Fluorescence Properties of Paracetamol During Interactions with Mitochondria

Paracetamol interaction with rat liver mitochondria in respiration media in the presence of succinate was the focus of this experiment. Fluorescence of paracetamol in water was studied by three-dimensional synchronous fluorescence fingerprint (SFF) and by excitation emission matrix (EEM). The direct molecular interactions of paracetamol and mitochondria were studied by fluorescence polarization technique. The paracetamol fluorescence maximum of SFF was Δλ = 110/λ_ex = 320 nm, F_max = 508 nm, and EEM maximum was λ_ex = (320 nm)/λ_em = 425 nm, F_max = 508. The fluorescence polarization results showed nonsignificant elevation of fluorescence polarization after addition of paracetamol into mitochondria in comparison to the control mitochondria group without paracetamol at time point t = 0. Paracetamol probably covalently bound to the mitochondrial surface proteins at time point t = 0, but paracetamol also entered mitochondria, which was observed as nonsignificant decline of fluorescence polarization during 30 min in the paracetamol-treated group. The practical advantages of spectral techniques (EEM, SFF, fluorescence polarization) are high sensitivity, reproducibility, minimal quantity of material, and capability to measure the mitochondrial autofluorescence.