Effect of venlafaxine on bone loss associated with ligature-induced periodontitis in Wistar rats

Wistar rats were subjected to a ligature placement around the second upper left molar. The treated groups received orally venlafaxine (10 or 50 mg/kg) one hour before the experimental periodontal disease induction and daily for 10 days. Vehicle-treated experimental periodontal disease and a sham-operated (SO) controls were included. Bone loss was analyzed morphometrically and histopathological analysis was based on cell influx, alveolar bone, and cementum integrity. Lipid peroxidation quantification and immunohistochemistry to TNF-α and iNOS were performed.Experimental periodontal disease rats showed an intense bone loss compared to SO ones (SO = 1.61 ± 1.36; EPD = 4.47 ± 1.98 mm, p < 0.001) and evidenced increased cellular infiltration and immunoreactivity for TNF-α and iNOS. Venlafaxine treatment while at low dose (10 mg/kg) afforded no significant protection against bone loss (3.25 ± 1.26 mm), a high dose (50 mg/kg) caused significantly enhanced bone loss (6.81 ± 3.31 mm, p < 0.05). Venlafaxine effectively decreased the lipid peroxidation but showed no significant change in TNF-α or iNOS immunoreactivity.The increased bone loss associated with high dose venlafaxine may possibly be a result of synaptic inhibition of serotonin uptake.Although depression and periodontitis are common conditions in older adults, past studies could not establish that these two conditions are related [1]. However, recent studies evidence that stress and depression may affect the onset and progression of periodontal disease through behavioral and physiologic mechanisms [2,3]. Depression may dysregulate regulatory mechanisms within the brain involved in immune regulation, and thereby alter immune responses and influence the development and progression of infections and inflammatory diseases, including periodontitis [4,5]. In this context, using ligature-induced model of experimental periodontitis Breivik et al [6], have shown an enhanced susceptibility to periodontitis in the animal model