, which indicates effective sewage treatment. In conclusion, wastewater samples can induce inflammatory activities in RAW264.7 cells. The RAW264.7 cells, therefore, can be used as a model for monitoring the quality of treated sewage.