The aim of the present study was to investigate histological alterations of rat thyroid gland after short-term treatment with supraphysiological doses of thyroid hormones. Rats from experimental groups were treated with triiodothyronine (T3) or thyroxine (T4) during five days. In both treated groups, thyrocyte height was reduced and follicular lumens were distended. Progressive involutive changes of the thyroid parenchyma were apparent, including follicular remodeling (fusion) and death of thyrocytes. Morphological changes confirmed by quantitative analysis were more pronounced in the T4-treated group. Our results demonstrate that thyrotoxicosis, whether induced by T3 or T4, leads to different grades of thyroid tissue injury, including some irreversible damages. These changes might be explained at least in part by lack of trophic and cytoprotective effects of the thyroid stimulating hormone. Since the period required for morphophysiological recovery may be unpredictable, findings presented here should be taken into consideration in cases where the thyroid hormones are used as a treatment for thyroid and non-thyroid related conditions.

Cadmium (Cd) is a highly toxic metal that is distributed worldwide. Exposure to it is correlated with a vast number of diseases and organism malfunctions. Exopolysaccharides (EPS) derived from Lactiplantibacillus plantarum BGAN8, EPS-AN8, previously showed great potential for the in vitro protection of intestinal cells from this metal. Here, we investigated the potential of food supplemented with EPS-AN8 to protect rats from the hazardous effects of Cd exposure. After thirty days of exposure to lower (5 ppm) and higher (50 ppm)-Cd doses, the administration of EPS-AN8 led to decreased Cd content in the kidneys, liver, and blood compared to only Cd-treated groups, whereas the fecal Cd content was strongly enriched. In addition, EPS-AN8 reversed Cd-provoked effects on the most significant parameters of oxidative stress (MDA, CAT, GST, and GSH) and inflammation (IL-1β, TNF-α, and IFN-γ) in the duodenum. Moreover, micrographs of the duodenum were in line with these findings. As the gut microbiota has an important role in maintaining homeostasis, we used 16S rRNA amplicon sequencing and investigated the effects of Cd and EPS-AN8 on one part of the microbiota presented in the duodenum. Although Cd decreased the growth of lactobacilli and mostly favored the blooming of opportunistic pathogen bacteria, parallel intake of EPS-AN8 reversed those changes. Therefore, our results imply that EPS-AN8 might be extremely noteworthy in combatting this toxic environmental pollutant.

The aim of this study was to determine the effects of long-term sucrose overfeeding on functional capacity and ultrastructural characteristics of the rat brown adipose tissue (BAT). For the study, sixteen male Wistar rats, chow-fed and kept under standard laboratory conditions were divided into 2 equal groups. The rats from a control group drank tap water, while those from a sucrose overfed group were allowed to drink 10% sucrose solution for 21 days. Structural changes of BAT were analysed at the level of light and electron microscopy on routinely prepared tissue sections or using immunohistochemical staining, in combination with stereological methods. Obtained results have shown that significantly increased energy intake in sucrose overfed rats did not result in elevated body mass gain. The light microscopy analysis revealed that the BAT acquired the appearance of a thermogenically active tissue, with intensified vascularisation, reduced size of brown adipocytes and increased multilocularity. At the ultrastructural level, mitochondria of brown adipocytes became more abundant, enlarged, and contained more cristae in comparison to control animals. The immunoexpression of uncoupling protein 1 (UCP1) and noradrenaline, as markers of BAT thermogenic status was increased, while the pattern of PGC1α was slightly modified. Taken together, the results of this investigation indicated that BAT possesses the ability to increase thermogenic capacity/activity in response to high energy intake and to prevent body mass gain. These findings are particularly relevant in the view of recent reports on the existence of functional BAT in adult humans and its potential use to combat obesity.

The skin is a direct target of the air pollutant benzo[a]pyrene (BaP). While its carcinogenic qualities are well-studied, the immunotoxicity of BaP after dermal exposure is less understood. This study examines the immunomodulatory effects of a 10-day epicutaneous BaP application, in environmentally/occupationally relevant doses, by analyzing ex vivo skin immune response (skin explant, epidermal cells and draining lymph node/DLN cell activity), alongside the skin’s reaction to sensitization with experimental hapten dinitrochlorobenzene (DNCB). The results show that BaP application disrupts the structure of the epidermal layer and promotes immune cell infiltration in the dermis. BaP exposure led to oxidative stress in epidermal cells, characterized by decreased reduced glutathione and increased AHR and Cyp1A1 expression. Production and gene expression of proinflammatory cytokines (TNF, IL-1β) by epidermal cells decreased, while IL-10 response increased. Decreased spontaneous production of IFN-γ and IL-17, along with unchanged IL-10, was observed in DLC cells, whereas ConA-stimulated production of these cytokines was elevated. Local immunosuppression caused by BaP application seems to reduce the skin’s response to an additional stimulus, evidenced by decreased effector activity of DLN cells three days after sensitization with DNCB. These findings provide new insight into the immunomodulatory effects and health risks associated with skin exposure to BaP.

Inflammatory/immune cells and mediators are substantial for wound healing because they orchestrate biological activities in this complex process. Among factors that affect wound healing, obesity, and metabolic diseases are among the most significant, particularly because of a relationship between obesity and a prediabetic state with immune reactivity. Using Dark Agouti (DA) and Albino Oxford (AO) rats, which differ in immune responses as well as in proneness to obesity, we examined the impact of these intrinsic factors on cutaneous wound healing. Dynamics of the process were monitored at days 3, 5, and 7 post‐wounding parallel in both rat strains by analysis of selected basic aspects of the wound repair process (cytokine and growth factor responses) in granulation tissue. Strain‐related differences in the extent of reduction of the wound area were shown, which coincided with differential proinflammatory and immune‐regulatory cytokines, as well as growth factors response in these rats. Some of these differences seem related to their dissimilarities in the proneness to obesity. Results in this study extended so far known differences in inflammatory/immune responses to a variety of stimuli between AO and DA rats and showed, for the first time, immune‐based differences in wound healing between rats that differ in body mass (BM) and obesity proneness (under ad libitum feeding conditions with normal rodent chow).

This study explored the relationship between soil properties and heavy metal concentrations in soil and selected plants from Kopaonik National Park and the Aleksandrovac municipality in Serbia. Soil samples were analyzed for texture, basic chemical properties, and the plant-available fraction of various metals, while plant material was assessed for macroand microelement content. Significant differences were observed between the localities, both in soil properties and plant metal accumulation. Prunus domestica L. exhibited strong bioaccumulation efficiency for most microelements, making it a significant candidate for phytoremediation. Notable accumulation of sodium, potassium, iron, nickel, copper, zinc, and chromium was observed in Capsicum annuum L., while Juniperus communis L. efficiently accumulated magnesium, calcium, manganese, molybdenum, and cobalt. Due to their capacity to bioaccumulate heavy metals, especially cadmium, these species highlight a dual role in phytoremediation efforts and underscore the need for careful agricultural management to mitigate consumer health risks in contaminated areas.