Salivary arginase in patients with adult periodontitis

Human saliva has been shown to possess enzymatic activities, one of which is derived from arginase. Arginase is known to be an arginine-depleting enzyme belonging to the L-arginine/nitric oxide pathway. The aim of this study was to examine the possible role of arginase activity of saliva in the pathogenesis of periodontal disease. Mixed saliva samples were collected from 20 adult periodontitis patients and 15 systemically and periodontally healthy subjects. Salivary arginase and total protein contents were determined by using spectrophotometrical enzyme analysis and salivary arginase was expressed as specific activity. Periodontal disease status was determined by clinical periodontal assessments including probing pocket depth, clinical attachment level, plaque index and gingival index. While the increase in total protein was not statistically significant, arginase levels in the patient group were significantly higher than the controls. All periodontal indices were found to be significantly higher in the periodontitis group, but no meaningful correlation was observed between the biochemical and periodontal variables in both groups. Furthermore, no significant correlation existed between the amount of arginase and total protein. In conclusion, it was suggested that salivary arginase activity in periodontitis along with the arginine-nitric oxide pathway may be involved in the disease process by using the common substrate L-arginine and inhibiting nitric oxide production.