Aim: 

Carbon tetrachloride (CCl₄) hepatotoxicity is related to an increase in free radical production and lipid peroxidation in hepatic cell membranes. Our aim was to investigate in vivo the effects of pinoline and melatonin in preserving hepatic cell membranes against oxidative damage due to CCl₄

Methods: 

Male Sprague-Dawley rats weighing 200-250 g were divided into six groups (n=8) as follows: Control, pinoline melatonin, CCl₄, CCl₄ + pinoline, and CCl₄ + melatonin. CCl₄ (5 mL/kg), pinoline (10 mg/kg) and melatonin (10 mg/kg) were administered intraperitoneally. Rats were treated with CCl₄ 3 hour before sacrifice. Pinoline and melatonin were injected 30 min before and 60 min after CCl₄ administration. Hepatic cell membranes were isolated by differential centrifugation and its fluidity was monitored by fluorescence spectroscopy using 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene-p-toluene-sulfonate.

Results: 

Without CCl₄ treatment, neither the pinoline or melatonin animals modified significantly membrane fluidity (control: 3.44 0.02; pinoline: 3.42 0.02; melatonin: 3.41 0.02). CCl₄ exposition caused a significant reduction in the membrane fluidity (CCl₄: 3.35 0.01) and was completely reversed by pinoline or melatonin treatments (CCl₄ + pinoline: 3.45 0.01; CCl₄ + melatonin: 3.40 0.01).

Conclusion: 

Pinoline and melatonin reduced the membrane rigidity due to CCl₄. Since both amines are widely-acting scavenger molecules able to detoxify several reactive oxygen species, their protective effects are likely due to their antioxidant properties.