Enhanced Chemiluminescent Assay for Measuring the Total Antioxidant Capacity of Serum, Saliva and Crevicular Fluid

Abstract

SUMMARY. This paper reports the development of an enhanced chemiluminescent (ECL) assay for measuring the total antioxidant (AO) capacity of serum, saliva and a fluid collectable from the gum margin called gingival crevicular fluid (GCF). The theory behind the assay is explained, and the optimum conditions for the assay, and for storage of reagents and clinical samples is described. Calibration lines were linear (R~0'99; P<O·OOOI) and the within batch coefficient of variations for a water soluble vitamin E analogue (Trolox), serum and saliva samples were < 5%. In saliva and GCF, a characteristic AO response not seen in serum of the same patients, was identified. Total peripheral (serum) and local (saliva) AO capacities (jlmol/L Trolox) were investigated in patients with (n = 18) and without (n = 16) adult periodontitis. Serum AO status did not differ between groups. Salivary total AO concentrations were lower in the periodontitis (P) group [175 (53) /-lmol/L] than in the nonperiodontitis (NP) group [254 (11O)/-lmol/U: P<O'OIJ, as were saliva:serum AO ratio's [0'37 (0·11) versus 0·5 (0'18): P<O·Olj. Periodontitis patients may have a reduced salivary AO concentration, which could result from, or predispose to, the damaging effects of reactive oxygen species (ROS). The potential for ROS production in the oral and periodontal environment may explain the presence of a specific antioxidant in oral fluids that is not detectable in serum. The ECL assay described provides a rapid, simple and reproducible method of measuring total antioxidant defence in small volumes of biological fluids.

Salivary Markers of Oxidative Stress and Antioxidant Status: Influence of External Factors

“…The study demonstrated decreased oxidative damage in gingiva and potential contribution to reduced circulating oxidative stress [10]. Higher antioxidant values may also be caused by expulsion of gingival crevicular fluid following tooth-brushing and artificially increased antioxidant concentration in saliva [21]. Hoek et al has reported increased albumin levels even more than 45 minutes after toothbrushing [19].…”

Total Antioxidant Capacity (TAC) Values and Their Correlation with Individual Antioxidants in Healthy Beagles

“…These include ascorbic acid, α-tocopherol, β-carotene, uric acid, bilirubin, and albumin. In addition, trace amounts of antioxidant enzymes such as glutathione peroxidase and superoxide dismutase are found in serum to a lesser extent (Cao et al 1993;Chapple 1997;Chapple et al 1997). In diabetes, markers of oxidative stress have been shown to be elevated whereas vitamin C levels are reduced.…”

Salivary antioxidants and periodontal disease status

“…Advanced periodontitis is distinguished by excessive tissue loss of the gingiva and alveolar bone and pockets greater than 5·5 mm in depth. This condition often leads to tooth exfoliation due to the destruction of the tooth connective ligaments (Chapple et al 1997). …”

“…These bacteria, known as periodontal pathogens, are Actinobacillus actinomycetemcomitans, Bacteroides forsythus and Porphyromonas gingivalis (Jenkinson & Dymock, 1999). Of these, P. gingivalis shows extensive proliferation in diseased individuals (Haffajee & Socransky, 1994;Chapple et al 1997;Lamont & Jenkinson, 1998).…”