The objective of this study was to investigate glutathione peroxidase, lactoferrin and myeloperoxidase, which play an essential role in free radical production and defenses, and the proinflammatory cytokine interleukin-1 (IL-1), which is important in the regulation of immunological and inflammatory reactions in human periodontal diseases.

The periodontal diseases are inflammatory disorders that result from complex interactions between periodontal pathogens and the host's immune response. Two important and interrelated factors are involved in the progression of periodontal diseases, i.e. the activation of immune system and the production of oxygen radicals and their related metabolites. Increased production of oxygen radicals may contribute to oxidative stress, which is reported to be involved in many diseases, including periodontal diseases.

The researchers found that periodontitis sites exhibited significantly greater total amount of glutathione peroxidase, lactoferrin, myeloperoxidase and IL-1 than healthy sites. Total amount of glutathione peroxidase, lactoferrin, myeloperoxidase and IL-1 was positively correlated with plaque index, gingival index, probing depth and probing attachment level (p<0.05).

The researchers concluded that if an imbalance between the levels of myeloperoxidase/IL-1 and glutathione peroxidase/lactoferrin occurs this could result in tissue damage by reactive oxygen species (ROS) in periodontitis. On thei basis therefore it could be suggested that ensuring adequate gluathione peroxidase activity in patients suffering from periodontitis, may provide adjunctive therapy.