Ameliorative Effects of Omega-3 Fatty Acids on Alveolar Bone Resorption

Objectives: Omega-3 fatty acids have been recognized as anti-inflammatory effect in a variety of inflammatory diseases, including atherosclerosis, diabetes, asthma and arthritis. Periodontitis is a chronic inflammatory disease characterized by loss of alveolar bone and destruction of connective tissues. The objective of this study was to investigate the characteristics of omega-3 fatty acids as a preventive dietary supplement for periodontitis.
Methods: Four-week old C57BL/6J mice were fed on omega-3 diet, omega-6 diet or regular diet for 57 days. After 14 days, mice on each diet were inoculated orally with P. gingivalis ATCC 33277 (1.0 × 10⁹ CFU) or carboxymethylcellulose three times at 48-h intervals. The mice were sacrificed and horizontal bone loss around the maxillary molars was assessed morphometrically. The distance from the cemento-enamel junction to the alveolar bone crest was measured at seven buccal sites per mouse. Bone marrow cells (BM) on each diet were cultured in the presence of macrophage colony stimulating factor (M-CSF) and RANKL for 4 days to examine osteoclast differentiation. To investigate the effect of resolvin E1 (RvE1), eicosapentaenoic acid metabolic product, mouse BM were cultured to differentiate into osteoclasts in the presence of RvE1 at the concentration of 0 ng/ml, 0.01 ng/ml, 0.1 ng/ml, 1 ng/ml.
Results: Mice fed omega-3 diet and inoculated with P. gingivalis exhibited significantly less alveolar bone loss, compared to those on the other diets with P. gingivalis-infection groups. P. gingivalis infection had no effect on differentiation of mouse BM into osteoclasts. Supplementation of omega-3 fatty acids significantly reduced the number of multinucleated osteoclasts in BM culture. Furthermore, RvE1 inhibited differentiation of BM into the mature osteoclast in a dose-dependent manner.
Conclusions: These results suggest that omega-3 fatty acids have ameliorative effects on periodontal tissue breakdown.