Fig 1.
Effect of the DDS-NHOH on methemoglobin formation in human erythrocytes.
Erythrocytes were incubated with different concentrations of DDS-NHOH (2.5; 5.0 and 7.5 μg/mL) for 1 h at 37°C. Data are reported as means ± S.E.M from three independent experiments done in triplicate. *P < 0.05 compared to methanol group.
Fig 2.
Effect of the pretreatment with different concentration of resveratrol (RSV) on methemoglobin formation induced by DDS-NHOH.
Erythrocytes were pretreated with different concentrations of RSV(10, 100, 200 and 1000 μM) for 1 h at 37°C, then these cells were incubated with different concentrations of DDS-NHOH (2.5; 5.0 and 7.5 μg/mL) for 1 h at 37°C. Data are reported as means ± S.E.M from three independent experiments done in triplicate. #P < 0.05 compared to DDS-NHOH group.
Fig 3.
Comparative effect of the pretreatment with resveratrol (RSV) or methylene blue (MET) on methemoglobin formation induced by DDS-NHOH.
Erythrocytes were pre-incubated with RSV (100 μM) for 1 h or MET (40 nM) for 30 min, after these cells were incubated for 1 h with different concentrations of DDS-NHOH (2.5, 5.0 and 7,5 μg/mL). Data are reported as mean ± S.E.M. #P < 0.05 compared to DDS-NHOH group.**P < 0.05 compared to resveratrol group.
Fig 4.
Comparative effect of post-treatment with resveratrol (RSV) or methylene blue (MET) on methemoglobin formation induced by DDS-NHOH.
Erythrocytes were incubated for 1 h with DDS-NHOH (2.5 μg/mL), then these cells were incubated with RSV (100μM) for 1 h or MET(40 nM). Data are reported as mean ± S.E.M. *P < 0.05 compared to methanol group. #P < 0.05 compared to DDS-NHOH group.
Fig 5.
Effect of treatment with resveratrol on DNA damage induced by DDS-NHOH.
Tail Length (μm—A), DNA in tail (%—B) Tail Moment (TM—C) and Olive Moment (OM—D) were used as a marker of DNA damage in lymphocyte using Comet assay. As positive control was used H2O2 (200 μM). All values are depicted as mean ± S.E.M.
Fig 6.
Reactive oxygen species (ROS) generation.
Erythrocytes were pretreated with resveratrol (RSV, 100 μM and 1000 μM) for 1 h at 37°C and incubated for 30 min with DDS-NHOH (2.5 μg/ml and 7.5 μg/ml). As positive control was used T-BHP (200 μM). ROS production was measured as dichlorofluorescein (DCF) fluorescence. Values are means ± S.E.M. *P < 0.05 compared to methanol group. #P < 0.05 compared to DDS-NHOH group.
Fig 7.
Erythrocytes were pretreated with resveratrol (RSV, 100 μM and 1000 μM) for 1 h at 37°C and incubated for 30 min with DDS-NHOH (2.5 μg/ml) or T-BHP (200 μM). Results are expressed as mean ± S.E.M. *P < 0.05 compared to methanol group.
Fig 8.
Structure for HOMO of the dapsone hydroxylamine (DDS-NHOH), resveratrol (RSV), and methylene blue (MET). All nodal patterns related to individual group contributions are presented by blue or yellow for negative or positive wave function, respectively.
Table 1.
Theoretical parameters for redox mechanism.
HOMO, LUMO, GAP, Ionization potential (IP) and stabilization energy (ΔEiso) of DDS hydroxylamine (DDS-NHOH), resveratrol (RSV), and methylene blue (MET). All values are given in eV.
Fig 9.
Ionization potential and stabilization energy of dapsone hydroxylamine (DDS-NHOH), resveratrol (RSV), and methylene blue (MET) on antioxidant and methemoglobinemia reversion.
Fig 10.
Proposal for a possible action mechanism of resveratrol (RSV) in inhibiting methemoglobin formation and DNA damage induced by DDS hydroxylamine (DDS-NHOH) in vitro model.