Effect of fixed orthodontic appliances on nonmicrobial salivary parameters.

Objectives:: To examine possible changes in the levels of salivary antioxidants, C-reactive protein (CRP), cortisol, pH, proteins, and blood in patients treated with fixed orthodontic appliances.

Materials And Methods:: Salivary samples from 21 orthodontic patients who met specific inclusion criteria were collected before the beginning of orthodontic treatment (T0; baseline), 1 hour after bonding (T1), and 4-6 weeks after bonding (T2). Oxidant-scavenging ability (OSA) was quantified using a luminol-dependent chemiluminescence assay.

Coffee polyphenols protect human plasma from postprandial carbonyl modifications.

The antioxidant capability of coffee polyphenols to inhibit red-meat lipid peroxidation in stomach medium and absorption into blood of malondialdehyde (MDA) in humans was studied. Roasted-ground coffee polyphenols that were found to inhibit lipid peroxidation in stomach medium are 2- to 5-fold more efficient antioxidant than those found in instant coffee. Human plasma from ten volunteers analyzed after a meal of red-meat cutlets (250 g) revealed a rapid accumulation of MDA.

Protection by polyphenols of postprandial human plasma and low-density lipoprotein modification: the stomach as a bioreactor.

Recent studies dramatically showed that the removal of circulating modified low-density lipoprotein (LDL) results in complete prevention of atherosclerosis. The gastrointestinal tract is constantly exposed to food, some of it containing oxidized compounds. Lipid oxidation in the stomach was demonstrated by ingesting heated red meat in rats.

The stomach as a "bioreactor": when red meat meets red wine.

To determine the stomach bioreactor capability for food oxidation or antioxidation, rats were fed red turkey meat cutlets (meal A) or red turkey meat cutlets and red wine concentrate (meal B). The hydroperoxides (LOOH) and malondialdehyde (MDA) levels of the stomach contents were evaluated during and after digestion; the postprandial plasma MDA level was also evaluated. In independently fed rats, the stomach LOOH concentration fell substantially 90 min following the meal, and the addition of red wine polyphenols enhanced LOOH reduction 3-fold.

A novel function of red wine polyphenols in humans: prevention of absorption of cytotoxic lipid peroxidation products.

Current evidence supports a contribution of polyphenols to the prevention of cardiovascular disease, but their mechanisms of action are not understood. We investigated the impact of red wine polyphenols on postprandial cytotoxic lipid peroxidation products (MDA) levels in humans. In a randomized, crossover study, the effect of red wine polyphenols on postprandial levels of plasma and urine MDA was investigated.

Lipid peroxidation and coupled vitamin oxidation in simulated and human gastric fluid inhibited by dietary polyphenols: health implications.

The Western diet contains large quantities of oxidized lipids, because a large proportion of the food in the diet is consumed in a fried, heated, processed, or stored form. We investigated the reaction that could occur in the acidic pH of the stomach and accelerate the generation of lipid hydroperoxides and cooxidation of dietary vitamins. To estimate the oxygen content in the stomach after food consumption, oxygen released from masticated bread (20 g) into deoxygenated water (100 mL) was measured.