-
PloS One 2024Aluminum (Al) toxicity is an important factor restricting the normal growth of plants in acidic soil. Rhododendron (Ericaceae) can grow relatively well in acidic soil....
Aluminum (Al) toxicity is an important factor restricting the normal growth of plants in acidic soil. Rhododendron (Ericaceae) can grow relatively well in acidic soil. To uncover the adaptive mechanisms of photosynthesis under Al stress, the influence of Al stress on the photosynthetic activities of Al-sensitive (Baijinpao) and Al-resistant (Kangnaixin) rhododendron cultivars was examined by measuring gas exchange, chlorophyll fluorescence, and the modulated reflection of light at 820 nm. Under Al stress conditions, the net photosynthetic rate and stomatal conductance of the rhododendron leaves decreased, whereas the intercellular CO2 concentration increased. The Al stress treatment damaged the oxygen-evolving complex of the rhododendron seedlings, while also inhibiting electron transport on the photosystem II (PSII) donor side. In addition, the exposure to Al stress restricted the oxidation of plastocyanin (PC) and the photosystem I (PSI) reaction center (P700) and led to the re-reduction of PC+ and P700+. The comparison with Kangnaixin revealed an increase in the PSII connectivity in Baijinpao. Additionally, the donor-side electron transport efficiency was more inhibited and the overall activity of PSII, PSI, and the intersystem electron transport chain decreased more extensively in Baijinpao than in Kangnaixin. On the basis of the study findings, we concluded that Al stress adversely affects photosynthesis in rhododendron seedlings by significantly decreasing the activity of PSII and PSI. Under Al stress, Kangnaixin showed stronger tolerance compared with Baijinpao.
Topics: Rhododendron; Aluminum; Chlorophyll; Photosynthesis; Fluorescence; Photosystem II Protein Complex; Stress, Physiological; Plant Leaves; Electron Transport; Light; Photosystem I Protein Complex
PubMed: 38935623
DOI: 10.1371/journal.pone.0305133 -
Infection and Drug Resistance 2024Persistent infections caused by (), which are resistant to antibiotic treatment, pose a growing global public health concern. Biofilm formation is known to be...
BACKGROUND
Persistent infections caused by (), which are resistant to antibiotic treatment, pose a growing global public health concern. Biofilm formation is known to be associated with persistent infections due to its role in enhancing antimicrobial resistance and the tolerance of many pathogenic bacteria.
OBJECTIVE
This study aims to evaluate the biofilm formation of clinical isolates of and its impact on antibiotic eradication.
METHODS
The thickness, morphology, and structure of biofilms derived from nine strains were examined using confocal laser scanning microscopy, scanning electron microscopy, and transmission electron microscopy. Subsequently, the susceptibility of both planktonic and biofilm bacteria was assessed through the determination of minimum inhibitory concentration and minimum biofilm eradication concentration for amoxicillin, clarithromycin, levofloxacin, and tetracycline.
RESULTS
The results revealed varying biofilm thicknesses and densities among the strains, characterised by the presence of numerous filaments intertwining and connecting bacterial cells. Additionally, several cases exhibited susceptibility based on MIC measurements but resistance according to MBEC measurements, with MBEC indicating a higher resistance rate. Pearson Correlation analysis demonstrated a positive correlation between biofilm thickness and MBEC results (0 < < 1), notably significant for amoxicillin ( = 0.801, = 0.009) and tetracycline ( = 0.696, = 0.037).
CONCLUSION
Different strains of exhibit variations in their capacity to release outer membrane vesicles (OMVs) and form biofilms. Biofilm formation can influence the effectiveness of amoxicillin and tetracycline in eradicating susceptible bacterial strains.
PubMed: 38933776
DOI: 10.2147/IDR.S468126 -
IBRO Neuroscience Reports Dec 2024First-line pharmacotherapy for peripheral neuropathic pain (NP) of diverse pathophysiology consists of antidepressants and gabapentinoids, but only a minority achieve...
First-line pharmacotherapy for peripheral neuropathic pain (NP) of diverse pathophysiology consists of antidepressants and gabapentinoids, but only a minority achieve sufficient analgesia with these drugs. Opioids are considered third-line analgesics in NP due to potential severe and unpredictable adverse effects in long-term use. Also, opioid tolerance and NP may have shared mechanisms, raising further concerns about opioid use in NP. We set out to further elucidate possible shared and separate mechanisms after chronic morphine treatment and oxaliplatin-induced and diabetic polyneuropathies, and to identify potential diagnostic markers and therapeutic targets. We analysed thermal nociceptive behaviour, the transcriptome of dorsal root ganglia (DRG) and the metabolome of cerebrospinal fluid (CSF) in these three conditions, in rats. Several genes were differentially expressed, most following oxaliplatin and least after chronic morphine treatment, compared with saline-treated rats. A few genes were differentially expressed in the DRGs in all three models (e.g. and ). Some, e.g. were differentially expressed in both diabetic and oxaliplatin models. Other differentially expressed genes were associated with nociception, inflammation, and glial cells. The CSF metabolome was most significantly affected in the diabetic rats. Interestingly, we saw changes in nicotinamide metabolism, which has been associated with opioid addiction and withdrawal, in the CSF of morphine-tolerant rats. Our results offer new hypotheses for the pathophysiology and treatment of NP and opioid tolerance. In particular, the role of nicotinamide metabolism in opioid addiction deserves further study.
PubMed: 38933596
DOI: 10.1016/j.ibneur.2024.05.006 -
Nutrients Jun 2024Obesity is acknowledged as a significant risk factor for cardiovascular disease, often accompanied by increased inflammation and diabetes. Bioactive peptides derived...
Obesity is acknowledged as a significant risk factor for cardiovascular disease, often accompanied by increased inflammation and diabetes. Bioactive peptides derived from marine animal proteins show promise as safe and effective anti-obesity agents by regulating adipocyte differentiation through the AMPK signaling pathway. Therefore, this study aims to investigate the anti-obesity and anti-diabetic effects of bioactive compounds derived from a Protamex enzymatic hydrolysate (MLP) fraction (≤1 kDa) through a 6-week treatment (150 mg/kg or 300 mg/kg, administered once daily) in leptin receptor-deficient mice. The MLP treatment significantly decreased the body weight, serum total cholesterol, triglycerides, and LDL-cholesterol levels while also exhibiting a beneficial effect on hepatic and serum marker parameters in mice. A histological analysis revealed a reduction in hepatic steatosis and epididymal fat following MLP treatment. Furthermore, poor glucose tolerance was improved, and hepatic antioxidant enzyme activities were elevated in MLP-treated mice compared to control mice. Western blot analysis showed an increased expression of the AMPK protein after MLP treatment. In addition, the expression of lipogenic genes decreased in mice. These findings indicate that bioactive peptides, which are known to regulate blood glucose levels, lipid metabolism, and adipogenesis, could be beneficial functional food additives and pharmaceuticals.
Topics: Animals; Obesity; Mice; Male; Peptides; Anti-Obesity Agents; Protein Hydrolysates; Liver; Blood Glucose; Hypoglycemic Agents; Lipid Metabolism; AMP-Activated Protein Kinases; Mice, Inbred C57BL; Receptors, Leptin; Adipogenesis; Body Weight
PubMed: 38931268
DOI: 10.3390/nu16121913 -
Nutrients Jun 2024Fermented foods, including cheeses, have garnered increased interest in recent years for their potential health benefits. This study explores the biological properties...
Fermented foods, including cheeses, have garnered increased interest in recent years for their potential health benefits. This study explores the biological properties of eight French raw-milk cheeses-goat cheese, Saint-Nectaire, Cantal, Bleu d'Auvergne, Roquefort, Comté, Brie de Meaux, and Epoisses-on oxidative processes using both in vivo () and in vitro (human leukocytes) models. A cheese fractionation protocol was adapted to study four fractions for each cheese: a freeze-dried fraction (FDC) corresponding to whole cheese, an apolar (ApE), and two polar extracts (W40 and W70). We showed that all cheese fractions significantly improved () survival rates when exposed to oxidative conditions by up to five times compared to the control, regardless of the fractionation protocol and the cheese type. They were also all able to reduce the in vivo accumulation of reactive oxygen species (ROS) by up to 70% under oxidative conditions, thereby safeguarding from oxidative damage. These beneficial effects were explained by a reduction in ROS production up to 50% in vitro in human leukocytes and overexpression of antioxidant factor-encoding genes (, , , and ) in .
Topics: Caenorhabditis elegans; Animals; Cheese; Humans; Oxidative Stress; Leukocytes; Reactive Oxygen Species; Antioxidants; Milk; Oxidation-Reduction; France
PubMed: 38931217
DOI: 10.3390/nu16121862 -
Nutrients Jun 2024Zinc deficiency has been associated with the worsening of diabetes while zinc supplementation has been proposed to ameliorate diabetes. This study examined the effects...
Zinc deficiency has been associated with the worsening of diabetes while zinc supplementation has been proposed to ameliorate diabetes. This study examined the effects of marginal zinc deficiency (MZD) and zinc supplementation (ZS) on obesity, glycemic control, pancreatic islets, hepatic steatosis and renal function of Zucker diabetic fatty (ZDF) rats. Male ZDF rats were fed an MZD, zinc control (ZC) or ZS diet (4, 30 and 300 mg Zn/kg diet, respectively), and lean Zucker rats were fed a ZC diet for 8 weeks. MZD and ZS did not alter body weight or whole-body composition in ZDF rats. MZD ZDF rats had reduced zinc concentrations in the femur and pancreas, a greater number of enlarged pancreatic islets and a diminished response to an oral glucose load based on a 1.8-fold greater incremental area-under-the-curve (AUC) for glucose compared to ZC ZDF. ZS ZDF rats had elevated serum, femur and pancreatic zinc concentrations, unchanged pancreatic parameters and a 50% reduction in the AUC for insulin compared to ZC ZDF rats, suggesting greater insulin sensitivity. Dietary zinc intake did not alter hepatic steatosis, creatinine clearance, or levels of proteins that contribute to insulin signaling, inflammation or zinc transport in epididymal fat. Potential adverse effects of ZS were suggested by reduced hepatic copper concentrations and elevated serum urea compared to ZC ZDF rats. In summary, ZS improved the pancreatic insulin response but not the glucose handling. In contrast, reduced zinc status in ZDF rats led to impaired glucose tolerance and a compensatory increase in the number and size of pancreatic islets which could lead to β-cell exhaustion.
Topics: Animals; Rats, Zucker; Zinc; Dietary Supplements; Male; Insulin; Islets of Langerhans; Rats; Blood Glucose; Obesity; Insulin Resistance; Pancreas; Liver; Diabetes Mellitus, Experimental
PubMed: 38931174
DOI: 10.3390/nu16121819 -
Microorganisms Jun 2024serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid, a notifiable infectious disease in poultry. However, the pathogenic mechanism of SG-induced systemic...
serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid, a notifiable infectious disease in poultry. However, the pathogenic mechanism of SG-induced systemic infection in chickens remains unclear. Thioredoxin reductase (TrxB) is a redox protein crucial for regulating various enzyme activities in serovar, but the role in SG-induced chicken systemic infection has yet to be determined. Here, we constructed a mutant SG strain lacking the gene (::Cm) and used chicken embryo inoculation and chicken oral infection to investigate the role of gene in the pathogenicity of SG. Our results showed that ::Cm exhibited no apparent differences in colony morphology and growth conditions but exhibited reduced tolerance to HO and increased resistance to bile acids. In the chicken embryo inoculation model, there was no significant difference in the pathogenicity of ::Cm and wild-type (WT) strains. In the chicken oral infection, the WT-infected group exhibited typical clinical symptoms of fowl typhoid, with complete mortality between days 6 and 9 post infection. In contrast, the ::Cm group showed a 100% survival rate, with no apparent clinical symptoms or pathological changes observed. The viable bacterial counts in the liver and spleen of the ::Cm-infected group were significantly reduced, accompanied by decreased expression of cytokines and chemokines (IL-1β, IL-6, IL-12, CXCLi1, TNF-α, and IFN-γ), which were significantly lower than those in the WT group. These results show that the pathogenicity of the -deficient strain was significantly attenuated, indicating that the gene is a crucial virulence factor in SG-induced systemic infection in chickens, suggesting that may become a potentially effective target for controlling and preventing SG infection in chickens.
PubMed: 38930562
DOI: 10.3390/microorganisms12061180 -
Antioxidants (Basel, Switzerland) May 2024Fluconazole (FLC) is extensively employed for the prophylaxis and treatment of invasive fungal infections (IFIs). However, the fungistatic nature of FLC renders...
Fluconazole (FLC) is extensively employed for the prophylaxis and treatment of invasive fungal infections (IFIs). However, the fungistatic nature of FLC renders pathogenic fungi capable of developing tolerance towards it. Consequently, converting FLC into a fungicidal agent using adjuvants assumes significance to circumvent FLC resistance and the perpetuation of fungal infections. This drug repurposing study has successfully identified pitavastatin calcium (PIT) as a promising adjuvant for enhancing the fungicidal activity of FLC from a comprehensive library of 2372 FDA-approved drugs. PIT could render FLC fungicidal even at concentrations as low as 1 μM. The median lethal dose (LD) of PIT was determined to be 103.6 mg/kg. We have discovered that PIT achieves its synergistic effect by inhibiting the activity of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, thereby impeding ubiquinone biosynthesis, inducing reactive oxygen species (ROS) generation, triggering apoptosis, and disrupting Golgi function. We employed a strain that demonstrated a notable tolerance to FLC to infect mice and found that PIT effectively augmented the antifungal efficacy of FLC against IFIs. This study is an illustrative example of how FDA-approved drugs can effectively eliminate fungal tolerance to FLC.
PubMed: 38929106
DOI: 10.3390/antiox13060667 -
International Journal of Molecular... Jun 2024Salt stress seriously affects crop growth, leading to a decline in crop quality and yield. Application of exogenous substances to improve the salt tolerance of crops and...
Salt stress seriously affects crop growth, leading to a decline in crop quality and yield. Application of exogenous substances to improve the salt tolerance of crops and promote their growth under salt stress has become a widespread and effective means. Eugenol is a small molecule of plant origin with medicinal properties such as antibacterial, antiviral, and antioxidant properties. In this study, tobacco seedlings were placed in Hoagland's solution containing NaCl in the presence or absence of eugenol, and physiological indices related to stress tolerance were measured along with transcriptome sequencing. The results showed that eugenol improved the growth of tobacco seedlings under salt stress. It promoted carbon and nitrogen metabolism, increased the activities of nitrate reductase (NR), sucrose synthase (SS), and glutamine synthetase (GS) by 31.03, 5.80, and 51.06%. It also activated the enzymatic and non-enzymatic antioxidant systems, reduced the accumulation of reactive oxygen species in the tobacco seedlings, and increased the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) by 24.38%, 18.22%, 21.60%, and 28.8%, respectively. The content of glutathione (GSH) was increased by 29.49%, and the content of superoxide anion (O) and malondialdehyde (MDA) were reduced by 29.83 and 33.86%, respectively. Promoted osmoregulation, the content of Na decreased by 34.34, K increased by 41.25%, and starch and soluble sugar increased by 7.72% and 25.42%, respectively. It coordinated hormone signaling in seedlings; the content of abscisic acid (ABA) and gibberellic acid 3 (GA) increased by 51.93% and 266.28%, respectively. The transcriptome data indicated that the differentially expressed genes were mainly enriched in phenylpropanoid biosynthesis, the MAPK signaling pathway, and phytohormone signal transduction pathways. The results of this study revealed the novel role of eugenol in regulating plant resistance and provided a reference for the use of exogenous substances to alleviate salt stress.
Topics: Nicotiana; Seedlings; Antioxidants; Signal Transduction; Eugenol; Gene Expression Regulation, Plant; Salt Stress; Plant Growth Regulators; Salt Tolerance; Reactive Oxygen Species
PubMed: 38928476
DOI: 10.3390/ijms25126771 -
International Journal of Molecular... Jun 2024The objective of this study was to assess the impact of acute and chronic treatment with oxcarbazepine on its anticonvulsant activity, neurological adverse effects, and...
The objective of this study was to assess the impact of acute and chronic treatment with oxcarbazepine on its anticonvulsant activity, neurological adverse effects, and protective index in mice. Oxcarbazepine was administered in four protocols: once or twice daily for one week (7 × 1 or 7 × 2) and once or twice daily for two weeks (14 × 1 or 14 × 2). A single dose of the drug was employed as a control. The anticonvulsant effect was evaluated in the maximal electroshock test in mice. Motor and long-term memory impairment were assessed using the chimney test and the passive avoidance task, respectively. The concentrations of oxcarbazepine in the brain and plasma were determined via high-performance liquid chromatography. Two weeks of oxcarbazepine treatment resulted in a significant reduction in the anticonvulsant (in the 14 × 1; 14 × 2 protocols) and neurotoxic (in the 14 × 2 schedule) effects of this drug. In contrast, the protective index for oxcarbazepine in the 14 × 2 protocol was found to be lower than that calculated for the control. No significant deficits in memory or motor coordination were observed following repeated administration of oxcarbazepine. The plasma and brain concentrations of this anticonvulsant were found to be significantly higher in the one-week protocols. Chronic treatment with oxcarbazepine may result in the development of tolerance to its anticonvulsant and neurotoxic effects, which appears to be dependent on pharmacodynamic mechanisms.
Topics: Animals; Oxcarbazepine; Mice; Anticonvulsants; Electroshock; Male; Disease Models, Animal; Seizures; Brain; Memory, Long-Term; Carbamazepine; Avoidance Learning
PubMed: 38928457
DOI: 10.3390/ijms25126751