Oxidative Modification of Biomolecules in the Nonstimulated and Stimulated Saliva of Patients with Morbid Obesity Treated with Bariatric Surgery

Abstract

Morbid obesity leads to progressive failure of many human organs and systems; however, the role of oxidative damage to salivary composition is still unknown in the obese patients. In this study, we assessed the effect of bariatric surgery on oxidative damage in nonstimulated (NS) and stimulated (S) whole saliva. The study included 47 subjects with morbid obesity as well as 47 age- and gender-matched healthy volunteers. Oxidative modifications to lipids (4-hydroxynonenal (4-HNE) and 8-isoprostanes (8-isoP)), proteins (advanced oxidation protein products (AOPP) and protein carbonyl groups (PC)), and DNA (8-hydroxy-D-guanosine (8-OHdG)) were analyzed in morbidly obese patients before and after bariatric surgery as well as in the healthy controls. The concentrations of 8-isoP, AOPP, PC, and 8-OHdG were significantly higher in both NS and S of patients with morbid obesity than in the control patients and compared to the results obtained 6 months after bariatric surgery. The levels of oxidative damage markers were also higher in S versus NS of morbidly obese patients. In summary, morbid obesity is associated with oxidative damage to salivary proteins, lipids, and DNA, while bariatric treatment generally lowers the levels of salivary oxidative damage.

A Longitudinal Study of the Antioxidant Barrier and Oxidative Stress in Morbidly Obese Patients after Bariatric Surgery. Does the Metabolic Syndrome Affect the Redox Homeostasis of Obese People?

“…However, knowledge of lipid oxidation in the course of bariatric treatment is still limited. In our previous study [7] we evaluated lipid oxidation products in the nonstimulated and stimulated saliva of patients with morbid obesity treated with bariatric surgery. We [7] found a significantly higher concentration of 8-isoP and 4-HNE in nonstimulated and stimulated saliva of obese cases before, as well as six months after the surgery.…”

“…In our previous study [7] we evaluated lipid oxidation products in the nonstimulated and stimulated saliva of patients with morbid obesity treated with bariatric surgery. We [7] found a significantly higher concentration of 8-isoP and 4-HNE in nonstimulated and stimulated saliva of obese cases before, as well as six months after the surgery. In this study, the 8-isop concentration was significantly greater in both obese groups before bariatric surgery as well as in every time period after the treatment (as compared to the control).…”

“…It is well known that the development of obesity is caused by adipokine secretion like leptin, adipokine or resistin as well as an increased expression of fatty acid/cholesterol transporters in the target tissues [3][4][5]. Nevertheless, recent studies emphasize the critical role of oxidative stress (OS) in the development of obesity and its metabolic complications [6,7]. OS occurs when cellular components (e.g., lipids and proteins) are oxidized and cellular metabolism is disturbed.…”

“…Antioxidants not only inhibit ROS-induced oxidation but also repair some forms of oxidative modification in biomolecules. The most important blood antioxidants include superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione (GSH) and uric acid (UA) [7,8,11]. It is suggested that antioxidant supplementation could reduce metabolic disorders and improve the condition of obese patients.…”

“…However, the exact reason for these changes is still unknown. It is postulated that the improvement of obese patients is associated with the reduction of oxidative stress levels [7,8,11]; however, there is no longitudinal data about the redox homeostasis of patients undergoing bariatric treatment. Therefore, the aim of our study was to evaluate the impact of morbid obesity as well as huge weight loss on the blood antioxidant systems/oxidative stress before as well as one, three, six and twelve months after bariatric surgery.…”