Antiinflammatory effect of atorvastatin on ligature-induced periodontitis in rats

Periodontitis is a disease characterized by leukocyte influx, loss of connective tissue and bone resorption. Statins are drugs widely used to hyperlidemia treatment, in which stand out Atorvastatin (ATV) due to its important pleiotropic effects, such as antiinflammatory activity and anabolic bone capacity, with great potential to modify chronic inflammatory disease course. In this way the aim of this work was to evaluate the aniinflammatory effect of ATV, through ligature-induced periodontitis model in rats. Wistar male, located in experimental groups: control (0.9% Saline), and 5 subgroups (ATV 0.3, 1, 3, 9 or 27 mg/kg), given orally daily, 30 min before nylon thread 3.0 aroud cervix of second left upper molars during 11 d, when then, rats were sacrified, and the following parameters were analyzed: 1) alveolar bone loss (ABL), evaluated through morphometric, histologic and radiographic studies; 2) Sistemic evaluation through a) leucograms performed before and after ligature (6h and 2, 7, and 11 d); b) corporal mass variation; c) of liver and kidney analysis, by serum biochemical dosage and histological study; and d) serum evaluation of Bone-Specific Alkaline Phosphatase (BALP). Animals submitted to 11 d periodontitis presented intense bone resoption. Low dose of ATV (0.3 mg/kg) was not able to prevent ABL (p>0.05), meanwhile the other dose ATV (1, 3, 9 or 27 mg/kg) were , in a significant way able to reduce ABL by 35%, 39%, 53%, 56%, respectively. Such inhibition was corroborated by histological analysis where was observed that ATV (27 mg/kg) caused greater periodontal tissue preservation [Mean 1.5 (0-2)], when compared to Saline [Mean 3 (2-3)] . In addition, animals submitted to periodontitis presented a significant reduction on periodontal radiographic density (58%). ATV (1, 3 ou 9 mg/kg) preserved such density in 5%, 9% e 20%, respectively. The leucogram of animals submitted to periodontitis presented leukocytosis peak on the 6th h mediated by neutrophils and new leukocytosis after 7th d due mononuclear cells. ATV (27 mg/kg) was able to reduce leukocytosis, decreasing neutrophils or mononuclear cells respectivelly (p0.05). It was observed a raise on serum BALP dosage variation of animals with 11 d periodontitis (Saline: 63.4±10.8 U/l), while ATV (27 mg/kg) prevented that increase (13.6±3.5 U/l) (p0,05), contudo, todas as demais (ATV 1, 3, 9 ou 27 mg/kg) foram, de forma significante, capazes de reduzir a POA em 35%, 39%, 53%, 56%, respectivamente. Tal inibição foi corroborada pela análise histopatológica, onde se observou que a ATV (27 mg/kg) causou maior preservação do tecido periodontal [Mediana: 1,5 (0-2)], quando comparada à Salina [Mediana: 3 (2-3)]. Adicionalmente, animais submetidos a 11 d de periodontite apresentaram redução significante de densidade radiográfica periodontal (58%). ATV (1, 3 ou 9 mg/kg) preservou tal densidade em 5%, 9% e 20%, respectivamente. O leucograma dos animais com periodontite apresentou pico de leucocitose na 6ª h, mediado por neutrófilos, e nova leucocitose a partir do 7º d, à custa de mononucleares. ATV (27 mg/kg) foi capaz de reduzir a leucocitose, reduzindo o número de neutrófilos ou mononucleares, respectivamente (p0,05). Observou-se aumento nas variações de dosagens séricas de FAO dos animais com 11 d de periodontite (Salina: 63,4±10,8 U/l), enquanto que ATV (27 mg/kg) previniu tal aumento (13,6±3,5 U/l) (p