Background and objective: Paraquat is one of the
most widely used global herbicides for weed control.
Recently, paraquat has been reported to have immune
toxic effects in animal models, while effects on human
T cell function remain undetermined. To resolve these
issues, the effects of paraquat on IFN-γ production
by human T cells in vitro were evaluated.
Methods: Peripheral blood mononuclear cells were
co-cultured with various concentrations of paraquat
dichloride or phytohemagglutinin (PHA). Cell viability
was determined by trypan blue exclusion and relative
metabolic activity was assayed by MTT method. IFN-γ
production was measured after co-culture with
phytohemagglutinin by ELISA.
Results: Paraquat at 100 μg/mL did not affect cell
viability, whereas 300 μg/mL paraquat significantly
reduced the percentage of viable cells compared with
the control (p< 0.05). Addition of 100 and 300 μg/mL
of paraquat significantly increased the percentage of
IFN-γ production inhibition compared with the
control (p< 0.05). Moreover, inhibition of IFN-γ
production by paraquat was observed after 24 h
co-culture and showed a robust effect in all
individuals after 48 h co-culture.Conclusion: Data indicated that paraquat at the concentration
of 100 and 300 μg/mL had an inhibitory
effect on IFN-γ production by T cells. Thus, direct
contact with paraquat or paraquat contaminated
environments and agricultural products increased risk
of diseases caused by T cell dysfunction