1. Proteolytic enzymes as indicators of periodontal health in gingival crevicular fluid of patients with Sjögren's syndrome
T Tervahartiala, T Ingman, T Sorsa, Y Ding, P Kangaspunta, Y T Konttinen Eur J Oral Sci. 1995 Feb;103(1):11-6. doi: 10.1111/j.1600-0722.1995.tb00004.x.
The present study characterizes the periodontal status of patients with Sjögren's syndrome (SS) and measures collagenase, elastase and gelatinase in gingival crevicular fluid (GCF) from these patients compared with adult individuals with periodontitis and healthy controls. The periodontal status was assessed by the Gingival Bleeding Index (GBI), the Visible Plaque Index (VPI), and pocket depth. Activity measurements were performed for collagenase with SDS-PAGE/laser densitometry, for elastase spectrophotometrically using a synthetic N-succinyl-Ala-Ala-Val p-nitroanilide peptide substrate, and for gelatinase with zymography. Seven of the 8 patients with SS and xerostomia showed a periodontium comparable to that seen in healthy controls. The GCF collagenase and elastase were significantly lower in patients with SS and in healthy controls than in patients with adult periodontitis. It was noteworthy that the one SS patient with periodontitis had high GCF collagenase and elastase activity. In all study groups multiple forms of gelatinases were present, indicating that they represent constitutively expressed proteinases involved in normal tissue remodeling processes. Our findings suggest that periodontal pockets/GCF form a micromilieu not affected by involvement of glandular tissue and, therefore, patients with SS show, clinically and biochemically, a periodontal status comparable to that seen in healthy controls.
2. 7-Hydroxycoumarin modulates the oxidative metabolism, degranulation and microbial killing of human neutrophils
Luciana M Kabeya, et al. Chem Biol Interact. 2013 Oct 25;206(1):63-75. doi: 10.1016/j.cbi.2013.08.010. Epub 2013 Aug 28.
In the present study, we assessed whether 7-hydroxycoumarin (umbelliferone), 7-hydroxy-4-methylcoumarin, and their acetylated analogs modulate some of the effector functions of human neutrophils and display antioxidant activity. These compounds decreased the ability of neutrophils to generate superoxide anion, release primary granule enzymes, and kill Candida albicans. Cytotoxicity did not mediate their inhibitory effect, at least under the assessed conditions. These coumarins scavenged hypochlorous acid and protected ascorbic acid from electrochemical oxidation in cell-free systems. On the other hand, the four coumarins increased the luminol-enhanced chemiluminescence of human neutrophils stimulated with phorbol-12-myristate-13-acetate and serum-opsonized zymosan. Oxidation of the hydroxylated coumarins by the neutrophil myeloperoxidase produced highly reactive coumarin radical intermediates, which mediated the prooxidant effect observed in the luminol-enhanced chemiluminescence assay. These species also oxidized ascorbic acid and the spin traps α-(4-pyridyl-1-oxide)-N-tert-butylnitrone and 5-dimethyl-1-pyrroline-N-oxide. Therefore, 7-hydroxycoumarin and the derivatives investigated here were able to modulate the effector functions of human neutrophils and scavenge reactive oxidizing species; they also generated reactive coumarin derivatives in the presence of myeloperoxidase. Acetylation of the free hydroxyl group, but not addition of the 4-methyl group, suppressed the biological effects of 7-hydroxycoumarin. These findings help clarify how 7-hydroxycoumarin acts on neutrophils to produce relevant anti-inflammatory effects.
