Melatonin Restricts Periodontitis Related Neurodegeneration in Rats

This experimental rat study aims to investigate the preventive role of melatonin in potential neurodegenerative changes associated with periodontitis in the hippocampus and cerebral cortex.

Twenty-four Sprague Dawley rats were divided into three groups: Control (n = 8), Ep (n = 8), Ep + Mel (n = 8). Systemic melatonin (10 mg/kg/day) was administered to the Ep + Mel group for 35 days of periodontitis induction, starting from the application of bilateral lower first molar ligation. Following sacrification of all groups, periodontal bone loss was analyzed in Micro-CT sections (sagittal and coronal). Cerebral cortex and hippocampus tissues and serum samples were analyzed histopathologically, immunohistochemically, and biochemically.

Micro-CT results showed that the experimental periodontitis model was successful. When Ep + Mel and Ep were compared, a significant difference was observed in terms of histopathological damage, Caspase-3, GFAP, and Iba-1 immunopositivity (p < 0.05). Systemic melatonin administration was found to significantly reduce tissue and serum levels of IL-1β, IL-1β/IL-10, and Aβ1-42 (p < 0.05). Additionally, serum TNF-α and tissue TOS and OSI levels were significantly reduced in the melatonin group (p < 0.05). Tissue TAS and serum IL-10 showed no significant change (p > 0.05).

This study demonstrated that systemic melatonin may limit periodontal tissue destruction and periodontitis-associated neuroinflammatory, neurooxidative, and neuroapoptotic changes in the cerebral cortex and hippocampus.