The Effect of Selenium on Ischemia-Reperfusion Injury: An Experimental Study on a Transverse Rectus Abdominis Musculocutaneous Flap Model

Products of Selenite/Thiols Interaction Have Reducing Properties, Cleave Plasmid DNA and Decrease Rat Blood Pressure and Tension of Rat Mesenteric Artery

Selenium compounds exert their antioxidant activity mostly when the selenium atom is incorporated into selenoproteins. In our work, we tested the possibility that selenite itself interacts with thiols to form active species that have reducing properties. Therefore, we studied the reduction of 2-(4-carboxyphenyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazol-1-yloxy-3-oxide radical (•cPTIO), damage of plasmid DNA (pDNA), modulation of rat hemodynamic parameters and tension of isolated arteries induced by products of interaction of selenite with thiols. We found that the products of selenite interaction with thiols had significant reducing properties that could be attributed mainly to the selenide and that selenite had catalytic properties in the access of thiols. The potency of thiols to reduce •cPTIO in the interaction with selenite was cysteine > homocysteine > glutathione reduced > N-acetylcysteine. Thiol/selenite products cleaved pDNA, with superoxide dismutase enhancing these effects suggesting a positive involvement of superoxide anion in the process. The observed •cPTIO reduction and pDNA cleavage were significantly lower when selenomethionine was used instead of selenite. The products of glutathione/selenite interaction affected several hemodynamic parameters including rat blood pressure decrease. Notably, the products relaxed isolated mesenteric artery, which may explain the observed decrease in rat blood pressure. In conclusion, we found that the thiol/selenite interaction products exhibited significant reducing properties which can be used in further studies of the treatment of pathological conditions caused by oxidative stress. The results of decreased rat blood pressure and the tension of mesenteric artery may be perspective in studies focused on cardiovascular disease and their prevention.

The Phthalic Selenoanhydride Decreases Rat Blood Pressure and Tension of Isolated Mesenteric, Femoral and Renal Arteries

Phthalic selenoanhydride (R-Se) solved in physiological buffer releases various reactive selenium species including H₂Se. It is a potential compound for Se supplementation which exerts several biological effects, but its effect on the cardiovascular system is still unknown. Therefore, herein we aimed to study how R-Se affects rat hemodynamic parameters and vasoactive properties in isolated arteries. The right jugular vein of anesthetized Wistar male rats was cannulated for IV administration of R-Se. The arterial pulse waveform (APW) was detected by cannulation of the left carotid artery, enabling the evaluation of 35 parameters. R-Se (1-2 µmol kg^-1), but not phthalic anhydride or phthalic thioanhydride, transiently modulated most of the APW parameters including a decrease in systolic and diastolic blood pressure, heart rate, dP/dt_max relative level, or anacrotic/dicrotic notches, whereas systolic area, dP/dt_min delay, dP/dt_d delay, anacrotic notch relative level or its delay increased. R-Se (~10-100 µmol L^-1) significantly decreased the tension of precontracted mesenteric, femoral, and renal arteries, whereas it showed a moderate vasorelaxation effect on thoracic aorta isolated from normotensive Wistar rats. The results imply that R-Se acts on vascular smooth muscle cells, which might underlie the effects of R-Se on the rat hemodynamic parameters.

The metabolic effects of multi-trace elements on parenteral nutrition for critically ill pediatric patients: a randomized controlled trial and metabolomic research

BACKGROUND

We investigated the efficacy and metabolic dose-effect of multi-trace element injection I [MTEI-(I)] for severe pediatric patients via a parallel, randomized control study.

METHODS

The inclusion criteria were as follows: (I) patients who required parenteral nutrition (PN) due to various diseases, and were expected to receive PN for >5 days; (II) patients aged <18 years; (III) patients with no serious cardiac, hepatic, renal, or pulmonary dysfunction; and (IV) patients with an established central venous pathway. Enrolled patients were randomly assigned into two groups using sequentially numbered, sealed, opaque envelopes: Group A (low-dose group) received MTEI-(I) at 1 mL/kg/d, and Group B (high-dose group) received MTEI-(I) at 2 mL/kg/d, up to a maximum dose of 15 mL/d. The concentrations of manganese (Mn), copper (Cu), zinc (Zn), and selenium (Se) were detected. The following indexes were measured after 5 days of treatment (T5): β-oxidation of very-long-chain fatty acids, arginine and proline metabolism, pentose phosphate metabolism, ketone body metabolism, citric acid cycle, purine metabolism, caffeine metabolism, and pyruvate metabolism. The participants, care givers, and data analysis staff were blinded to the group assignment.

RESULTS

Overall, at T5, Mn and Cu levels were decreased, while Zn and Se levels were increased. The increase of Zn levels (A: 0.170±0.479 vs. B: 0.193±0.900) and decrease of Cu levels (A: -0.240±0.382 vs. B: -0.373±0.465) of patients in Group B (n=22) were significantly higher than those in Group A (n=18). At T5, the β-oxidation of very-long-chain fatty acids, arginine and proline metabolism, pentose phosphate metabolism, ketone body metabolism, citric acid cycle, purine metabolism, caffeine metabolism, and pyruvate metabolism were variably decreased (P<0.05) in Group B compared to Group A.

CONCLUSIONS

Our results suggested that the high-dose administration of MTEI-(I) is safe for severe pediatric patients, and may alleviate inflammation and antioxidation, relieve hyperactivity caused by stress, and improve tissues-based hypoxia and renal function.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2100052198.

Comparison of the efficacy of multiple antioxidant and hyperbaric oxygen treatments in the prevention of ischemia and necrosis of local random McFarlane skin flap

OBJECTIVE

The aim of this study was to compare the efficacy of multiple antioxidant (Proxeed Plus (PP) with Carnitine, Selenium, Zinc, Coenzyme Q10, Vitamin C, Folic Acid, Vitamin B12) on local random skin flap healing with the hyperbaric oxygen (HBO) therapy.

METHODS

Fourty rats were equally divided into five groups (Control, PP, HBO, HBO + PP, PP + HBO + PP). Local random McFarlane skin flap was applied to all rats. Following the applications, evaluations were made biochemical (TAS, TOS, OSI, IL-1β, IL-6, TNF-α, TGF-β, VEGF) and histopathological parameters.

RESULTS

Necrosis percentage was found to be lower in the PP + HBO + PP group than all other groups whereas the necrosis percentages of PP and HBO groups were similar. Oxidative stress rates were significantly higher in the control group compared to the other groups whereas it was lower in the PP + HBO + PP group than all other groups. The inflammation parameters were the highest in the control group and the lowest in the PP + HBO + PP group. Growth factors were higher in the PP + HBO + PP group than all other groups. Epithelialization and wound healing were better in the HBO and PP groups than in the control group. The greatest healing, epithelialization and vascularization was seen in the PP + HBO + PP group. The histopathological findings in the PP + HBO + PP group were better in each inner region than in the other groups.

CONCLUSION

Biochemical and histopathological parameters have shown that PP reduces ischemia and necrosis and increases oxygenation in flap healing by providing significant improvement thanks to the multiple molecular structures in its content.