D-galactose (d-gal) plays numerous roles in the organism as an energy-providing nutrient and also an important constituent of the complex glycoconjugates. However, excessive amounts of d-gal activate alternative metabolic pathways that can lead to the development of a pro-oxidative environment. This feature is used in numerous aging studies which implied intraperitoneal (i.p.) or subcutaneous (s.c.) administration of d-gal for a prolonged time. The present study aims to investigate the systemic effects of orally administered d-gal (200 mg/kg and 500 mg/kg, dissolved in tap water, for 6 weeks) by analyzing oxidative stress parameters in the liver, kidney, and heart. For comparison with natural aging, the effects were studied in rats aged 12, 18, 24, and 30 months. In addition, histopathologic analyzes and serum biochemical measurements were performed to investigate the potential structural and functional organ damage induced by d-gal administration. Our findings show that chronic oral administration of d-gal induces oxidative stress in rat organs and mimics some aspects of natural aging similar to those of 30-month-old rats. Consistent with its primary role in galactose metabolism, the liver exhibited the most pronounced oxidative damage. However, despite the increased oxidative stress, only minor histopathological changes were observed, while organ function remained largely unaffected. Oral intake of d-gal was found to have milder effects compared to i.p. or s.c. injections, suggesting that this model may induce some features of natural aging but without overt organ dysfunction.

Nanoparticles (NPs), a distinct class of particles ranging in size from 1 to 100 nm, are one of the most promising technologies of the 21st century, and titanium dioxide NPs (TiO₂ NPs) are among the most widely produced and used NPs globally. The increased application of TiO₂ NPs raises concerns regarding their global safety and risks of exposure. Many animal studies have reported the accumulation of TiO₂ NPs in female reproductive organs; however, evidence of the resultant toxicity remains ambiguous. Since the surface area and chemical modifications of NPs can significantly change their cytotoxicity, we aimed to compare the toxic effects of pristine TiO₂ powder with surface-modified TiO₂ powders with salicylic acid (TiO₂/SA) and 5-aminosalicylic acid (TiO₂/5-ASA) on the ovaries, oviducts, and uterus on the 14th day following acute oral treatment. The results, based on alterations in food and water intake, body mass, organ-to-body mass ratio, hormonal status, histological features of tissues of interest, and antioxidant parameters, suggest that the modification with 5-ASA can mitigate some of the observed toxic effects of TiO₂ powder and encourage future investigations to create NPs that can potentially reduce the harmful effects of TiO₂ NPs while preserving their positive impacts.

The careful monitoring of patients with mild/moderate COVID-19 is of particular importance because of the rapid progression of complications associated with COVID-19. For prognostic reasons and for the economic management of health care resources, additional biomarkers need to be identified, and their monitoring can conceivably be performed in the early stages of the disease. In this retrospective cross-sectional study, we found that serum concentrations of high-mobility group box 1 (HMGB1) and heme oxygenase-1 (HO-1), at the time of hospital admission, could be useful biomarkers for COVID-19 management. The study included 160 randomly selected recovered patients with mild to moderate COVID-19 on admission. Compared with healthy controls, serum HMGB1 and HO-1 levels increased by 487.6 pg/mL versus 43.1 pg/mL and 1497.7 pg/mL versus 756.1 pg/mL, respectively. Serum HO-1 correlated significantly with serum HMGB1, oxidative stress parameters (malondialdehyde (MDA), the phosphatidylcholine/lysophosphatidylcholine ratio (PC/LPC), the ratio of reduced and oxidative glutathione (GSH/GSSG)), and anti-inflammatory acute phase proteins (ferritin, haptoglobin). Increased heme catabolism/hemolysis were not detected. We hypothesize that the increase in HO-1 in the early phase of COVID-19 disease is likely to have a survival benefit by providing protection against oxidative stress and inflammation, whereas the level of HMGB1 increase reflects the activity of the innate immune system and represents levels within which the disease can be kept under control.

Titanium dioxide nanoparticles (TiO2 NPs) are emerging in many technologies, owing to their chemical stability, antibacterial and photocatalytic properties. However, they tend to accumulate in cells inducing oxidative stress, inflammation, and even apoptosis. The main goal of this study was to determine whether surface modification with 5-aminosalicylic acid (5-ASA) could reduce TiO2 NPs toxicity. Therefore, female adult Wistar rats were orally treated in a single dose with 2.5 ml 0.01 M HCl (nanoparticle solvent); 1000 mg/kg of bare, commercially available TiO2 or TiO2 NPs surface- modified with 5-ASA (5-ASA/TiO2 NPs). Oxidative stress parameters, including prooxidant/antioxidant balance (PAB), advanced oxidation protein products (AOPP), and lipid peroxidation (LPO) were measured in the serum. Treatment with 5-ASA/TiO2 NPs showed potential to diminish LPO, but not AOPP or PAB, compared to bare TiO2 NPs. It can be concluded that this modification only partially alleviates oxidative stress induced by TiO2 NPs, and the underlying mechanisms remain unclear.

Although the use of flaxseed oil that is rich with essential nutrients, has been associated with health benefits, robust scientific evidence supporting its efficacy is currently lacking. In this study, we evaluated the impact of chronic intragastric treatment of commercially available flaxseed oil by assessing several parameters of oxidative stress including pro/antioxidant balance (PAB), levels of lipid peroxidation (LPO) products and advanced oxidation protein products (AOPP) as well as activity of total superoxide dismutase (totSOD) in rat stomach. Obtained results indicate that treatment maintains the general prooxidant load and antioxidant capacity, as evidenced by the unchanged PAB levels. However, it notably elevated LPO products and AOPP levels along with totSOD activity suggesting that increased oxidative changes of lipids and proteins might be attenuated by antioxidant system.