Morphological and biochemical evaluation of RAW 264.7 cells exposed to polychlorinated biphenyl

The effects of PCBs exposure, at low doses ranging between 10-100 mg PCB (Arclor-1254), on the viability of RAW 264.7 macrophage cells after 24, 48, and 72 hours of incubation was investigated. Furthermore, this study was designed to determine the interrelationship between PCBs and estrogen (E, 10 mg) and its role in the viability of RAW cells. Macrophages were cultured and plated in 24 well-plates according to standard protocols. The wells were divided into eight groups (n = 4 wells/group, 1 x 10(4) cells/well). The cells in groups 1-3 were treated with vehicle (serum-control for estrogen, DMSO-control for PCB, and media alone, respectively). Cells in groups 4 and 5 were treated with low (10 mg) and high (100 mg) doses of PCB. Cells in group 6 were treated with E, and cells in groups 7 and 8 were treated with low dose PCB + E and high dose PCB + E, respectively. Cell viability and damage (Malianodialdehyde, MDA level) were determined after 24, 48, and 72 hours, as well as, cell morphology. The results of this study showed that low and high doses of PCB depressed cell number by 52%. Estrogen treatment caused no effect on cell number in comparison to cells treated with serum alone. Cell number in response to E and low and high doses of PCB decreased cell number by 50%. Similar results were also observed at 48 hour time phase. In contrast, at the 72 hour phase, no significant changes were observed for cell count. Morphological evaluation of the cells revealed healthy spindle shaped multinucleated cells in the control group but, groups exposed to PCB induced morphological changes that included: cells became small, round, and increased evidence of cellular injury and debris. Estrogen treatment did not show changes from the control group. However E and PCB treatments caused the cells to become round, tightly compact nuclei with evidence of cell fragmentation. The results of this investigation showed that exposure to either 10 or 100 mg of PCB had detrimental effects on the RAW 264.7 macrophage cells as early as 24 hours. Combination treatment with E didn't provide any protective measures to the viability of RAW cells exposed to PCBs.