Steroid plant hormones: effects outside plant kingdom

Bioactive Steroids Bearing Oxirane Ring

This review explores the biological activity and structural diversity of steroids and related isoprenoid lipids, with a particular focus on compounds containing an oxirane ring. These natural compounds are derived from fungi, fungal endophytes, as well as extracts of plants, algae, and marine invertebrates. To evaluate their biological activity, an extensive examination of refereed literature sources was conducted, including in vivo and in vitro studies and the utilization of the QSAR method. Notable properties observed among these compounds include strong anti-inflammatory, antineoplastic, antiproliferative, anti-hypercholesterolemic, antiparkinsonian, diuretic, anti-eczematic, anti-psoriatic, and various other activities. Throughout this review, 3D graphs illustrating the activity of individual steroids are presented, accompanied by images of selected terrestrial or marine organisms. Furthermore, this review provides explanations for specific types of biological activity associated with these compounds. The data presented in this review are of scientific interest to the academic community and carry practical implications in the fields of pharmacology and medicine. By analyzing the biological activity and structural diversity of steroids and related isoprenoid lipids, this review offers valuable insights that contribute to both theoretical understanding and applied research. This review draws upon data from various authors to compile information on the biological activity of natural steroids containing an oxirane ring.

Anti-Inflammatory, Anti-Oxidative and Anti-Apoptotic Effects of Thymol and 24-Epibrassinolide in Zebrafish Larvae

Thymol (THY) and 24-epibrassinolide (24-EPI) are two examples of plant-based products with promising therapeutic effects. In this study, we investigated the anti-inflammatory, antioxidant and anti-apoptotic effects of the THY and 24-EPI. We used zebrafish (Danio rerio) larvae transgenic line (Tg(mpxGFP)ⁱ¹¹⁴) to evaluate the recruitment of neutrophils as an inflammatory marker to the site of injury after tail fin amputation. In another experiment, wild-type AB larvae were exposed to a well known pro-inflammatory substance, copper (CuSO4), and then exposed for 4 h to THY, 24-EPI or diclofenac (DIC), a known anti-inflammatory drug. In this model, the antioxidant (levels of reactive oxygen species-ROS) and anti-apoptotic (cell death) effects were evaluated in vivo, as well as biochemical parameters such as the activity of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), the biotransformation activity of glutathione-S-transferase, the levels of glutathione reduced and oxidated, lipid peroxidation, acetylcholinesterase activity, lactate dehydrogenase activity, and levels of nitric acid (NO). Both compounds decreased the recruitment of neutrophils in Tg(mpxGFP)ⁱ¹¹⁴, as well as showed in vivo antioxidant effects by reducing ROS production and anti-apoptotic effects in addition to a decrease in NO compared to CuSO4. The observed data substantiate the potential of the natural compounds THY and 24-EPI as anti-inflammatory and antioxidant agents in this species. These results support the need for further research to understand the molecular pathways involved, particularly their effect on NO.

Cancer and brassinosteroids: Mechanisms of action, SAR and future perspectives

Brassinosteroids are plant hormones whose main function is to stimulate plant growth. However, they have been studied for their biological applications in humans. Brassinosteroid compounds have displayed an important role in the study of cancer pathology and show potential for developing novel anticancer drugs. In this review we describe the relationship of brassinosteroids with cancer with focus on the last decade, the mechanisms of cytotoxic activity described to date, and a structure-activity relationship based on the available information.

Synthesis and biological activity of 21,22-cyclosteroids and their derivatives

Synthesis of 21,22-cyclosteroids has been achieved starting from pregnenolone acetate. The key transformation was the Kulinkovich reaction of 17-vinyl steroids with esters. The resulting cyclopropanols were further subjected to three-membered ring-opening under various conditions including to base-, palladium or visible light-promoted isomerization and cross-coupling reaction. A number of steroidal Δ2-6-ketones and 3β-hydroxy-Δ5-enes with functional groups at C-21 - C-23 have been synthesized via the 21,22-cyclosteroids. The antiproliferative and antihormonal activity of the obtained compounds on the cell lines of prostate (22Rv1) and breast (MCF-7) cancer was studied. The androgen receptor activity was assessed by reporter assay when the expression of signalling proteins was evaluated by immunoblotting. (20S,22R)-22-Acetoxy-21,22-cyclo-5α-cholest-5-ene with the moderate antiandrogenic potency revealed IC50 values of 18.4 ± 1.2 and 14.6 ± 1.4 µM against MCF-7 and 22Rv1 cells, respectively, and its effects on the expression of AR-V7, cyclin D1 and BCL2 were explored.

Extracts of Common Vegetables Inhibit the Growth of Ovary Cancer Cells

There is recent interest in a diet that can be recommended for patients suffering from cancer. In this respect, the effects were studied of the extracts of several common fruits, herbs and vegetables on the viability of two human ovary cancer cell lines (SKOV-3 and PEO1) in vitro. Normal human MRC-5 fibroblasts were used as a control cell line. The extracts of garlic, horseradish and curly kale as well as green and black tea were the most effective in lowering the viability of ovarian cancer cells, while not affecting the viability of MRC-5 fibroblasts. Except for garlic and horseradish, the cytotoxic effects of the extracts correlated with their polyphenol content. The examination of changes in the content of ATP and glutathione, in the level of reactive oxygen species, mitochondrial potential and mitochondrial mass did not show a consistent pattern, suggesting that various extracts may act via different mechanisms. Although the extracts’ toxicity to cells in vitro is a first and direct suggestion concerning their possible anticancer effects in vivo, these results point to potential vegetable candidates to become diet components recommended for ovary cancer patients.

Osteoblasts impair cholesterol synthesis in chondrocytes via Notch1 signalling

Objectives

Previous reports have proposed the importance of signalling and material exchange between cartilage and subchondral bone. However, the specific experimental evidence is still insufficient to support the effect of this interdependent relationship on mutual cell behaviours. In this study, we aimed to investigate cellular lipid metabolism in chondrocytes induced by osteoblasts.

Methods

Osteoblast‐induced chondrocytes were established in a Transwell chamber. A cholesterol detection kit was used to detect cholesterol contents. RNA sequencing and qPCR were performed to assess changes in mRNA expression. Western blot analysis was performed to detect protein expression. Immunofluorescence staining was conducted to show the cellular distribution of proteins.

Results

Cholesterol levels were significantly decreased in chondrocytes induced by osteoblasts. Osteoblasts reduced cholesterol synthesis in chondrocytes by reducing the expression of a series of synthetases, including Fdft1, Sqle, Lss, Cyp51, Msmo1, Nsdhl, Sc5d, Dhcr24 and Dhcr7. This modulatory process involves Notch1 signalling. The expression of ncstn and hey1, an activator and a specific downstream target of Notch signalling, respectively, were decreased in chondrocytes induced by osteoblasts.

Conclusions

For the first time, we elucidated that communication with osteoblasts reduces cholesterol synthesis in chondrocytes through Notch1 signalling. This result may provide a better understanding of the effect of subchondral bone signalling on chondrocytes.

Boronic Acid-Functionalized Scholl-Coupling Mesoporous Polymers for Online Solid-Phase Extraction of Brassinosteroids from Plant-Derived Foodstuffs

Brassinosteroids (BRs) are natural, nontoxic, non-hazardous, biosafe, and eco-friendly plant hormones, possessing diverse pharmacological activities. However, little is known about the type and content of BRs in frequently consumed plant-derived foodstuffs because of their low abundance and high abundance of interference. In this study, a selective, accurate, and sensitive method based on the online solid-phase extraction using the boronic acid-functionalized Scholl-coupling microporous polymer was developed for the analysis of BRs in plant-derived foodstuffs. Under optimum conditions, an excellent linearity (R² ≥ 0.9970) and lower limits of detection (0.010-0.070 pg mL^-1) were obtained. The high relative recoveries were in the range of 90.33-109.34% with relative standard deviations less than 9.73%. The method was successfully used for the determination of BRs in fifteen plant-derived foodstuffs. The present work offers a valuable tool for exploring BRs from the plant-derived foodstuffs and can provide useful information for developing functional foods.

Untargeted Metabolomics Reveals Multiple Phytometabolites in the Agricultural Waste Materials and Medicinal Materials of Codonopsis pilosula

Codonopsis pilosula has been used in traditional Chinese medicine for hundreds of years, where it has been used to treat anaemia, fatigue, a weak spleen, and stomach problems, among other ailments. The roots of C. pilosula are considered medicinal, while the aerial parts are always directly discarded after harvest in autumn or winter. Some studies have shown that the stems and leaves of C. pilosula also contain a variety of active metabolites, including saponins, flavonoids, terpenoids, and polysaccharides. To efficiently utilise resources, waste products from C. pilosula leaves and stems were analysed by untargeted metabolomics and chemometrics. A total of 1508 metabolites were detected and annotated, of which 463 were identified as differentially expressed metabolites (DEMs). These DEMs were grouped into classes, such as carboxylic acids and derivatives, steroids, organic oxygen compounds, fatty acyls, prenol lipids, and flavonoids. Metabolic profiling of C. pilosula tissues showed that the contents of polyacetylenes, polyenes, flavonoids, some alkaloids, steroids, terpenoids, and organic acids were higher in stems and leaves, whereas the contents of the main lignans and some alkaloids were more enriched in roots. Moreover, C. pilosula stems and leaves also contained a lobetyolin, syringin and atractylenolide III, which were detected by LC-MS/MS and HPLC-UV. The extracts of C. pilosula aerial parts also showed stronger antioxidant properties than roots. C. pilosula stems and leaves were rich in active ingredients and might have great value for development and utilisation.

Engineering of Phytosterol-Producing Yeast Platforms for Functional Reconstitution of Downstream Biosynthetic Pathways

As essential structural molecules for plant plasma membranes, phytosterols are key intermediates for the synthesis of many downstream specialized metabolites of pharmaceutical or agricultural significance, such as brassinosteroids and withanolides. Saccharomyces cerevisiae has been widely used as an alternative producer for plant secondary metabolites. Establishment of heterologous sterol pathways in yeast, however, has been challenging due to either low efficiency or structural diversity, likely a result of crosstalk between the heterologous phytosterol and the endogenous ergosterol biosynthesis. For example, in this study, we engineered campesterol production in yeast using plant enzymes; although we were able to enhance the titer of campesterol to ∼40 mg/L by upregulating the mevalonate pathway, no conversion to downstream products was detected upon the introduction of downstream plant enzymes. Further investigations uncovered two interesting observations about sterol engineering in yeast. First, many heterologous sterols tend to be efficiently and intensively esterified in yeast, which drastically impedes the function of downstream enzymes. Second, yeast can overcome the growth deficiency caused by altered sterol metabolism through repeated culture. By employing metabolic engineering, strain evolution, fermentation engineering, and pathway reconstitution, we were able to reconstruct the multienzyme pathways for the synthesis of a set of phytosterols: campesterol (∼7 mg/L), β-sitosterol (∼2 mg/L), 22-hydroxycampesterol (∼1 mg/L), and 22-hydroxycampest-4-en-3-one (∼4 mg/L). This work identified and addressed some of the technical bottlenecks in phytosterol-derived pathway reconstitution in the baker's yeast and opens up opportunities for efficient bioproduction and metabolic pathway elucidation of this group of phytochemicals.

Delving into the evolutionary origin of steroid sensing in plants

Brassinosteroids (BRs) are steroid hormones that play crucial roles in plant growth, development and adaptation to shifting environmental conditions. Our current understanding of the origin, evolution and functional significance of BRs is influenced by a double-edged bias: most we know stems from studies on a single species and, on the flip side, dearth of information from a phylogenetically broad and significant array of land plants precludes well-grounded comparisons. Here, we provide an update on BR presence and sensing along land plant evolution. Furthermore, a comprehensive search in all major plant lineages reveals the widespread presence of BR-receptor related sequences, suggesting that steroid-related signals may have been functional early in the evolution of land plants.

24-Epibrassinolide protects against ethanol-induced behavioural teratogenesis in zebrafish embryo

Embryonic studies have demonstrated the neurotoxic, teratogenic, and neurobehavioral toxicity of ethanol (EtOH). Although multiple mechanisms may contribute to these effects, oxidative stress has been described as the major damage pathway. In this regard, natural antioxidants have the potential to counteract oxidative stress-induced cellular damage. Therefore, the present study aimed to investigate the potential protective role of 24-epibrassinolide (24-EPI), a natural brassinosteroid with proved antioxidant properties, in EtOH-induced teratogenic effects during early zebrafish development. Embryos (~2 h post-fertilization - hpf) were exposed to 1 % EtOH, co-exposed to 24-EPI (0.01, 0.1 and 1 μM) and to 24-EPI alone (1 μM) for 24 h. Following exposure, biochemical evaluations were made at 26 hpf, developmental analysis was made throughout the embryo-larval period, and behavioural responses were evaluated at 120 hpf. Exposure to 1 % EtOH caused an increase in the number of malformations, which were diminished by 24-EPI. In addition, EtOH induced an accumulation of GSSG and consequent reduction of GSH:GSSG ratio, indicating the involvement of oxidative mechanisms in the EtOH-induced effects. These were reverted by 24-EPI as proved by the GSSG levels and GSH:GSSG ratio that returned to control values. Furthermore, exposure to EtOH resulted in behavioural deficits at 120 hpf as observed by the disrupted response to an aversive stimulus, suggesting the involvement of neurotoxic mechanisms. 24-EPI restored the behavioural deficits observed in a dose-dependent manner. The absence of effects in the embryos exposed solely to 24-EPI showed its safety during the exposure period. In conclusion, EtOH caused developmental teratogenicity and behavioural toxicity by inducing glutathione changes, which were prevented by 24-EPI.

Therapeutic Potential of Brassinosteroids in Biomedical and Clinical Research

Steroids are a pivotal class of hormones with a key role in growth modulation and signal transduction in multicellular organisms. Synthetic steroids are widely used to cure large array of viral, fungal, bacterial, and cancerous infections. Brassinosteroids (BRs) are a natural collection of phytosterols, which have structural similarity with animal steroids. BRs are dispersed universally throughout the plant kingdom. These plant steroids are well known to modulate a plethora of physiological responses in plants leading to improvement in quality as well as yield of food crops. Moreover, they have been found to play imperative role in stress-fortification against various stresses in plants. Over a decade, BRs have conquered worldwide interest due to their diverse biological activities in animal systems. Recent studies have indicated anticancerous, antiangiogenic, antiviral, antigenotoxic, antifungal, and antibacterial bioactivities of BRs in the animal test systems. BRs inhibit replication of viruses and induce cytotoxic effects on cancerous cell lines. Keeping in view the biological activities of BRs, this review is an attempt to update the information about prospects of BRs in biomedical and clinical application.

Synthesis and bioevaluation of novel steroidal isatin conjugates derived from epiandrosterone/androsterone

Steroids are classes of natural products widely distributed in nature, which have been demonstrated to exhibit broad biological functions, and have also attracted increasing interest from bioorganic and pharmaceutical researches. In order to develop novel chemical entities as potential cytotoxic agents, a series of steroidal isatin conjugations derived from epiandrosterone and androsterone were efficiently prepared and characterized, and all these obtained compounds were screened for their potential cytotoxic activities. The preliminary bioassay indicated that most of the newly synthesized compounds exhibited good cytotoxic activities against human gastric cancer (SGC-7901), melanoma (A875), and hepatocellular liver carcinoma (HepG2) cell lines compared with 5-fluorouracil (5-FU), which might be considered as promising scaffold for further development of potential anticancer agents.

Regio- and stereoselective C-H functionalization of brassinosteroids

Late stage CH functionalization is a powerful tool for modification of natural compounds. Herein we report that the rhodium-catalyzed reaction of brassinosteroids with aryloxysulfonamides proceeds regio- and stereoselectively at C15 position. The derivative obtained from 24-epibrassinolide was easily transformed to the conjugate with a BODIPY dye bearing unaffected functional groups of the native brassinosteroid.

Time-Dependent Changes in the Intestinal Microbiome of Gilts Exposed to Low Zearalenone Doses

Zearalenone is a frequent contaminant of cereals and their by-products in regions with a temperate climate. This toxic molecule is produced naturally by Fusarium fungi in crops. The aim of this study was to determine the influence of low zearalenone doses (LOAEL, NOAEL and MABEL) on the intestinal microbiome of gilts on different days of exposure (days 7, 21 and 42). Intestinal contents were sampled from the duodenal cap, the third part of the duodenum, jejunum, caecum and the descending colon. The experiment was performed on 60 clinically healthy gilts with average BW of 14.5 ± 2 kg, divided into three experimental groups and a control group. Group ZEN5 animals were orally administered ZEN at 5 μg /kg BW, group ZEN10-10 μg ZEN/kg BW and group ZEN15-15 µg ZEN/kg BW. Five gilts from every group were euthanized on analytical dates 1, 2 and 3. Differences in the log values of microbial counts, mainly Escherichia coli and Enterococcus faecalis, were observed between the proximal and distal segments of the intestinal tract on different analytical dates as well as in the entire intestinal tract. Zearalenone affected the colony counts of intestinal microbiota rather than microbiome diversity, and its effect was greatest in groups ZEN10 and ZEN15. Microbial colony counts were similar in groups ZEN5 and C. In the analysed mycobiome, ZEN exerted a stimulatory effect on the log values of yeast and mould counts in all intestinal segments, in particular in the colon, and the greatest increase was noted on the first analytical date.

Occurrence of brassinosteroids and influence of 24-epibrassinolide with brassinazole on their content in the leaves and roots of Hordeum vulgare L. cv. Golden Promise

24-epibrassinolide overcame the inhibitory effect of brassinazole on the barley growth and the content of brassinosteroids. The present work demonstrates the occurrence of mainly castasterone, brassinolide and cathasterone and lower amounts of 24-epibrassinolide, 24-epicastasterone, 28-homobrassinolide, typhasterol, 6-deoxocastasterone and 6-deoxotyphasterol in 14-day-old de-etiolated barley (Hordeum vulgare L. cv. Golden Promise). We also investigated the endogenous level of brassinosteroids (BRs) in barley seedlings treated with 24-epibrassinolide (EBL) and/or brassinazole (Brz). To our knowledge, this is the first report related to the occurrence of BRs and application of EBL and Brz in terms of the endogenous content of BRs in barley. Brz as a specific inhibitor of BR biosynthetic reactions decreased the level of BRs in the leaves. Application of EBL showed a weak promotive effect on the BR content in Brz-treated seedlings. Brz also inhibited growth of the seedlings; however, addition of EBL overcame the inhibition. The EBL applied alone at 0.01-1 µM increased the BR level in the leaves but at 10 µM lowered the BR content. In opposition to leaves, the Brz in the concentration range from 0.1 to 1 µM did not significantly affect the content of BRs in the roots. However, application of 10 µM Brz caused BRs to decrease, but treatment of EBL concentrations overcame the inhibitory effect of Brz.

Steroids-specific target library for steroids target prediction

Steroids exist universally and play critical roles in various biological processes. Identifying potential targets of steroids is of great significance in studying their physiological and biochemical activities, the side effects and for drug repurposing. Herein, aiming at more precise steroids targets prediction, a steroids-specific target library integrating 3325 PDB or homology modeling structures categorized into 196 proteins was built by considering chemical similarity from DrugBank and biological processes from KEGG. The main properties of this library include: (1) It was manually prepared and checked to eliminate mistakes. (2) The library enriched the possible steroids targets and could decrease the false positives of structure-based target screening for steroids. (3) The ranking by protein name instead of PDB ID could make the screening more efficiency and precise. (4) Protein flexibility was taken into account partially by the different active conformations through the structural redundancy of each category of protein, which leads to more accurate prediction. The case studies of glycocholic acid and 24-epibrassinolide proved its powerful predictive accuracy. In summary, our strategy to build the steroids-specific protein library for steroids target prediction is a promising approach and it provides a novel idea for the target prediction of small molecules.

Growth performance, selected blood biochemical parameters and body weights of pre-pubertal gilts fed diets supplemented with different doses of zearalenone (ZEN)

The aim of this study was to determine whether exposure to low doses of zearalenone (ZEN) induces changes in the serum biochemical profile and body weights (BW). Pre-pubertal gilts (with BW of up to 14.5 kg) were administered ZEN in daily doses of 5 μg/kg BW (group 1, n = 15), 10 μg/kg BW (group 2, n = 15), 15 μg/kg BW (group 3, n = 15) or placebo (control group C, n = 15) throughout the experiment. Blood was sampled for analysis on 10 dates (at five-day intervals). Minor but statistically significant differences in the analysed serum biochemical parameters (ALT, AST, ALP, total cholesterol, total bilirubin, glucose, total protein, iron, BUN and urea) were observed in the studied groups. The biochemical parameters of the analysed gilts indicate that the maintenance of homeostasis and biotransformation of ZEN require considerable energy expenditure. Beginning on the fourth analytical date, BW gains were consistently higher in the experimental groups than in group C. The observed decrease in glucose and total protein levels can probably be attributed to higher BW gains and the ongoing ZEN biotransformation processes in the enterocytes and the liver.

Metabolic analyses reveal different mechanisms of leaf color change in two purple-leaf tea plant (Camellia sinensis L.) cultivars

Purple-leaf tea plants, as anthocyanin-rich cultivars, are valuable materials for manufacturing teas with unique colors or flavors. In this study, a new purple-leaf cultivar "Zixin" ("ZX") was examined, and its biochemical variation and mechanism of leaf color change were elucidated. The metabolomes of leaves of "ZX" at completely purple, intermediately purple, and completely green stages were analyzed using ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-QTOF-MS). Metabolites in the flavonoid biosynthetic pathway remained at high levels in purple leaves, whereas intermediates of porphyrin and chlorophyll metabolism and carotenoid biosynthesis exhibited high levels in green leaves. In addition, fatty acid metabolism was more active in purple leaves, and steroids maintained higher levels in green leaves. Saponin, alcohol, organic acid, and terpenoid-related metabolites also changed significantly during the leaf color change process. Furthermore, the substance changes between "ZX" and "Zijuan" (a thoroughly studied purple-leaf cultivar) were also compared. The leaf color change in "Zijuan" was mainly caused by a decrease in flavonoids/anthocyanins. However, a decrease in flavonoids/anthocyanins, an enhancement of porphyrin, chlorophyll metabolism, carotenoid biosynthesis, and steroids, and a decrease in fatty acids synergistically caused the leaf color change in "ZX". These findings will facilitate comprehensive research on the regulatory mechanisms of leaf color change in purple-leaf tea cultivars.

Structure-activity relationship of brassinosteroids and their agricultural practical usages

Brassinosteroids (BRs) control several important agronomic traits, such as strengthening resistance to diverse adversity, improving the quality, and increasing crop yield. Their chemical structures and varieties, specific methods for the evaluation of bioactivities, structure-activity relationships, potential novel compounds, and practical agricultural uses were summarized. The findings allow the examination of brassinosteroids in two important issues: 1) Do the results of different bioevaluation protocols provide similar activities for BRs? and 2) which bioevaluated compounds would proof to have a greater potential for application in agricultural usages?

Synthesis of sulfated brassinosteroids

A number of water soluble sulfates of 24-epibrassinolide including the 2α,3α-disulfate and all possible monosulfates were synthesized. The target compounds were isolated in crystalline form as the corresponding sodium salts. Pyridine-sulfur trioxide complex was used as sulfating agent followed by transformation of the resulting pyridinium salts into the sodium sulfates by treatment with NaOH. The control of the regioselectivity was achieved by an appropriate use of acetyl and benzyl protecting groups.

Flow-cytometric analysis of reactive oxygen species in cancer cells under treatment with brassinosteroids

To explore the underlying mechanism of cancer cell growth inhibition by brassinosteroids (BS), reactive oxygen species (ROS) generation under treatment with 28-homocastasterone and its synthetic derivatives (22S,23S)-28-homocastasterone was measured in A549 human lung adenocarcinoma cells. BS induced ROS generation in A549 cells and their growth in a time and dose-dependent manner. The maximal effect was observed for (22S,23S)-28-homocastasterone which at 30μM concentration showed a 6-fold increase of ROS generation in comparison with the control.

Activity of Zearalenone in the Porcine Intestinal Tract

This study demonstrates that low doses (somewhat above the No Observed Adverse Effect Level, NOAEL) of the mycoestrogen zearalenone (ZEN) and its metabolites display multispecificity towards various biological targets in gilts. The observed responses in gilts were surprising. The presence of ZEN and zearalenols (ZELs) did not evoke a response in the porcine gastrointestinal tract, which was attributed to dietary tolerance. Lymphocyte proliferation was intensified in jejunal mesenteric lymph nodes, and lymphocyte counts increased in the jejunal epithelium with time of exposure. In the distal digestive tract, fecal bacterial counts decreased, the activity of fecal bacterial enzymes and lactic acid bacteria increased, and cecal water was characterized by higher genotoxicity. The accompanying hyperestrogenism led to changes in mRNA activity of selected enzymes (cytochrome P450, hydroxysteroid dehydrogenases, nitric oxide synthases) and receptors (estrogen and progesterone receptors), and it stimulated post-translational modifications which play an important role in non-genomic mechanisms of signal transmission. Hyperestrogenism influences the regulation of the host's steroid hormones (estron, estradiol and progesteron), it affects the virulence of bacterial genes encoding bacterial hydroxysteroid dehydrogenases (HSDs), and it participates in detoxification processes by slowing down intestinal activity, provoking energy deficits and promoting antiporter activity at the level of enterocytes. In most cases, hyperestrogenism fulfils all of the above roles. The results of this study indicate that low doses of ZEN alleviate inflammatory processes in the digestive system, in particular in the proximal and distal intestinal tract, and increase body weight gains in gilts.

Changes in the metabolic profile and body weight of pre-pubertal gilts during prolonged monotonic exposure to low doses of zearalenone and deoxynivalenol

The aim of this study was to determine whether exposure to low doses of ZEN + DON induces changes in serum biochemical and hematological parameters in pre-pubertal gilts. In the evaluated groups, minor but statistically significant changes were noted in selected serum biochemical parameters, including glucose, total cholesterol, ALT, AST, AP, total bilirubin, P_in, Fe, K and Cl, and in hematological parameters, including WBC, eosinophils, basophils, monocytes, Ht, Hb, MCHC, HDW and PLT. A statistical analysis of the results revealed significant differences between groups in the values of WBC, eosinophils, basophils, Hb, Ht, PLT, glucose, ALT, AP, total bilirubin, Fe and K. Change trends were noted mainly in weeks II and V-VI. An analysis of the metabolic profile of pre-pubertal gilts exposed to ZEN + DON indicates that homeostasis and biotransformation of ZEN + DON can be toned down at the expense of the animals' energy reserves. Body weight gains were lower in group E, and BW gains were not observed in weeks II and VI. The activity levels of gilts decreased in the first weeks of exposure (I and II), but the drop was minimized by a compensatory effect, or in the last two weeks of exposure due to nutrient deficiency or insufficient supply of protein and energy with feed and feed additives, which decreased BW gains. Low doses of mycotoxins induce completely different changes in the metabolic test than higher doses. The above can probably be attributed to: (i) a negative compensatory effect, (ii) initiation of adaptive mechanisms and stimulation of the immune system, probably due to the allergizing properties of mycotoxins, (iii) excessive loss of energy and protein due to more effective feed utilization, or (iv) involvement in detoxification processes which leads to fatigue. Depending on the body's energy stores, the above processes tend to tone down the biotransformation of low doses of the examined mycotoxins but in the present study, the BW of gilts did not increase under exposure to a combination of ZEN + DON.

Risk assessment for changes in the metabolic profile and body weights of pre-pubertal gilts during long-term monotonic exposure to low doses of zearalenone (ZEN)

The aim of the study was to examine whether the process of exposure to low doses of ZEN generates changes in the hematological and biochemical image of blood serum. During the experiment, pre-pubertal gilts (up to 25kg) were administered per os ZEN at a dose of 40μg/kg BW (Group E, n=18) or placebo (Group C, n=21) on a daily basis for 42days. Blood samples for investigation were collected seven times at intervals of one week. In the experimental groups, slight but statistically significant changes in the values of selected biochemical blood indices such as glucose, ALT, P_in, total protein and Fe, or in hematological indices such as RBC, MCV, PLT, WBC, basophils, eosinophils and monocytes were observed. Based on statistical analysis between the groups, differences in the values of WBC, basophils, peroxidase negative cells, Hb, Ht, MCV, HDW, glucose, ALT, AP, total protein, iron or potassium were found. In Group E, decreasing trends in the values of PLT and glucose, and increasing trends in the values of total protein, P_in, Na and Cl were found. The described situations occurred during the last three weeks of exposure. Low levels of exposure to ZEN lead to completely different changes in the metabolic profile than those resulting from higher doses of the toxin. The stimulatory effect of mycotoxins, observed in initial stages of exposure, is eliminated when the compensatory response and adaptive mechanisms are triggered, and due to excessive loss of energy, which may point to more efficient feed utilization and/or detoxification processes. The values of body weight gain obtained in Group E were monotonically higher in four out of the six investigated weeks of exposure. The above changes were accompanied by a decrease in glucose concentrations and higher total protein levels (a rising tendency), which could have affected the rate of body weight gain.

Brassinosteroids and Response of Plants to Heavy Metals Action

Brassinosteroids (BRs) are a widespread group of plant hormones. These phytohormones play a crucial role in the regulation of growth and development of various plant species, and they demonstrate high biological activity. BRs are considered to demonstrate protective activity in the plants exposed to various stresses. Due to rapid industrialization and urbanization, heavy metals have become one of the most important plant stressors. In plants, accumulation of heavy metals beyond the critical levels leads to oxidative stress. However, BRs may inhibit the degradation of lipids, resulted from the overproduction of reactive oxygen species under stress conditions, and increase the activity of antioxidants. They also have the ability to promote phytochelatins synthesis.

A new synthesis of brassinosteroids with a cholestane framework based on a highly functionalized starting material

A new route to the synthesis of minor brassinosteroids with a cholestane framework (28-norcastasterone and 28-norbrassinolide) has been proposed. It makes use of commercially available 24-epicastasterone as a starting material. In addition, [26,26,26-(2)H3]-28-norcastasterone and [26,26,26-(2)H3]-28-norbrassinolide have been prepared as tools for analytical applications. The key steps were regioselective manipulations of functional groups in 24-epicastasterone, oxidative cleavage of 22,23-diol group and Claisen rearrangement.

Redtail and red colobus monkeys show intersite urinary cortisol concentration variation in Kibale National Park, Uganda

Non-invasive measurement of urinary cortisol is a proven method of evaluating the impact of environmental stressors on wild primates. Variation in cortisol concentrations can reflect physiological stress, and prolonged elevation of circulating cortisol can significantly affect individual and population-level health. In a previous study, we found that urinary cortisol concentrations in grey-cheeked mangabeys (Lophocebus albigena) were higher at a highly disturbed site (Mainaro) in Kibale National Park, Uganda compared with a minimally disturbed site (Ngogo) in the same habitat. Here, we expand on this research, reporting on cortisol concentrations in two other cercopithecid monkeys (Cercopithecus ascanius and Piliocolobus rufomitratus) at the same two sites. We hypothesized that C. ascanius would show no difference between sites, given its preference for secondary forests, while P. rufomitratus would have higher cortisol concentrations at the disturbed site. Contrary to expectations, both species exhibited significantly higher cortisol concentrations at Ngogo (minimally disturbed) compared with Mainaro (disturbed). We suggest that these results may be caused by inter- or intragroup social dynamics, intersite differences in predation rate, fruit/food availability and chemistry, or a combination of these factors. These initial evaluations of urinary cortisol concentrations provide testable hypotheses on habitat disturbance and Kibale primate ecophysiology.