Comparison of the effect of phenol and its derivatives on protein and free radical formation in human erythrocytes (in vitro)

The effect of phenolic compounds: phenol, 2,4–dichlorophenol (2,4-DCP), 2,4-dimethylphenol (2,4-DMP) and catechol on human erythrocytes was studied. The level of fluorescent label – 6-carboxy-2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA) oxidation by phenolic compounds in erythrocytes as well as the carbonyl group content and hemoglobin denaturation were monitored. H2DCFDA has been utilized extensively as a marker for studies of oxidative stress at the cellular level. We noted that 2,4-DCP, 2,4-DMP and catechol induced an increase in the concentration- and time-dependent H2DCFDA oxidation. We also observed an increase in carbonyl group content and the changes in parameter T (denaturation of hemoglobin) in erythrocytes incubated with 2,4-DCP, catechol and 2,4-DMP. The highest level of H2DCFDA oxidation was provoked by 2,4-DCP. The biggest changes of proteins in erythrocytes measured as the carbonyl group content were induced by 2,4-DMP, but measured as parameter T they were induced by catechol. It was observed that phenol did not oxidize H2DCFDA up to the concentration of 2.5 mM after 3 h of incubation. Phenol did not affect the carbonyl group content but decreased parameter T (induced denaturation of hemoglobin). To sum up, the kind of the substituent in a phenolic ring determines the molecular mechanism of action of the individual compound and the capacity of reactive oxygen species generation and thus damages the specified structures in human erythrocytes.