Multi-organ injuries caused by lipopolysaccharide-induced periodontal inflammation in rats: role of melatonin.

ABSTRACT

BACKGROUND AND OBJECTIVE: Periodontitis, a chronic inflammatory disease caused by oral bacterial infection, is considered to be a risk factor for systemic diseases including diabetes mellitus, bacterial pneumonia, hyperlipidemia and atherosclerosis. The aim of this study was to evaluate the effectiveness of melatonin against periodontal inflammation-induced multiple organ injury in rats. MATERIAL AND METHODS: Eighteen female Wistar albino rats were randomly divided into three groups of six rats each control; lipopolysaccharide (LPS); and LPS + melatonin. During the experimental period (10 d) all rats in the LPS and LPS + melatonin groups were given 10 µL of LPS (from a 10 mg/mL standard solution of LPS dissolved in saline) on days 1, 3 and 5. The rats in the LPS + melatonin group were given 50 mg/kg of melatonin, daily for 10 d, starting on day 1 after the administration of LPS. All rats were killed at the end of the experimental period. Liver, kidney and lung tissues were removed for investigation by light microscopy. RESULTS: The levels of serum aspartate aminotransferase (AST), alanine transaminase (ALT) and blood urea nitrogen (BUN) were significantly increased in the LPS group compared with the LPS + melatonin group (p < 0.05). There was no significant change in the serum creatinine levels in the groups. However, the changes in serum AST, ALT and BUN levels in the experimental groups did not correlate with changes in histological data. Both LPS and LPS + melatonin groups displayed structural features similar to those of the control group. CONCLUSION: The results revealed that increased serum AST, ALT and BUN levels following periodontitis are ameliorated with melatonin treatment.