Histological and Physiological Study of the Effects of Exogenous Melatonin on Liver of Female Rats Exposed to Formalin in Drinking Water

Abstract

Aim: The presented study was established to evaluate the impact of formalin (FA) on the blood levels ofsuperoxide dismutase (SOD), lipid profile, total serum protein and serum albumin in female rats. Materialsand methods: The animals were assigned randomly into groups of six; control group, and treated other fivegroups as follow, first group exposed to formalin at 200ppm (F200 group), the second exposed to formalinat 400ppm (F400 group), third group exposed to formalin at 200ppm plus melatonin at 10mg/kg (F200Mgroup), fourth group exposed to formalin at 400ppm plus melatonin at 10mg/kg (F400M group), and thefifth exposed to melatonin at 10mg/kg (M group). Samples of blood from the rats were collected at day one,day and day 30 of the experimental period that was continued for 30 days. Results: Using immune-basedtechniques, the SOD activity, it has been here-resulted in significant (p?0.05) after-formalin-exposuredecreases in the blood samples of female rats from F200 and F400 groups, especially, when comparedwith the control group. The total cholesterol levels revealed significant (p?0.05) increases in the blood ofthe tested animals of the F200 and F400 groups. These increases affected the rates of LDL, VLDL, andtriglycerides in the blood of the studied rat-females of both F200 and F400 groups when compared withthe control animals. Interestingly, low levels of HDL were noticed in the blood of the animals of the F200and F400 when comparisons with control animals. The concentrations of the LDL, HDL, and triglyceridesin the serum of the formalin-exposed females showed significant (p?0.05) low levels when compared withcontrol animals. For day-30 collection, albumin concentrations revealed significant (p?0.05) elevation in theblood of the F200 and F400 animals.. Histological examination revealed that the liver of female rats exposedto 200ppm or 400 ppm of formalin for 30 days have been adversely affected. Whereas, the histologicalexamination of the liver of animals treated with melatonin and formalin were less affected due to formalinexposure. Conclusions: These results demonstrate the formalin high toxic effects on the hepatic tissues canbe overcome by the use of exogenous melatonin.