Abstract
Background
Naphthalene (NA), a polycyclic aromatic hydrocarbon, is an environmental pollutant from different sources exhibiting toxicities via free radical generation. However, NA has been used in the industry as surfactants, solvents, resins, and in medicine – as an anti-viral, anti-bacterial, and antiinflammatory drug. Malondialdehyde (MDA), a by-product in lipid peroxidation and prostaglandin synthesis, is a biomarker in lipid peroxidation evaluation and cyclooxygenase (COX) and lipoxygenase (LOX) activities assessment via inhibition.
Results
The twenty-four adult male Wistar rats were randomly divided into six groups of four rats each. The animals in the control groups were given food and water only while the NA-exposed groups: group 3 (N1) rats exposed to NA at 0.75 mg/m3 for 2 hours, group 4 (N2) rats exposed to NA at 1.5 mg/m3 for 2 hours, group 5 (N3) rats exposed to NA at 0.75 mg/m3 for 4 hours and group 6 (N4) rats exposed to NA at 1.5 mg/m3 for 4 hours. In addition, in silico work was carried out on the homologs of COX and LOX with NA and its selected metabolites. The in vivo result revealed a significant increase (7.50 ± 0.29) in MDA synthesis at the lower dose (0.75 g/m3) during the 2 hrs exposure time compared to the control while the higher dose (1.50 g/m3) showed a significant reduction in MDA level (1.00 ± 0.01) compared to the control. Furthermore, docking result depicted highest binding score for 1-nitronaphthalene towards COX and LOX.
Conclusions
This study suggested that NA could reduce the synthesis of MDA in the in vivo work, and 1-nitronaphthalene showed the highest binding affinity in the in silico work.